WorldWideScience

Sample records for large-scale solar wind

  1. Solar wind fluctuations at large scale: A comparison between low and high solar activity conditions

    International Nuclear Information System (INIS)

    Bavassano, B.; Bruno, R.

    1991-01-01

    The influence of the Sun's activity cycle on the solar wind fluctuations at time scales from 1 hour to 3 days in the inner heliosphere (0.3 to 1 AU) is investigated. Hourly averages of plasma and magnetic field data by Helios spacecraft are used. Since fluctuations behave quite differently with changing scale, the analysis is performed separately for two different ranges in time scale. Between 1 and 6 hours Alfvenic fluctuations and pressure-balanced structures are extensively observed. At low solar activity and close to 0.3 AU, Alfvenic fluctuations are more frequent than pressure-balanced structures. This predominance, however, weakens for rising solar activity and radial distance, to the point that a role exchange, in terms of occurrence rate, is found at the maximum of the cycle close to 1 AU. On the other hand, in all cases Alfvenic fluctuations have a larger amplitude than pressure-balanced structures. On the whole, the Alfvenic contribution to the solar wind energy spectrum comes out to be dominant at all solar activity conditions. At scales from 0.5 to 3 days the most important feature is the growth, as the solar wind expansion develops, of strong positive correlations between magnetic and thermal pressures. These structures are progressively built up by the interaction between different wind flows. This effect is more pronounced at low than at high activity. Our findings support the conclusion that the solar cycle evolution of the large-scale velocity pattern is the factor governing the observed variations

  2. Solar wind fluctuations at large scale - A comparison between low and high solar activity conditions

    Science.gov (United States)

    Bavassano, B.; Bruno, R.

    1991-02-01

    The influence of the sun's activity cycle on the solar wind fluctuations at time scales from 1 hour to 3 days in the inner heliosphere (0.3 to 1 AU) is investigated. Hourly averages of plasma and magnetic field data by Helios spacecraft are used. Since fluctuations behave quite differently with changing scale, the analysis is performed separately for two different ranges in time scale. Between 1 and 6 hours Alfvenic fluctuations and pressure-balanced structures are extensively observed. At low solar activity and close to 0.3 AU Alfvenic fluctuations are more frequent than pressure-balanced structures. This predominance, however, weakens for rising solar activity and radial distance, to the point that a role-exchange, in terms of occurrence rate, is found at the maximum of the cycle close to 1 AU. On the other hand, in all cases Alfvenic fluctuations have a larger amplitude than pressure-balanced structures. The Alfvenic contribution to the solar wind energy spectrum comes out to be dominant at all solar activity conditions. These findings support the conclusion that the solar cycle evolution of the large-scale velocity pattern is the factor governing the observed variations.

  3. Large Scale Solar Heating

    DEFF Research Database (Denmark)

    Heller, Alfred

    2001-01-01

    The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the simulation tool for design studies and on a local energy planning case. The evaluation was mainly carried out...... model is designed and validated on the Marstal case. Applying the Danish Reference Year, a design tool is presented. The simulation tool is used for proposals for application of alternative designs, including high-performance solar collector types (trough solar collectors, vaccum pipe collectors......). Simulation programs are proposed as control supporting tool for daily operation and performance prediction of central solar heating plants. Finaly the CSHP technolgy is put into persepctive with respect to alternatives and a short discussion on the barries and breakthrough of the technology are given....

  4. Effects of large scale integration of wind and solar energy in Japan

    Science.gov (United States)

    Esteban, Miguel; Zhang, Qi; Utama, Agya; Tezuka, Tetsuo; Ishihara, Keiichi

    2010-05-01

    results for the country as a whole are considered it is still substantial. The results are greatly dependant on the mix between the proposed renewables (solar and wind), and by comparing different distributions and mixes, the optimum composition for the target country can be established. The methodology proposed is able to obtain the optimum mix of solar and wind power for a given system, provided that adequate storage capacity exists to allow for excess capacity to be used at times of low electricity production (at the comparatively rare times when there is neither enough sun nor wind throughout the country). This highlights the challenges of large-scale integration of renewable technologies into the electricity grid, and the necessity to combine such a system with other renewables such as hydro or ocean energy to further even out the peaks and lows in the demand.

  5. Reconstruction of a large-scale reconnection exhaust structure in the solar wind

    Directory of Open Access Journals (Sweden)

    W.-L. Teh

    2009-02-01

    Full Text Available We recover two-dimensional (2-D magnetic field and flow field configurations from three spacecraft encounters with a single large-scale reconnection exhaust structure in the solar wind, using a new reconstruction method (Sonnerup and Teh, 2008 based on the ideal single-fluid MHD equations in a steady-state, 2-D geometry. The reconstruction is performed in the rest frame of the X-line, where the flow into, and the plasma jetting within, the exhaust region are clearly visible. The event was first identified by Phan et al. (2006 in the ACE, Cluster, and Wind data sets; they argued that quasi-steady reconnection persisted for over 2 h at a long (390 RE X-line. The reconnection exhaust is sandwiched between two discontinuities, both of which contain elements of intermediate- and slow-mode behavior; these elements are co-located rather than being spatially separated. These composite discontinuities do not satisfy the coplanarity condition or the standard MHD jump conditions. For all three spacecraft, the Walén regression line slope was positive (negative for the leading (trailing discontinuity. Our MHD reconstruction shows that: (1 the X-line orientation was close to the bisector of the overall magnetic shear angle and exhibited a slow rotating motion toward the Sun-Earth line; (2 the X-line moved earthward, dawnward, and southward; (3 the reconnection electric field was small (~0.02 mV/m on average and gradually decreased from the first crossing (ACE to the last (Wind. The magnetic field and flow field configurations recovered from ACE and Cluster are similar while those recovered from Wind also include a magnetic island and an associated vortex. Reconnection persisted for at least 2.4 h involving inflow into the exhaust region from its two sides. Time-dependence in the reconnection electric fields seen by ACE and Wind indicates local temporal variations in the field configuration. In addition to the reconstruction results, we

  6. Reconstruction of a large-scale reconnection exhaust structure in the solar wind

    International Nuclear Information System (INIS)

    Teh, W.L.; Sonnerup, B.U.Oe.; Hu, Q.; Farrugia, C.J.

    2009-01-01

    We recover two-dimensional (2-D) magnetic field and flow field configurations from three spacecraft encounters with a single large-scale reconnection exhaust structure in the solar wind, using a new reconstruction method (Sonnerup and Teh, 2008) based on the ideal single-fluid MHD equations in a steady-state, 2-D geometry. The reconstruction is performed in the rest frame of the X-line, where the flow into, and the plasma jetting within, the exhaust region are clearly visible. The event was first identified by Phan et al. (2006) in the ACE, Cluster, and Wind data sets; they argued that quasi-steady reconnection persisted for over 2 h at a long (390 R E ) X-line. The reconnection exhaust is sandwiched between two discontinuities, both of which contain elements of intermediate- and slow-mode behavior; these elements are co-located rather than being spatially separated. These composite discontinuities do not satisfy the coplanarity condition or the standard MHD jump conditions. For all three spacecraft, the Walen regression line slope was positive (negative) for the leading (trailing) discontinuity. Our MHD reconstruction shows that: (1) the X-line orientation was close to the bisector of the overall magnetic shear angle and exhibited a slow rotating motion toward the Sun-Earth line; (2) the X-line moved earthward, dawnward, and southward; (3) the reconnection electric field was small (∝0.02 mV/m on average) and gradually decreased from the first crossing (ACE) to the last (Wind). The magnetic field and flow field configurations recovered from ACE and Cluster are similar while those recovered from Wind also include a magnetic island and an associated vortex. Reconnection persisted for at least 2.4 h involving inflow into the exhaust region from its two sides. Time-dependence in the reconnection electric fields seen by ACE and Wind indicates local temporal variations in the field configuration. In addition to the reconstruction results, we provide a description and

  7. Reconstruction of a large-scale reconnection exhaust structure in the solar wind

    Directory of Open Access Journals (Sweden)

    W.-L. Teh

    2009-02-01

    Full Text Available We recover two-dimensional (2-D magnetic field and flow field configurations from three spacecraft encounters with a single large-scale reconnection exhaust structure in the solar wind, using a new reconstruction method (Sonnerup and Teh, 2008 based on the ideal single-fluid MHD equations in a steady-state, 2-D geometry. The reconstruction is performed in the rest frame of the X-line, where the flow into, and the plasma jetting within, the exhaust region are clearly visible. The event was first identified by Phan et al. (2006 in the ACE, Cluster, and Wind data sets; they argued that quasi-steady reconnection persisted for over 2 h at a long (390 RE X-line. The reconnection exhaust is sandwiched between two discontinuities, both of which contain elements of intermediate- and slow-mode behavior; these elements are co-located rather than being spatially separated. These composite discontinuities do not satisfy the coplanarity condition or the standard MHD jump conditions. For all three spacecraft, the Walén regression line slope was positive (negative for the leading (trailing discontinuity. Our MHD reconstruction shows that: (1 the X-line orientation was close to the bisector of the overall magnetic shear angle and exhibited a slow rotating motion toward the Sun-Earth line; (2 the X-line moved earthward, dawnward, and southward; (3 the reconnection electric field was small (~0.02 mV/m on average and gradually decreased from the first crossing (ACE to the last (Wind. The magnetic field and flow field configurations recovered from ACE and Cluster are similar while those recovered from Wind also include a magnetic island and an associated vortex. Reconnection persisted for at least 2.4 h involving inflow into the exhaust region from its two sides. Time-dependence in the reconnection electric fields seen by ACE and Wind indicates local temporal variations in the field configuration. In addition to the reconstruction results, we provide a description

  8. Large-scale solar purchasing

    International Nuclear Information System (INIS)

    1999-01-01

    The principal objective of the project was to participate in the definition of a new IEA task concerning solar procurement (''the Task'') and to assess whether involvement in the task would be in the interest of the UK active solar heating industry. The project also aimed to assess the importance of large scale solar purchasing to UK active solar heating market development and to evaluate the level of interest in large scale solar purchasing amongst potential large scale purchasers (in particular housing associations and housing developers). A further aim of the project was to consider means of stimulating large scale active solar heating purchasing activity within the UK. (author)

  9. Dynamics of large-scale solar wind streams obtained by the double superposed epoch analysis

    Science.gov (United States)

    Yermolaev, Yu. I.; Lodkina, I. G.; Nikolaeva, N. S.; Yermolaev, M. Yu.

    2015-09-01

    Using the OMNI data for period 1976-2000, we investigate the temporal profiles of 20 plasma and field parameters in the disturbed large-scale types of solar wind (SW): corotating interaction regions (CIR), interplanetary coronal mass ejections (ICME) (both magnetic cloud (MC) and Ejecta), and Sheath as well as the interplanetary shock (IS). To take into account the different durations of SW types, we use the double superposed epoch analysis (DSEA) method: rescaling the duration of the interval for all types in such a manner that, respectively, beginning and end for all intervals of selected type coincide. As the analyzed SW types can interact with each other and change parameters as a result of such interaction, we investigate separately eights sequences of SW types: (1) CIR, (2) IS/CIR, (3) Ejecta, (4) Sheath/Ejecta, (5) IS/Sheath/Ejecta, (6) MC, (7) Sheath/MC, and (8) IS/Sheath/MC. The main conclusion is that the behavior of parameters in Sheath and in CIR are very similar both qualitatively and quantitatively. Both the high-speed stream (HSS) and the fast ICME play a role of pistons which push the plasma located ahead them. The increase of speed in HSS and ICME leads at first to formation of compression regions (CIR and Sheath, respectively) and then to IS. The occurrence of compression regions and IS increases the probability of growth of magnetospheric activity.

  10. A Parametric Genetic Algorithm Approach to Assess Complementary Options of Large Scale Wind-solar Coupling

    Institute of Scientific and Technical Information of China (English)

    Tim; Mareda; Ludovic; Gaudard; Franco; Romerio

    2017-01-01

    The transitional path towards a highly renewable power system based on wind and solar energy sources is investigated considering their intermittent and spatially distributed characteristics. Using an extensive weather-driven simulation of hourly power mismatches between generation and load, we explore the interplay between geographical resource complementarity and energy storage strategies. Solar and wind resources are considered at variable spatial scales across Europe and related to the Swiss load curve, which serve as a typical demand side reference. The optimal spatial distribution of renewable units is further assessed through a parameterized optimization method based on a genetic algorithm. It allows us to explore systematically the effective potential of combined integration strategies depending on the sizing of the system, with a focus on how overall performance is affected by the definition of network boundaries. Upper bounds on integration schemes are provided considering both renewable penetration and needed reserve power capacity. The quantitative trade-off between grid extension, storage and optimal wind-solar mix is highlighted.This paper also brings insights on how optimal geographical distribution of renewable units evolves as a function of renewable penetration and grid extent.

  11. Large-scale interaction of the solar wind with cometary plasma tails

    International Nuclear Information System (INIS)

    Niedner, M.B. Jr.

    1979-01-01

    The study of the behavior of plasma tails in the context of their interaction with the solar wind could have important implications for the structure of the interplanetary medium in three dimensions. Comet Kohoutek 1973f exhibited a broad range of plasma tail behavior. On 1974 January 20, the tail was in a highly disturbed condition. Comet Kohoutek was encountering the leading edge of a very strong high-speed stream at the time the plasma tail disturbance started to develop. Comparison of the observed tail geometry on January 20 with the theoretical position angles generated from the wind sock theory of plasma tails and the corotated satellite observations shows that the tail disturbance was probably caused by large gradients of the polar component of the solar-wind velocity. Within hours after the disturbance of January 20, the plasma tail of comet Kohoutek became disconnected from the cometary head, and was replaced by a new plasma tail. The comet was very near an interplanetary sector boundary at the time of disconnection. The disconnection event (DE) is suggested to have resulted from the magnetic reconnection of plasma tail field lines. A similar analysis of other DEs found in original plate material and in published photographs shows the most DEs occur near corotated sector boundaries. Thus, the sector boundary model is further supported, and the finding provides the only known method of probing sector structure to high latitudes. Sector boundaries can often extend to high latitudes in a nearly North-South orientation, and this property is not restricted to times away from solar minimum. Furthermore, the boundaries are inferred to be randomly tilted with respect to the polarity sequence across the boundary and to the magnetic signs of the solar poles

  12. A large-scale view of Space Technology 5 magnetometer response to solar wind drivers.

    Science.gov (United States)

    Knipp, D J; Kilcommons, L M; Gjerloev, J; Redmon, R J; Slavin, J; Le, G

    2015-04-01

    In this data report we discuss reprocessing of the Space Technology 5 (ST5) magnetometer database for inclusion in NASA's Coordinated Data Analysis Web (CDAWeb) virtual observatory. The mission consisted of three spacecraft flying in elliptical orbits, from 27 March to 27 June 2006. Reprocessing includes (1) transforming the data into the Modified Apex Coordinate System for projection to a common reference altitude of 110 km, (2) correcting gain jumps, and (3) validating the results. We display the averaged magnetic perturbations as a keogram, which allows direct comparison of the full-mission data with the solar wind values and geomagnetic indices. With the data referenced to a common altitude, we find the following: (1) Magnetic perturbations that track the passage of corotating interaction regions and high-speed solar wind; (2) unexpectedly strong dayside perturbations during a solstice magnetospheric sawtooth oscillation interval characterized by a radial interplanetary magnetic field (IMF) component that may have enhanced the accompanying modest southward IMF; and (3) intervals of reduced magnetic perturbations or "calms," associated with periods of slow solar wind, interspersed among variable-length episodic enhancements. These calms are most evident when the IMF is northward or projects with a northward component onto the geomagnetic dipole. The reprocessed ST5 data are in very good agreement with magnetic perturbations from the Defense Meteorological Satellite Program (DMSP) spacecraft, which we also map to 110 km. We briefly discuss the methods used to remap the ST5 data and the means of validating the results against DMSP. Our methods form the basis for future intermission comparisons of space-based magnetometer data.

  13. Large-scale solar heat

    Energy Technology Data Exchange (ETDEWEB)

    Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Engineering Physics and Mathematics

    1998-12-31

    In this project a large domestic solar heating system was built and a solar district heating system was modelled and simulated. Objectives were to improve the performance and reduce costs of a large-scale solar heating system. As a result of the project the benefit/cost ratio can be increased by 40 % through dimensioning and optimising the system at the designing stage. (orig.)

  14. Correlations at large scales and the onset of turbulence in the fast solar wind

    International Nuclear Information System (INIS)

    Wicks, R. T.; Roberts, D. A.; Mallet, A.; Schekochihin, A. A.; Horbury, T. S.; Chen, C. H. K.

    2013-01-01

    We show that the scaling of structure functions of magnetic and velocity fields in a mostly highly Alfvénic fast solar wind stream depends strongly on the joint distribution of the dimensionless measures of cross helicity and residual energy. Already at very low frequencies, fluctuations that are both more balanced (cross helicity ∼0) and equipartitioned (residual energy ∼0) have steep structure functions reminiscent of 'turbulent' scalings usually associated with the inertial range. Fluctuations that are magnetically dominated (residual energy ∼–1), and so have closely anti-aligned Elsasser-field vectors, or are imbalanced (cross helicity ∼1), and so have closely aligned magnetic and velocity vectors, have wide '1/f' ranges typical of fast solar wind. We conclude that the strength of nonlinear interactions of individual fluctuations within a stream, diagnosed by the degree of correlation in direction and magnitude of magnetic and velocity fluctuations, determines the extent of the 1/f region observed, and thus the onset scale for the turbulent cascade.

  15. The large scale and long term evolution of the solar wind speed distribution and high speed streams

    International Nuclear Information System (INIS)

    Intriligator, D.S.

    1977-01-01

    The spatial and temporal evolution of the solar wind speed distribution and of high speed streams in the solar wind are examined. Comparisons of the solar wind streaming speeds measured at Earth, Pioneer 11, and Pioneer 10 indicate that between 1 AU and 6.4 AU the solar wind speed distributions are narrower (i.e. the 95% value minus the 5% value of the solar wind streaming speed is less) at extended heliocentric distances. These observations are consistent with one exchange of momentum in the solar wind between high speed streams and low speed streams as they propagate outward from the Sun. Analyses of solar wind observations at 1 AU from mid 1964 through 1973 confirm the earlier results reported by Intriligator (1974) that there are statistically significant variations in the solar wind in 1968 and 1969, years of solar maximum. High speed stream parameters show that the number of high speed streams in the solar wind in 1968 and 1969 is considerably more than the predicted yearly average, and in 1965 and 1972 less. Histograms of solar wind speed from 1964 through 1973 indicate that in 1968 there was the highest percentage of elevated solar wind speeds and in 1965 and 1972 the lowest. Studies by others also confirm these results although the respective authors did not indicate this fact. The duration of the streams and the histograms for 1973 imply a shifting in the primary stream source. (Auth.)

  16. Large-scale solar heating

    Energy Technology Data Exchange (ETDEWEB)

    Tolonen, J.; Konttinen, P.; Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland). Advanced Energy Systems

    1998-10-01

    Solar heating market is growing in many European countries and annually installed collector area has exceeded one million square meters. There are dozens of collector manufacturers and hundreds of firms making solar heating installations in Europe. One tendency in solar heating is towards larger systems. These can be roof integrated, consisting of some tens or hundreds of square meters of collectors, or they can be larger centralized solar district heating plants consisting of a few thousand square meters of collectors. The increase of size can reduce the specific investments of solar heating systems, because e.g. the costs of some components (controllers, pumps, and pipes), planning and installation can be smaller in larger systems. The solar heat output can also be higher in large systems, because more advanced technique is economically viable

  17. Large-scale Motion of Solar Filaments

    Indian Academy of Sciences (India)

    tribpo

    Large-scale Motion of Solar Filaments. Pavel Ambrož, Astronomical Institute of the Acad. Sci. of the Czech Republic, CZ-25165. Ondrejov, The Czech Republic. e-mail: pambroz@asu.cas.cz. Alfred Schroll, Kanzelhöehe Solar Observatory of the University of Graz, A-9521 Treffen,. Austria. e-mail: schroll@solobskh.ac.at.

  18. Emerging large-scale solar heating applications

    International Nuclear Information System (INIS)

    Wong, W.P.; McClung, J.L.

    2009-01-01

    Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

  19. Emerging large-scale solar heating applications

    Energy Technology Data Exchange (ETDEWEB)

    Wong, W.P.; McClung, J.L. [Science Applications International Corporation (SAIC Canada), Ottawa, Ontario (Canada)

    2009-07-01

    Currently the market for solar heating applications in Canada is dominated by outdoor swimming pool heating, make-up air pre-heating and domestic water heating in homes, commercial and institutional buildings. All of these involve relatively small systems, except for a few air pre-heating systems on very large buildings. Together these applications make up well over 90% of the solar thermal collectors installed in Canada during 2007. These three applications, along with the recent re-emergence of large-scale concentrated solar thermal for generating electricity, also dominate the world markets. This paper examines some emerging markets for large scale solar heating applications, with a focus on the Canadian climate and market. (author)

  20. Dynamics of Large-Scale Solar-Wind Streams Obtained by the Double Superposed Epoch Analysis: 2. Comparisons of CIRs vs. Sheaths and MCs vs. Ejecta

    Science.gov (United States)

    Yermolaev, Y. I.; Lodkina, I. G.; Nikolaeva, N. S.; Yermolaev, M. Y.

    2017-12-01

    This work is a continuation of our previous article (Yermolaev et al. in J. Geophys. Res. 120, 7094, 2015), which describes the average temporal profiles of interplanetary plasma and field parameters in large-scale solar-wind (SW) streams: corotating interaction regions (CIRs), interplanetary coronal mass ejections (ICMEs including both magnetic clouds (MCs) and ejecta), and sheaths as well as interplanetary shocks (ISs). As in the previous article, we use the data of the OMNI database, our catalog of large-scale solar-wind phenomena during 1976 - 2000 (Yermolaev et al. in Cosmic Res., 47, 2, 81, 2009) and the method of double superposed epoch analysis (Yermolaev et al. in Ann. Geophys., 28, 2177, 2010a). We rescale the duration of all types of structures in such a way that the beginnings and endings for all of them coincide. We present new detailed results comparing pair phenomena: 1) both types of compression regions ( i.e. CIRs vs. sheaths) and 2) both types of ICMEs (MCs vs. ejecta). The obtained data allow us to suggest that the formation of the two types of compression regions responds to the same physical mechanism, regardless of the type of piston (high-speed stream (HSS) or ICME); the differences are connected to the geometry ( i.e. the angle between the speed gradient in front of the piston and the satellite trajectory) and the jumps in speed at the edges of the compression regions. In our opinion, one of the possible reasons behind the observed differences in the parameters in MCs and ejecta is that when ejecta are observed, the satellite passes farther from the nose of the area of ICME than when MCs are observed.

  1. Time-scale and extent at which large-scale circulation modes determine the wind and solar potential in the Iberian Peninsula

    International Nuclear Information System (INIS)

    Jerez, Sonia; Trigo, Ricardo M

    2013-01-01

    The North Atlantic Oscillation (NAO), the East Atlantic (EA) and the Scandinavian (SCAND) modes are the three main large-scale circulation patterns driving the climate variability of the Iberian Peninsula. This study assesses their influence in terms of solar (photovoltaic) and wind power generation potential (SP and WP) and evaluates their skill as predictors. For that we use a hindcast regional climate simulation to retrieve the primary meteorological variables involved, surface solar radiation and wind speed. First we identify that the maximum influence of the various modes occurs on the interannual variations of the monthly mean SP and WP series, being generally more relevant in winter. Second we find that in this time-scale and season, SP (WP) varies up to 30% (40%) with respect to the mean climatology between years with opposite phases of the modes, although the strength and the spatial distribution of the signals differ from one month to another. Last, the skill of a multi-linear regression model (MLRM), built using the NAO, EA and SCAND indices, to reconstruct the original wintertime monthly series of SP and WP was investigated. The reconstructed series (when the MLRM is calibrated for each month individually) correlate with the original ones up to 0.8 at the interannual time-scale. Besides, when the modeled series for each individual month are merged to construct an October-to-March monthly series, and after removing the annual cycle in order to account for monthly anomalies, these correlate 0.65 (0.55) with the original SP (WP) series in average. These values remain fairly stable when the calibration and reconstruction periods differ, thus supporting up to a point the predictive potential of the method at the time-scale assessed here. (letter)

  2. Results of large scale wind climatologically estimations

    Directory of Open Access Journals (Sweden)

    Andrea Kircsi

    2008-05-01

    Full Text Available The aim of this article is to describe theparticular field of climatology which analyzes airmovement characteristics regarding utilization of windfor energy generation. The article describes features ofwind energy potential available in Hungary compared towind conditions in other areas of the northern quartersphere in order to assist the wind energy use developmentin Hungary. Information on wind climate gives a solidbasis for financial and economic decisions ofstakeholders in the field of wind energy utilization.

  3. Large scale wind power penetration in Denmark

    DEFF Research Database (Denmark)

    Karnøe, Peter

    2013-01-01

    he Danish electricity generating system prepared to adopt nuclear power in the 1970s, yet has become the world's front runner in wind power with a national plan for 50% wind power penetration by 2020. This paper deploys a sociotechnical perspective to explain the historical transformation...... of "networks of power" via the interactions of politics, the techno-physics of electrons, and the market setting. The Danish case is about how an assemblage of new agencies has reorganized and reshaped society by building a new sociotechnical network. This has rendered developments highly unpredictable...... and highly experimental. The transformation process can be followed through the way successive technical engineering reports have represented the challenges associated with the penetration of wind power. The iteration shows how novel technical phenomena emerge and are assimilated, and how new engineering...

  4. Superconductivity for Large Scale Wind Turbines

    Energy Technology Data Exchange (ETDEWEB)

    R. Fair; W. Stautner; M. Douglass; R. Rajput-Ghoshal; M. Moscinski; P. Riley; D. Wagner; J. Kim; S. Hou; F. Lopez; K. Haran; J. Bray; T. Laskaris; J. Rochford; R. Duckworth

    2012-10-12

    A conceptual design has been completed for a 10MW superconducting direct drive wind turbine generator employing low temperature superconductors for the field winding. Key technology building blocks from the GE Wind and GE Healthcare businesses have been transferred across to the design of this concept machine. Wherever possible, conventional technology and production techniques have been used in order to support the case for commercialization of such a machine. Appendices A and B provide further details of the layout of the machine and the complete specification table for the concept design. Phase 1 of the program has allowed us to understand the trade-offs between the various sub-systems of such a generator and its integration with a wind turbine. A Failure Modes and Effects Analysis (FMEA) and a Technology Readiness Level (TRL) analysis have been completed resulting in the identification of high risk components within the design. The design has been analyzed from a commercial and economic point of view and Cost of Energy (COE) calculations have been carried out with the potential to reduce COE by up to 18% when compared with a permanent magnet direct drive 5MW baseline machine, resulting in a potential COE of 0.075 $/kWh. Finally, a top-level commercialization plan has been proposed to enable this technology to be transitioned to full volume production. The main body of this report will present the design processes employed and the main findings and conclusions.

  5. Optimal Site Selection of Wind-Solar Complementary Power Generation Project for a Large-Scale Plug-In Charging Station

    Directory of Open Access Journals (Sweden)

    Wenjun Chen

    2017-10-01

    Full Text Available The wind-solar hybrid power generation project combined with electric vehicle charging stations can effectively reduce the impact on the power system caused by the random charging of electric cars, contribute to the in-situ wind-solar complementary system and reduce the harm arising from its output volatility. In this paper, the site selection index system of a landscape complementary power generation project is established by using the statistical methods and statistical analysis in the literature. Subsequently, using the Analytic Network Process to calculate the index weight, a cloud model was used in combination with preference ranking organization method for enrichment evaluations to transform and sort uncertain language information. Finally, using the results of the decision-making for the location of the Shanghai wind-solar complementary project and by carrying out contrast analysis and sensitivity analysis, the superiority and stability of the decision model constructed in this study was demonstrated.

  6. Thermal power generation projects ``Large Scale Solar Heating``; EU-Thermie-Projekte ``Large Scale Solar Heating``

    Energy Technology Data Exchange (ETDEWEB)

    Kuebler, R.; Fisch, M.N. [Steinbeis-Transferzentrum Energie-, Gebaeude- und Solartechnik, Stuttgart (Germany)

    1998-12-31

    The aim of this project is the preparation of the ``Large-Scale Solar Heating`` programme for an Europe-wide development of subject technology. The following demonstration programme was judged well by the experts but was not immediately (1996) accepted for financial subsidies. In November 1997 the EU-commission provided 1,5 million ECU which allowed the realisation of an updated project proposal. By mid 1997 a small project was approved, that had been requested under the lead of Chalmes Industriteteknik (CIT) in Sweden and is mainly carried out for the transfer of technology. (orig.) [Deutsch] Ziel dieses Vorhabens ist die Vorbereitung eines Schwerpunktprogramms `Large Scale Solar Heating`, mit dem die Technologie europaweit weiterentwickelt werden sollte. Das daraus entwickelte Demonstrationsprogramm wurde von den Gutachtern positiv bewertet, konnte jedoch nicht auf Anhieb (1996) in die Foerderung aufgenommen werden. Im November 1997 wurden von der EU-Kommission dann kurzfristig noch 1,5 Mio ECU an Foerderung bewilligt, mit denen ein aktualisierter Projektvorschlag realisiert werden kann. Bereits Mitte 1997 wurde ein kleineres Vorhaben bewilligt, das unter Federfuehrung von Chalmers Industriteknik (CIT) in Schweden beantragt worden war und das vor allem dem Technologietransfer dient. (orig.)

  7. Status of large scale wind turbine technology development abroad?

    Institute of Scientific and Technical Information of China (English)

    Ye LI; Lei DUAN

    2016-01-01

    To facilitate the large scale (multi-megawatt) wind turbine development in China, the foreign e?orts and achievements in the area are reviewed and summarized. Not only the popular horizontal axis wind turbines on-land but also the o?shore wind turbines, vertical axis wind turbines, airborne wind turbines, and shroud wind turbines are discussed. The purpose of this review is to provide a comprehensive comment and assessment about the basic work principle, economic aspects, and environmental impacts of turbines.

  8. Balancing modern Power System with large scale of wind power

    DEFF Research Database (Denmark)

    Basit, Abdul; Altin, Müfit; Hansen, Anca Daniela

    2014-01-01

    Power system operators must ensure robust, secure and reliable power system operation even with a large scale integration of wind power. Electricity generated from the intermittent wind in large propor-tion may impact on the control of power system balance and thus deviations in the power system...... frequency in small or islanded power systems or tie line power flows in interconnected power systems. Therefore, the large scale integration of wind power into the power system strongly concerns the secure and stable grid operation. To ensure the stable power system operation, the evolving power system has...... to be analysed with improved analytical tools and techniques. This paper proposes techniques for the active power balance control in future power systems with the large scale wind power integration, where power balancing model provides the hour-ahead dispatch plan with reduced planning horizon and the real time...

  9. Challenges and options for large scale integration of wind power

    International Nuclear Information System (INIS)

    Tande, John Olav Giaever

    2006-01-01

    Challenges and options for large scale integration of wind power are examined. Immediate challenges are related to weak grids. Assessment of system stability requires numerical simulation. Models are being developed - validation is essential. Coordination of wind and hydro generation is a key for allowing more wind power capacity in areas with limited transmission corridors. For the case study grid depending on technology and control the allowed wind farm size is increased from 50 to 200 MW. The real life example from 8 January 2005 demonstrates that existing marked based mechanisms can handle large amounts of wind power. In wind integration studies it is essential to take account of the controllability of modern wind farms, the power system flexibility and the smoothing effect of geographically dispersed wind farms. Modern wind farms contribute to system adequacy - combining wind and hydro constitutes a win-win system (ml)

  10. Optimal Wind Energy Integration in Large-Scale Electric Grids

    Science.gov (United States)

    Albaijat, Mohammad H.

    profit for investors for renting their transmission capacity, and cheaper electricity for end users. We propose a hybrid method based on a heuristic and deterministic method to attain new transmission lines additions and increase transmission capacity. Renewable energy resources (RES) have zero operating cost, which makes them very attractive for generation companies and market participants. In addition, RES have zero carbon emission, which helps relieve the concerns of environmental impacts of electric generation resources' carbon emission. RES are wind, solar, hydro, biomass, and geothermal. By 2030, the expectation is that more than 30% of electricity in the U.S. will come from RES. One major contributor of RES generation will be from wind energy resources (WES). Furthermore, WES will be an important component of the future generation portfolio. However, the nature of WES is that it experiences a high intermittency and volatility. Because of the great expectation of high WES penetration and the nature of such resources, researchers focus on studying the effects of such resources on the electric grid operation and its adequacy from different aspects. Additionally, current market operations of electric grids add another complication to consider while integrating RES (e.g., specifically WES). Mandates by market rules and long-term analysis of renewable penetration in large-scale electric grid are also the focus of researchers in recent years. We advocate a method for high-wind resources penetration study on large-scale electric grid operations. PMU is a geographical positioning system (GPS) based device, which provides immediate and precise measurements of voltage angle in a high-voltage transmission system. PMUs can update the status of a transmission line and related measurements (e.g., voltage magnitude and voltage phase angle) more frequently. Every second, a PMU can provide 30 samples of measurements compared to traditional systems (e.g., supervisory control and

  11. Fatigue Analysis of Large-scale Wind turbine

    Directory of Open Access Journals (Sweden)

    Zhu Yongli

    2017-01-01

    Full Text Available The paper does research on top flange fatigue damage of large-scale wind turbine generator. It establishes finite element model of top flange connection system with finite element analysis software MSC. Marc/Mentat, analyzes its fatigue strain, implements load simulation of flange fatigue working condition with Bladed software, acquires flange fatigue load spectrum with rain-flow counting method, finally, it realizes fatigue analysis of top flange with fatigue analysis software MSC. Fatigue and Palmgren-Miner linear cumulative damage theory. The analysis result indicates that its result provides new thinking for flange fatigue analysis of large-scale wind turbine generator, and possesses some practical engineering value.

  12. Variability in large-scale wind power generation: Variability in large-scale wind power generation

    Energy Technology Data Exchange (ETDEWEB)

    Kiviluoma, Juha [VTT Technical Research Centre of Finland, Espoo Finland; Holttinen, Hannele [VTT Technical Research Centre of Finland, Espoo Finland; Weir, David [Energy Department, Norwegian Water Resources and Energy Directorate, Oslo Norway; Scharff, Richard [KTH Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Söder, Lennart [Royal Institute of Technology, Electric Power Systems, Stockholm Sweden; Menemenlis, Nickie [Institut de recherche Hydro-Québec, Montreal Canada; Cutululis, Nicolaos A. [DTU, Wind Energy, Roskilde Denmark; Danti Lopez, Irene [Electricity Research Centre, University College Dublin, Dublin Ireland; Lannoye, Eamonn [Electric Power Research Institute, Palo Alto California USA; Estanqueiro, Ana [LNEG, Laboratorio Nacional de Energia e Geologia, UESEO, Lisbon Spain; Gomez-Lazaro, Emilio [Renewable Energy Research Institute and DIEEAC/EDII-AB, Castilla-La Mancha University, Albacete Spain; Zhang, Qin [State Grid Corporation of China, Beijing China; Bai, Jianhua [State Grid Energy Research Institute Beijing, Beijing China; Wan, Yih-Huei [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA; Milligan, Michael [National Renewable Energy Laboratory, Transmission and Grid Integration Group, Golden Colorado USA

    2015-10-25

    The paper demonstrates the characteristics of wind power variability and net load variability in multiple power systems based on real data from multiple years. Demonstrated characteristics include probability distribution for different ramp durations, seasonal and diurnal variability and low net load events. The comparison shows regions with low variability (Sweden, Spain and Germany), medium variability (Portugal, Ireland, Finland and Denmark) and regions with higher variability (Quebec, Bonneville Power Administration and Electric Reliability Council of Texas in North America; Gansu, Jilin and Liaoning in China; and Norway and offshore wind power in Denmark). For regions with low variability, the maximum 1 h wind ramps are below 10% of nominal capacity, and for regions with high variability, they may be close to 30%. Wind power variability is mainly explained by the extent of geographical spread, but also higher capacity factor causes higher variability. It was also shown how wind power ramps are autocorrelated and dependent on the operating output level. When wind power was concentrated in smaller area, there were outliers with high changes in wind output, which were not present in large areas with well-dispersed wind power.

  13. Energetic particle, solar wind plasma and magnetic field measurements on board Prognoz-6 during the large scale interplanetary disturbance of Jan. 3-4, 1978

    International Nuclear Information System (INIS)

    Kurt, V.G.; Stolpovskij, V.G.; Gombosi, T.I.; Kecskemety, K.; Somogyi, J.; Gringauz, K.I.; Kotova, G.A.; Verigin, M.I.; Styazhkin, V.A.

    1980-05-01

    The interplanetary shock, generated during the solar flare of Jan. 1, 1978 reached the Earth's orbit on January 3, 21sup(h) UT. Aboard Prognoz-6 satellite the fluxes and spectra of energetic electron (E>30 keV) and proton (E>500 keV) fluxes and energy spectra of solar wind ions up to 4.5 keV and magnetic field were measured, with a time resolution approximately 10 sec. Time variation of these characteristics are given including preshock and postshock frequency spectra of magnetic field fluctuations. Effective acceleration of protons in the oblique shock was observed. The mean free path of protons with E<6 MeV was determined by using the time interval of anisotropic particle flux observations as lambda approximately 0.2 a.u. (author)

  14. Research on large-scale wind farm modeling

    Science.gov (United States)

    Ma, Longfei; Zhang, Baoqun; Gong, Cheng; Jiao, Ran; Shi, Rui; Chi, Zhongjun; Ding, Yifeng

    2017-01-01

    Due to intermittent and adulatory properties of wind energy, when large-scale wind farm connected to the grid, it will have much impact on the power system, which is different from traditional power plants. Therefore it is necessary to establish an effective wind farm model to simulate and analyze the influence wind farms have on the grid as well as the transient characteristics of the wind turbines when the grid is at fault. However we must first establish an effective WTGs model. As the doubly-fed VSCF wind turbine has become the mainstream wind turbine model currently, this article first investigates the research progress of doubly-fed VSCF wind turbine, and then describes the detailed building process of the model. After that investigating the common wind farm modeling methods and pointing out the problems encountered. As WAMS is widely used in the power system, which makes online parameter identification of the wind farm model based on off-output characteristics of wind farm be possible, with a focus on interpretation of the new idea of identification-based modeling of large wind farms, which can be realized by two concrete methods.

  15. Electric vehicles and large-scale integration of wind power

    DEFF Research Database (Denmark)

    Liu, Wen; Hu, Weihao; Lund, Henrik

    2013-01-01

    with this imbalance and to reduce its high dependence on oil production. For this reason, it is interesting to analyse the extent to which transport electrification can further the renewable energy integration. This paper quantifies this issue in Inner Mongolia, where the share of wind power in the electricity supply...... was 6.5% in 2009 and which has the plan to develop large-scale wind power. The results show that electric vehicles (EVs) have the ability to balance the electricity demand and supply and to further the wind power integration. In the best case, the energy system with EV can increase wind power...... integration by 8%. The application of EVs benefits from saving both energy system cost and fuel cost. However, the negative consequences of decreasing energy system efficiency and increasing the CO2 emission should be noted when applying the hydrogen fuel cell vehicle (HFCV). The results also indicate...

  16. Temporal Variation of Large Scale Flows in the Solar Interior ...

    Indian Academy of Sciences (India)

    tribpo

    Temporal Variation of Large Scale Flows in the Solar Interior. 355. Figure 2. Zonal and meridional components of the time-dependent residual velocity at a few selected depths as marked above each panel, are plotted as contours of constant velocity in the longitude-latitude plane. The left panels show the zonal component, ...

  17. Large scale solar district heating. Evaluation, modelling and designing - Appendices

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    The appendices present the following: A) Cad-drawing of the Marstal CSHP design. B) Key values - large-scale solar heating in Denmark. C) Monitoring - a system description. D) WMO-classification of pyranometers (solarimeters). E) The computer simulation model in TRNSYS. F) Selected papers from the author. (EHS)

  18. Generation Expansion Planning Considering Integrating Large-scale Wind Generation

    DEFF Research Database (Denmark)

    Zhang, Chunyu; Ding, Yi; Østergaard, Jacob

    2013-01-01

    necessitated the inclusion of more innovative and sophisticated approaches in power system investment planning. A bi-level generation expansion planning approach considering large-scale wind generation was proposed in this paper. The first phase is investment decision, while the second phase is production...... optimization decision. A multi-objective PSO (MOPSO) algorithm was introduced to solve this optimization problem, which can accelerate the convergence and guarantee the diversity of Pareto-optimal front set as well. The feasibility and effectiveness of the proposed bi-level planning approach and the MOPSO...

  19. Geospatial Optimization of Siting Large-Scale Solar Projects

    Energy Technology Data Exchange (ETDEWEB)

    Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Quinby, Ted [National Renewable Energy Lab. (NREL), Golden, CO (United States); Caulfield, Emmet [Stanford Univ., CA (United States); Gerritsen, Margot [Stanford Univ., CA (United States); Diffendorfer, Jay [U.S. Geological Survey, Boulder, CO (United States); Haines, Seth [U.S. Geological Survey, Boulder, CO (United States)

    2014-03-01

    Recent policy and economic conditions have encouraged a renewed interest in developing large-scale solar projects in the U.S. Southwest. However, siting large-scale solar projects is complex. In addition to the quality of the solar resource, solar developers must take into consideration many environmental, social, and economic factors when evaluating a potential site. This report describes a proof-of-concept, Web-based Geographical Information Systems (GIS) tool that evaluates multiple user-defined criteria in an optimization algorithm to inform discussions and decisions regarding the locations of utility-scale solar projects. Existing siting recommendations for large-scale solar projects from governmental and non-governmental organizations are not consistent with each other, are often not transparent in methods, and do not take into consideration the differing priorities of stakeholders. The siting assistance GIS tool we have developed improves upon the existing siting guidelines by being user-driven, transparent, interactive, capable of incorporating multiple criteria, and flexible. This work provides the foundation for a dynamic siting assistance tool that can greatly facilitate siting decisions among multiple stakeholders.

  20. A Statistical Model for Hourly Large-Scale Wind and Photovoltaic Generation in New Locations

    DEFF Research Database (Denmark)

    Ekstrom, Jussi; Koivisto, Matti Juhani; Mellin, Ilkka

    2017-01-01

    The analysis of large-scale wind and photovoltaic (PV) energy generation is of vital importance in power systems where their penetration is high. This paper presents a modular methodology to assess the power generation and volatility of a system consisting of both PV plants (PVPs) and wind power...... of new PVPs and WPPs in system planning. The model is verified against hourly measured wind speed and solar irradiance data from Finland. A case study assessing the impact of the geographical distribution of the PVPs and WPPs on aggregate power generation and its variability is presented....

  1. On the measurements of large scale solar velocity fields

    International Nuclear Information System (INIS)

    Andersen, B.N.

    1985-01-01

    A general mathematical formulation for the correction of the scattered light influence on solar Doppler shift measurements has been developed. This method has been applied to the straylight correction of measurements of solar rotation, limb effect, large scale flows and oscillations. It is shown that neglecting the straylight errors may cause spurious large scale velocity fields, oscillations and erronous values for the solar rotation and limb effect. The influence of active regions on full disc velocity measurements has been studied. It is shown that a 13 day periodicity in the global velocity signal will be introduced by the passage of sunspots over the solar disc. With different types of low resolution apertures, other periodicities may be introduced. Accurate measurements of the center-to-limb velocity shift are presented for a set of magnetic insensitive lines well suited for solar velocity measurements. The absolute wavelenght shifts are briefly discussed. The stronger lines have a ''supergravitational'' shift of 300-400 m/s at the solar limb. The results may be explained by the presence of a 20-25 m/s poleward meridional flow and a latitudinal dependence of the granular parameters. Using a simple model it is shown that the main properites of the observations are explained by a 5% increase in the granular size with latitude. Data presented indicate that the resonance line K I, 769.9 nm has a small but significant limb effect of 125 m/s from center to limb

  2. Large scale solar district heating. Evaluation, modelling and designing

    Energy Technology Data Exchange (ETDEWEB)

    Heller, A.

    2000-07-01

    The main objective of the research was to evaluate large-scale solar heating connected to district heating (CSDHP), to build up a simulation tool and to demonstrate the application of the tool for design studies and on a local energy planning case. The evaluation of the central solar heating technology is based on measurements on the case plant in Marstal, Denmark, and on published and unpublished data for other, mainly Danish, CSDHP plants. Evaluations on the thermal, economical and environmental performances are reported, based on the experiences from the last decade. The measurements from the Marstal case are analysed, experiences extracted and minor improvements to the plant design proposed. For the detailed designing and energy planning of CSDHPs, a computer simulation model is developed and validated on the measurements from the Marstal case. The final model is then generalised to a 'generic' model for CSDHPs in general. The meteorological reference data, Danish Reference Year, is applied to find the mean performance for the plant designs. To find the expectable variety of the thermal performance of such plants, a method is proposed where data from a year with poor solar irradiation and a year with strong solar irradiation are applied. Equipped with a simulation tool design studies are carried out spreading from parameter analysis over energy planning for a new settlement to a proposal for the combination of plane solar collectors with high performance solar collectors, exemplified by a trough solar collector. The methodology of utilising computer simulation proved to be a cheap and relevant tool in the design of future solar heating plants. The thesis also exposed the demand for developing computer models for the more advanced solar collector designs and especially for the control operation of CSHPs. In the final chapter the CSHP technology is put into perspective with respect to other possible technologies to find the relevance of the application

  3. Contextual Compression of Large-Scale Wind Turbine Array Simulations

    Energy Technology Data Exchange (ETDEWEB)

    Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Potter, Kristin C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Clyne, John [National Center for Atmospheric Research (NCAR)

    2017-12-04

    Data sizes are becoming a critical issue particularly for HPC applications. We have developed a user-driven lossy wavelet-based storage model to facilitate the analysis and visualization of large-scale wind turbine array simulations. The model stores data as heterogeneous blocks of wavelet coefficients, providing high-fidelity access to user-defined data regions believed the most salient, while providing lower-fidelity access to less salient regions on a block-by-block basis. In practice, by retaining the wavelet coefficients as a function of feature saliency, we have seen data reductions in excess of 94 percent, while retaining lossless information in the turbine-wake regions most critical to analysis and providing enough (low-fidelity) contextual information in the upper atmosphere to track incoming coherent turbulent structures. Our contextual wavelet compression approach has allowed us to deliver interative visual analysis while providing the user control over where data loss, and thus reduction in accuracy, in the analysis occurs. We argue this reduced but contextualized representation is a valid approach and encourages contextual data management.

  4. Optimal Capacity Allocation of Large-Scale Wind-PV-Battery Units

    Directory of Open Access Journals (Sweden)

    Kehe Wu

    2014-01-01

    Full Text Available An optimal capacity allocation of large-scale wind-photovoltaic- (PV- battery units was proposed. First, an output power model was established according to meteorological conditions. Then, a wind-PV-battery unit was connected to the power grid as a power-generation unit with a rated capacity under a fixed coordinated operation strategy. Second, the utilization rate of renewable energy sources and maximum wind-PV complementation was considered and the objective function of full life cycle-net present cost (NPC was calculated through hybrid iteration/adaptive hybrid genetic algorithm (HIAGA. The optimal capacity ratio among wind generator, PV array, and battery device also was calculated simultaneously. A simulation was conducted based on the wind-PV-battery unit in Zhangbei, China. Results showed that a wind-PV-battery unit could effectively minimize the NPC of power-generation units under a stable grid-connected operation. Finally, the sensitivity analysis of the wind-PV-battery unit demonstrated that the optimization result was closely related to potential wind-solar resources and government support. Regions with rich wind resources and a reasonable government energy policy could improve the economic efficiency of their power-generation units.

  5. The challenge of integrating large scale wind power

    Energy Technology Data Exchange (ETDEWEB)

    Kryszak, B.

    2007-07-01

    The support of renewable energy sources is one of the key issues in current energy policies. The paper presents aspects of the integration of wind power in the electric power system from the perspective of a Transmission System Operator (TSO). Technical, operational and market aspects related to the integration of more than 8000 MW of installed wind power into the Transmission Network of Vattenfall Europe Transmission are discussed, and experiences with the transmission of wind power, wind power prediction, balancing of wind power, power production behaviour and fluctuations are reported. Moreover, issues for wind power integration on a European level will be discussed with the background of a wind power study. (auth)

  6. Investigation on the integral output power model of a large-scale wind farm

    Institute of Scientific and Technical Information of China (English)

    BAO Nengsheng; MA Xiuqian; NI Weidou

    2007-01-01

    The integral output power model of a large-scale wind farm is needed when estimating the wind farm's output over a period of time in the future.The actual wind speed power model and calculation method of a wind farm made up of many wind turbine units are discussed.After analyzing the incoming wind flow characteristics and their energy distributions,and after considering the multi-effects among the wind turbine units and certain assumptions,the incoming wind flow model of multi-units is built.The calculation algorithms and steps of the integral output power model of a large-scale wind farm are provided.Finally,an actual power output of the wind farm is calculated and analyzed by using the practical measurement wind speed data.The characteristics of a large-scale wind farm are also discussed.

  7. Optimal Selection of AC Cables for Large Scale Offshore Wind Farms

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Chen, Zhe

    2014-01-01

    The investment of large scale offshore wind farms is high in which the electrical system has a significant contribution to the total cost. As one of the key components, the cost of the connection cables affects the initial investment a lot. The development of cable manufacturing provides a vast...... and systematical way for the optimal selection of cables in large scale offshore wind farms....

  8. Power System Operation with Large Scale Wind Power Integration

    DEFF Research Database (Denmark)

    Suwannarat, A.; Bak-Jensen, B.; Chen, Z.

    2007-01-01

    to the uncertain nature of wind power. In this paper, proposed models of generations and control system are presented which analyze the deviation of power exchange at the western Danish-German border, taking into account the fluctuating nature of wind power. The performance of the secondary control of the thermal......The Danish power system starts to face problems of integrating thousands megawatts of wind power, which produce in a stochastic behavior due to natural wind fluctuations. With wind power capacities increasing, the Danish Transmission System Operator (TSO) is faced with new challenges related...... power plants and the spinning reserves control from the Combined Heat and Power (CHP) units to achieve active power balance with the increased wind power penetration is presented....

  9. Variability in large-scale wind power generation

    DEFF Research Database (Denmark)

    Kiviluoma, Juha; Holttinen, Hannele; Weir, David

    2016-01-01

    The paper demonstrates the characteristics of wind power variability and net load variability in multiple power systems based on real data from multiple years. Demonstrated characteristics include probability distribution for different ramp durations, seasonal and diurnal variability and low net ...... with well-dispersed wind power. Copyright © 2015 John Wiley & Sons, Ltd....

  10. Design Performance Standards for Large Scale Wind Farms

    DEFF Research Database (Denmark)

    Gordon, Mark

    2009-01-01

    of connection into the Eastern Australian power system under the Rules and guidelines set out by AEMC and NEMMCO (AEMO). Where applicable some international practices are also mentioned. Standards are designed to serve as a technical envelope under which wind farm proponents design the plant and maintain...... ongoing technical compliance of the plant during its operational lifetime. This report is designed to provide general technical information for the wind farm connection engineer to be aware of during the process of connection, registration and operation of wind power plants interconnected into the HV TSO......’s network. No special NER Rule has been used in this document, however V30 (year 2009) has been used as the latest reference on some of the topics discussed. Care has been taken to emphasise certain wind farm design and connection issues that could be considered throughout different stages of the wind farm...

  11. Grid Integration Issues for Large Scale Wind Power Plants (WPPs)

    DEFF Research Database (Denmark)

    Wu, Qiuwei; Xu, Zhao; Østergaard, Jacob

    2010-01-01

    transmission system operators (TSOs) over the world have come up the grid codes to request the wind power plants (WPPs) to have more or less the same operating capability as the conventional power plants. The grid codes requirements from other TSOs are under development. This paper covers the steady state......The penetration level of wind power into the power system over the world have been increasing very fast in the last few years and is still keeping the fast growth rate. It is just a matter of time that the wind power will be comparable to the conventional power generation. Therefore, many...

  12. Impacts of Large Scale Wind Penetration on Energy Supply Industry

    Directory of Open Access Journals (Sweden)

    John Kabouris

    2009-11-01

    Full Text Available Large penetration of Renewable Energy Sources (RES impacts Energy Supply Industry (ESI in many aspects leading to a fundamental change in electric power systems. It raises a number of technical challenges to the Transmission System Operators (TSOs, Distribution System Operators (DSOs and Wind Turbine Generators (WTG constructors. This paper aims to present in a thorough and coherent way the redrawn picture for Energy Systems under these conditions. Topics related to emergent technical challenges, technical solutions required and finally the impact on ESI due to large wind power penetration, are analyzed. Finally, general conclusions are extracted about the ESI current and future state and general directions are recommended.

  13. Dynamic Reactive Power Compensation of Large Scale Wind Integrated Power System

    DEFF Research Database (Denmark)

    Rather, Zakir Hussain; Chen, Zhe; Thøgersen, Paul

    2015-01-01

    wind turbines especially wind farms with additional grid support functionalities like dynamic support (e,g dynamic reactive power support etc.) and ii) refurbishment of existing conventional central power plants to synchronous condensers could be one of the efficient, reliable and cost effective option......Due to progressive displacement of conventional power plants by wind turbines, dynamic security of large scale wind integrated power systems gets significantly compromised. In this paper we first highlight the importance of dynamic reactive power support/voltage security in large scale wind...... integrated power systems with least presence of conventional power plants. Then we propose a mixed integer dynamic optimization based method for optimal dynamic reactive power allocation in large scale wind integrated power systems. One of the important aspects of the proposed methodology is that unlike...

  14. Implementation of large-scale average geostrophic wind shear in WAsP12.1

    DEFF Research Database (Denmark)

    Floors, Rogier Ralph; Troen, Ib; Kelly, Mark C.

    The vertical extrapolation model described in the European Wind Atlas Troen and Petersen (1989) is modified to take into account large-scale average geostrophic wind shear to describe the effect of horizontal temperature gradients on the geostrophic wind. The method is implemented by extracting...... the average geostrophic wind shear from Climate Forecast System Reanalysis (CFSR) data and the values of nearest grid point are automatically used in the WAsP 12.1 user interface to provide better AEP predictions....

  15. Reliability, availability and maintenance aspects of large-scale offshore wind farms, a concepts study

    NARCIS (Netherlands)

    Van Bussel, G.J.W.; Zaayer, M.B.

    2001-01-01

    The DOWEC projects aims at implementation of large wind turbines in large scale wind farms. part of the DOWEC project a concepts study was performed regarding the achievable reliability and availability levels. A reduction with a factor of 2 with regard to the present state of the art seems fairly

  16. European research school on large scale solar thermal – SHINE

    DEFF Research Database (Denmark)

    Bales, Chris; Forteza, Pau Joan Cortés; Furbo, Simon

    2014-01-01

    The Solar Heat Integration NEtwork (SHINE) is a European research school in which 13 PhD students in solar thermal technologies are funded by the EU Marie-Curie program. It has five PhD course modules as well as workshops and seminars dedicated to PhD students both within the project as well...... as outside of it. The SHINE research activities focus on large solar heating systems and new applications: on district heating, industrial processes and new storage systems. The scope of this paper is on systems for district heating for which there are five PhD students, three at universities and two...

  17. Dynamic model of frequency control in Danish power system with large scale integration of wind power

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    2013-01-01

    This work evaluates the impact of large scale integration of wind power in future power systems when 50% of load demand can be met from wind power. The focus is on active power balance control, where the main source of power imbalance is an inaccurate wind speed forecast. In this study, a Danish...... power system model with large scale of wind power is developed and a case study for an inaccurate wind power forecast is investigated. The goal of this work is to develop an adequate power system model that depicts relevant dynamic features of the power plants and compensates for load generation...... imbalances, caused by inaccurate wind speed forecast, by an appropriate control of the active power production from power plants....

  18. Testing, development and demonstration of large scale solar district heating systems

    DEFF Research Database (Denmark)

    Furbo, Simon; Fan, Jianhua; Perers, Bengt

    2015-01-01

    In 2013-2014 the project “Testing, development and demonstration of large scale solar district heating systems” was carried out within the Sino-Danish Renewable Energy Development Programme, the so called RED programme jointly developed by the Chinese and Danish governments. In the project Danish...... know how on solar heating plants and solar heating test technology have been transferred from Denmark to China, large solar heating systems have been promoted in China, test capabilities on solar collectors and large scale solar heating systems have been improved in China and Danish-Chinese cooperation...

  19. OffshoreDC DC grids for integration of large scale wind power

    DEFF Research Database (Denmark)

    Zeni, Lorenzo; Endegnanew, Atsede Gualu; Stamatiou, Georgios

    The present report summarizes the main findings of the Nordic Energy Research project “DC grids for large scale integration of offshore wind power – OffshoreDC”. The project is been funded by Nordic Energy Research through the TFI programme and was active between 2011 and 2016. The overall...... objective of the project was to drive the development of the VSC based HVDC technology for future large scale offshore grids, supporting a standardised and commercial development of the technology, and improving the opportunities for the technology to support power system integration of large scale offshore...

  20. Bi-Level Decentralized Active Power Control for Large-Scale Wind Farm Cluster

    DEFF Research Database (Denmark)

    Huang, Shengli; Wu, Qiuwei; Guo, Yifei

    2018-01-01

    This paper presents a bi-level decentralized active power control (DAPC) for a large-scale wind farm cluster, consisting of several wind farms for better active power dispatch. In the upper level, a distributed active power control scheme based on the distributed consensus is designed to achieve...... fair active power sharing among multiple wind farms, which generates the power reference for each wind farm. A distributed estimator is used to estimate the total available power of all wind farms. In the lower level, a centralized control scheme based on the Model Predictive Control (MPC) is proposed...... to regulate active power outputs of all wind turbines (WTs) within a wind farm, which reduces the fatigue loads of WTs while tracking the power reference obtained from the upper level control. A wind farm cluster with 8 wind farms and totally 160 WTs, was used to test the control performance of the proposed...

  1. Accident of Large-scale Wind Turbines Disconnecting from Power Grid and Its Protection

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    There were many accidents of large-scale wind turbines disconnecting from power grid in 2011. As single- phase-to-ground fault cannot be correctly detected, single-phase-to-ground fault evolved to phase-to-phase fault. Phase-to-phase fault was isolated slowly, thus leading to low voltage. And wind turbines without enough low voltage ride-through capacity had to be disconnected from the grid. After some wind turbines being disconnected from the grid, overvoltage caused by reactive power surplus made more wind turbines disconnect from the grid. Based on the accident analysis, this paper presents solutions to above problems, including travelling waves based single-phase-to-ground protection, adaptive low voltage protection, integrated protection and control, and high impedance fault detection. The solutions lay foundations in theory and technology to prevent large-scale wind turbines disconnecting from the operating power grid.

  2. Potential climatic impacts and reliability of large-scale offshore wind farms

    International Nuclear Information System (INIS)

    Wang Chien; Prinn, Ronald G

    2011-01-01

    The vast availability of wind power has fueled substantial interest in this renewable energy source as a potential near-zero greenhouse gas emission technology for meeting future world energy needs while addressing the climate change issue. However, in order to provide even a fraction of the estimated future energy needs, a large-scale deployment of wind turbines (several million) is required. The consequent environmental impacts, and the inherent reliability of such a large-scale usage of intermittent wind power would have to be carefully assessed, in addition to the need to lower the high current unit wind power costs. Our previous study (Wang and Prinn 2010 Atmos. Chem. Phys. 10 2053) using a three-dimensional climate model suggested that a large deployment of wind turbines over land to meet about 10% of predicted world energy needs in 2100 could lead to a significant temperature increase in the lower atmosphere over the installed regions. A global-scale perturbation to the general circulation patterns as well as to the cloud and precipitation distribution was also predicted. In the later study reported here, we conducted a set of six additional model simulations using an improved climate model to further address the potential environmental and intermittency issues of large-scale deployment of offshore wind turbines for differing installation areas and spatial densities. In contrast to the previous land installation results, the offshore wind turbine installations are found to cause a surface cooling over the installed offshore regions. This cooling is due principally to the enhanced latent heat flux from the sea surface to lower atmosphere, driven by an increase in turbulent mixing caused by the wind turbines which was not entirely offset by the concurrent reduction of mean wind kinetic energy. We found that the perturbation of the large-scale deployment of offshore wind turbines to the global climate is relatively small compared to the case of land

  3. Large-Scale Nanophotonic Solar Selective Absorbers for High-Efficiency Solar Thermal Energy Conversion.

    Science.gov (United States)

    Li, Pengfei; Liu, Baoan; Ni, Yizhou; Liew, Kaiyang Kevin; Sze, Jeff; Chen, Shuo; Shen, Sheng

    2015-08-19

    An omnidirectional nanophotonic solar selective absorber is fabricated on a large scale using a template-stripping method. The nanopyramid nickel structure achieves an average absorptance of 95% at a wavelength range below 1.3 μm and a low emittance less than 10% at wavelength >2.5 μm. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Large-scale Flow and Transport of Magnetic Flux in the Solar ...

    Indian Academy of Sciences (India)

    tribpo

    Abstract. Horizontal large-scale velocity field describes horizontal displacement of the photospheric magnetic flux in zonal and meridian directions. The flow systems of solar plasma, constructed according to the velocity field, create the large-scale cellular-like patterns with up-flow in the center and the down-flow on the ...

  5. A new method of presentation the large-scale magnetic field structure on the Sun and solar corona

    Science.gov (United States)

    Ponyavin, D. I.

    1995-01-01

    The large-scale photospheric magnetic field, measured at Stanford, has been analyzed in terms of surface harmonics. Changes of the photospheric field which occur within whole solar rotation period can be resolved by this analysis. For this reason we used daily magnetograms of the line-of-sight magnetic field component observed from Earth over solar disc. We have estimated the period during which day-to-day full disc magnetograms must be collected. An original algorithm was applied to resolve time variations of spherical harmonics that reflect time evolution of large-scale magnetic field within solar rotation period. This method of magnetic field presentation can be useful enough in lack of direct magnetograph observations due to sometimes bad weather conditions. We have used the calculated surface harmonics to reconstruct the large-scale magnetic field structure on the source surface near the sun - the origin of heliospheric current sheet and solar wind streams. The obtained results have been compared with spacecraft in situ observations and geomagnetic activity. We tried to show that proposed technique can trace shon-time variations of heliospheric current sheet and short-lived solar wind streams. We have compared also our results with those obtained traditionally from potential field approximation and extrapolation using synoptic charts as initial boundary conditions.

  6. Large-scale utilization of wind power in China: Obstacles of conflict between market and planning

    International Nuclear Information System (INIS)

    Zhao Xiaoli; Wang Feng; Wang Mei

    2012-01-01

    The traditional strict planning system that regulates China's power market dominates power industry operations. However, a series of market-oriented reforms since 1997 call for more decentralized decision-making by individual market participants. Moreover, with the rapid growth of wind power in China, the strict planning system has become one of the significant factors that has curtailed the generation of wind power, which contradicts with the original purpose of using the government's strong control abilities to promote wind power development. In this paper, we first present the reasons why market mechanisms are important for large-scale utilization of wind power by using a case analysis of the Northeast Grid, and then we illustrate the impact of conflicts between strict planning and market mechanisms on large-scale wind power utilization. Last, we explore how to promote coordination between markets and planning to realize large-scale wind power utilization in China. We argue that important measures include implementing flexible power pricing mechanisms instead of the current fixed pricing approach, formulating a more reasonable mechanism for distributing benefits and costs, and designing an appropriate market structure for large-scale wind power utilization to promote market liquidity and to send clear market equilibrium signals. - Highlights: ► We present the reasons why market is important for utilization of wind power. ► We discuss the current situation of the conflict between planning and market. ► We study the impact of conflict between planning and market on wind power output. ► We argue how to promote coordination between market and planning.

  7. Studies of Sub-Synchronous Oscillations in Large-Scale Wind Farm Integrated System

    Science.gov (United States)

    Yue, Liu; Hang, Mend

    2018-01-01

    With the rapid development and construction of large-scale wind farms and grid-connected operation, the series compensation wind power AC transmission is gradually becoming the main way of power usage and improvement of wind power availability and grid stability, but the integration of wind farm will change the SSO (Sub-Synchronous oscillation) damping characteristics of synchronous generator system. Regarding the above SSO problem caused by integration of large-scale wind farms, this paper focusing on doubly fed induction generator (DFIG) based wind farms, aim to summarize the SSO mechanism in large-scale wind power integrated system with series compensation, which can be classified as three types: sub-synchronous control interaction (SSCI), sub-synchronous torsional interaction (SSTI), sub-synchronous resonance (SSR). Then, SSO modelling and analysis methods are categorized and compared by its applicable areas. Furthermore, this paper summarizes the suppression measures of actual SSO projects based on different control objectives. Finally, the research prospect on this field is explored.

  8. Large-scale use of solar energy with central receivers

    Science.gov (United States)

    Kreith, F.; Meyer, R. T.

    1983-12-01

    The working principles of solar central receiver power plants are outlined and applications are discussed. Heliostat arrays direct sunlight into a receiver cavity mounted on a tower, heating the working fluid in the tower to temperatures exceeding 500 C. The formulation for the image plane and the geometric concentration ratio for a heliostat field are provided, noting that commercial electric power plants will require concentration ratios of 200-1000. Automated controls consider imperfections in the mirrors, tracking errors, and seasonal insolation intensity and angular variations. Membranes may be used instead of rigid heliostat mirrors to reduce costs, while trade-offs exist between the efficiencies of cavity and exterior receivers on the tower. Sensible heat storage has proved most effective for cloudy or nighttime operations. Details of the DOE Solar One 10 MW plant, which began operation in 1982, are provided, with mention given to the 33.6 continuous hours of power generation that have been achieved. Projected costs of commercial installations are $700/kWt, and possible applications include recovering and refining oil, processing natural gas, uranium ore, and sugar cane, drying gypsum board, and manufacturing ammonia.

  9. The economics and environmental impacts of large-scale wind power in a carbon constrained world

    Science.gov (United States)

    Decarolis, Joseph Frank

    Serious climate change mitigation aimed at stabilizing atmospheric concentrations of CO2 will require a radical shift to a decarbonized energy supply. The electric power sector will be a primary target for deep reductions in CO2 emissions because electric power plants are among the largest and most manageable point sources of emissions. With respect to new capacity, wind power is currently one of the most inexpensive ways to produce electricity without CO2 emissions and it may have a significant role to play in a carbon constrained world. Yet most research in the wind industry remains focused on near term issues, while energy system models that focus on century-long time horizons undervalue wind by imposing exogenous limits on growth. This thesis fills a critical gap in the literature by taking a closer look at the cost and environmental impacts of large-scale wind. Estimates of the average cost of wind generation---now roughly 4¢/kWh---do not address the cons arising from the spatial distribution and intermittency of wind. This thesis develops a theoretical framework for assessing the intermittency cost of wind. In addition, an economic characterization of a wind system is provided in which long-distance electricity transmission, storage, and gas turbines are used to supplement variable wind power output to meet a time-varying load. With somewhat optimistic assumptions about the cost of wind turbines, the use of wind to serve 50% of demand adds ˜1--2¢/kWh to the cost of electricity, a cost comparable to that of other large-scale low carbon technologies. This thesis also explores the environmental impacts posed by large-scale wind. Though avian mortality and noise caused controversy in the early years of wind development, improved technology and exhaustive siting assessments have minimized their impact. The aesthetic valuation of wind farms can be improved significantly with better design, siting, construction, and maintenance procedures, but opposition may

  10. Line Capacity Expansion and Transmission Switching in Power Systems With Large-Scale Wind Power

    DEFF Research Database (Denmark)

    Villumsen, Jonas Christoffer; Bronmo, Geir; Philpott, Andy B.

    2013-01-01

    In 2020 electricity production from wind power should constitute nearly 50% of electricity demand in Denmark. In this paper we look at optimal expansion of the transmission network in order to integrate 50% wind power in the system, while minimizing total fixed investment cost and expected cost...... of power generation. We allow for active switching of transmission elements to reduce congestion effects caused by Kirchhoff's voltage law. Results show that actively switching transmission lines may yield a better utilization of transmission networks with large-scale wind power and increase wind power...

  11. Large-scale brightness inhomogeneities in the solar atmosphere

    International Nuclear Information System (INIS)

    Mitchell, W.E. Jr.

    1982-01-01

    The intensity residuals are analyzed from a series of solar limb-darkening measurements in the wavelength range 5656 to 2997 A. The lengths of residual strings of the same sign exceed expectation by several orders of magnitude. The power spectrum fo the residuals shows a weak excess around 6000 km. For further study the 34000 limb-darkening residuals are subdivided into 5100 bright and faint cells. The frequency distribution of cell sizes peaks around 4500 km and increases from center to limb, the faint cells showing the greater center-limb effect. The cells are also studied as to contrast. A synoptic view indicates that only 12% of the cells are identifiable after a half hour. Phenomena that may combine to produce the observed wide spectrum of brightness inhomogeneities are briefly discussed. (orig.)

  12. Solar total energy-large scale experiment, Shenandoah, Georgia

    Science.gov (United States)

    Hensley, W. R.

    1980-01-01

    The design and development of a 7 meter diameter parabolic dish solar collector are discussed. Each of the four main subsystems of the collector: (1) reflector, (2) mount and drives, (3) receiver and (4) the controls, is discussed briefly with the major emphasis on the receiver design. To minimize development risks and production costs, a dish design based on use of stamped aluminum petals (sectors) was chosen. This design is similar to the design of a communication antenna already commercially produced. The reflective surface of the petals has a total reflectance of .86 and a specularity (dispersion) of 8 mrd. This performance is obtained by mechanical polishing and chemical brightening of the petal surface, followed by application of a clear RTV silicone protective coating. Selection of the material and weather proofing coated are discussed. Results from performance tests on an engineering development dish collector are presented and compared with pretest predictions.

  13. Intelligent control for large-scale variable speed variable pitch wind turbines

    Institute of Scientific and Technical Information of China (English)

    Xinfang ZHANG; Daping XU; Yibing LIU

    2004-01-01

    Large-scale wind turbine generator systems have strong nonlinear multivariable characteristics with many uncertain factors and disturbances.Automatic control is crucial for the efficiency and reliability of wind turbines.On the basis of simplified and proper model of variable speed variable pitch wind turbines,the effective wind speed is estimated using extended Kalman filter.Intelligent control schemes proposed in the paper include two loops which operate in synchronism with each other.At below-rated wind speed,the inner loop adopts adaptive fuzzy control based on variable universe for generator torque regulation to realize maximum wind energy capture.At above-rated wind speed, a controller based on least square support vector machine is proposed to adjust pitch angle and keep rated output power.The simulation shows the effectiveness of the intelligent control.

  14. Combining offshore wind energy and large-scale mussel farming: background & technical, ecological and economic considerations

    NARCIS (Netherlands)

    Lagerveld, S.; Rockmann, C.; Scholl, M.M.; Bartelings, H.; Burg, van den S.W.K.; Jak, R.G.; Jansen, H.M.; Klijnstra, J.; Leopold, M.F.; Poelman, M.; Smith, S.R.; Stavenuiter, J.; Veenstra, F.A.; Veltman, C.; Westra, C.

    2014-01-01

    This Blauwdruk project report presents background and technical, ecological and economic considerations of the potential combination of offshore wind energy production and large-scale mussel farming in offshore areas in the North Sea. The main objective of the Blauwdruk project was to study the

  15. Compensating active power imbalances in power system with large-scale wind power penetration

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Altin, Müfit

    2016-01-01

    Large-scale wind power penetration can affectthe supply continuity in the power system. This is a matterof high priority to investigate, as more regulating reservesand specified control strategies for generation control arerequired in the future power system with even more highwind power penetrat...

  16. Prospects for investment in large-scale, grid-connected solar power in Africa

    DEFF Research Database (Denmark)

    Hansen, Ulrich Elmer; Nygaard, Ivan; Pedersen, Mathilde Brix

    since the 1990s have changed the competiveness of solar PV in all markets, ranging from individual households via institutions to mini-grids and grid-connected installations. In volume and investment, the market for large-scale grid-connected solar power plants is by far the most important......-scale investments in grid-connected solar power plants and local assembly facilities for PV panels, have exceeded even optimistic scenarios. Finally, therefore, there seem to be bright prospects for investment in large-scale grid-connected solar power in Africa....

  17. Size Reduction Techniques for Large Scale Permanent Magnet Generators in Wind Turbines

    Science.gov (United States)

    Khazdozian, Helena; Hadimani, Ravi; Jiles, David

    2015-03-01

    Increased wind penetration is necessary to reduce U.S. dependence on fossil fuels, combat climate change and increase national energy security. The U.S Department of Energy has recommended large scale and offshore wind turbines to achieve 20% wind electricity generation by 2030. Currently, geared doubly-fed induction generators (DFIGs) are typically employed in the drivetrain for conversion of mechanical to electrical energy. Yet, gearboxes account for the greatest downtime of wind turbines, decreasing reliability and contributing to loss of profit. Direct drive permanent magnet generators (PMGs) offer a reliable alternative to DFIGs by eliminating the gearbox. However, PMGs scale up in size and weight much more rapidly than DFIGs as rated power is increased, presenting significant challenges for large scale wind turbine application. Thus, size reduction techniques are needed for viability of PMGs in large scale wind turbines. Two size reduction techniques are presented. It is demonstrated that 25% size reduction of a 10MW PMG is possible with a high remanence theoretical permanent magnet. Additionally, the use of a Halbach cylinder in an outer rotor PMG is investigated to focus magnetic flux over the rotor surface in order to increase torque. This work was supported by the National Science Foundation under Grant No. 1069283 and a Barbara and James Palmer Endowment at Iowa State University.

  18. The viability of balancing wind generation with large scale energy storage

    International Nuclear Information System (INIS)

    Nyamdash, Batsaikhan; Denny, Eleanor; O'Malley, Mark

    2010-01-01

    This paper studies the impact of combining wind generation and dedicated large scale energy storage on the conventional thermal plant mix and the CO 2 emissions of a power system. Different strategies are proposed here in order to explore the best operational strategy for the wind and storage system in terms of its effect on the net load. Furthermore, the economic viability of combining wind and large scale storage is studied. The empirical application, using data for the Irish power system, shows that combined wind and storage reduces the participation of mid-merit plants and increases the participation of base-load plants. Moreover, storage negates some of the CO 2 emissions reduction of the wind generation. It was also found that the wind and storage output can significantly reduce the variability of the net load under certain operational strategies and the optimal strategy depends on the installed wind capacity. However, in the absence of any supporting mechanism none of the storage devices were economically viable when they were combined with the wind generation on the Irish power system. - Research Highlights: → Energy storage would displace the peaking and mid-merit plants generations by the base-load plants generations. Energy storage may negate the CO 2 emissions reduction that is due to the increased wind generations. →Energy storage reduces the variation of the net load. →Under certain market conditions, merchant type energy storage is not viable.

  19. Survey of large-scale solar water heaters installed in Taiwan, China

    Energy Technology Data Exchange (ETDEWEB)

    Chang Keh-Chin; Lee Tsong-Sheng; Chung Kung-Ming [Cheng Kung Univ., Tainan (China); Lien Ya-Feng; Lee Chine-An [Cheng Kung Univ. Research and Development Foundation, Tainan (China)

    2008-07-01

    Almost all the solar collectors installed in Taiwan, China were used for production of hot water for homeowners (residential systems), in which the area of solar collectors is less than 10 square meters. From 2001 to 2006, there were only 39 large-scale systems (defined as the area of solar collectors being over 100 m{sup 2}) installed. Their utilization purposes are for rooming house (dormitory), swimming pool, restaurant, and manufacturing process. A comprehensive survey of those large-scale solar water heaters was conducted in 2006. The objectives of the survey were to asses the systems' performance and to have the feedback from the individual users. It is found that lack of experience in system design and maintenance are the key factors for reliable operation of a system. For further promotion of large-scale solar water heaters in Taiwan, a more compressive program on a system design for manufacturing process should be conducted. (orig.)

  20. Electricity network limitations on large-scale deployment of wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Fairbairn, R.J.

    1999-07-01

    This report sought to identify limitation on large scale deployment of wind energy in the UK. A description of the existing electricity supply system in England, Scotland and Wales is given, and operational aspects of the integrated electricity networks, licence conditions, types of wind turbine generators, and the scope for deployment of wind energy in the UK are addressed. A review of technical limitations and technical criteria stipulated by the Distribution and Grid Codes, the effects of system losses, and commercial issues are examined. Potential solutions to technical limitations are proposed, and recommendations are outlined.

  1. Development of polymers for large scale roll-to-roll processing of polymer solar cells

    DEFF Research Database (Denmark)

    Carlé, Jon Eggert

    Development of polymers for large scale roll-to-roll processing of polymer solar cells Conjugated polymers potential to both absorb light and transport current as well as the perspective of low cost and large scale production has made these kinds of material attractive in solar cell research....... The research field of polymer solar cells (PSCs) is rapidly progressing along three lines: Improvement of efficiency and stability together with the introduction of large scale production methods. All three lines are explored in this work. The thesis describes low band gap polymers and why these are needed....... Polymer of this type display broader absorption resulting in better overlap with the solar spectrum and potentially higher current density. Synthesis, characterization and device performance of three series of polymers illustrating how the absorption spectrum of polymers can be manipulated synthetically...

  2. Advances in Large-Scale Solar Heating and Long Term Storage in Denmark

    DEFF Research Database (Denmark)

    Heller, Alfred

    2000-01-01

    According to (the) information from the European Large-Scale Solar Heating Network, (See http://www.hvac.chalmers.se/cshp/), the area of installed solar collectors for large-scale application is in Europe, approximately 8 mill m2, corresponding to about 4000 MW thermal power. The 11 plants...... the last 10 years and the corresponding cost per collector area for the final installed plant is kept constant, even so the solar production is increased. Unfortunately large-scale seasonal storage was not able to keep up with the advances in solar technology, at least for pit water and gravel storage...... of the total 51 plants are equipped with long-term storage. In Denmark, 7 plants are installed, comprising of approx. 18,000-m2 collector area with new plants planned. The development of these plants and the involved technologies will be presented in this paper, with a focus on the improvements for Danish...

  3. A probabilistic assessment of large scale wind power development for long-term energy resource planning

    Science.gov (United States)

    Kennedy, Scott Warren

    A steady decline in the cost of wind turbines and increased experience in their successful operation have brought this technology to the forefront of viable alternatives for large-scale power generation. Methodologies for understanding the costs and benefits of large-scale wind power development, however, are currently limited. In this thesis, a new and widely applicable technique for estimating the social benefit of large-scale wind power production is presented. The social benefit is based upon wind power's energy and capacity services and the avoidance of environmental damages. The approach uses probabilistic modeling techniques to account for the stochastic interaction between wind power availability, electricity demand, and conventional generator dispatch. A method for including the spatial smoothing effect of geographically dispersed wind farms is also introduced. The model has been used to analyze potential offshore wind power development to the south of Long Island, NY. If natural gas combined cycle (NGCC) and integrated gasifier combined cycle (IGCC) are the alternative generation sources, wind power exhibits a negative social benefit due to its high capacity cost and the relatively low emissions of these advanced fossil-fuel technologies. Environmental benefits increase significantly if charges for CO2 emissions are included. Results also reveal a diminishing social benefit as wind power penetration increases. The dependence of wind power benefits on natural gas and coal prices is also discussed. In power systems with a high penetration of wind generated electricity, the intermittent availability of wind power may influence hourly spot prices. A price responsive electricity demand model is introduced that shows a small increase in wind power value when consumers react to hourly spot prices. The effectiveness of this mechanism depends heavily on estimates of the own- and cross-price elasticities of aggregate electricity demand. This work makes a valuable

  4. Wind speed reductions by large-scale wind turbine deployments lower turbine efficiencies and set low wind power potentials

    Science.gov (United States)

    Miller, Lee; Kleidon, Axel

    2017-04-01

    Wind turbines generate electricity by removing kinetic energy from the atmosphere. Large numbers of wind turbines are likely to reduce wind speeds, which lowers estimates of electricity generation from what would be presumed from unaffected conditions. Here, we test how well wind power potentials that account for this effect can be estimated without explicitly simulating atmospheric dynamics. We first use simulations with an atmospheric general circulation model (GCM) that explicitly simulates the effects of wind turbines to derive wind power limits (GCM estimate), and compare them to a simple approach derived from the climatological conditions without turbines [vertical kinetic energy (VKE) estimate]. On land, we find strong agreement between the VKE and GCM estimates with respect to electricity generation rates (0.32 and 0.37 We m-2) and wind speed reductions by 42 and 44%. Over ocean, the GCM estimate is about twice the VKE estimate (0.59 and 0.29 We m-2) and yet with comparable wind speed reductions (50 and 42%). We then show that this bias can be corrected by modifying the downward momentum flux to the surface. Thus, large-scale limits to wind power can be derived from climatological conditions without explicitly simulating atmospheric dynamics. Consistent with the GCM simulations, the approach estimates that only comparatively few land areas are suitable to generate more than 1 We m-2 of electricity and that larger deployment scales are likely to reduce the expected electricity generation rate of each turbine. We conclude that these atmospheric effects are relevant for planning the future expansion of wind power.

  5. Development of large scale wind energy conservation system. Development of large scale wind energy conversion system; Ogata furyoku hatsuden system no kaihatsu. Ogata furyoku hatsuden system no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Takita, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    Described herein are the results of the FY1994 research program for development of large scale wind energy conversion system. The study on technological development of key components evaluates performance of, and confirms reliability and applicability of, hydraulic systems centered by those equipped with variable pitch mechanisms and electrohydraulic servo valves that control them. The study on blade conducts fatigue and crack-propagation tests, which show that the blades developed have high strength. The study on speed-increasing gear conducts load tests, confirming the effects of reducing vibration and noise by modification of the gear teeth. The study on NACELLE cover conducts vibration tests to confirm its vibration characteristics, and analyzes three-dimensional vibration by the finite element method. Some components for a 500kW commercial wind mill are fabricated, including rotor heads, variable pitch mechanisms, speed-increasing gears, YAW systems, and hydraulic control systems. The others fabricated include a remote supervisory control system for maintenance, system to integrate the wind mill into a power system, and electrical control devices in which site conditions, such as atmospheric temperature and lightening, are taken into consideration.

  6. Progresses in application of computational ?uid dynamic methods to large scale wind turbine aerodynamics?

    Institute of Scientific and Technical Information of China (English)

    Zhenyu ZHANG; Ning ZHAO; Wei ZHONG; Long WANG; Bofeng XU

    2016-01-01

    The computational ?uid dynamics (CFD) methods are applied to aerody-namic problems for large scale wind turbines. The progresses including the aerodynamic analyses of wind turbine pro?les, numerical ?ow simulation of wind turbine blades, evalu-ation of aerodynamic performance, and multi-objective blade optimization are discussed. Based on the CFD methods, signi?cant improvements are obtained to predict two/three-dimensional aerodynamic characteristics of wind turbine airfoils and blades, and the vorti-cal structure in their wake ?ows is accurately captured. Combining with a multi-objective genetic algorithm, a 1.5 MW NH-1500 optimized blade is designed with high e?ciency in wind energy conversion.

  7. Impacts of large-scale offshore wind farm integration on power systems through VSC-HVDC

    DEFF Research Database (Denmark)

    Liu, Hongzhi; Chen, Zhe

    2013-01-01

    The potential of offshore wind energy has been commonly recognized and explored globally. Many countries have implemented and planned offshore wind farms to meet their increasing electricity demands and public environmental appeals, especially in Europe. With relatively less space limitation......, an offshore wind farm could have a capacity rating to hundreds of MWs or even GWs that is large enough to compete with conventional power plants. Thus the impacts of a large offshore wind farm on power system operation and security should be thoroughly studied and understood. This paper investigates...... the impacts of integrating a large-scale offshore wind farm into the transmission system of a power grid through VSC-HVDC connection. The concerns are focused on steady-state voltage stability, dynamic voltage stability and transient angle stability. Simulation results based on an exemplary power system...

  8. Aeroelastic Stability Investigations for Large-scale Vertical Axis Wind Turbines

    Science.gov (United States)

    Owens, B. C.; Griffith, D. T.

    2014-06-01

    The availability of offshore wind resources in coastal regions, along with a high concentration of load centers in these areas, makes offshore wind energy an attractive opportunity for clean renewable electricity production. High infrastructure costs such as the offshore support structure and operation and maintenance costs for offshore wind technology, however, are significant obstacles that need to be overcome to make offshore wind a more cost-effective option. A vertical-axis wind turbine (VAWT) rotor configuration offers a potential transformative technology solution that significantly lowers cost of energy for offshore wind due to its inherent advantages for the offshore market. However, several potential challenges exist for VAWTs and this paper addresses one of them with an initial investigation of dynamic aeroelastic stability for large-scale, multi-megawatt VAWTs. The aeroelastic formulation and solution method from the BLade Aeroelastic STability Tool (BLAST) for HAWT blades was employed to extend the analysis capability of a newly developed structural dynamics design tool for VAWTs. This investigation considers the effect of configuration geometry, material system choice, and number of blades on the aeroelastic stability of a VAWT, and provides an initial scoping for potential aeroelastic instabilities in large-scale VAWT designs.

  9. System Dynamics Simulation of Large-Scale Generation System for Designing Wind Power Policy in China

    Directory of Open Access Journals (Sweden)

    Linna Hou

    2015-01-01

    Full Text Available This paper focuses on the impacts of renewable energy policy on a large-scale power generation system, including thermal power, hydropower, and wind power generation. As one of the most important clean energy, wind energy has been rapidly developed in the world. But in recent years there is a serious waste of wind power equipment and investment in China leading to many problems in the industry from wind power planning to its integration. One way overcoming the difficulty is to analyze the influence of wind power policy on a generation system. This paper builds a system dynamics (SD model of energy generation to simulate the results of wind energy generation policies based on a complex system. And scenario analysis method is used to compare the effectiveness and efficiency of these policies. The case study shows that the combinations of lower portfolio goal and higher benchmark price and those of higher portfolio goal and lower benchmark price have large differences in both effectiveness and efficiency. On the other hand, the combinations of uniformly lower or higher portfolio goal and benchmark price have similar efficiency, but different effectiveness. Finally, an optimal policy combination can be chosen on the basis of policy analysis in the large-scale power system.

  10. Aeroelastic Stability Investigations for Large-scale Vertical Axis Wind Turbines

    International Nuclear Information System (INIS)

    2 P O Box 5800, Albuquerque, NM, 87185 (United States))" data-affiliation=" (Senior Member of Technical Staff, Analytical Structural Dynamics Sandia National Laboratories2 P O Box 5800, Albuquerque, NM, 87185 (United States))" >Owens, B C; 2 P O Box 5800, Albuquerque, NM, 87185 (United States))" data-affiliation=" (Principal Member of Technical Staff, Wind Energy Technologies Sandia National Laboratories2 P O Box 5800, Albuquerque, NM, 87185 (United States))" >Griffith, D T

    2014-01-01

    The availability of offshore wind resources in coastal regions, along with a high concentration of load centers in these areas, makes offshore wind energy an attractive opportunity for clean renewable electricity production. High infrastructure costs such as the offshore support structure and operation and maintenance costs for offshore wind technology, however, are significant obstacles that need to be overcome to make offshore wind a more cost-effective option. A vertical-axis wind turbine (VAWT) rotor configuration offers a potential transformative technology solution that significantly lowers cost of energy for offshore wind due to its inherent advantages for the offshore market. However, several potential challenges exist for VAWTs and this paper addresses one of them with an initial investigation of dynamic aeroelastic stability for large-scale, multi-megawatt VAWTs. The aeroelastic formulation and solution method from the BLade Aeroelastic STability Tool (BLAST) for HAWT blades was employed to extend the analysis capability of a newly developed structural dynamics design tool for VAWTs. This investigation considers the effect of configuration geometry, material system choice, and number of blades on the aeroelastic stability of a VAWT, and provides an initial scoping for potential aeroelastic instabilities in large-scale VAWT designs

  11. Large-scale wind power in New Brunswick : a regional scenario study towards 2025

    International Nuclear Information System (INIS)

    2008-08-01

    This paper discussed the large-scale development of wind power in New Brunswick and evaluated Danish experiences with wind development as a template for developing wind resources in the Maritimes region. The study showed that New Brunswick and the Maritimes region have good wind resources, and that the province will gain significant economic benefits from deploying between 5500 and 7500 MW of wind power capacity by 2025. Wind power development will contribute to the security of supply in the region and reduce air pollution. Carbon regulation and renewable portfolio standards will improve the competitiveness of wind power. Electricity generated by wind power plants in the Maritimes can be sold to other provinces in Canada, as well as to the heavily populated New England region of the United States. A high level of cooperation between markets in the Maritimes area and neighbouring New England and Quebec systems will be required in addition to load flow analyses of electricity systems. Denmark's experiences with developing wind power indicate that existing market designs must be restructured to allow for higher levels of competition. A strong system operator is required to integrate wind power into the system. It was concluded that strong political leadership is required to ensure the sustainable development of the region. 5 refs., 4 tabs., 9 figs

  12. Wind and Photovoltaic Large-Scale Regional Models for hourly production evaluation

    DEFF Research Database (Denmark)

    Marinelli, Mattia; Maule, Petr; Hahmann, Andrea N.

    2015-01-01

    This work presents two large-scale regional models used for the evaluation of normalized power output from wind turbines and photovoltaic power plants on a European regional scale. The models give an estimate of renewable production on a regional scale with 1 h resolution, starting from a mesosca...... of the transmission system, especially regarding the cross-border power flows. The tuning of these regional models is done using historical meteorological data acquired on a per-country basis and using publicly available data of installed capacity.......This work presents two large-scale regional models used for the evaluation of normalized power output from wind turbines and photovoltaic power plants on a European regional scale. The models give an estimate of renewable production on a regional scale with 1 h resolution, starting from a mesoscale...

  13. Experimental study of the impact of large-scale wind farms on land–atmosphere exchanges

    International Nuclear Information System (INIS)

    Zhang Wei; Markfort, Corey D; Porté-Agel, Fernando

    2013-01-01

    Large-scale wind farms, covering a significant portion of the land and ocean surface, may affect the transport of momentum, heat, mass and moisture between the atmosphere and the land locally and globally. To understand the wind-farm–atmosphere interaction, we conducted wind-tunnel experiments to study the surface scalar (heat) flux using model wind farms, consisting of more than ten rows of wind turbines—having typical streamwise and spanwise spacings of five and four rotor diameters—in a neutral boundary layer with a heated surface. The spatial distribution of the surface heat flux was mapped with an array of surface heat flux sensors within the quasi-developed regime of the wind-farm flow. Although the overall surface heat flux change produced by the wind farms was found to be small, with a net reduction of 4% for a staggered wind farm and nearly zero change for an aligned wind farm, the highly heterogeneous spatial distribution of the surface heat flux, dependent on the wind-farm layout, was significant. The difference between the minimum and maximum surface heat fluxes could be up to 12% and 7% in aligned and staggered wind farms, respectively. This finding is important for planning intensive agriculture practice and optimizing farm land use strategy regarding wind energy project development. The well-controlled wind-tunnel experiments presented in this study also provide a first comprehensive dataset on turbulent flow and scalar transport in wind farms, which can be further used to develop and validate new parameterizations of surface scalar fluxes in numerical models. (letter)

  14. A review of large-scale solar heating systems in Europe

    International Nuclear Information System (INIS)

    Fisch, M.N.; Guigas, M.; Dalenback, J.O.

    1998-01-01

    Large-scale solar applications benefit from the effect of scale. Compared to small solar domestic hot water (DHW) systems for single-family houses, the solar heat cost can be cut at least in third. The most interesting projects for replacing fossil fuels and the reduction of CO 2 -emissions are solar systems with seasonal storage in combination with gas or biomass boilers. In the framework of the EU-APAS project Large-scale Solar Heating Systems, thirteen existing plants in six European countries have been evaluated. lie yearly solar gains of the systems are between 300 and 550 kWh per m 2 collector area. The investment cost of solar plants with short-term storage varies from 300 up to 600 ECU per m 2 . Systems with seasonal storage show investment costs twice as high. Results of studies concerning the market potential for solar heating plants, taking new collector concepts and industrial production into account, are presented. Site specific studies and predesign of large-scale solar heating plants in six European countries for housing developments show a 50% cost reduction compared to existing projects. The cost-benefit-ratio for the planned systems with long-term storage is between 0.7 and 1.5 ECU per kWh per year. (author)

  15. High-Efficiency, Multijunction Solar Cells for Large-Scale Solar Electricity Generation

    Science.gov (United States)

    Kurtz, Sarah

    2006-03-01

    A solar cell with an infinite number of materials (matched to the solar spectrum) has a theoretical efficiency limit of 68%. If sunlight is concentrated, this limit increases to about 87%. These theoretical limits are calculated using basic physics and are independent of the details of the materials. In practice, the challenge of achieving high efficiency depends on identifying materials that can effectively use the solar spectrum. Impressive progress has been made with the current efficiency record being 39%. Today's solar market is also showing impressive progress, but is still hindered by high prices. One strategy for reducing cost is to use lenses or mirrors to focus the light on small solar cells. In this case, the system cost is dominated by the cost of the relatively inexpensive optics. The value of the optics increases with the efficiency of the solar cell. Thus, a concentrator system made with 35%- 40%-efficient solar cells is expected to deliver 50% more power at a similar cost when compare with a system using 25%-efficient cells. Today's markets are showing an opportunity for large concentrator systems that didn't exist 5-10 years ago. Efficiencies may soon pass 40% and ultimately may reach 50%, providing a pathway to improved performance and decreased cost. Many companies are currently investigating this technology for large-scale electricity generation. The presentation will cover the basic physics and more practical considerations to achieving high efficiency as well as describing the current status of the concentrator industry. This work has been authored by an employee of the Midwest Research Institute under Contract No. DE- AC36-99GO10337 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this work, or allow

  16. Research on unit commitment with large-scale wind power connected power system

    Science.gov (United States)

    Jiao, Ran; Zhang, Baoqun; Chi, Zhongjun; Gong, Cheng; Ma, Longfei; Yang, Bing

    2017-01-01

    Large-scale integration of wind power generators into power grid brings severe challenges to power system economic dispatch due to its stochastic volatility. Unit commitment including wind farm is analyzed from the two parts of modeling and solving methods. The structures and characteristics can be summarized after classification has been done according to different objective function and constraints. Finally, the issues to be solved and possible directions of research and development in the future are discussed, which can adapt to the requirements of the electricity market, energy-saving power generation dispatching and smart grid, even providing reference for research and practice of researchers and workers in this field.

  17. A fiber-optic ice detection system for large-scale wind turbine blades

    Science.gov (United States)

    Kim, Dae-gil; Sampath, Umesh; Kim, Hyunjin; Song, Minho

    2017-09-01

    Icing causes substantial problems in the integrity of large-scale wind turbines. In this work, a fiber-optic sensor system for detection of icing with an arrayed waveguide grating is presented. The sensor system detects Fresnel reflections from the ends of the fibers. The transition in Fresnel reflection due to icing gives peculiar intensity variations, which categorizes the ice, the water, and the air medium on the wind turbine blades. From the experimental results, with the proposed sensor system, the formation of icing conditions and thickness of ice were identified successfully in real time.

  18. Impact of Wind Shear and Tower Shadow Effects on Power System with Large Scale Wind Power Penetration

    DEFF Research Database (Denmark)

    Hu, Weihao; Su, Chi; Chen, Zhe

    2011-01-01

    presents a simulation model of a variable speed wind farm with permanent magnet synchronous generators (PMSGs) and fullscale back-to-back converters in the simulation tool of DIgSILENT/PowerFactory. In this paper, the impacts of wind shear and tower shadow effects on the small signal stability of power......Grid connected wind turbines are fluctuating power sources due to wind speed variations, the wind shear and the tower shadow effects. The fluctuating power may be able to excite the power system oscillation at a frequency close to the natural oscillation frequency of a power system. This paper...... systems with large scale wind power penetrations are investigated during continuous operation based on the wind turbine model and the power system model....

  19. Two methods for estimating limits to large-scale wind power generation.

    Science.gov (United States)

    Miller, Lee M; Brunsell, Nathaniel A; Mechem, David B; Gans, Fabian; Monaghan, Andrew J; Vautard, Robert; Keith, David W; Kleidon, Axel

    2015-09-08

    Wind turbines remove kinetic energy from the atmospheric flow, which reduces wind speeds and limits generation rates of large wind farms. These interactions can be approximated using a vertical kinetic energy (VKE) flux method, which predicts that the maximum power generation potential is 26% of the instantaneous downward transport of kinetic energy using the preturbine climatology. We compare the energy flux method to the Weather Research and Forecasting (WRF) regional atmospheric model equipped with a wind turbine parameterization over a 10(5) km2 region in the central United States. The WRF simulations yield a maximum generation of 1.1 We⋅m(-2), whereas the VKE method predicts the time series while underestimating the maximum generation rate by about 50%. Because VKE derives the generation limit from the preturbine climatology, potential changes in the vertical kinetic energy flux from the free atmosphere are not considered. Such changes are important at night when WRF estimates are about twice the VKE value because wind turbines interact with the decoupled nocturnal low-level jet in this region. Daytime estimates agree better to 20% because the wind turbines induce comparatively small changes to the downward kinetic energy flux. This combination of downward transport limits and wind speed reductions explains why large-scale wind power generation in windy regions is limited to about 1 We⋅m(-2), with VKE capturing this combination in a comparatively simple way.

  20. HFSB-seeding for large-scale tomographic PIV in wind tunnels

    Science.gov (United States)

    Caridi, Giuseppe Carlo Alp; Ragni, Daniele; Sciacchitano, Andrea; Scarano, Fulvio

    2016-12-01

    A new system for large-scale tomographic particle image velocimetry in low-speed wind tunnels is presented. The system relies upon the use of sub-millimetre helium-filled soap bubbles as flow tracers, which scatter light with intensity several orders of magnitude higher than micron-sized droplets. With respect to a single bubble generator, the system increases the rate of bubbles emission by means of transient accumulation and rapid release. The governing parameters of the system are identified and discussed, namely the bubbles production rate, the accumulation and release times, the size of the bubble injector and its location with respect to the wind tunnel contraction. The relations between the above parameters, the resulting spatial concentration of tracers and measurement of dynamic spatial range are obtained and discussed. Large-scale experiments are carried out in a large low-speed wind tunnel with 2.85 × 2.85 m2 test section, where a vertical axis wind turbine of 1 m diameter is operated. Time-resolved tomographic PIV measurements are taken over a measurement volume of 40 × 20 × 15 cm3, allowing the quantitative analysis of the tip-vortex structure and dynamical evolution.

  1. Technology for the large-scale production of multi-crystalline silicon solar cells and modules

    International Nuclear Information System (INIS)

    Weeber, A.W.; De Moor, H.H.C.

    1997-06-01

    In cooperation with Shell Solar Energy (formerly R and S Renewable Energy Systems) and the Research Institute for Materials of the Catholic University Nijmegen the Netherlands Energy Research Foundation (ECN) plans to develop a competitive technology for the large-scale manufacturing of solar cells and solar modules on the basis of multi-crystalline silicon. The project will be carried out within the framework of the Economy, Ecology and Technology (EET) program of the Dutch ministry of Economic Affairs and the Dutch ministry of Education, Culture and Sciences. The aim of the EET-project is to reduce the costs of a solar module by 50% by means of increasing the conversion efficiency as well as the development of cheap processes for large-scale production

  2. Status of the technology development of large scale HTS generators for wind turbine

    Energy Technology Data Exchange (ETDEWEB)

    Le, T. D.; Kim, J. H.; Kim, D. J.; Boo, C. J.; Kim, H. M. [Jeju National University, Jeju (Korea, Republic of)

    2015-06-15

    Large wind turbine generators with high temperature superconductors (HTS) are in incessant development because of their advantages such as weight and volume reduction and the increased efficiency compared with conventional technologies. In addition, nowadays the wind turbine market is growing in a function of time, increasing the capacity and energy production of the wind farms installed and increasing the electrical power for the electrical generators installed. As a consequence, it is raising the wind power energy contribution for the global electricity demand. In this study, a forecast of wind energy development will be firstly emphasized, then it continue presenting a recent status of the technology development of large scale HTSG for wind power followed by an explanation of HTS wire trend, cryogenics cooling systems concept, HTS magnets field coil stability and other technological parts for optimization of HTS generator design-operating temperature, design topology, field coil shape and level cost of energy, as well. Finally, the most relevant projects and designs of HTS generators specifically for offshore wind power systems are also mentioned in this study.

  3. Status of the technology development of large scale HTS generators for wind turbine

    International Nuclear Information System (INIS)

    Le, T. D.; Kim, J. H.; Kim, D. J.; Boo, C. J.; Kim, H. M.

    2015-01-01

    Large wind turbine generators with high temperature superconductors (HTS) are in incessant development because of their advantages such as weight and volume reduction and the increased efficiency compared with conventional technologies. In addition, nowadays the wind turbine market is growing in a function of time, increasing the capacity and energy production of the wind farms installed and increasing the electrical power for the electrical generators installed. As a consequence, it is raising the wind power energy contribution for the global electricity demand. In this study, a forecast of wind energy development will be firstly emphasized, then it continue presenting a recent status of the technology development of large scale HTSG for wind power followed by an explanation of HTS wire trend, cryogenics cooling systems concept, HTS magnets field coil stability and other technological parts for optimization of HTS generator design-operating temperature, design topology, field coil shape and level cost of energy, as well. Finally, the most relevant projects and designs of HTS generators specifically for offshore wind power systems are also mentioned in this study

  4. 'Take the long way down': Integration of large-scale North Sea wind using HVDC transmission

    International Nuclear Information System (INIS)

    Weigt, Hannes; Jeske, Till; Leuthold, Florian; Hirschhausen, Christian von

    2010-01-01

    We analyze the impact of extensive wind development in Germany for the year 2015, focusing on grid extensions and price signals. We apply the electricity generation and network model ELMOD to compare zonal, nodal, and uniform pricing approaches. In addition to a reference case of network extensions recommended by the German Energy Agency (Dena), we develop a scenario to transmit wind energy to major load centers in Western and Southern Germany via high-voltage direct current (HVDC) connections. From an economic-engineering standpoint, our results indicate that these connections are the most economic way to manage the integration of large-scale offshore wind resources, and that nodal pricing is most likely to determine the locales for future investment to eliminate congestion. We conclude with a description of the model's potential limitations.

  5. The large-scale integration of wind generation: Impacts on price, reliability and dispatchable conventional suppliers

    International Nuclear Information System (INIS)

    MacCormack, John; Hollis, Aidan; Zareipour, Hamidreza; Rosehart, William

    2010-01-01

    This work examines the effects of large-scale integration of wind powered electricity generation in a deregulated energy-only market on loads (in terms of electricity prices and supply reliability) and dispatchable conventional power suppliers. Hourly models of wind generation time series, load and resultant residual demand are created. From these a non-chronological residual demand duration curve is developed that is combined with a probabilistic model of dispatchable conventional generator availability, a model of an energy-only market with a price cap, and a model of generator costs and dispatch behavior. A number of simulations are performed to evaluate the effect on electricity prices, overall reliability of supply, the ability of a dominant supplier acting strategically to profitably withhold supplies, and the fixed cost recovery of dispatchable conventional power suppliers at different levels of wind generation penetration. Medium and long term responses of the market and/or regulator in the long term are discussed.

  6. Application of bamboo laminates in large-scale wind turbine blade design?

    Institute of Scientific and Technical Information of China (English)

    Long WANG; Hui LI; Tongguang WANG

    2016-01-01

    From the viewpoint of material and structure in the design of bamboo blades of large-scale wind turbine, a series of mechanical property tests of bamboo laminates as the major enhancement materials for blades are presented. The basic mechanical characteristics needed in the design of bamboo blades are brie?y introduced. Based on these data, the aerodynamic-structural integrated design of a 1.5 MW wind turbine bamboo blade relying on a conventional platform of upwind, variable speed, variable pitch, and doubly-fed generator is carried out. The process of the structural layer design of bamboo blades is documented in detail. The structural strength and fatigue life of the designed wind turbine blades are certified. The technical issues raised from the design are discussed. Key problems and direction of the future study are also summarized.

  7. Review of DC System Technologies for Large Scale Integration of Wind Energy Systems with Electricity Grids

    Directory of Open Access Journals (Sweden)

    Sheng Jie Shao

    2010-06-01

    Full Text Available The ever increasing development and availability of power electronic systems is the underpinning technology that enables large scale integration of wind generation plants with the electricity grid. As the size and power capacity of the wind turbine continues to increase, so is the need to place these significantly large structures at off-shore locations. DC grids and associated power transmission technologies provide opportunities for cost reduction and electricity grid impact minimization as the bulk power is concentrated at single point of entry. As a result, planning, optimization and impact can be studied and carefully controlled minimizing the risk of the investment as well as power system stability issues. This paper discusses the key technologies associated with DC grids for offshore wind farm applications.

  8. Performance of automatic generation control mechanisms with large-scale wind power

    Energy Technology Data Exchange (ETDEWEB)

    Ummels, B.C.; Gibescu, M.; Paap, G.C. [Delft Univ. of Technology (Netherlands); Kling, W.L. [Transmission Operations Department of TenneT bv (Netherlands)

    2007-11-15

    The unpredictability and variability of wind power increasingly challenges real-time balancing of supply and demand in electric power systems. In liberalised markets, balancing is a responsibility jointly held by the TSO (real-time power balancing) and PRPs (energy programs). In this paper, a procedure is developed for the simulation of power system balancing and the assessment of AGC performance in the presence of large-scale wind power, using the Dutch control zone as a case study. The simulation results show that the performance of existing AGC-mechanisms is adequate for keeping ACE within acceptable bounds. At higher wind power penetrations, however, the capabilities of the generation mix are increasingly challenged and additional reserves are required at the same level. (au)

  9. Energy System Analysis of Large-Scale Integration of Wind Power

    International Nuclear Information System (INIS)

    Lund, Henrik

    2003-11-01

    The paper presents the results of two research projects conducted by Aalborg University and financed by the Danish Energy Research Programme. Both projects include the development of models and system analysis with focus on large-scale integration of wind power into different energy systems. Market reactions and ability to exploit exchange on the international market for electricity by locating exports in hours of high prices are included in the analyses. This paper focuses on results which are valid for energy systems in general. The paper presents the ability of different energy systems and regulation strategies to integrate wind power, The ability is expressed by three factors: One factor is the degree of electricity excess production caused by fluctuations in wind and CHP heat demands. The other factor is the ability to utilise wind power to reduce CO 2 emission in the system. And the third factor is the ability to benefit from exchange of electricity on the market. Energy systems and regulation strategies are analysed in the range of a wind power input from 0 to 100% of the electricity demand. Based on the Danish energy system, in which 50 per cent of the electricity demand is produced in CHP, a number of future energy systems with CO 2 reduction potentials are analysed, i.e. systems with more CHP, systems using electricity for transportation (battery or hydrogen vehicles) and systems with fuel-cell technologies. For the present and such potential future energy systems different regulation strategies have been analysed, i.e. the inclusion of small CHP plants into the regulation task of electricity balancing and grid stability and investments in electric heating, heat pumps and heat storage capacity. Also the potential of energy management has been analysed. The results of the analyses make it possible to compare short-term and long-term potentials of different strategies of large-scale integration of wind power

  10. Cost optimization of wind turbines for large-scale offshore wind farms

    International Nuclear Information System (INIS)

    Fuglsang, P.; Thomsen, K.

    1998-02-01

    This report contains a preliminary investigation of site specific design of off-shore wind turbines for a large off-shore wind farm project at Roedsand that is currently being proposed by ELKRAFT/SEAS. The results were found using a design tool for wind turbines that involve numerical optimization and aeroelastic calculations of response. The wind climate was modeled in detail and a cost function was used to estimate costs from manufacture and installation. Cost of energy is higher for off-shore installations. A comparison of an off-shore wind farm site with a typical stand alone on-shore site showed an increase of the annual production of 28% due to the difference in wind climate. Extreme loads and blade fatigue loads were nearly identical, however,fatigue loads on other main components increased significantly. Optimizations were carried out to find the optimum overall off-shore wind turbine design. A wind turbine for the off-shore wind farm should be different compared with a stand-alone on-shore wind turbine. The overall design changed were increased swept area and rated power combined with reduced rotor speed and tower height. Cost was reduced by 12% for the final 5D/14D off-shore wind turbine from 0.306 DKr/kWh to 0.270 DKr/kWh. These figures include capital costs from manufacture and installation but not on-going costs from maintenance. These results make off-shore wind farms more competitive and comparable to the reference on-shore stand-alone wind turbine. A corresponding reduction of cost of energy could not be found for the stand alone on-shore wind turbine. Furthermore the fatigue loads on wind turbines in on-shore wind farms will increase and cost of energy will increase in favor of off-shore wind farms. (au) EFP-95; EU-JOULE-3; 21 tabs., 7 ills., 8 refs

  11. Contribution of large scale coherence to wind turbine power: A large eddy simulation study in periodic wind farms

    Science.gov (United States)

    Chatterjee, Tanmoy; Peet, Yulia T.

    2018-03-01

    Length scales of eddies involved in the power generation of infinite wind farms are studied by analyzing the spectra of the turbulent flux of mean kinetic energy (MKE) from large eddy simulations (LES). Large-scale structures with an order of magnitude bigger than the turbine rotor diameter (D ) are shown to have substantial contribution to wind power. Varying dynamics in the intermediate scales (D -10 D ) are also observed from a parametric study involving interturbine distances and hub height of the turbines. Further insight about the eddies responsible for the power generation have been provided from the scaling analysis of two-dimensional premultiplied spectra of MKE flux. The LES code is developed in a high Reynolds number near-wall modeling framework, using an open-source spectral element code Nek5000, and the wind turbines have been modelled using a state-of-the-art actuator line model. The LES of infinite wind farms have been validated against the statistical results from the previous literature. The study is expected to improve our understanding of the complex multiscale dynamics in the domain of large wind farms and identify the length scales that contribute to the power. This information can be useful for design of wind farm layout and turbine placement that take advantage of the large-scale structures contributing to wind turbine power.

  12. Pilot project wind power - Large scale wind power in northern Sweden; Pilotprojekt vindkraft - Storskalig vindkraft i norra Sverige

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The Swedish Energy Agency granted 2009-04-20 Svevind AB financial aid to implement {sup P}ilot project wind power- Large scale wind power in northern Sweden{sup .} The purpose of the aid is to implement pilot sub-projects in wind power, to to increase knowledge for the larger establishments. The Energy Agency said in its decision that the projects Dragaliden and Gabriel Mountain is of 'great importance for future large-scale development of wind power in Sweden'. The special conditions prevailing in the project, forest environment and cold climate, gives the possibility of studies of wind turbines on birds, reindeer herding and hunting and the more technical aspects, such as de-icing and obstacle lighting. The objectives of the project, in addition to the construction and operation of 32 wind turbines, has been to include evaluating the permit process, studying the social effects around the wind power, to study the impact on small game hunting, perform tests of the de-icing system, investigate impacts on reindeer herding and explain the outcome of the project-generated rural funds. Some of the above sub-projects have been completed, which are reported in this report. For the sub-projects still in progress, the report presents the results to date, until the completion.

  13. Large-scale introduction of wind power stations in the Swedish grid: a simulation study

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, L

    1978-08-01

    This report describes a simulation study on the factors to be considered if wind power were to be introduced to the south Swedish power grid on a large scale. The simulations are based upon a heuristic power generation planning model, developed for the purpose. The heuristic technique reflects the actual running strategies of a big power company with suitable accuracy. All simulations refer to certain typical days in 1976 to which all wind data and system characteristics are related. The installed amount of wind power will not be subject to optimization. All differences between planned and real wind power generation is equalized by regulation of the hydro power. The simulations made differ according to how the installed amount of wind power is handled in the power generation planning. The simulations indicate that the power system examined could well bear an introduction of wind power up to a level of 20% of the total power installed. This result is of course valid only for the days examined and does not necessarily apply to the present day structure of the system.

  14. Potential climatic impacts and reliability of very large-scale wind farms

    Directory of Open Access Journals (Sweden)

    C. Wang

    2010-02-01

    Full Text Available Meeting future world energy needs while addressing climate change requires large-scale deployment of low or zero greenhouse gas (GHG emission technologies such as wind energy. The widespread availability of wind power has fueled substantial interest in this renewable energy source as one of the needed technologies. For very large-scale utilization of this resource, there are however potential environmental impacts, and also problems arising from its inherent intermittency, in addition to the present need to lower unit costs. To explore some of these issues, we use a three-dimensional climate model to simulate the potential climate effects associated with installation of wind-powered generators over vast areas of land or coastal ocean. Using wind turbines to meet 10% or more of global energy demand in 2100, could cause surface warming exceeding 1 °C over land installations. In contrast, surface cooling exceeding 1 °C is computed over ocean installations, but the validity of simulating the impacts of wind turbines by simply increasing the ocean surface drag needs further study. Significant warming or cooling remote from both the land and ocean installations, and alterations of the global distributions of rainfall and clouds also occur. These results are influenced by the competing effects of increases in roughness and decreases in wind speed on near-surface turbulent heat fluxes, the differing nature of land and ocean surface friction, and the dimensions of the installations parallel and perpendicular to the prevailing winds. These results are also dependent on the accuracy of the model used, and the realism of the methods applied to simulate wind turbines. Additional theory and new field observations will be required for their ultimate validation. Intermittency of wind power on daily, monthly and longer time scales as computed in these simulations and inferred from meteorological observations, poses a demand for one or more options to ensure

  15. A new framework to increase the efficiency of large-scale solar power plants.

    Science.gov (United States)

    Alimohammadi, Shahrouz; Kleissl, Jan P.

    2015-11-01

    A new framework to estimate the spatio-temporal behavior of solar power is introduced, which predicts the statistical behavior of power output at utility scale Photo-Voltaic (PV) power plants. The framework is based on spatio-temporal Gaussian Processes Regression (Kriging) models, which incorporates satellite data with the UCSD version of the Weather and Research Forecasting model. This framework is designed to improve the efficiency of the large-scale solar power plants. The results are also validated from measurements of the local pyranometer sensors, and some improvements in different scenarios are observed. Solar energy.

  16. Spatial correlation of atmospheric wind at scales relevant for large scale wind turbines

    Science.gov (United States)

    Bardal, L. M.; Sætran, L. R.

    2016-09-01

    Wind measurements a short distance upstream of a wind turbine can provide input for a feedforward wind turbine controller. Since the turbulent wind field will be different at the point/plane of measurement and the rotor plane the degree of correlation between wind speed at two points in space both in the longitudinal and lateral direction should be evaluated. This study uses a 2D array of mast mounted anemometers to evaluate cross-correlation of longitudinal wind speed. The degree of correlation is found to increase with height and decrease with atmospheric stability. The correlation is furthermore considerably larger for longitudinal separation than for lateral separation. The integral length scale of turbulence is also considered.

  17. How to correct for long-term externalities of large-scale wind power development by a capacity mechanism?

    International Nuclear Information System (INIS)

    Cepeda, Mauricio; Finon, Dominique

    2013-01-01

    This paper deals with the practical problems related to long-term security of supply in electricity markets in the presence of large-scale wind power development. The success of recent renewable promotion schemes adds a new dimension to ensuring long-term security of supply: it necessitates designing second-best policies to prevent large-scale wind power development from distorting long-run equilibrium prices and investments in conventional generation and in particular in peaking units. We rely upon a long-term simulation model which simulates electricity market players' investment decisions in a market regime and incorporates large-scale wind power development in the presence of either subsidized or market driven development scenarios. We test the use of capacity mechanisms to compensate for long-term effects of large-scale wind power development on prices and reliability of supply. The first finding is that capacity mechanisms can help to reduce the social cost of large scale wind power development in terms of decrease of loss of load probability. The second finding is that, in a market-based wind power deployment without subsidy, wind generators are penalised for insufficient contribution to the long term system's reliability. - Highlights: • We model power market players’ investment decisions incorporating wind power. • We examine two market designs: an energy-only market and a capacity mechanism. • We test two types of wind power development paths: subsidised and market-driven. • Capacity mechanisms compensate for the externalities of wind power developments

  18. Top Five Large-Scale Solar Myths | State, Local, and Tribal Governments |

    Science.gov (United States)

    shadow on neighboring properties, cause light flicker, or have the same visual impact as wind farms), the . Some communities have opted for mitigation measures to reduce visual impacts of solar farms through the

  19. Large-Scale Fabrication of Silicon Nanowires for Solar Energy Applications.

    Science.gov (United States)

    Zhang, Bingchang; Jie, Jiansheng; Zhang, Xiujuan; Ou, Xuemei; Zhang, Xiaohong

    2017-10-11

    The development of silicon (Si) materials during past decades has boosted up the prosperity of the modern semiconductor industry. In comparison with the bulk-Si materials, Si nanowires (SiNWs) possess superior structural, optical, and electrical properties and have attracted increasing attention in solar energy applications. To achieve the practical applications of SiNWs, both large-scale synthesis of SiNWs at low cost and rational design of energy conversion devices with high efficiency are the prerequisite. This review focuses on the recent progresses in large-scale production of SiNWs, as well as the construction of high-efficiency SiNW-based solar energy conversion devices, including photovoltaic devices and photo-electrochemical cells. Finally, the outlook and challenges in this emerging field are presented.

  20. Red Geyser: A New Class of Galaxy with Large-scale AGN-driven Winds

    Science.gov (United States)

    Roy, Namrata; Bundy, Kevin; Cheung, Edmond; MaNGA Team

    2018-01-01

    A new class of quiescent (non-star-forming) galaxies harboring possible AGN-driven winds have been discovered using the spatially resolved optical spectroscopy from the ongoing SDSS-IV MaNGA (Sloan Digital Sky Survey-IV Mapping Nearby Galaxies at Apache Point Observatory) survey. These galaxies named "red geysers" constitute 5%-10% of the local quiescent galaxy population and are characterized by narrow bisymmetric ionized gas emission patterns. These enhanced patterns are seen in equivalent width maps of Hα, [OIII] and other strong emission lines. They are co-aligned with the ionized gas velocity gradients but significantly misaligned with stellar velocity gradients. They also show very high gas velocity dispersions (~200 km/s). Considering these observations in light of models of the gravitational potential, Cheung et al. argued that red geysers host large-scale AGN-driven winds of ionized gas that may play a role in suppressing star formation at late times. In this work, we test the hypothesis that AGN activity is ultimately responsible for the red geyser phenomenon. We compare the nuclear radio activity of the red geysers to a matched control sample of galaxies of similar stellar mass, redshift, rest frame NUV–r color and axis ratio. and additionally, control for the presence of ionized gas. We have used 1.4 GHz radio continuum data from the VLA FIRST Survey to stack the radio flux from the red geyser sample and control sample. We find that the red geysers have a higher average radio flux than the control galaxies at > 3σ significance. Our sample is restricted to rest-frame NUV–r color > 5, thus ruling out possible radio emission due to star formation activity. We conclude that red geysers are associated with more active AGN, supporting a feedback picture in which episodic AGN activity drives large-scale but relatively weak ionized winds in many in many early-type galaxies.

  1. Fuzzy generation scheduling for a generation company (GenCo) with large scale wind farms

    International Nuclear Information System (INIS)

    Siahkali, H.; Vakilian, M.

    2010-01-01

    Wind power is a promising alternative in power generation because of its tremendous environmental and social benefits. Generation scheduling (GS) is more important in a power system integrating wind farms. Unlike conventional power generation sources, wind power generators supply intermittent power because of uncertainty in resource. This paper presents a fuzzy approach to the generation scheduling problem of a GenCo considering uncertainties in parameters or constraints such as load, reserve and available wind power generation. The modeling of constraints is an important issue in power system scheduling. A fuzzy optimization approach is an approach that can be used to obtain the generation scheduling under an uncertain environment. In this paper, a fuzzy optimization-based method is developed to solve power system GS problem with fuzzy objective and constraints. The crisp formulation of this GS problem is firstly defined and is rearranged by introduction of a membership function of some constraints and objective function. Then, this fuzzy optimization problem is converted to a crisp optimization and solved using GAMS software by mixed integer nonlinear programming. Employing the fuzzy optimization GS, it is expected that in practice a higher profit would be achieved in the operation and cost management of a real power system with large scale wind farms in different level of constraints' satisfaction. The proposed approach is applied to a sample system (including six conventional units and two wind farms) and the results are compared with the results of crisp solution. This approach is also applied to a larger test case to demonstrate the robustness of this fuzzy optimization method.

  2. Large-scale offshore wind energy. Cost analysis and integration in the Dutch electricity market

    International Nuclear Information System (INIS)

    De Noord, M.

    1999-02-01

    The results of analysis of the construction and integration costs of large-scale offshore wind energy (OWE) farms in 2010 are presented. The integration of these farms (1 and 5 GW) in the Dutch electricity distribution system have been regarded against the background of a liberalised electricity market. A first step is taken for the determination of costs involved in solving integration problems. Three different types of foundations are examined: the mono-pile, the jacket and a new type of foundation: the concrete caisson pile: all single-turbine-single-support structures. For real offshore applications (>10 km offshore, at sea-depths >20 m), the concrete caisson pile is regarded as the most suitable. The price/power ratios of wind turbines are analysed. It is assumed that in 2010 turbines in the power range of 3-5 MW are available. The main calculations have been conducted for a 3 MW turbine. The main choice in electrical infrastructure is for AC or DC. Calculations show that at distances of 30 km offshore and more, the use of HVDC will result in higher initial costs but lower operating costs. The share of operating and maintenance (O ampersand M) costs in the kWh cost price is approximately 3.3%. To be able to compare the two farms, a base case is derived with a construction time of 10 years for both. The energy yield is calculated for a wind regime offshore of 9.0 m/s annual mean wind speed. Per 3 MW turbine this results in an annual energy production of approximately 12 GWh. The total farm efficiency amounts to 82%, resulting in a total farm capacity factor of 38%. With a required internal rate of return of 15%, the kWh cost price amounts to 0.24 DFl and 0.21 DFl for the 1 GW and 5 GW farms respectively in the base case. The required internal rate of return has a large effect on the kWh cost price, followed by costs of subsystems. O ampersand M costs have little effect on the cost price. Parameter studies show that a small cost reduction of 5% is possible when

  3. Verification of high-speed solar wind stream forecasts using operational solar wind models

    DEFF Research Database (Denmark)

    Reiss, Martin A.; Temmer, Manuela; Veronig, Astrid M.

    2016-01-01

    and the background solar wind conditions. We found that both solar wind models are capable of predicting the large-scale features of the observed solar wind speed (root-mean-square error, RMSE ≈100 km/s) but tend to either overestimate (ESWF) or underestimate (WSA) the number of high-speed solar wind streams (threat......High-speed solar wind streams emanating from coronal holes are frequently impinging on the Earth's magnetosphere causing recurrent, medium-level geomagnetic storm activity. Modeling high-speed solar wind streams is thus an essential element of successful space weather forecasting. Here we evaluate...... high-speed stream forecasts made by the empirical solar wind forecast (ESWF) and the semiempirical Wang-Sheeley-Arge (WSA) model based on the in situ plasma measurements from the Advanced Composition Explorer (ACE) spacecraft for the years 2011 to 2014. While the ESWF makes use of an empirical relation...

  4. How to correct long-term system externality of large scale wind power development by a capacity mechanism?

    International Nuclear Information System (INIS)

    Cepeda, Mauricio; Finon, Dominique

    2013-04-01

    This paper deals with the practical problems related to long-term security of supply in electricity markets in the presence of large-scale wind power development. The success of renewable promotion schemes adds a new dimension to ensuring long-term security of supply. It necessitates designing second-best policies to prevent large-scale wind power development from distorting long-run equilibrium prices and investments in conventional generation and in particular in peaking units. We rely upon a long-term simulation model which simulates electricity market players' investment decisions in a market regime and incorporates large-scale wind power development either in the presence of either subsidised wind production or in market-driven development. We test the use of capacity mechanisms to compensate for the long-term effects of large-scale wind power development on the system reliability. The first finding is that capacity mechanisms can help to reduce the social cost of large scale wind power development in terms of decrease of loss of load probability. The second finding is that, in a market-based wind power deployment without subsidy, wind generators are penalized for insufficient contribution to the long term system's reliability. (authors)

  5. Large scale solar thermal power for the European Union{exclamation_point}

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1997-06-01

    Southern Europe, on the edge of the sunbelt, represents the ideal location for solar thermal generated power. Last year. SAWIE reported on the THESEUS project, a proposed 50 MWe solar thermal power plant for Frangokastello, southern Crete, which was submitted for support under the European Union`s THERMIE Programme. Funding was approved for the design phase for this innovative power plant, the first large-scale SEGS-style plant on European soil, at the end of last year. However, the THERMIE Programme also provided support for another Southern European plant, proposed by Colon Solar for Huelva in Southern Spain. Whilst hurdles remain to be overcome before both plants are built and commissioned, there is an excellent chance that by the start of the new Millennium, the solar collectors from these two plants could be generating over half a million MWh of energy a year. SAWIE compares the two projects. (author)

  6. A Review of Research on Large Scale Modern Vertical Axis Wind Turbines at Uppsala University

    Directory of Open Access Journals (Sweden)

    Senad Apelfröjd

    2016-07-01

    Full Text Available This paper presents a review of over a decade of research on Vertical Axis Wind Turbines (VAWTs conducted at Uppsala University. The paper presents, among others, an overview of the 200 kW VAWT located in Falkenberg, Sweden, as well as a description of the work done on the 12 kW prototype VAWT in Marsta, Sweden. Several key aspects have been tested and successfully demonstrated at our two experimental research sites. The effort of the VAWT research has been aimed at developing a robust large scale VAWT technology based on an electrical control system with a direct driven energy converter. This approach allows for a simplification where most or all of the control of the turbines can be managed by the electrical converter system, reducing investment cost and need for maintenance. The concept features an H-rotor that is omnidirectional in regards to wind direction, meaning that it can extract energy from all wind directions without the need for a yaw system. The turbine is connected to a direct driven permanent magnet synchronous generator (PMSG, located at ground level, that is specifically developed to control and extract power from the turbine. The research is ongoing and aims for a multi-megawatt VAWT in the near future.

  7. Calculation and characteristics analysis of blade pitch loads for large scale wind turbines

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Based on the electric pitch system of large scale horizontal-axis wind turbines,the blade pitch loads coming mainly from centrifugal force,aerodynamic force and gravity are analyzed,and the calculation models for them are established in this paper.For illustration,a 1.2 MW wind turbine is introduced as a practical sample,and its blade pitch loads from centrifugal force,aerodynamic force and gravity are calculated and analyzed separately and synthetically.The research results showed that in the process of rotor rotating 360o,the fluctuation of blade pitch loads is similar to cosine curve when the rotor rotational speed,in-flow wind speed and pitch angle are constant.Furthermore,the amplitude of blade pitch load presents quite a difference at a different pitch angle.The ways of calculation for blade pitch loads are of the universality,and are helpful for further research of the individual pitch control system.

  8. ARRA-Multi-Level Energy Storage and Controls for Large-Scale Wind Energy Integration

    Energy Technology Data Exchange (ETDEWEB)

    David Wenzhong Gao

    2012-09-30

    intelligent controller that increases battery life within hybrid energy storage systems for wind application was developed. Comprehensive studies have been conducted and simulation results are analyzed. A permanent magnet synchronous generator, coupled with a variable speed wind turbine, is connected to a power grid (14-bus system). A rectifier, a DC-DC converter and an inverter are used to provide a complete model of the wind system. An Energy Storage System (ESS) is connected to a DC-link through a DC-DC converter. An intelligent controller is applied to the DC-DC converter to help the Voltage Source Inverter (VSI) to regulate output power and also to control the operation of the battery and supercapacitor. This ensures a longer life time for the batteries. The detailed model is simulated in PSCAD/EMTP. Additionally, economic analysis has been done for different methods that can reduce the wind power output fluctuation. These methods are, wind power curtailment, dumping loads, battery energy storage system and hybrid energy storage system. From the results, application of single advanced HESS can save more money for wind turbines owners. Generally the income would be the same for most of methods because the wind does not change and maximum power point tracking can be applied to most systems. On the other hand, the cost is the key point. For short term and small wind turbine, the BESS is the cheapest and applicable method while for large scale wind turbines and wind farms the application of advanced HESS would be the best method to reduce the power fluctuation. The key outcomes of this project include a new intelligent controller that can reduce energy exchanged between the battery and DC-link, reduce charging/discharging cycles, reduce depth of discharge and increase time interval between charge/discharge, and lower battery temperature. This improves the overall lifetime of battery energy storages. Additionally, a new design method based on probability help optimize the

  9. Techno-economic Modeling of the Integration of 20% Wind and Large-scale Energy Storage in ERCOT by 2030

    Energy Technology Data Exchange (ETDEWEB)

    Baldick, Ross; Webber, Michael; King, Carey; Garrison, Jared; Cohen, Stuart; Lee, Duehee

    2012-12-21

    This study's objective is to examine interrelated technical and economic avenues for the Electric Reliability Council of Texas (ERCOT) grid to incorporate up to and over 20% wind generation by 2030. Our specific interests are to look at the factors that will affect the implementation of both high level of wind power penetration (> 20% generation) and installation of large scale storage.

  10. A Large-scale Plume in an X-class Solar Flare

    Energy Technology Data Exchange (ETDEWEB)

    Fleishman, Gregory D.; Nita, Gelu M.; Gary, Dale E. [Physics Department, Center for Solar-Terrestrial Research, New Jersey Institute of Technology Newark, NJ, 07102-1982 (United States)

    2017-08-20

    Ever-increasing multi-frequency imaging of solar observations suggests that solar flares often involve more than one magnetic fluxtube. Some of the fluxtubes are closed, while others can contain open fields. The relative proportion of nonthermal electrons among those distinct loops is highly important for understanding energy release, particle acceleration, and transport. The access of nonthermal electrons to the open field is also important because the open field facilitates the solar energetic particle (SEP) escape from the flaring site, and thus controls the SEP fluxes in the solar system, both directly and as seed particles for further acceleration. The large-scale fluxtubes are often filled with a tenuous plasma, which is difficult to detect in either EUV or X-ray wavelengths; however, they can dominate at low radio frequencies, where a modest component of nonthermal electrons can render the source optically thick and, thus, bright enough to be observed. Here we report the detection of a large-scale “plume” at the impulsive phase of an X-class solar flare, SOL2001-08-25T16:23, using multi-frequency radio data from Owens Valley Solar Array. To quantify the flare’s spatial structure, we employ 3D modeling utilizing force-free-field extrapolations from the line of sight SOHO /MDI magnetograms with our modeling tool GX-Simulator. We found that a significant fraction of the nonthermal electrons that accelerated at the flare site low in the corona escapes to the plume, which contains both closed and open fields. We propose that the proportion between the closed and open fields at the plume is what determines the SEP population escaping into interplanetary space.

  11. Valuation framework for large scale electricity storage in a case with wind curtailment

    International Nuclear Information System (INIS)

    Loisel, Rodica; Mercier, Arnaud; Gatzen, Christoph; Elms, Nick; Petric, Hrvoje

    2010-01-01

    This paper investigates the value of large scale applications of electricity storage in selected European power systems in the context of wind generation confronted with a grid bottleneck. It analyzes the market value to 2030 of two storage technologies, assuming the market situation projected for Germany and France. The analysis assesses the evolution of storage economics based on the net present value of cash flows. Sensitivities to market and regulatory drivers of value are assessed, e.g. electricity price spreads, ancillary services revenues, wind curtailment and the level of carbon prices. The paper concludes by suggesting possible ways to improve the competitiveness of electricity storage, such as research and development and deployment programmes, and changes to the design of power markets and regulatory arrangements to enable storage owners to better capture the benefits of storage. Such changes would allow electricity storage, where economically viable, to play a critical role in establishing a future sustainable European power system. - Research highlights: →CAES and PHS are not cost-effective for current market design in France and Germany → Market reforms are run to reward bottleneck avoiding and ancillary reserves → Storage is profitable when all potential socio-economic benefits are aggregated → R and D and D programs for storage improvement are economically and socially justified.

  12. A DATA-DRIVEN ANALYTIC MODEL FOR PROTON ACCELERATION BY LARGE-SCALE SOLAR CORONAL SHOCKS

    Energy Technology Data Exchange (ETDEWEB)

    Kozarev, Kamen A. [Smithsonian Astrophysical Observatory (United States); Schwadron, Nathan A. [Institute for the Study of Earth, Oceans, and Space, University of New Hampshire (United States)

    2016-11-10

    We have recently studied the development of an eruptive filament-driven, large-scale off-limb coronal bright front (OCBF) in the low solar corona, using remote observations from the Solar Dynamics Observatory ’s Advanced Imaging Assembly EUV telescopes. In that study, we obtained high-temporal resolution estimates of the OCBF parameters regulating the efficiency of charged particle acceleration within the theoretical framework of diffusive shock acceleration (DSA). These parameters include the time-dependent front size, speed, and strength, as well as the upstream coronal magnetic field orientations with respect to the front’s surface normal direction. Here we present an analytical particle acceleration model, specifically developed to incorporate the coronal shock/compressive front properties described above, derived from remote observations. We verify the model’s performance through a grid of idealized case runs using input parameters typical for large-scale coronal shocks, and demonstrate that the results approach the expected DSA steady-state behavior. We then apply the model to the event of 2011 May 11 using the OCBF time-dependent parameters derived by Kozarev et al. We find that the compressive front likely produced energetic particles as low as 1.3 solar radii in the corona. Comparing the modeled and observed fluences near Earth, we also find that the bulk of the acceleration during this event must have occurred above 1.5 solar radii. With this study we have taken a first step in using direct observations of shocks and compressions in the innermost corona to predict the onsets and intensities of solar energetic particle events.

  13. Environmental Impacts From the Installation and Operation of Large-scale Solar Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Fthenakis, V.; Turney, Damon

    2011-04-23

    Large-scale solar power plants are being developed at a rapid rate, and are setting up to use thousands or millions of acres of land globally. The environmental issues related to the installation and operation phases of such facilities have not, so far, been addressed comprehensively in the literature. Here we identify and appraise 32 impacts from these phases, under the themes of land use intensity, human health and well-being, plant and animal life, geohydrological resources, and climate change. Our appraisals assume that electricity generated by new solar power facilities will displace electricity from traditional U.S. generation technologies. Altogether we find 22 of the considered 32 impacts to be beneficial. Of the remaining 10 impacts, 4 are neutral, and 6 require further research before they can be appraised. None of the impacts are negative relative to traditional power generation. We rank the impacts in terms of priority, and find all the high-priority impacts to be beneficial. In quantitative terms, large-scale solar power plants occupy the same or less land per kW h than coal power plant life cycles. Removal of forests to make space for solar power causes CO{sub 2} emissions as high as 36 g CO{sub 2} kW h{sup -1}, which is a significant contribution to the life cycle CO{sub 2} emissions of solar power, but is still low compared to CO{sub 2} emissions from coal-based electricity that are about 1100 g CO{sub 2} kW h{sup -1}.

  14. Turbulence in the solar wind

    CERN Document Server

    Bruno, Roberto

    2016-01-01

    This book provides an overview of solar wind turbulence from both the theoretical and observational perspective. It argues that the interplanetary medium offers the best opportunity to directly study turbulent fluctuations in collisionless plasmas. In fact, during expansion, the solar wind evolves towards a state characterized by large-amplitude fluctuations in all observed parameters, which resembles, at least at large scales, the well-known hydrodynamic turbulence. This text starts with historical references to past observations and experiments on turbulent flows. It then introduces the Navier-Stokes equations for a magnetized plasma whose low-frequency turbulence evolution is described within the framework of the MHD approximation. It also considers the scaling of plasma and magnetic field fluctuations and the study of nonlinear energy cascades within the same framework. It reports observations of turbulence in the ecliptic and at high latitude, treating Alfvénic and compressive fluctuations separately in...

  15. Research on a Small Signal Stability Region Boundary Model of the Interconnected Power System with Large-Scale Wind Power

    Directory of Open Access Journals (Sweden)

    Wenying Liu

    2015-03-01

    Full Text Available For the interconnected power system with large-scale wind power, the problem of the small signal stability has become the bottleneck of restricting the sending-out of wind power as well as the security and stability of the whole power system. Around this issue, this paper establishes a small signal stability region boundary model of the interconnected power system with large-scale wind power based on catastrophe theory, providing a new method for analyzing the small signal stability. Firstly, we analyzed the typical characteristics and the mathematic model of the interconnected power system with wind power and pointed out that conventional methods can’t directly identify the topological properties of small signal stability region boundaries. For this problem, adopting catastrophe theory, we established a small signal stability region boundary model of the interconnected power system with large-scale wind power in two-dimensional power injection space and extended it to multiple dimensions to obtain the boundary model in multidimensional power injection space. Thirdly, we analyzed qualitatively the topological property’s changes of the small signal stability region boundary caused by large-scale wind power integration. Finally, we built simulation models by DIgSILENT/PowerFactory software and the final simulation results verified the correctness and effectiveness of the proposed model.

  16. A large-scale dataset of solar event reports from automated feature recognition modules

    Science.gov (United States)

    Schuh, Michael A.; Angryk, Rafal A.; Martens, Petrus C.

    2016-05-01

    The massive repository of images of the Sun captured by the Solar Dynamics Observatory (SDO) mission has ushered in the era of Big Data for Solar Physics. In this work, we investigate the entire public collection of events reported to the Heliophysics Event Knowledgebase (HEK) from automated solar feature recognition modules operated by the SDO Feature Finding Team (FFT). With the SDO mission recently surpassing five years of operations, and over 280,000 event reports for seven types of solar phenomena, we present the broadest and most comprehensive large-scale dataset of the SDO FFT modules to date. We also present numerous statistics on these modules, providing valuable contextual information for better understanding and validating of the individual event reports and the entire dataset as a whole. After extensive data cleaning through exploratory data analysis, we highlight several opportunities for knowledge discovery from data (KDD). Through these important prerequisite analyses presented here, the results of KDD from Solar Big Data will be overall more reliable and better understood. As the SDO mission remains operational over the coming years, these datasets will continue to grow in size and value. Future versions of this dataset will be analyzed in the general framework established in this work and maintained publicly online for easy access by the community.

  17. Contextual Compression of Large-Scale Wind Turbine Array Simulations: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Gruchalla, Kenny M [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Brunhart-Lupo, Nicholas J [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Potter, Kristin C [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Clyne, John [National Center for Atmospheric Research

    2017-11-03

    Data sizes are becoming a critical issue particularly for HPC applications. We have developed a user-driven lossy wavelet-based storage model to facilitate the analysis and visualization of large-scale wind turbine array simulations. The model stores data as heterogeneous blocks of wavelet coefficients, providing high-fidelity access to user-defined data regions believed the most salient, while providing lower-fidelity access to less salient regions on a block-by-block basis. In practice, by retaining the wavelet coefficients as a function of feature saliency, we have seen data reductions in excess of 94 percent, while retaining lossless information in the turbine-wake regions most critical to analysis and providing enough (low-fidelity) contextual information in the upper atmosphere to track incoming coherent turbulent structures. Our contextual wavelet compression approach has allowed us to deliver interactive visual analysis while providing the user control over where data loss, and thus reduction in accuracy, in the analysis occurs. We argue this reduced but contexualized representation is a valid approach and encourages contextual data management.

  18. LARGE-SCALE MAGNETIC HELICITY FLUXES ESTIMATED FROM MDI MAGNETIC SYNOPTIC CHARTS OVER THE SOLAR CYCLE 23

    International Nuclear Information System (INIS)

    Yang Shangbin; Zhang Hongqi

    2012-01-01

    To investigate the characteristics of large-scale and long-term evolution of magnetic helicity with solar cycles, we use the method of Local Correlation Tracking to estimate the magnetic helicity evolution over solar cycle 23 from 1996 to 2009 using 795 MDI magnetic synoptic charts. The main results are as follows: the hemispheric helicity rule still holds in general, i.e., the large-scale negative (positive) magnetic helicity dominates the northern (southern) hemisphere. However, the large-scale magnetic helicity fluxes show the same sign in both hemispheres around 2001 and 2005. The global, large-scale magnetic helicity flux over the solar disk changes from a negative value at the beginning of solar cycle 23 to a positive value at the end of the cycle, while the net accumulated magnetic helicity is negative in the period between 1996 and 2009.

  19. LARGE-SCALE MAGNETIC HELICITY FLUXES ESTIMATED FROM MDI MAGNETIC SYNOPTIC CHARTS OVER THE SOLAR CYCLE 23

    Energy Technology Data Exchange (ETDEWEB)

    Yang Shangbin; Zhang Hongqi, E-mail: yangshb@nao.cas.cn [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, 100012 Beijing (China)

    2012-10-10

    To investigate the characteristics of large-scale and long-term evolution of magnetic helicity with solar cycles, we use the method of Local Correlation Tracking to estimate the magnetic helicity evolution over solar cycle 23 from 1996 to 2009 using 795 MDI magnetic synoptic charts. The main results are as follows: the hemispheric helicity rule still holds in general, i.e., the large-scale negative (positive) magnetic helicity dominates the northern (southern) hemisphere. However, the large-scale magnetic helicity fluxes show the same sign in both hemispheres around 2001 and 2005. The global, large-scale magnetic helicity flux over the solar disk changes from a negative value at the beginning of solar cycle 23 to a positive value at the end of the cycle, while the net accumulated magnetic helicity is negative in the period between 1996 and 2009.

  20. ASSOCIATION OF {sup 3}He-RICH SOLAR ENERGETIC PARTICLES WITH LARGE-SCALE CORONAL WAVES

    Energy Technology Data Exchange (ETDEWEB)

    Bučík, Radoslav [Institut für Astrophysik, Georg-August-Universität Göttingen, D-37077, Göttingen (Germany); Innes, Davina E. [Max-Planck-Institut für Sonnensystemforschung, D-37077, Göttingen (Germany); Mason, Glenn M. [Applied Physics Laboratory, Johns Hopkins University, Laurel, MD 20723 (United States); Wiedenbeck, Mark E., E-mail: bucik@mps.mpg.de [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States)

    2016-12-10

    Small, {sup 3}He-rich solar energetic particle (SEP) events have been commonly associated with extreme-ultraviolet (EUV) jets and narrow coronal mass ejections (CMEs) that are believed to be the signatures of magnetic reconnection, involving field lines open to interplanetary space. The elemental and isotopic fractionation in these events are thought to be caused by processes confined to the flare sites. In this study, we identify 32 {sup 3}He-rich SEP events observed by the Advanced Composition Explorer , near the Earth, during the solar minimum period 2007–2010, and we examine their solar sources with the high resolution Solar Terrestrial Relations Observatory ( STEREO ) EUV images. Leading the Earth, STEREO -A has provided, for the first time, a direct view on {sup 3}He-rich flares, which are generally located on the Sun’s western hemisphere. Surprisingly, we find that about half of the {sup 3}He-rich SEP events in this survey are associated with large-scale EUV coronal waves. An examination of the wave front propagation, the source-flare distribution, and the coronal magnetic field connections suggests that the EUV waves may affect the injection of {sup 3}He-rich SEPs into interplanetary space.

  1. Association of 3He-rich solar energetic particles with large-scale coronal waves

    Science.gov (United States)

    Bucik, Radoslav; Innes, Davina; Guo, Lijia; Mason, Glenn M.; Wiedenbeck, Mark

    2016-07-01

    Impulsive or 3He-rich solar energetic particle (SEP) events have been typically associated with jets or small EUV brightenings. We identify 30 impulsive SEP events from ACE at L1 during the solar minimum period 2007-2010 and examine their solar sources with high resolution STEREO-A EUV images. At beginning of 2007, STEREO-A was near the Earth while at the end of the investigated period, when there were more events, STEREO-A was leading the Earth by 90°. Thus STEREO-A provided a better (more direct) view on 3He-rich flares generally located on the western Sun's hemisphere. Surprisingly, we find that about half of the events are associated with large-scale EUV coronal waves. This finding provides new insights on acceleration and transport of 3He-rich SEPs in solar corona. It is believed that elemental and isotopic fractionation in impulsive SEP events is caused by more localized processes operating in the flare sites. The EUV waves have been reported in gradual SEP events in association with fast coronal mass ejections. To examine their role on 3He-rich SEPs production the energy spectra and relative abundances are discussed. R. Bucik is supported by the Deutsche Forschungsgemeinschaft under grant BU 3115/2-1.

  2. Models of large-scale magnetic fields in stellar interiors. Application to solar and ap stars

    International Nuclear Information System (INIS)

    Duez, Vincent

    2009-01-01

    Stellar astrophysics needs today new models of large-scale magnetic fields, which are observed through spectropolarimetry at the surface of Ap/Bp stars, and thought to be an explanation for the uniform rotation of the solar radiation zone, deduced from helio seismic inversions. During my PhD, I focused on describing the possible magnetic equilibria in stellar interiors. The found configurations are mixed poloidal-toroidal, and minimize the energy for a given helicity, in analogy with Taylor states encountered in spheromaks. Taking into account the self-gravity leads us to the 'non force-free' equilibria family, that will thus influence the stellar structure. I derived all the physical quantities associated with the magnetic field; then I evaluated the perturbations they induce on gravity, thermodynamic quantities as well as energetic ones, for a solar model and an Ap star. 3D MHD simulations allowed me to show that these equilibria form a first stable states family, the generalization of such states remaining an open question. It has been shown that a large-scale magnetic field confined in the solar radiation zone can induce an oblateness comparable to a high core rotation law. I also studied the secular interaction between the magnetic field, the differential rotation and the meridional circulation in the aim of implementing their effects in a next generation stellar evolution code. The influence of the magnetism on convection has also been studied. Finally, hydrodynamic processes responsible for the mixing have been compared with diffusion and a change of convection's efficiency in the case of a CoRoT star target. (author) [fr

  3. New Earth-abundant Materials for Large-scale Solar Fuels Generation.

    Science.gov (United States)

    Prabhakar, Rajiv Ramanujam; Cui, Wei; Tilley, S David

    2018-05-30

    The solar resource is immense, but the power density of light striking the Earth's surface is relatively dilute, necessitating large area solar conversion devices in order to harvest substantial amounts of power for renewable energy applications. In addition, energy storage is a key challenge for intermittent renewable resources such as solar and wind, which adds significant cost to these energies. As the majority of humanity's present-day energy consumption is based on fuels, an ideal solution is to generate renewable fuels from abundant resources such as sunlight and water. In this account, we detail our recent work towards generating highly efficient and stable Earth-abundant semiconducting materials for solar water splitting to generate renewable hydrogen fuel.

  4. Variability of Power from Large-Scale Solar Photovoltaic Scenarios in the State of Gujarat: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Parsons, B.; Hummon, M.; Cochran, J.; Stoltenberg, B.; Batra, P.; Mehta, B.; Patel, D.

    2014-04-01

    India has ambitious goals for high utilization of variable renewable power from wind and solar, and deployment has been proceeding at a rapid pace. The western state of Gujarat currently has the largest amount of solar generation of any Indian state, with over 855 Megawatts direct current (MWDC). Combined with over 3,240 MW of wind, variable generation renewables comprise nearly 18% of the electric-generating capacity in the state. A new historic 10-kilometer (km) gridded solar radiation data set capturing hourly insolation values for 2002-2011 is available for India. We apply an established method for downscaling hourly irradiance data to one-minute irradiance data at potential PV power production locations for one year, 2006. The objective of this report is to characterize the intra-hour variability of existing and planned photovoltaic solar power generation in the state of Gujarat (a total of 1.9 gigawatts direct current (GWDC)), and of five possible expansion scenarios of solar generation that reflect a range of geographic diversity (each scenario totals 500-1,000 MW of additional solar capacity). The report statistically analyzes one year's worth of power variability data, applied to both the baseline and expansion scenarios, to evaluate diurnal and seasonal power fluctuations, different timescales of variability (e.g., from one to 15 minutes), the magnitude of variability (both total megawatts and relative to installed solar capacity), and the extent to which the variability can be anticipated in advance. The paper also examines how Gujarat Energy Transmission Corporation (GETCO) and the Gujarat State Load Dispatch Centre (SLDC) could make use of the solar variability profiles in grid operations and planning.

  5. Overview of Small and Large-Scale Space Solar Power Concepts

    Science.gov (United States)

    Potter, Seth; Henley, Mark; Howell, Joe; Carrington, Connie; Fikes, John

    2006-01-01

    poles to search for water ice and other frozen volatiles. Near such craters are mountain peaks and highlands that are in near permanent sunlight. Power can be beamed from a collector on a sunlit mountain or crater rim to a rover inside a crater. Near-term applications of space solar power technology can therefore pave the way toward large-scale commercial power from space.

  6. A study of rotor and platform design trade-offs for large-scale floating vertical axis wind turbines

    Science.gov (United States)

    Griffith, D. Todd; Paquette, Joshua; Barone, Matthew; Goupee, Andrew J.; Fowler, Matthew J.; Bull, Diana; Owens, Brian

    2016-09-01

    Vertical axis wind turbines are receiving significant attention for offshore siting. In general, offshore wind offers proximity to large populations centers, a vast & more consistent wind resource, and a scale-up opportunity, to name a few beneficial characteristics. On the other hand, offshore wind suffers from high levelized cost of energy (LCOE) and in particular high balance of system (BoS) costs owing to accessibility challenges and limited project experience. To address these challenges associated with offshore wind, Sandia National Laboratories is researching large-scale (MW class) offshore floating vertical axis wind turbines (VAWTs). The motivation for this work is that floating VAWTs are a potential transformative technology solution to reduce offshore wind LCOE in deep-water locations. This paper explores performance and cost trade-offs within the design space for floating VAWTs between the configurations for the rotor and platform.

  7. Development of large scale and wind energy conservation system. Operational studies on a large-scale wind energy conservation system; Ogata furyoku hatsuden system no kaihatsu. Ogata furyoku hatsuden system no unten kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    Takita, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    Described herein are the results of the FY1994 research program for operational studies on a large-scale wind energy conversion system. A total of 8 domestic and foreign cases are studied for wind energy conversion cost, to clarify the causes for higher cost of the Japanese system. The wind power systems studied include Japanese (5 units at Tappi Wind Park, the same type supplied by company M), US (California Wind Farm, 300 units) and UK (Wales Wind Farm, 103 units) systems. The investment costs are 639, 285 and 189 thousand yen/kW for the Japanese, US and UK systems, respectively. It is also revealed that the power plant itself and assembling costs account for a majority (70 to 88%) of the total investment cost. The higher cost of the Japanese system results from a smaller number of units installed, and the power plant cost can be drastically reduced by mass production. Increasing size also reduces cost greatly.

  8. Solar total energy: large scale experiment, Shenandoah, Georgia Site. Annual report, June 1978-June 1979

    Energy Technology Data Exchange (ETDEWEB)

    Ney, E.J.

    1979-07-01

    A background summary and a complete description of the progress and current status of activities relative to the Cooperative Agreement for the Solar Total Energy - Large Scale Experiment at the Bleyle Knitwear Plant at Shenandoah, Georgia are presented. A statement of objectives and an abstract of progress to date are included. This is followed by a short introduction containing a project overview, a summary of the participants and their respective roles, a brief description of the Solar Total Energy System (STES) design concept, and a chronological summary of progress to date. A general description of the site is given, a detailed report of progress is reported, and drawings and equipment lists are included. The closed-loop solar energy system planned for Shenandoah begins with circulation of Syltherm 800, a heat transfer fluid of the Dow-Corning Corporation, through the receiver tubes of a parabolic dish solar collector field. As solar energy is focused on the receivers, the heat transfer fluid is heated to approximately 399/sup 0/C (750/sup 0/F) and is pumped to a heat exchanger for immediate use, or to a thermal storage system for later use. Once in the heat exchanger, the fluid heats a working fluid that produces the steam required for operating the turbine. After performing this task, the heat transfer fluid returns to the collectors to repeat the cycle, while the steam turbine-generator system supplies the electrical demands for the knitwear plant and the STES. During STES operation, maximum thermal and electrical requirements of the application are expected to be at 1.08 MWth and 161 kWe, respectively. During the power generation phase, some of the steam is extracted for use as process steam in the knitwear manufacturing process, while exhaust steam from the turbine is passed through a condenser to produce hot water for heating, domestic use, and absorption air conditioning. (WHK)

  9. A LARGE-SCALE SEARCH FOR EVIDENCE OF QUASI-PERIODIC PULSATIONS IN SOLAR FLARES

    Energy Technology Data Exchange (ETDEWEB)

    Inglis, A. R.; Ireland, J.; Dennis, B. R. [Solar Physics Laboratory, Heliophysics Science Division, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Hayes, L; Gallagher, P. [Trinity College Dublin, Dublin (Ireland)

    2016-12-20

    The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1–300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 1–8 Å soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi /Gamma-ray Burst Monitor (GBM) 15–25 keV X-ray data for each of these flares associated with a Fermi /GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that ∼30% of GOES events and ∼8% of Fermi /GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic timescale of ∼5–30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic timescales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.

  10. A Large-Scale Search for Evidence of Quasi-Periodic Pulsations in Solar Flares

    Science.gov (United States)

    Inglis, A. R.; Ireland, J.; Dennis, B. R..; Hayes, L.; Gallagher, P.

    2016-01-01

    The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 18 soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi/Gamma-ray Burst Monitor (GBM) 1525 keV X-ray data for each of these flares associated with a Fermi/GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that approx. 30% of GOES events and approx. 8% of Fermi/GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic time-scale of approx. 5-30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic time-scales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.

  11. A LARGE-SCALE SEARCH FOR EVIDENCE OF QUASI-PERIODIC PULSATIONS IN SOLAR FLARES

    International Nuclear Information System (INIS)

    Inglis, A. R.; Ireland, J.; Dennis, B. R.; Hayes, L; Gallagher, P.

    2016-01-01

    The nature of quasi-periodic pulsations (QPP) in solar flares is poorly constrained, and critically the general prevalence of such signals in solar flares is unknown. Therefore, we perform a large-scale search for evidence of signals consistent with QPP in solar flares, focusing on the 1–300 s timescale. We analyze 675 M- and X-class flares observed by the Geostationary Operational Environmental Satellite (GOES) series in 1–8 Å soft X-rays between 2011 February 1 and 2015 December 31. Additionally, over the same era we analyze Fermi /Gamma-ray Burst Monitor (GBM) 15–25 keV X-ray data for each of these flares associated with a Fermi /GBM solar flare trigger, a total of 261 events. Using a model comparison method, we determine whether there is evidence for a substantial enhancement in the Fourier power spectrum that may be consistent with a QPP signature, based on three tested models; a power-law plus a constant, a broken power-law plus constant, and a power-law-plus-constant with an additional QPP signature component. From this, we determine that ∼30% of GOES events and ∼8% of Fermi /GBM events show strong signatures consistent with classical interpretations of QPP. For the remaining events either two or more tested models cannot be strongly distinguished from each other, or the events are well-described by single power-law or broken power-law Fourier power spectra. For both instruments, a preferred characteristic timescale of ∼5–30 s was found in the QPP-like events, with no dependence on flare magnitude in either GOES or GBM data. We also show that individual events in the sample show similar characteristic timescales in both GBM and GOES data sets. We discuss the implications of these results for our understanding of solar flares and possible QPP mechanisms.

  12. 8th international workshop on large-scale integration of wind power into power systems as well as on transmission networks for offshore wind farms. Proceedings

    International Nuclear Information System (INIS)

    Betancourt, Uta; Ackermann, Thomas

    2009-01-01

    Within the 8th International Workshop on Large-Scale Integration of Wind Power into Power Systems as well as on Transmission Networks for Offshore Wind Farms at 14th to 15th October, 2009 in Bremen (Federal Republic of Germany), lectures and posters were presented to the following sessions: (1) Keynote session and panel; (2) Grid integration studies and experience: Europe; (3) Connection of offshore wind farms; (4) Wind forecast; (5) High voltage direct current (HVDC); (6) German grid code issues; (7) Offshore grid connection; (8) Grid integration studies and experience: North America; (9) SUPWIND - Decision support tools for large scale integration of wind; (10) Windgrid - Wind on the grid: An integrated approach; (11) IEA Task 25; (12) Grid code issues; (13) Market Issues; (14) Offshore Grid; (15) Modelling; (16) Wind power and storage; (17) Power system balancing; (18) Wind turbine performance; (19) Modelling and offshore transformer.

  13. European wind integration study (EWIS). Towards a successful integration of large scale wind power into European electricity grids. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Winter, W.

    2010-03-15

    Large capacities of wind generators have already been installed and are operating in Germany (26GW) and Spain (16GW). Installations which are as significant in terms of proportion to system size are also established in Denmark (3.3GW), the All Island Power System of Ireland and Northern Ireland (1.5GW), and Portugal (3.4GW). Many other countries expect significant growth in wind generation such that the total currently installed capacity in Europe of 68GW is expected to at least double by 2015. Yet further increases can be expected in order to achieve Europe's 2020 targets for renewable energy. The scale of this development poses big challenges for wind generation developers in terms of obtaining suitable sites, delivering large construction projects, and financing the associated investments from their operations. Such developments also impact the networks and it was to address the immediate transmission related challenges that the European Wind Integration Study (EWIS) was initiated by Transmission System Operators (TSOs) with the objective of ensuring the most effective integration of large scale wind generation into Europe's transmission networks and electricity system. The challenges anticipated and addressed include: 1) How to efficiently accommodate wind generation when markets and transmission access arrangements have evolved for the needs of traditional controllable generation. 2) How to ensure supplies remain secure as wind varies (establishing the required backup/reserves for low wind days and wind forecast errors as well as managing network congestion in windy conditions). 3) How to maintain the quality and reliability of supplies given the new generation characteristics. 4) How to achieve efficient network costs by suitable design and operation of network connections, the deeper infrastructure including offshore connections, and crossborder interconnections. EWIS has focused on the immediate network related challenges by analysing detailed

  14. Effects of torsional degree of freedom, geometric nonlinearity, and gravity on aeroelastic behavior of large-scale horizontal axis wind turbine blades under varying wind speed conditions

    DEFF Research Database (Denmark)

    Jeong, Min-Soo; Cha, Myung-Chan; Kim, Sang-Woo

    2014-01-01

    Modern horizontal axis wind turbine blades are long, slender, and flexible structures that can undergo considerable deformation, leading to blade failures (e.g., blade-tower collision). For this reason, it is important to estimate blade behaviors accurately when designing large-scale wind turbine...

  15. Influence of large-scale deployment of concentrated solar power on North African countries: Socio-economic aspects (Conference Paper)

    OpenAIRE

    Komendantova, N.; Patt, A.

    2010-01-01

    To prevent catastrophic results of climate change, the stabilization of atmospheric concentrations of CO2 below 450 or even 350 parts per million is necessary. The large-scale electricity generation from renewable energy sources is one of possible options to satisfy the world's growing energy demand and to reduce green house gas emissions from electricity generation. Several studies show technical viability of large-scale deployment of concentrated solar power in North African countries and i...

  16. Study of large-scale vertical axis wind turbine wake through numerical modelling and fullscale experiments

    DEFF Research Database (Denmark)

    Immas, Alexandre; Kluczewska-Bordier, Joanna; Beneditti, Pascal

    Offshore wind capacity is increasing exponentially over the years in Europe, taking advantage of the strong winds available over the ocean and of the political incentives to reduce greenhouse gases. The technology is however not yet competitive when compared to fossil fuels or onshore wind. One k...... horizontal axis wind turbine wind farm....... improvement that could make offshore wind more attractive is the reduction of the wake effect [1]. The latter corresponds to the velocity deficit generated by each wind turbine wake which affects the production of the others. This effect accounts for approximately 10% of the energy losses for a typical......Offshore wind capacity is increasing exponentially over the years in Europe, taking advantage of the strong winds available over the ocean and of the political incentives to reduce greenhouse gases. The technology is however not yet competitive when compared to fossil fuels or onshore wind. One key...

  17. CORONAL AND CHROMOSPHERIC SIGNATURES OF LARGE-SCALE DISTURBANCES ASSOCIATED WITH A MAJOR SOLAR ERUPTION

    Energy Technology Data Exchange (ETDEWEB)

    Zong, Weiguo [Key Laboratory of Space Weather, National Center for Space Weather, China Meteorological Administration, Beijing 100081 (China); Dai, Yu, E-mail: ydai@nju.edu.cn [Key Laboratory of Modern Astronomy and Astrophysics (Nanjing University), Ministry of Education, Nanjing 210023 (China)

    2015-08-20

    We present both coronal and chromospheric observations of large-scale disturbances associated with a major solar eruption on 2005 September 7. In the Geostationary Operational Environmental Satellites/Solar X-ray Imager (SXI), arclike coronal brightenings are recorded propagating in the southern hemisphere. The SXI front shows an initially constant speed of 730 km s{sup −1} and decelerates later on, and its center is near the central position angle of the associated coronal mass ejection (CME) but away from the flare site. Chromospheric signatures of the disturbances are observed in both Mauna Loa Solar Observatory (MLSO)/Polarimeter for Inner Coronal Studies Hα and MLSO/Chromospheric Helium I Imaging Photometer He i λ10830 and can be divided into two parts. The southern signatures occur in regions where the SXI front sweeps over, with the Hα bright front coincident with the SXI front, while the He i dark front lags the SXI front but shows a similar kinematics. Ahead of the path of the southern signatures, oscillations of a filament are observed. The northern signatures occur near the equator, with the Hα and He i fronts coincident with each other. They first propagate westward and then deflect to the north at the boundary of an equatorial coronal hole. Based on these observational facts, we suggest that the global disturbances are associated with the CME lift-off and show a hybrid nature: a mainly non-wave CME flank nature for the SXI signatures and the corresponding southern chromospheric signatures, and a shocked fast-mode coronal MHD wave nature for the northern chromospheric signatures.

  18. CORONAL AND CHROMOSPHERIC SIGNATURES OF LARGE-SCALE DISTURBANCES ASSOCIATED WITH A MAJOR SOLAR ERUPTION

    International Nuclear Information System (INIS)

    Zong, Weiguo; Dai, Yu

    2015-01-01

    We present both coronal and chromospheric observations of large-scale disturbances associated with a major solar eruption on 2005 September 7. In the Geostationary Operational Environmental Satellites/Solar X-ray Imager (SXI), arclike coronal brightenings are recorded propagating in the southern hemisphere. The SXI front shows an initially constant speed of 730 km s −1 and decelerates later on, and its center is near the central position angle of the associated coronal mass ejection (CME) but away from the flare site. Chromospheric signatures of the disturbances are observed in both Mauna Loa Solar Observatory (MLSO)/Polarimeter for Inner Coronal Studies Hα and MLSO/Chromospheric Helium I Imaging Photometer He i λ10830 and can be divided into two parts. The southern signatures occur in regions where the SXI front sweeps over, with the Hα bright front coincident with the SXI front, while the He i dark front lags the SXI front but shows a similar kinematics. Ahead of the path of the southern signatures, oscillations of a filament are observed. The northern signatures occur near the equator, with the Hα and He i fronts coincident with each other. They first propagate westward and then deflect to the north at the boundary of an equatorial coronal hole. Based on these observational facts, we suggest that the global disturbances are associated with the CME lift-off and show a hybrid nature: a mainly non-wave CME flank nature for the SXI signatures and the corresponding southern chromospheric signatures, and a shocked fast-mode coronal MHD wave nature for the northern chromospheric signatures

  19. Aerodynamic loads calculation and analysis for large scale wind turbine based on combining BEM modified theory with dynamic stall model

    Energy Technology Data Exchange (ETDEWEB)

    Dai, J.C. [College of Mechanical and Electrical Engineering, Central South University, Changsha (China); School of Electromechanical Engineering, Hunan University of Science and Technology, Xiangtan (China); Hu, Y.P.; Liu, D.S. [School of Electromechanical Engineering, Hunan University of Science and Technology, Xiangtan (China); Long, X. [Hara XEMC Windpower Co., Ltd., Xiangtan (China)

    2011-03-15

    The aerodynamic loads for MW scale horizontal-axis wind turbines are calculated and analyzed in the established coordinate systems which are used to describe the wind turbine. In this paper, the blade element momentum (BEM) theory is employed and some corrections, such as Prandtl and Buhl models, are carried out. Based on the B-L semi-empirical dynamic stall (DS) model, a new modified DS model for NACA63-4xx airfoil is adopted. Then, by combing BEM modified theory with DS model, a set of calculation method of aerodynamic loads for large scale wind turbines is proposed, in which some influence factors such as wind shear, tower, tower and blade vibration are considered. The research results show that the presented dynamic stall model is good enough for engineering purpose; the aerodynamic loads are influenced by many factors such as tower shadow, wind shear, dynamic stall, tower and blade vibration, etc, with different degree; the single blade endures periodical changing loads but the variations of the rotor shaft power caused by the total aerodynamic torque in edgewise direction are very small. The presented study approach of aerodynamic loads calculation and analysis is of the university, and helpful for thorough research of loads reduction on large scale wind turbines. (author)

  20. Electrical network limitations on large-scale deployment of offshore wind energy

    Energy Technology Data Exchange (ETDEWEB)

    Power, P.B.

    2001-07-01

    In this report we have summarised the electrical network limitations to the connection of offshore wind energy schemes in the United Kingdom. The offshore wind resource in the United Kingdom could enable energy production in excess of 230 TWh to be realised. The wind resource of the UK coast should enable 4 GW of wind generation (13.4 GWh assuming 30% load factor) to be developed, providing appropriate technical and commercial arrangements can be made. (author)

  1. Videometric research on deformation measurement of large-scale wind turbine blades

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Utilization of wind energy is a promising way to generate power,and wind turbine blades play a key role in collecting the wind energy effectively.This paper attempts to measure the deformation parameter of wind turbine blades in mechanics experiments using a videometric method. In view that the blades experience small buckling deformation and large integral deformation simultaneously, we proposed a parallel network measurement(PNM) method including the key techniques such as camera network construction,c...

  2. Witnessing a Large-scale Slipping Magnetic Reconnection along a Dimming Channel during a Solar Flare

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Ju; Lee, Jeongwoo; Xu, Yan; Liu, Chang; Wang, Haimin [Center for Solar-Terrestrial Research, New Jersey Institute of Technology, Newark, NJ 07102-1982 (United States); Liu, Rui [CAS Key Laboratory of Geospace Environment, Department of Geophysics and Planetary Sciences, University of Science and Technology of China, Hefei 230026 (China); Cheung, Mark C. M. [Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304 (United States); Zhu, Chunming, E-mail: ju.jing@njit.edu [Department of Physics, Montana State University, Bozeman, MT 59717 (United States)

    2017-06-20

    We report the intriguing large-scale dynamic phenomena associated with the M6.5 flare (SOL2015-06-22T18:23) in NOAA active region 12371, observed by RHESSI , Fermi , and the Atmospheric Image Assembly (AIA) and Magnetic Imager (HMI) on the Solar Dynamics Observatory ( SDO ). The most interesting feature of this event is a third ribbon (R3) arising in the decay phase, propagating along a dimming channel (seen in EUV passbands) toward a neighboring sunspot. The propagation of R3 occurs in the presence of hard X-ray footpoint emission and is broadly visible at temperatures from 0.6 MK to over 10 MK through the differential emission measure analysis. The coronal loops then undergo an apparent slipping motion following the same path of R3, after a ∼80 minute delay. To understand the underlying physics, we investigate the magnetic configuration and the thermal structure of the flaring region. Our results are in favor of a slipping-type reconnection followed by the thermodynamic evolution of coronal loops. In comparison with those previously reported slipping reconnection events, this one proceeds across a particularly long distance (∼60 Mm) over a long period of time (∼50 minutes) and shows two clearly distinguished phases: the propagation of the footpoint brightening driven by nonthermal particle injection and the apparent slippage of loops governed by plasma heating and subsequent cooling.

  3. Power System Operation with Large-Scale Wind Power in Liberalised Environments

    International Nuclear Information System (INIS)

    Ummels, B.C.

    2009-01-01

    The disadvantages of producing electricity from fossil fuels are that their supply is finite and unevenly distributed across the earth. Conventional power stations also emit greenhouse gases. Therefore, sustainable alternatives must be developed, such as wind power. The disadvantages of wind are that it may or may not blow and that it is unpredictable. Th generation of electricity must however always equal the consumption. This makes the integration of wind power in the electricity system more difficult. This thesis investigates the integration of wind power into the existing power system. Simulation models are developed and used to explore the operation of power systems with a lot of wind power. The simulations provide a picture of the reliability, cost and emission of CO2 of the generation of electricity, with and without wind power. The research also takes into account electricity exchange on international markets. Possible solutions for integrating wind power, such as flexible power plants and energy storage, are investigated as well

  4. Literature Review on Reasons and Countermeasures on Large-scale Off-grid of Wind Turbine Generator System

    Directory of Open Access Journals (Sweden)

    Zhu Jun

    2015-01-01

    Full Text Available This paper reviews the present situation of the application of wind turbines generator system(WTGS at home and abroad, describes the strategic significance and the value of sustainable development of the wind power in the country, illustrates the problems, a variety of reasons and responses on large-scale off-grid of WTGS, compares the advantages and disadvantages of various methods, gives full consideration to the actual demand for WTGS works and characteristics and points out the further research.

  5. Optimal Siting and Sizing of Energy Storage System for Power Systems with Large-scale Wind Power Integration

    DEFF Research Database (Denmark)

    Zhao, Haoran; Wu, Qiuwei; Huang, Shaojun

    2015-01-01

    This paper proposes algorithms for optimal sitingand sizing of Energy Storage System (ESS) for the operationplanning of power systems with large scale wind power integration.The ESS in this study aims to mitigate the wind powerfluctuations during the interval between two rolling Economic......Dispatches (EDs) in order to maintain generation-load balance.The charging and discharging of ESS is optimized consideringoperation cost of conventional generators, capital cost of ESSand transmission losses. The statistics from simulated systemoperations are then coupled to the planning process to determinethe...

  6. Turbulent Transport in a Three-dimensional Solar Wind

    Energy Technology Data Exchange (ETDEWEB)

    Shiota, D. [Institute for Space-Earth Environmental Research, Nagoya University, Nagoya, Aichi 464-8601 (Japan); Zank, G. P.; Adhikari, L.; Hunana, P. [Center for Space Plasma and Aeronomic Research (CSPAR), Department of Space Science, University of Alabama in Huntsville, Huntsville, AL 35805 (United States); Telloni, D. [INAF—Astrophysical Observatory of Torino, Via Osservatorio 20, I-10025 Pino Torinese (Italy); Bruno, R., E-mail: shiota@isee.nagoya-u.ac.jp [INAF-IAPS Istituto di Astrofisica e Planetologia Spaziali, Via del Fosso del Cavaliere 100, I-00133 Roma (Italy)

    2017-03-01

    Turbulence in the solar wind can play essential roles in the heating of coronal and solar wind plasma and the acceleration of the solar wind and energetic particles. Turbulence sources are not well understood and thought to be partly enhanced by interaction with the large-scale inhomogeneity of the solar wind and the interplanetary magnetic field and/or transported from the solar corona. To investigate the interaction with background inhomogeneity and the turbulence sources, we have developed a new 3D MHD model that includes the transport and dissipation of turbulence using the theoretical model of Zank et al. We solve for the temporal and spatial evolution of three moments or variables, the energy in the forward and backward fluctuating modes and the residual energy and their three corresponding correlation lengths. The transport model is coupled to our 3D model of the inhomogeneous solar wind. We present results of the coupled solar wind-turbulence model assuming a simple tilted dipole magnetic configuration that mimics solar minimum conditions, together with several comparative intermediate cases. By considering eight possible solar wind and turbulence source configurations, we show that the large-scale solar wind and IMF inhomogeneity and the strength of the turbulence sources significantly affect the distribution of turbulence in the heliosphere within 6 au. We compare the predicted turbulence distribution results from a complete solar minimum model with in situ measurements made by the Helios and Ulysses spacecraft, finding that the synthetic profiles of the turbulence intensities show reasonable agreement with observations.

  7. Impact of large scale wind power on the Nordic electricity system

    International Nuclear Information System (INIS)

    Holttinen, Hannele

    2006-01-01

    Integration costs of wind power depend on how much wind power and where, and the power system: load, generation flexibility, interconnections. When wind power is added to a large interconnected power system there is considerable smoothing effect for the production. Increase of reserve requirements will stay at a low level. 10 percent penetration of wind power is not a problem in Nordic countries, as long as wind power is built to all 4 countries. Increasing the share of wind power will increase the integration costs. 20 percent penetration would need more flexibility in the system. That will not happen in the near future for Nordel, and the power system will probably also contain more flexible elements at that stage, like producing fuel for vehicles (ml)

  8. TradeWind. Integrating wind. Developing Europe's power market for the large-scale integration of wind power. Final report

    Energy Technology Data Exchange (ETDEWEB)

    2009-02-15

    Based on a single European grid and power market system, the TradeWind project explores to what extent large-scale wind power integration challenges could be addressed by reinforcing interconnections between Member States in Europe. Additionally, the project looks at the conditions required for a sound power market design that ensures a cost-effective integration of wind power at EU level. In this way, the study addresses two issues of key importance for the future integration of renewable energy, namely the weak interconnectivity levels between control zones and the inflexibility and fragmented nature of the European power market. Work on critical transmission paths and interconnectors is slow for a variety of reasons including planning and administrative barriers, lack of public acceptance, insufficient economic incentives for TSOs, and the lack of a joint European approach by the key stakeholders. (au)

  9. Greenhouse gas emissions from operating reserves used to backup large-scale wind power.

    Science.gov (United States)

    Fripp, Matthias

    2011-11-01

    Wind farms provide electricity with no direct emissions. However, their output cannot be forecasted perfectly, even a short time ahead. Consequently, power systems with large amounts of wind power may need to keep extra fossil-fired generators turned on and ready to provide power if wind farm output drops unexpectedly. In this work, I introduce a new model for estimating the uncertainty in short-term wind power forecasts, and how this uncertainty varies as wind power is aggregated over larger regions. I then use this model to estimate the reserve requirements in order to compensate for wind forecast errors to a 99.999% level of reliability, and an upper limit on the amount of carbon dioxide that would be emitted if natural gas power plants are used for this purpose. I find that for regions larger than 500 km across, operating reserves will undo 6% or less of the greenhouse gas emission savings that would otherwise be expected from wind power.

  10. Manifestation of solar activity in solar wind particle flux density

    International Nuclear Information System (INIS)

    Kovalenko, V.A.

    1988-01-01

    An analysis has been made of the origin of long-term variations in flux density of solar wind particles (nv) for different velocity regimes. The study revealed a relationship of these variations to the area of the polar coronal holes (CH). It is shown that within the framework of the model under development, the main longterm variations of nv are a result of the latitude redistribution of the solar wind mass flux in the heliosphere and are due to changes in the large-scale geometry of the solar plasma flow in the corona. A study has been made of the variations of nv for high speed solar wind streams. It is found that nv in high speed streams which are formed in CH, decreases from minimum to maximum solar activity. The analysis indicates that this decrease is attributable to the magnetic field strength increase in coronal holes. It has been found that periods of rapid global changes of background magnetic fields on the Sun are accompanied by a reconfiguration of coronal magnetic fields, rapid changes in the length of quiescent filaments, and by an increase in the density of the particle flux of a high speed solar wind. It has been established that these periods precede the formation of CH, corresponding to the increase in solar wind velocity near the Earth and to enhancement of the level of geomagnetic disturbance. (author)

  11. Environmental aspects of large-scale wind-power systems in the UK

    Science.gov (United States)

    Robson, A.

    1984-11-01

    Environmental issues relating to the introduction of large, MW-scale wind turbines at land-based sites in the UK are discussed. Noise, television interference, hazards to bird life, and visual effects are considered. Areas of uncertainty are identified, but enough is known from experience elsewhere in the world to enable the first UK machines to be introduced in a safe and environementally acceptable manner. Research to establish siting criteria more clearly, and significantly increase the potential wind-energy resource is mentioned. Studies of the comparative risk of energy systems are shown to be overpessimistic for UK wind turbines.

  12. Environmental implications of large-scale adoption of wind power: a scenario-based life cycle assessment

    International Nuclear Information System (INIS)

    Arvesen, Anders; Hertwich, Edgar G

    2011-01-01

    We investigate the potential environmental impacts of a large-scale adoption of wind power to meet up to 22% of the world’s growing electricity demand. The analysis builds on life cycle assessments of generic onshore and offshore wind farms, meant to represent average conditions for global deployment of wind power. We scale unit-based findings to estimate aggregated emissions of building, operating and decommissioning wind farms toward 2050, taking into account changes in the electricity mix in manufacturing. The energy scenarios investigated are the International Energy Agency’s BLUE scenarios. We estimate 1.7–2.6 Gt CO 2 -eq climate change, 2.1–3.2 Mt N-eq marine eutrophication, 9.2–14 Mt NMVOC photochemical oxidant formation, and 9.5–15 Mt SO 2 -eq terrestrial acidification impact category indicators due to global wind power in 2007–50. Assuming lifetimes 5 yr longer than reference, the total climate change indicator values are reduced by 8%. In the BLUE Map scenario, construction of new capacity contributes 64%, and repowering of existing capacity 38%, to total cumulative greenhouse gas emissions. The total emissions of wind electricity range between 4% and 14% of the direct emissions of the replaced fossil-fueled power plants. For all impact categories, the indirect emissions of displaced fossil power are larger than the total emissions caused by wind power.

  13. Large-scale integration of wind power into different energy systems

    DEFF Research Database (Denmark)

    Lund, Henrik

    2005-01-01

    The paper presents the ability of different energy systems and regulation strategies to integrate wind power. The ability is expressed by the following three factors: the degree of electricity excess production caused by fluctuations in wind and Combined Heat and Power (CHP) heat demands......, the ability to utilise wind power to reduce CO2 emission in the system, and the ability to benefit from exchange of electricity on the market. Energy systems and regulation strategies are analysed in the range of a wind power input from 0 to 100% of the electricity demand. Based on the Danish energy system...... and such potential future energy systems different regulation strategies have been analysed, i.e. the inclusion of small CHP plants into the regulation task of electricity balancing and ancillary grid stability services and investments in electric heating, heat pumps and heat storage capacity. The results...

  14. Computer model for large-scale offshore wind-power systems

    Energy Technology Data Exchange (ETDEWEB)

    Dambolena, I G [Bucknell Univ., Lewisburg, PA; Rikkers, R F; Kaminsky, F C

    1977-01-01

    A computer-based planning model has been developed to evaluate the cost and simulate the performance of offshore wind-power systems. In these systems, the electricity produced by wind generators either satisfies directly demand or produces hydrogen by water electrolysis. The hydrogen is stored and later used to produce electricity in fuel cells. Using as inputs basic characteristics of the system and historical or computer-generated time series for wind speed and electricity demand, the model simulates system performance over time. A history of the energy produced and the discounted annual cost of the system are used to evaluate alternatives. The output also contains information which is useful in pointing towards more favorable design alternatives. Use of the model to analyze a specific wind-power system for New England indicates that electric energy could perhaps be generated at a competitive cost.

  15. Large-scale integration of wind power into the existing Chinese energy system

    DEFF Research Database (Denmark)

    Liu, Wen; Lund, Henrik; Mathiesen, Brian Vad

    2011-01-01

    stability, the maximum feasible wind power penetration in the existing Chinese energy system is approximately 26% from both technical and economic points of view. A fuel efficiency decrease occurred when increasing wind power penetration in the system, due to its rigid power supply structure and the task......This paper presents the ability of the existing Chinese energy system to integrate wind power and explores how the Chinese energy system needs to prepare itself in order to integrate more fluctuating renewable energy in the future. With this purpose in mind, a model of the Chinese energy system has...... been constructed by using EnergyPLAN based on the year 2007, which has then been used for investigating three issues. Firstly, the accuracy of the model itself has been examined and then the maximum feasible wind power penetration in the existing energy system has been identified. Finally, barriers...

  16. Aerodynamic flow deflector to increase large scale wind turbine power generation by 10%.

    Science.gov (United States)

    2015-11-01

    The innovation proposed in this paper has the potential to address both the efficiency demands of wind farm owners as well as to provide a disruptive design innovation to turbine manufacturers. The aerodynamic deflector technology was created to impr...

  17. Offshore Variability in Critical Weather Conditions in Large-Scale Wind Based Danish Power System

    DEFF Research Database (Denmark)

    Cutululis, Nicolaos Antonio; Litong-Palima, Marisciel; Sørensen, Poul Ejnar

    2013-01-01

    of the variability for the 2020 Danish power system, one can see that in the worst case, up to 1500 MW of power can be lost in 30 minutes. We present results showing how this issue is partially solved by the new High Wind Storm Controller presented by Siemens in the TWENTIES project.......Offshore wind power has a significant development potential, especially in North Europe. The geographical concentration of offshore wind power leads to increased variability and in the case of critical weather conditions it may lead to sudden and considerable loss of production. In this context......, the chances of losing several GW of wind power due to critical weather conditions in a very short time period could potentially jeopardize the whole system’s reliability and stability. Forecasting such events is not trivial and the results so far are not encouraging. When assessing the impact...

  18. Integrating large-scale cogeneration of hydrogen and electricity from wind and nuclear sources (NUWINDTM)

    International Nuclear Information System (INIS)

    Miller, A. I.; Duffey, R. B.

    2008-01-01

    As carbon-free fuels, hydrogen and electricity are headed for major roles in replacing hydrocarbons as the world constrains carbon dioxide (CO 2 ) emissions. This will apply particularly to the transport sector. A general trend toward electric drive on-board vehicles is already evident and hydrogen converted to electricity by a fuel cell is likely to be a major source of on-board electricity. The major car manufacturers continue to invest heavily in this option and significant government initiatives in both the USA and Canada are beginning demonstration deployments of the infrastructure needed for hydrogen refueling. However, early adoption of hydrogen as a transport fuel may well be concentrated on heavy-duty transportation: trains, ships and trucks, where battery storage of electricity is unlikely to be practical. But both hydrogen and electricity are secondary fuels and are only effective if the source of the primary energy is a low CO 2 emitter such as nuclear and wind. A competitive cost is also essential and, to achieve this, one must rely on off-peak electricity prices. This paper examines historical data for electricity prices and the actual output of the main wind farms in Ontario to show how nuclear and wind can be combined to generate hydrogen by water electrolysis at prices that are competitive with fossil-based hydrogen production. The NuWind TM concept depends on operating electrolysis cells over an extended range of current densities to accommodate the inherent variability of wind and of electricity prices as they vary in open markets. The cost of co-producing hydrogen with electricity originating from nuclear plants (80%) and from wind turbines (20%) is very close to that of production from a constantly available electricity source. In contrast, the price of hydrogen produced using electricity from wind alone is estimated to cost about $1500/tonne more than hydrogen from NuWind or nuclear alone because the electrolysis facility must be much larger

  19. 9{sup th} international workshop on large-scale integration of wind power into power systems as well as on transmission networks for offshore wind power plants. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Betancourt, Uta; Ackermann, Thomas (eds.)

    2010-07-01

    Within the 9th International Workshop on large-scale integration of wind power into power systems as well as on transmission networks for offshore wind power plants at 18th to 19th October, 2010 in Quebec (Canada), lectures and poster papers were presented to the following themes: (1) Keynote session and panel; (2) European grid integration studies; (3) Modeling; (4) Wind forecasting; (5) North American grid integration studies; (6) Voltage stability and control; (7) Grid codes and impact studies; (8) Canadian University research (WESNet); (9) Operation and dispatch; (9) Offshore wind power plants; (10) Frequency Control; (11) Methodologies to estimate wind power impacts on power systems, summaries from IEAWIND collaboration; (12) HVDC; (13) Grid codes and system impact studies; (14) Modeling and validation; (15) Regulations, markets and offshore wind energy; (16) Integration issues; (17) Wind turbine control system; (18) Energy management and IT solutions.

  20. Total cost estimates for large-scale wind scenarios in UK

    International Nuclear Information System (INIS)

    Dale, Lewis; Milborrow, David; Slark, Richard; Strbac, Goran

    2004-01-01

    The recent UK Energy White Paper suggested that the Government should aim to secure 20% of electricity from renewable sources by 2020. A number of estimates of the extra cost of such a commitment have been made, but these have not necessarily included all the relevant cost components. This analysis sets out to identify these and to calculate the extra cost to the electricity consumer, assuming all the renewable electricity is sourced from wind energy. This enables one of the more controversial issues--the implications of wind intermittency--to be addressed. The basis of the assumptions associated with generating costs, extra balancing costs and distribution and transmission system reinforcement costs are all clearly identified and the total costs of a '20% wind' scenario are compared with a scenario where a similar amount of energy is generated by gas-fired plant. This enables the extra costs of the renewables scenario to be determined. The central estimate of the extra costs to electricity consumers is just over 0.3 p/kW h in current prices (around 5% extra on average domestic unit prices). Sensitivity analyses examine the implications of differing assumptions. The extra cost would rise if the capital costs of wind generation fall slower than anticipated, but would fall if gas prices rise more rapidly than has been assumed, or if wind plant are more productive. Even if it is assumed that wind has no capacity displacement value, the added cost to the electricity consumer rises by less than 0.1 p/kW h. It is concluded that there does not appear to be any technical reason why a substantial proportion of the country's electricity requirements could not be delivered by wind

  1. Titius--Bode law and the possibility of recent large-scale evolution in the solar system

    International Nuclear Information System (INIS)

    Neito, M.M.

    1974-01-01

    Although it is by no means clear that the Titius--Bode law of planetary distances is indeed a ''law'' (even though there are enticing indications), it is proposed that if one assumes that the law is a ''law'' and that the planets obey it, then this argues against recent large-scale evolution in the solar system. Put another way: one can believe in the Titius--Bode law or in recent large-scale evolution or in neither of them. But it appears difficult to believe in both of them

  2. Modeling and Coordinated Control Strategy of Large Scale Grid-Connected Wind/Photovoltaic/Energy Storage Hybrid Energy Conversion System

    Directory of Open Access Journals (Sweden)

    Lingguo Kong

    2015-01-01

    Full Text Available An AC-linked large scale wind/photovoltaic (PV/energy storage (ES hybrid energy conversion system for grid-connected application was proposed in this paper. Wind energy conversion system (WECS and PV generation system are the primary power sources of the hybrid system. The ES system, including battery and fuel cell (FC, is used as a backup and a power regulation unit to ensure continuous power supply and to take care of the intermittent nature of wind and photovoltaic resources. Static synchronous compensator (STATCOM is employed to support the AC-linked bus voltage and improve low voltage ride through (LVRT capability of the proposed system. An overall power coordinated control strategy is designed to manage real-power and reactive-power flows among the different energy sources, the storage unit, and the STATCOM system in the hybrid system. A simulation case study carried out on Western System Coordinating Council (WSCC 3-machine 9-bus test system for the large scale hybrid energy conversion system has been developed using the DIgSILENT/Power Factory software platform. The hybrid system performance under different scenarios has been verified by simulation studies using practical load demand profiles and real weather data.

  3. Environmental aspects of large-scale wind-power systems in the UK

    Energy Technology Data Exchange (ETDEWEB)

    Robson, A

    1983-12-01

    Environmental issues relating to the introduction of large, MW-scale wind turbines at land-based sites in the U.K. are discussed. Areas of interest include noise, television interference, hazards to bird life and visual effects. A number of areas of uncertainty are identified, but enough is known from experience elsewhere in the world to enable the first U.K. machines to be introduced in a safe and environmentally acceptable manner. Research currently under way will serve to establish siting criteria more clearly, and could significantly increase the potential wind-energy resource. Certain studies of the comparative risk of energy systems are shown to be overpessimistic for U.K. wind turbines.

  4. Self-optimizing Pitch Control for Large Scale Wind Turbine Based on ADRC

    Science.gov (United States)

    Xia, Anjun; Hu, Guoqing; Li, Zheng; Huang, Dongxiao; Wang, Fengxiang

    2018-01-01

    Since wind turbine is a complex nonlinear and strong coupling system, traditional PI control method can hardly achieve good control performance. A self-optimizing pitch control method based on the active-disturbance-rejection control theory is proposed in this paper. A linear model of the wind turbine is derived by linearizing the aerodynamic torque equation and the dynamic response of wind turbine is transformed into a first-order linear system. An expert system is designed to optimize the amplification coefficient according to the pitch rate and the speed deviation. The purpose of the proposed control method is to regulate the amplification coefficient automatically and keep the variations of pitch rate and rotor speed in proper ranges. Simulation results show that the proposed pitch control method has the ability to modify the amplification coefficient effectively, when it is not suitable, and keep the variations of pitch rate and rotor speed in proper ranges

  5. Round-the-year security analysis with large-scale wind power integration

    NARCIS (Netherlands)

    Ciupuliga, A.R.; Gibescu, M.; Pelgrum, E.; Jacobs, P.G.H.; Jansen, K.P.G.; Kling, W.L.

    2012-01-01

    The ongoing liberalization process together with the growing penetration of renewable energy sources (RES), e.g., wind power, require an internationally oriented transmission planning approach that considers the increased uncertainties in terms of trade, location of generation, and output of

  6. Solar wind ion trends and signatures: STEREO PLASTIC observations approaching solar minimum

    Directory of Open Access Journals (Sweden)

    A. B. Galvin

    2009-10-01

    Full Text Available STEREO has now completed the first two years of its mission, moving from close proximity to Earth in 2006/2007 to more than 50 degrees longitudinal separation from Earth in 2009. During this time, several large-scale structures have been observed in situ. Given the prevailing solar minimum conditions, these structures have been predominantly coronal hole-associated solar wind, slow solar wind, their interfaces, and the occasional transient event. In this paper, we extend earlier solar wind composition studies into the current solar minimum using high-resolution (1-h sampling times for the charge state analysis. We examine 2-year trends for iron charge states and solar wind proton speeds, and present a case study of Carrington Rotation 2064 (December 2007 which includes minor ion (He, Fe, O kinetic and Fe composition parameters in comparison with proton and magnetic field signatures at large-scale structures observed during this interval.

  7. Large scale hydrogen production from wind energy in the Magallanes area for consumption in the central zone of Chile

    International Nuclear Information System (INIS)

    Zolezzi, J.M.; Garay, A.; Reveco, M.

    2010-01-01

    The energy proposal of this research suggests the use of places with abundant wind resources for the production of H 2 on a large scale to be transported and used in the central zone of Chile with the purpose of diversifying the country's energy matrix in order to decrease its dependence on fossil fuels, increase its autonomy, and cover the future increases in energy demand. This research showed that the load factor of the proposed wind park reaches a value of 54.5%, putting in evidence the excellent wind conditions of the zone. This implies that the cost of the electricity produced by the wind park located in the Chilean Patagonia would have a cost of 0.0213 US$ kWh -1 in the year 2030. The low prices of the electricity obtained from the park, thanks to the economy of scale and the huge wind potential, represent a very attractive scenario for the production of H 2 in the future. The study concludes that by the year 2030 the cost of the H 2 generated in Magallanes and transported to the port of Quinteros would be 18.36 US$ MBTU -1 , while by that time the cost of oil would be about 17.241 US$ MBTU -1 , a situation that places H 2 in a very competitive position as a fuel. (author)

  8. Voltage stability issues for a benchmark grid model including large scale wind power

    DEFF Research Database (Denmark)

    Eek, J.; Lund, T.; Marzio, G. Di

    2006-01-01

    The objective of the paper is to investigate how the voltage stability of a relatively weak network after a grid fault is affected by the connection of a large wind park. A theoretical discussion of the stationary and dynamic characteristics of the Short Circuit Induction Generator and the Doubly...... Fed Induction Generator is given. Further, a case study of a wind park connected to the transmission system through an existing regional 132 kV regional distribution line is presented. For the SCIG it is concluded that a stationary torque curve calculated under consideration of the impedance...... of the network and saturation of the external reactive power compensation units provides a good basis for evaluation of the voltage stability. For the DFIG it is concluded that the speed stability limit is mainly determined by the voltage limitation of the rotor converter...

  9. Diagnosis of Short-Circuit Fault in Large-Scale Permanent-Magnet Wind Power Generator Based on CMAC

    Directory of Open Access Journals (Sweden)

    Chin-Tsung Hsieh

    2013-01-01

    Full Text Available This study proposes a method based on the cerebellar model arithmetic controller (CMAC for fault diagnosis of large-scale permanent-magnet wind power generators and compares the results with Error Back Propagation (EBP. The diagnosis is based on the short-circuit faults in permanent-magnet wind power generators, magnetic field change, and temperature change. Since CMAC is characterized by inductive ability, associative ability, quick response, and similar input signals exciting similar memories, it has an excellent effect as an intelligent fault diagnosis implement. The experimental results suggest that faults can be diagnosed effectively after only training CMAC 10 times. In comparison to training 151 times for EBP, CMAC is better than EBP in terms of training speed.

  10. Large-scale integration of optimal combinations of PV, wind and wave power into the electricity supply

    DEFF Research Database (Denmark)

    Lund, Henrik

    2006-01-01

    This article presents the results of analyses of large-scale integration of wind power, photo voltaic (PV) and wave power into a Danish reference energy system. The possibility of integrating Renewable Energy Sources (RES) into the electricity supply is expressed in terms of the ability to avoid...... ancillary services are needed in order to secure the electricity supply system. The idea is to benefit from the different patterns in the fluctuations of different renewable sources. And the purpose is to identify optimal mixtures from a technical point of view. The optimal mixture seems to be when onshore...... wind power produces approximately 50% of the total electricity production from RES. Meanwhile, the mixture between PV and wave power seems to depend on the total amount of electricity production from RES. When the total RES input is below 20% of demand, PV should cover 40% and wave power only 10%. When...

  11. A Combined Ethical and Scientific Analysis of Large-scale Tests of Solar Climate Engineering

    Science.gov (United States)

    Ackerman, T. P.

    2017-12-01

    Our research group recently published an analysis of the combined ethical and scientific issues surrounding large-scale testing of stratospheric aerosol injection (SAI; Lenferna et al., 2017, Earth's Future). We are expanding this study in two directions. The first is extending this same analysis to other geoengineering techniques, particularly marine cloud brightening (MCB). MCB has substantial differences to SAI in this context because MCB can be tested over significantly smaller areas of the planet and, following injection, has a much shorter lifetime of weeks as opposed to years for SAI. We examine issues such as the role of intent, the lesser of two evils, and the nature of consent. In addition, several groups are currently considering climate engineering governance tools such as a code of ethics and a registry. We examine how these tools might influence climate engineering research programs and, specifically, large-scale testing. The second direction of expansion is asking whether ethical and scientific issues associated with large-scale testing are so significant that they effectively preclude moving ahead with climate engineering research and testing. Some previous authors have suggested that no research should take place until these issues are resolved. We think this position is too draconian and consider a more nuanced version of this argument. We note, however, that there are serious questions regarding the ability of the scientific research community to move to the point of carrying out large-scale tests.

  12. A central solar-industrial waste heat heating system with large scale borehole thermal storage

    NARCIS (Netherlands)

    Guo, F.; Yang, X.; Xu, L.; Torrens, I.; Hensen, J.L.M.

    2017-01-01

    In this paper, a new research of seasonal thermal storage is introduced. This study aims to maximize the utilization of renewable energy source and industrial waste heat (IWH) for urban district heating systems in both heating and non-heating seasons through the use of large-scale seasonal thermal

  13. How to deal with negative power price spikes?-Flexible voluntary curtailment agreements for large-scale integration of wind

    International Nuclear Information System (INIS)

    Brandstaett, Christine; Brunekreeft, Gert; Jahnke, Katy

    2011-01-01

    For the large-scale integration of electricity from renewable energy sources (RES-E), the German system seems to reach its limits. In 2009, the electricity wholesale market experienced serious negative prices at times of high wind and low demand. The feed-in system in Germany consists of a fixed feed-in price, a take-off obligation and a RES priority rule, and in practice only very restrictive use of RES-E curtailment. Exactly the latter is the problem. We argue that the overall performance of the system would improve seriously by lifting the restrictions on the use of voluntary curtailment agreements, while retaining the priority rule as such. Since generators of RES-E can only improve under this system reform, investment conditions improve, leading to higher installed RES-E capacity. This in turn implies that reduced wind output due to curtailment can actually be offset by higher wind output in all periods in which there is no problem. - Highlights: → We examine the large-scale integration of electricity from renewable sources (RES-E) into the German energy market. → Seriously negative prices at the wholesale market suggest that market design could be improved. → We argue that allowing flexible use of voluntary curtailment agreements (VCA), while keeping the priority feed-in rule, would increase the total system's efficiency. → Improved investment conditions due to flexible use of VCAs leading to higher installed RES-E capacity could offset the reduced wind output and would not impede climate policy goals.

  14. Local and regional effects of large scale atmospheric circulation patterns on winter wind power output in Western Europe

    Science.gov (United States)

    Zubiate, Laura; McDermott, Frank; Sweeney, Conor; O'Malley, Mark

    2014-05-01

    Recent studies (Brayshaw, 2009, Garcia-Bustamante, 2010, Garcia-Bustamante, 2013) have drawn attention to the sensitivity of wind speed distributions and likely wind energy power output in Western Europe to changes in low-frequency, large scale atmospheric circulation patterns such as the North Atlantic Oscillation (NAO). Wind speed variations and directional shifts as a function of the NAO state can be larger or smaller depending on the North Atlantic region that is considered. Wind speeds in Ireland and the UK for example are approximately 20 % higher during NAO + phases, and up to 30 % lower during NAO - phases relative to the long-term (30 year) climatological means. By contrast, in southern Europe, wind speeds are 15 % lower than average during NAO + phases and 15 % higher than average during NAO - phases. Crucially however, some regions such as Brittany in N.W. France have been identified in which there is negligible variability in wind speeds as a function of the NAO phase, as observed in the ERA-Interim 0.5 degree gridded reanalysis database. However, the magnitude of these effects on wind conditions is temporally and spatially non-stationary. As described by Comas-Bru and McDermott (2013) for temperature and precipitation, such non-stationarity is caused by the influence of two other patterns, the East Atlantic pattern, (EA), and the Scandinavian pattern, (SCA), which modulate the position of the NAO dipole. This phenomenon has also implications for wind speeds and directions, which has been assessed using the ERA-Interim reanalysis dataset and the indices obtained from the PC analysis of sea level pressure over the Atlantic region. In order to study the implications for power production, the interaction of the NAO and the other teleconnection patterns with local topography was also analysed, as well as how these interactions ultimately translate into wind power output. The objective is to have a better defined relationship between wind speed and power

  15. Large-scale wind energy application. Transporting wind energy over long distances using an HVDC transmission line, in combination with hydro energy or biomass energy

    International Nuclear Information System (INIS)

    Coelingh, J.P.; Van Wijk, A.J.M.; Betcke, J.W.H.; Geuzendam, C.; Gilijamse, W.; Westra, C.A.; Curvers, A.P.W.M.; Beurskens, H.J.M.

    1995-08-01

    The main objective of the study on the title subject is to assess the long-term prospects for large-scale application of wind energy, in combination with hydro energy in Norway and in combination with biomass energy in Scotland. These countries have high wind resource areas, however they are located far away from load centres. The development of new transmission technologies as High Voltage Direct Current (HVDC) transmission lines, in combination with highly suitable places for wind energy in Norway and Scotland, forms the driving force behind this study. The following two cases are being considered: (1) a large-scale wind farm (1,000 MW) in Norway from which electricity is transmitted to The Netherlands by using an HVDC transmission line, in combination with hydro energy. Hydro energy already makes a large contribution to the energy supply of Norway. Wind farms can contribute to the electricity production and save hydro energy generated electricity and make the export of electricity profitable; and (2) a large-scale wind farm (1,000 MW) in Scotland from which electricity is transmitted to The Netherlands by using an HVDC transmission line, in combination with biomass energy. Scotland has a large potential for biomass production such as energy crops and forestry. Poplars and willows cultivated on set-aside land can be gasified and fed into modern combined-cycle plants to generate electricity. In Scotland the usable potential of wind energy may be limited in the short and medium term by the capacity of the grid. New connections can overcome this constraint and allow wind energy to be treated as a European Union resource rather than as a national resource. Thus, the concept of this study is to look at the possibilities of making a 1,000 MW link from The Netherlands to Norway or to Scotland, in order to supply electricity at competitive costs generated with renewable energy sources. 16 figs., 24 tabs., 80 refs

  16. Large-scale Wind Power integration in a Hydro-Thermal Power Market

    OpenAIRE

    Trøtscher, Thomas

    2007-01-01

    This master thesis describes a quadratic programming model used to calculate the spot prices in an efficient multi-area power market. The model has been adapted to Northern Europe, with focus on Denmark West and the integration of large quantities of wind power. In the model, demand and supply of electricity are equated, at an hourly time resolution, to find the spot price in each area. Historical load values are used to represent demand which is assumed to be completely inelastic. Supply i...

  17. Large-scale wind power integration and wholesale electricity trading benefits: Estimation via an ex post approach

    International Nuclear Information System (INIS)

    Gil, Hugo A.; Gomez-Quiles, Catalina; Riquelme, Jesus

    2012-01-01

    The integration of large-scale wind power has brought about a series of challenges to the power industry, but at the same time a number of benefits are being realized. Among those, the ability of wind power to cause a decline in the electricity market prices has been recognized. In quantifying this effect, some models used in recent years are based on simulations of the market supply-side and the price clearing process. The accuracy of the estimates depend on the quality of the input data, the veracity of the adopted scenarios and the rigorousness of the solution technique. In this work, a series of econometric techniques based on actual ex post wind power and electricity price data are implemented for the estimation of the impact of region-wide wind power integration on the local electricity market clearing prices and the trading savings that stem from this effect. The model is applied to the case of Spain, where the estimated savings are compared against actual credit and bonus expenses to ratepayers. The implications and extent of these results for current and future renewable energy policy-making are discussed. - Highlights: ► Wholesale electricity market trading benefits by wind power are quantified. ► Actual wind power forecast-based bids and electricity price data from Spain are used. ► Different econometric tools are used and compared for improved estimation accuracy. ► Estimated benefits outweigh current credit overhead paid to wind farms in Spain. ► An economically efficient benefit surplus allocation framework is proposed.

  18. Implications of environmental regulation and coal plant retirements in systems with large scale penetration of wind power

    International Nuclear Information System (INIS)

    Rahmani, Mohsen; Jaramillo, Paulina; Hug, Gabriela

    2016-01-01

    Over the last decade there have been a growing number of federal and state regulations aimed at controlling air emissions at power plants and/or increasing the penetration of renewable resources in the grid. Environmental Protection Agency regulations will likely lead to the retrofit, retirement, or replacement of coal-fired power plants while the state Renewable Portfolio Standards will continue to drive large-scale deployment of renewable energy sources, primarily wind. Combined, these changes in the generation fleet could have profound implications for the operations of the power system. In this paper, we aim to better understand the interaction between coal plant retirements and increased levels of wind power. We extensively analyze the operations of the PJM electricity system under a broad set of scenarios that include varying levels of wind penetration and coal plant retirements. Not surprisingly, we find that without transmission upgrades, retirement of coal-fired power plants will likely result in considerable transmission congestion and higher energy prices. Increased wind penetration, with high geographic diversity, could mitigate some of the negative effects of coal plant retirement and lead to a significant reduction in air emissions, but wind forecast error might impose operational constraints on the system at times of peak load. - Highlights: •Retirement of coal plants may increase transmission congestion and LMP prices. •EPA rules might lead to significant reductions in emission of air pollutants. •Wind geographical diversity may reduce transmission constraints and air emissions. •At times of high peak load, wind may not reduce system stress caused by retirement. •RPS policies can support and mitigate negative impacts of EPA regulations.

  19. Performance Analysis of a Wind Turbine Driven Swash Plate Pump for Large Scale Offshore Applications

    International Nuclear Information System (INIS)

    Buhagiar, D; Sant, T

    2014-01-01

    This paper deals with the performance modelling and analysis of offshore wind turbine-driven hydraulic pumps. The concept consists of an open loop hydraulic system with the rotor main shaft directly coupled to a swash plate pump to supply pressurised sea water. A mathematical model is derived to cater for the steady state behaviour of entire system. A simplified model for the pump is implemented together with different control scheme options for regulating the rotor shaft power. A new control scheme is investigated, based on the combined use of hydraulic pressure and pitch control. Using a steady-state analysis, the study shows how the adoption of alternative control schemes in a the wind turbine-hydraulic pump system may result in higher energy yields than those from a conventional system with an electrical generator and standard pitch control for power regulation. This is in particular the case with the new control scheme investigated in this study that is based on the combined use of pressure and rotor blade pitch control

  20. Large-scale analysis and forecast experiments with wind data from the Seasat A scatterometer

    Science.gov (United States)

    Baker, W. E.; Atlas, R.; Kalnay, E.; Halem, M.; Woiceshyn, P. M.; Peteherych, S.; Edelmann, D.

    1984-01-01

    A series of data assimilation experiments is performed to assess the impact of Seasat A satellite scatterometer (SASS) wind data on Goddard Laboratory for Atmospheric Sciences (GLAS) model forecasts. The SASS data are dealiased as part of an objective analysis system utilizing a three-pass procedure. The impact of the SASS data is evaluated with and without temperature soundings from the NOAA 4 Vertical Temperature Profile Radiometer (VTPR) instrument in order to study possible redundancy between surface wind data and upper air temperature data. In the northern hemisphere the SASS data are generally found to have a negligible effect on the forecasts. In the southern hemisphere the forecast impact from SASS data is somewhat larger and primarily beneficial in the absence of VTPR data. However, the inclusion of VTPR data effectively eliminates the positive impact over Australia and South America. This indicates that SASS data can be beneficial for numerical weather prediction in regions with large data gaps, but in the presence of satellite soundings the usefulness of SASS data is significantly reduced.

  1. Large-scale kinetic energy spectra from Eulerian analysis of EOLE wind data

    Science.gov (United States)

    Desbois, M.

    1975-01-01

    A data set of 56,000 winds determined from the horizontal displacements of EOLE balloons at the 200 mb level in the Southern Hemisphere during the period October 1971-February 1972 is utilized for the computation of planetary- and synoptic-scale kinetic energy space spectra. However, the random distribution of measurements in space and time presents some problems for the spectral analysis. Two different approaches are used, i.e., a harmonic analysis of daily wind values at equi-distant points obtained by space-time interpolation of the data, and a correlation method using the direct measurements. Both methods give similar results for small wavenumbers, but the second is more accurate for higher wavenumbers (k above or equal to 10). The spectra show a maximum at wavenumbers 5 and 6 due to baroclinic instability and then decrease for high wavenumbers up to wavenumber 35 (which is the limit of the analysis), according to the inverse power law k to the negative p, with p close to 3.

  2. Coordinated Pitch & Torque Control of Large-Scale Wind Turbine Based on Pareto Eciency Analysis

    DEFF Research Database (Denmark)

    Lin, Zhongwei; Chen, Zhenyu; Wu, Qiuwei

    2018-01-01

    For the existing pitch and torque control of the wind turbine generator system (WTGS), further development on coordinated control is necessary to improve effectiveness for practical applications. In this paper, the WTGS is modeled as a coupling combination of two subsystems: the generator torque...... control subsystem and blade pitch control subsystem. Then, the pole positions in each control subsystem are adjusted coordinately to evaluate the controller participation and used as the objective of optimization. A two-level parameters-controllers coordinated optimization scheme is proposed and applied...... to optimize the controller coordination based on the Pareto optimization theory. Three solutions are obtained through optimization, which includes the optimal torque solution, optimal power solution, and satisfactory solution. Detailed comparisons evaluate the performance of the three selected solutions...

  3. Optimized Placement of Wind Turbines in Large-Scale Offshore Wind Farm using Particle Swarm Optimization Algorithm

    DEFF Research Database (Denmark)

    Hou, Peng; Hu, Weihao; Soltani, Mohsen

    2015-01-01

    With the increasing size of wind farm, the impact of the wake effect on wind farm energy yields become more and more evident. The arrangement of the wind turbines’ (WT) locations will influence the capital investment and contribute to the wake losses which incur the reduction of energy production....... As a consequence, the optimized placement of the wind turbines may be done by considering the wake effect as well as the components cost within the wind farm. In this paper, a mathematical model which includes the variation of both wind direction and wake deficit is proposed. The problem is formulated by using...... Levelized Production Cost (LPC) as the objective function. The optimization procedure is performed by Particle Swarm Optimization (PSO) algorithm with the purpose of maximizing the energy yields while minimizing the total investment. The simulation results indicate that the proposed method is effective...

  4. Grid matching of large-scale wind energy conversion systems, alone and in tandem with large-scale photovoltaic systems: An Israeli case study

    International Nuclear Information System (INIS)

    Solomon, A.A.; Faiman, D.; Meron, G.

    2010-01-01

    This paper presents a grid matching analysis of wind energy conversion systems (WECSs) and photovoltaic (PV)-WECS hybrid systems. The study was carried out using hourly load data of the Israel Electric Corporation (IEC) for the year 2006 and the corresponding simulated hourly performance of large PV and WECS plants in the Negev Desert. Our major objective was to compare the grid-matching capabilities of wind with those of our previously published PV results, and to assess the extent to which the combined employment of WECS and PV can improve the grid matching capability of either technology when used on its own. We find that, due to the differences in diurnal and seasonal output profiles of WECS and PV, their tandem employment significantly improves grid penetration compared to their use individually.

  5. General Forced Oscillations in a Real Power Grid Integrated with Large Scale Wind Power

    Directory of Open Access Journals (Sweden)

    Ping Ju

    2016-07-01

    Full Text Available According to the monitoring of the wide area measurement system, inter-area oscillations happen more and more frequently in a real power grid of China, which are close to the forced oscillation. Applying the conventional forced oscillation theory, the mechanism of these oscillations cannot be explained well, because the oscillations vary with random amplitude and a narrow frequency band. To explain the mechanism of such oscillations, the general forced oscillation (GFO mechanism is taken into consideration. The GFO is the power system oscillation excited by the random excitations, such as power fluctuations from renewable power generation. Firstly, properties of the oscillations observed in the real power grid are analyzed. Using the GFO mechanism, the observed oscillations seem to be the GFO caused by some random excitation. Then the variation of the wind power measured in this power gird is found to be the random excitation which may cause the GFO phenomenon. Finally, simulations are carried out and the power spectral density of the simulated oscillation is compared to that of the observed oscillation, and they are similar with each other. The observed oscillation is thus explained well using the GFO mechanism and the GFO phenomenon has now been observed for the first time in real power grids.

  6. Lightning Surge Analysis on a Large Scale Grid-Connected Solar Photovoltaic System

    OpenAIRE

    Nur Hazirah Zaini; Mohd Zainal Abidin Ab. Kadir; Mohd Amran Mohd Radzi; Mahdi Izadi; Norhafiz Azis; Nor Izzati Ahmad; Mohd Solehin Mohd Nasir

    2017-01-01

    Solar photovoltaic (PV) farms currently play a vital role in the generation of electrical power in different countries, such as Malaysia, which is moving toward the use of renewable energy. Malaysia is one of the countries with abundant sunlight and thus can use solar PV farms as alternative sources for electricity generation. However, lightning strikes frequently occur in the country. Being installed in open and flat areas, solar PV farms, especially their electronic components, are at great...

  7. Solar wind stagnation near comets

    International Nuclear Information System (INIS)

    Galeev, A.A.; Cravens, T.E.; Gombosi, T.I.

    1983-03-01

    The nature of the solar wind flow near comets is examined analytically. In particular, the typical values for the stagnation pressure and magnetic barrier strength are estimated, taking into account the magnetic field line tension and the charge exchange cooling of the mass loaded solar wind. Knowledge of the strength of the magnetic barrier is required in order to determine the location of the contact discontinuity which separates the contaminated solar wind plasma and the outflowing plasma of the cometary ionosphere. (author)

  8. Wind-tunnel investigation of the thrust augmentor performance of a large-scale swept wing model. [in the Ames 40 by 80 foot wind tunnel

    Science.gov (United States)

    Koenig, D. G.; Falarski, M. D.

    1979-01-01

    Tests were made in the Ames 40- by 80-foot wind tunnel to determine the forward speed effects on wing-mounted thrust augmentors. The large-scale model was powered by the compressor output of J-85 driven viper compressors. The flap settings used were 15 deg and 30 deg with 0 deg, 15 deg, and 30 deg aileron settings. The maximum duct pressure, and wind tunnel dynamic pressure were 66 cmHg (26 in Hg) and 1190 N/sq m (25 lb/sq ft), respectively. All tests were made at zero sideslip. Test results are presented without analysis.

  9. Fault Ride Through Capability Enhancement of a Large-Scale PMSG Wind System with Bridge Type Fault Current Limiters

    Directory of Open Access Journals (Sweden)

    ALAM, M. S.

    2018-02-01

    Full Text Available In this paper, bridge type fault current limiter (BFCL is proposed as a potential solution to the fault problems of permanent magnet synchronous generator (PMSG based large-scale wind energy system. As PMSG wind system is more vulnerable to disturbances, it is essential to guarantee the stability during severe disturbances by enhancing the fault ride through capability. BFCL controller has been designed to insert resistance and inductance during the inception of system disturbances in order to limit fault current. Constant capacitor voltage has been maintained by the grid voltage source converter (GVSC controller while current extraction or injection has been achieved by machine VSC (MVSC controller. Symmetrical and unsymmetrical faults have been applied in the system to show the effectiveness of the proposed BFCL solution. PMSG wind system, BFCL and their controllers have been implemented by real time hardware in loop (RTHIL setup with real time digital simulator (RTDS and dSPACE. Another significant feature of this work is that the performance of the proposed BFCL is compared with that of series dynamic braking resistor (SDBR. Comparative RTHIL implementation results show that the proposed BFCL is very efficient in improving system fault ride through capability by limiting the fault current and outperforms SDBR.

  10. Lightning Surge Analysis on a Large Scale Grid-Connected Solar Photovoltaic System

    Directory of Open Access Journals (Sweden)

    Nur Hazirah Zaini

    2017-12-01

    Full Text Available Solar photovoltaic (PV farms currently play a vital role in the generation of electrical power in different countries, such as Malaysia, which is moving toward the use of renewable energy. Malaysia is one of the countries with abundant sunlight and thus can use solar PV farms as alternative sources for electricity generation. However, lightning strikes frequently occur in the country. Being installed in open and flat areas, solar PV farms, especially their electronic components, are at great risk of damage caused by lightning. In this paper, the effects of lightning currents with different peak currents and waveshapes on grid-connected solar PV farms were determined to approximate the level of transient effect that can damage solar PV modules, inverters and transformers. Depending on the location of the solar PV farm, engineer can obtain information on the peak current and median current of the site from the lightning location system (LLS and utilise the results obtained in this study to appropriately assign an SPD to protect the solar panel, inverter and the main panel that connected to the grid. Therefore, the simulation results serve as the basis for controlling the effects of lightning strikes on electrical equipment and power grids where it provides proper justification on the ‘where to be installed’ and ‘what is the rating’ of the SPD. This judgment and decision will surely reduce the expensive cost of repair and replacement of electrical equipment damages due to the lightning.

  11. Potential for large-scale solar collector system to offset carbon-based heating in the Ontario greenhouse sector

    Science.gov (United States)

    Semple, Lucas M.; Carriveau, Rupp; Ting, David S.-K.

    2018-04-01

    In the Ontario greenhouse sector the misalignment of available solar radiation during the summer months and large heating demand during the winter months makes solar thermal collector systems an unviable option without some form of seasonal energy storage. Information obtained from Ontario greenhouse operators has shown that over 20% of annual natural gas usage occurs during the summer months for greenhouse pre-heating prior to sunrise. A transient model of the greenhouse microclimate and indoor conditioning systems is carried out using TRNSYS software and validated with actual natural gas usage data. A large-scale solar thermal collector system is then incorporated and found to reduce the annual heating energy demand by approximately 35%. The inclusion of the collector system correlates to a reduction of about 120 tonnes of CO2 equivalent emissions per acre of greenhouse per year. System payback period is discussed considering the benefits of a future Ontario carbon tax.

  12. Wind power integration into the automatic generation control of power systems with large-scale wind power

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Altin, Müfit

    2014-01-01

    Transmission system operators have an increased interest in the active participation of wind power plants (WPP) in the power balance control of power systems with large wind power penetration. The emphasis in this study is on the integration of WPPs into the automatic generation control (AGC......) of the power system. The present paper proposes a coordinated control strategy for the AGC between combined heat and power plants (CHPs) and WPPs to enhance the security and the reliability of a power system operation in the case of a large wind power penetration. The proposed strategy, described...... and exemplified for the future Danish power system, takes the hour-ahead regulating power plan for generation and power exchange with neighbouring power systems into account. The performance of the proposed strategy for coordinated secondary control is assessed and discussed by means of simulations for different...

  13. An overview of wind power forecast types and their use in large-scale integration of wind power

    Energy Technology Data Exchange (ETDEWEB)

    Nielsen, Henrik Aalborg; Nielsen, Torben Skov [ENFOR A/S, Horslholm (Denmark); Madsen, Henrik [Technical Univ. of Denmark, Lyngby (Denmark). Informatics and Mathematical Modelling

    2011-07-01

    Wind power forecast characteristics are described and it is shown how analyses of actual decision problems can be used to derive the forecast characteristics important in a given situation. Generally, characteristics related to resolution in space and time, together with the required maximal forecast horizon are easily identified. However, identification of forecast characteristics required for optimal decision support requires a more thorough investigation, which is illustrated by examples. Generally, quantile forecasts of the future wind power production are required, but the transformation of a quantile forecast into an actual decisions is highly dependent on the precise formulation of the decision problem. Furthermore, when consequences of neighbouring time steps interact, quantile forecasts are not sufficient. It is argued that a general solution in such cases is to base the decision on reliable scenarios of the future wind power production. (orig.)

  14. Large-scale, high-resolution wind resource mapping for wind farm planning and development in South Africa

    DEFF Research Database (Denmark)

    Mortensen, Niels Gylling; Badger, Jake; Hansen, Jens Carsten

    2014-01-01

    estimates are designed for national and provincial planning and strategic environmental impact assessment for wind power in South Africa and the results have therefore been made available in common GIS formats. The database of results is in the public domain and can be downloaded from the WASA web site...

  15. Wind power integration into the automatic generation control of power systems with large-scale wind power

    Directory of Open Access Journals (Sweden)

    Abdul Basit

    2014-10-01

    Full Text Available Transmission system operators have an increased interest in the active participation of wind power plants (WPP in the power balance control of power systems with large wind power penetration. The emphasis in this study is on the integration of WPPs into the automatic generation control (AGC of the power system. The present paper proposes a coordinated control strategy for the AGC between combined heat and power plants (CHPs and WPPs to enhance the security and the reliability of a power system operation in the case of a large wind power penetration. The proposed strategy, described and exemplified for the future Danish power system, takes the hour-ahead regulating power plan for generation and power exchange with neighbouring power systems into account. The performance of the proposed strategy for coordinated secondary control is assessed and discussed by means of simulations for different possible future scenarios, when wind power production in the power system is high and conventional production from CHPs is at a minimum level. The investigation results of the proposed control strategy have shown that the WPPs can actively help the AGC, and reduce the real-time power imbalance in the power system, by down regulating their production when CHPs are unable to provide the required response.

  16. Solar wind stream interfaces

    International Nuclear Information System (INIS)

    Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.

    1978-01-01

    Measurements aboard Imp 6, 7, and 8 reveal that approximately one third of all high-speed solar wind streams observed at 1 AU contain a sharp boundary (of thickness less than approx.4 x 10 4 km) near their leading edge, called a stream interface, which separates plasma of distinctly different properties and origins. Identified as discontinuities across which the density drops abruptly, the proton temperature increases abruptly, and the speed rises, stream interfaces are remarkably similar in character from one stream to the next. A superposed epoch analysis of plasma data has been performed for 23 discontinuous stream interfaces observed during the interval March 1971 through August 1974. Among the results of this analysis are the following: (1) a stream interface separates what was originally thick (i.e., dense) slow gas from what was originally thin (i.e., rare) fast gas; (2) the interface is the site of a discontinuous shear in the solar wind flow in a frame of reference corotating with the sun; (3) stream interfaces occur at speeds less than 450 km s - 1 and close to or at the maximum of the pressure ridge at the leading edges of high-speed streams; (4) a discontinuous rise by approx.40% in electron temperature occurs at the interface; and (5) discontinuous changes (usually rises) in alpha particle abundance and flow speed relative to the protons occur at the interface. Stream interfaces do not generally recur on successive solar rotations, even though the streams in which they are embedded often do. At distances beyond several astronomical units, stream interfaces should be bounded by forward-reverse shock pairs; three of four reverse shocks observed at 1 AU during 1971--1974 were preceded within approx.1 day by stream interfaces. Our observations suggest that many streams close to the sun are bounded on all sides by large radial velocity shears separating rapidly expanding plasma from more slowly expanding plasma

  17. Large scale deployment of polymer solar cells on land, on sea and in the air

    DEFF Research Database (Denmark)

    Espinosa Martinez, Nieves; Hösel, Markus; Jørgensen, Mikkel

    2014-01-01

    With the development of patterns that connect all cells in series, organic photovoltaics have leapt a step forward being ahead of other solar and even other energy technologies in terms of manufacturing speed and energy density. The important questions of how they are meant to be installed...... for producing power and what the requirements are yet to be explored. We present here the installation of organic solar cell modules in different settings (terrestrial, marine and airborne). For the evaluation of these installations deployed at DTU, we have used the life cycle assessment tools, and calculated...... key parameters in order to assess their environmental impact. The novel technology when installed in a solar park system can generate more than 1300 kW h kWp-1 of electricity a year, which means that the whole system can pay the energy invested back before the first year of operation, in 320 days...

  18. Concentrated Solar Power as part of the European energy supply. The realization of large-scale solar power plants. Options, constraints and recommendations

    International Nuclear Information System (INIS)

    Bouwmans, I.; Carton, L.J.; Dijkema, G.P.J.; Stikkelman, R.M.; De Vries, L.J.

    2006-01-01

    Next to solar cells and solar collectors for decentralized power generation Concentrated Solar Power (CSP) technology is available and proven for large-scale application of solar energy. However, after 20 years of demonstration projects and semi-commercial installations, CSP is still not widely used. In this quick-scan an overview is given of strong and weak points of CSP, as well as its' options and constraints with regard to a sustainable energy supply, focusing on technical, economical and administrative constraints and chances in Europe and European Union member states [nl

  19. Flexibility of Large-Scale Solar Heating Plant with Heat Pump and Thermal Energy Storage

    DEFF Research Database (Denmark)

    Luc, Katarzyna Marta; Heller, Alfred; Rode, Carsten

    2017-01-01

    to decrease biomass use in a district heating system. The paper focuses on the renewable energy-based district heating system in Marstal, Denmark, with heat produced in central solar heating plant, wood pellet boiler, heat pump and bio-oil boiler. The plant has been the object of research and developments...

  20. Large Scale Variability of Phytoplankton Blooms in the Arctic and Peripheral Seas: Relationships with Sea Ice, Temperature, Clouds, and Wind

    Science.gov (United States)

    Comiso, Josefino C.; Cota, Glenn F.

    2004-01-01

    Spatially detailed satellite data of mean color, sea ice concentration, surface temperature, clouds, and wind have been analyzed to quantify and study the large scale regional and temporal variability of phytoplankton blooms in the Arctic and peripheral seas from 1998 to 2002. In the Arctic basin, phytoplankton chlorophyll displays a large symmetry with the Eastern Arctic having about fivefold higher concentrations than those of the Western Arctic. Large monthly and yearly variability is also observed in the peripheral seas with the largest blooms occurring in the Bering Sea, Sea of Okhotsk, and the Barents Sea during spring. There is large interannual and seasonal variability in biomass with average chlorophyll concentrations in 2002 and 2001 being higher than earlier years in spring and summer. The seasonality in the latitudinal distribution of blooms is also very different such that the North Atlantic is usually most expansive in spring while the North Pacific is more extensive in autumn. Environmental factors that influence phytoplankton growth were examined, and results show relatively high negative correlation with sea ice retreat and strong positive correlation with temperature in early spring. Plankton growth, as indicated by biomass accumulation, in the Arctic and subarctic increases up to a threshold surface temperature of about 276-277 degree K (3-4 degree C) beyond which the concentrations start to decrease suggesting an optimal temperature or nutrient depletion. The correlation with clouds is significant in some areas but negligible in other areas, while the correlations with wind speed and its components are generally weak. The effects of clouds and winds are less predictable with weekly climatologies because of unknown effects of averaging variable and intermittent physical forcing (e.g. over storm event scales with mixing and upwelling of nutrients) and the time scales of acclimation by the phytoplankton.

  1. Estimating the electricity prices, generation costs and CO_2 emissions of large scale wind energy exports from Ireland to Great Britain

    International Nuclear Information System (INIS)

    Cleary, Brendan; Duffy, Aidan; Bach, Bjarne; Vitina, Aisma; O’Connor, Alan; Conlon, Michael

    2016-01-01

    The share of wind generation in the Irish and British electricity markets is set to increase by 2020 due to renewable energy (RE) targets. The United Kingdom (UK) and Ireland have set ambitious targets which require 30% and 40% of electricity demand to come from RE, mainly wind, by 2020, respectively. Ireland has sufficient indigenous onshore wind energy resources to exceed the RE target, while the UK faces uncertainty in achieving its target. A possible solution for the UK is to import RE directly from large scale onshore and offshore wind energy projects in Ireland; this possibility has recently been explored by both governments but is currently on hold. Thus, the aim of this paper is to estimate the effects of large scale wind energy in the Irish and British electricity markets in terms of wholesale system marginal prices, total generation costs and CO_2 emissions. The results indicate when the large scale Irish-based wind energy projects are connected directly to the UK there is a decrease of 0.6% and 2% in the Irish and British wholesale system marginal prices under the UK National Grid slow progression scenario, respectively. - Highlights: • Modelling the Irish and British electricity markets. • Investigating the impacts of large scale wind energy within the markets. • Results indicate a reduction in wholesale system marginal prices in both markets. • Decrease in total generation costs and CO_2 emissions in both markets.

  2. Large-scale and Long-duration Simulation of a Multi-stage Eruptive Solar Event

    Science.gov (United States)

    Jiang, chaowei; Hu, Qiang; Wu, S. T.

    2015-04-01

    We employ a data-driven 3D MHD active region evolution model by using the Conservation Element and Solution Element (CESE) numerical method. This newly developed model retains the full MHD effects, allowing time-dependent boundary conditions and time evolution studies. The time-dependent simulation is driven by measured vector magnetograms and the method of MHD characteristics on the bottom boundary. We have applied the model to investigate the coronal magnetic field evolution of AR11283 which was characterized by a pre-existing sigmoid structure in the core region and multiple eruptions, both in relatively small and large scales. We have succeeded in producing the core magnetic field structure and the subsequent eruptions of flux-rope structures (see https://dl.dropboxusercontent.com/u/96898685/large.mp4 for an animation) as the measured vector magnetograms on the bottom boundary evolve in time with constant flux emergence. The whole process, lasting for about an hour in real time, compares well with the corresponding SDO/AIA and coronagraph imaging observations. From these results, we show the capability of the model, largely data-driven, that is able to simulate complex, topological, and highly dynamic active region evolutions. (We acknowledge partial support of NSF grants AGS 1153323 and AGS 1062050, and data support from SDO/HMI and AIA teams).

  3. Solar wind velocity and temperature in the outer heliosphere

    Science.gov (United States)

    Gazis, P. R.; Barnes, A.; Mihalov, J. D.; Lazarus, A. J.

    1994-01-01

    At the end of 1992, the Pioneer 10, Pioneer 11, and Voyager 2 spacecraft were at heliocentric distances of 56.0, 37.3, and 39.0 AU and heliographic latitudes of 3.3 deg N, 17.4 deg N, and 8.6 deg S, respectively. Pioneer 11 and Voyager 2 are at similar celestial longitudes, while Pioneer 10 is on the opposite side of the Sun. All three spacecraft have working plasma analyzers, so intercomparison of data from these spacecraft provides important information about the global character of the solar wind in the outer heliosphere. The averaged solar wind speed continued to exhibit its well-known variation with solar cycle: Even at heliocentric distances greater than 50 AU, the average speed is highest during the declining phase of the solar cycle and lowest near solar minimum. There was a strong latitudinal gradient in solar wind speed between 3 deg and 17 deg N during the last solar minimum, but this gradient has since disappeared. The solar wind temperature declined with increasing heliocentric distance out to a heliocentric distance of at least 20 AU; this decline appeared to continue at larger heliocentric distances, but temperatures in the outer heliosphere were suprisingly high. While Pioneer 10 and Voyager 2 observed comparable solar wind temperatures, the temperature at Pioneer 11 was significantly higher, which suggests the existence of a large-scale variation of temperature with heliographic longitude. There was also some suggestion that solar wind temperatures were higher near solar minimum.

  4. Solar total energy-large scale experiment, Shenandoah, Georgia site. Annual report, June 1977--June 1978. [For Bleyle Knitwear Plant

    Energy Technology Data Exchange (ETDEWEB)

    None,

    1978-06-01

    The site was described in terms of location, suitably, accessibility, and other factors. Detailed descriptions of the Solar Total Energy-Large Scale Experiment Application (STE-LSE) (Bleyle of America, Inc., Knitwear Plant), the DOE owned Meteorology Station operating at the site, and the instrumentation provided by the Georgia Power Company to measure energy usage within the knitwear plant are included. A detailed report of progress is given at the Shenandoah Site, introduced by the STE-LSE schedule and the Cooperative Agreement work tasks. Progress is described in terms of the following major task areas: site/application; instrumentation/data acquisition; meteorology station; site to STES interface; information dissemination. A brief overview of milestones to be accomplished is given, followed by these appendices: solar easement agreement, interface drawing set, and additional site background data. (MHR)

  5. The large-scale solar feed-in tariff reverse auction in the Australian Capital Territory, Australia

    International Nuclear Information System (INIS)

    Buckman, Greg; Sibley, Jon; Bourne, Richard

    2014-01-01

    Feed-in tariffs (FiTs) offer renewable energy developers significant investor certainty but sometimes at the cost of being misaligned with generation costs. Reverse FiT auctions, where the FiT rights for a predetermined capacity are auctioned, can overcome this problem but can be plagued by non-delivery risks, particularly of competitively priced proposals. In 2012 and 2013 the Australian Capital Territory (ACT) Government in Australia conducted a FiT reverse auction for 40 MW of large-scale solar generating capacity, the first such auction undertaken in the country. The auction was highly competitive in relation to price and demonstrating low delivery risks. Proposal capital costs, particularly engineering, procurement and construction costs, as well as internal rates of return, were lower than expected. The auction process revealed limited land availability for large-scale solar developments in the ACT as well as a significant perceived sovereign risk issue. The auction process was designed to mitigate non-delivery risk by requiring proposals to be pre-qualified on the basis of delivery risk, before considering FiT pricing. The scheme is likely to be used by the ACT Government to support further large-scale renewable energy development as part of its greenhouse gas reduction strategy which is underpinned by a 90-per cent-by-2020 renewable energy target. - Highlights: • Evolution of the reverse auction process in the Australian Capital Territory. • Analysis of the outcomes of the first Australian feed-in tariff reverse auction. • Identification of the major drivers of the low FiT prices achieved in the auction. • Identification of major issues that emerged in the auction

  6. SWAP OBSERVATIONS OF THE LONG-TERM, LARGE-SCALE EVOLUTION OF THE EXTREME-ULTRAVIOLET SOLAR CORONA

    Energy Technology Data Exchange (ETDEWEB)

    Seaton, Daniel B.; De Groof, Anik; Berghmans, David; Nicula, Bogdan [Royal Observatory of Belgium-SIDC, Avenue Circulaire 3, B-1180 Brussels (Belgium); Shearer, Paul [Department of Mathematics, 2074 East Hall, University of Michigan, 530 Church Street, Ann Arbor, MI 48109-1043 (United States)

    2013-11-01

    The Sun Watcher with Active Pixels and Image Processing (SWAP) EUV solar telescope on board the Project for On-Board Autonomy 2 spacecraft has been regularly observing the solar corona in a bandpass near 17.4 nm since 2010 February. With a field of view of 54 × 54 arcmin, SWAP provides the widest-field images of the EUV corona available from the perspective of the Earth. By carefully processing and combining multiple SWAP images, it is possible to produce low-noise composites that reveal the structure of the EUV corona to relatively large heights. A particularly important step in this processing was to remove instrumental stray light from the images by determining and deconvolving SWAP's point-spread function from the observations. In this paper, we use the resulting images to conduct the first-ever study of the evolution of the large-scale structure of the corona observed in the EUV over a three year period that includes the complete rise phase of solar cycle 24. Of particular note is the persistence over many solar rotations of bright, diffuse features composed of open magnetic fields that overlie polar crown filaments and extend to large heights above the solar surface. These features appear to be related to coronal fans, which have previously been observed in white-light coronagraph images and, at low heights, in the EUV. We also discuss the evolution of the corona at different heights above the solar surface and the evolution of the corona over the course of the solar cycle by hemisphere.

  7. Collapsible Photovoltaic Module for a Large-Scale Solar Power Plant

    DEFF Research Database (Denmark)

    2014-01-01

    An elongate photovoltaic (PV) module for use in a solar energy conversion plant for the production of electricity from incident light, the PV-module comprising a top portion with a support panel (G) carrying on a front side a plurality of electrically connected PV cells (D), and a transparent...... protective layer (A) sealed to the support panel (G) so as to encapsulate the PV-cells (D) between the support panel (G) and the protective layer (A), wherein prior to installation of the PV-module at the deployment site a collapsible portion of the PV-module is configured to be collapsible in a longitudinal...... direction by folding and/or rolling, wherein the collapsible portion includes at least the top portion, wherein the PV-module further comprises one or more integrated ballast chambers (I) in a bottom portion of the PV-module arranged on a rear side of the support panel (G), wherein said integrated ballast...

  8. Large scale circulation in the convection zone and solar differential rotation

    Energy Technology Data Exchange (ETDEWEB)

    Belvedere, G [Instituto di Astronomia dell' Universita di Catania, 95125 Italy; Paterno, L [Osservatorio Astrofisico di Catania, 95125 Italy

    1976-04-01

    In this paper the dependence on depth and latitude of the solar angular velocity produced by a meridian circulation in the convection zone is studied assuming that the main mechanism responsible for setting up and driving the circulation is the interaction of rotation with convection. The first order equations (perturbation of the spherically symmetric state are solved in the Boussinesq approximation and in the steady state for the axissymmetric case. The interaction of convection with rotation is modelled by a convective transport coefficient. The model is consistent with the fact that the interaction of convection with rotation sets up a circulation (driven by the temperature gradient) which carries angular momentum toward the equator against the viscous friction. Unfortunately also a large flux variation at the surface is obtained. Nevertheless it seems that the model has the basic requisites for correct dynamo action.

  9. Large-scale Roll-to-Roll Fabrication of Organic Solar Cells for Energy Production

    DEFF Research Database (Denmark)

    Hösel, Markus

    intelligent connection of single cells that should involve as less as possible manual processes such as wiring or soldering. The problem was solved by serially connecting thousands of single cells entirely during the R2R processing by printing thin-film silver conductors. High voltage networks require only...... be produced cheaply and very fast from solution with printing processes. The current research all around the world is still focused on lab-scale sized devices « cm2, ITO-glass substrates, and spin coating as the main fabrication method. These OPV devices are far from any practical application although record...... substrates and ITO-free transparent conductive electrodes made from special designed flexo printed silver grids, rotary screen printed PEDOT:PSS, and slot-die coated ZnO (= Flextrode). The organic solar cell was fabricated by slot-die coating a light absorbing photoactive layer (e. g. P3HT:PCBM) on top...

  10. Helioseismic Constraints on the Depth Dependence of Large-Scale Solar Convection

    Science.gov (United States)

    Woodard, Martin F.

    2017-08-01

    A recent helioseismic statistical waveform analysis of subsurface flow based on a 720-day time series of SOHO/MDI Medium-l spherical-harmonic coefficients has been extended to cover a greater range of subphotospheric depths. The latest analysis provides estimates of flow-dependent oscillation-mode coupling-strength coefficients b(s,t;n,l) over the range l = 30 to 150 of mode degree (angular wavenumber) for solar p-modes in the approximate frequency range 2 to 4 mHz. The range of penetration depths of this mode set covers most of the solar convection zone. The most recent analysis measures spherical harmonic (s,t) components of the flow velocity for odd s in the angular wavenumber range 1 to 19 for t not much smaller than s at a given s. The odd-s b(s,t;n,l) coefficients are interpreted as averages over depth of the depth-dependent amplitude of one spherical-harmonic (s,t) component of the toroidal part of the flow velocity field. The depth-dependent weighting function defining the average velocity is the fractional kinetic energy density in radius of modes of the (n,l) multiplet. The b coefficients have been converted to estimates of root velocity power as a function of l0 = nu0*l/nu(n,l), which is a measure of mode penetration depth. (nu(n,l) is mode frequency and nu0 is a reference frequency equal to 3 mHz.) A comparison of the observational results with simple convection models will be presented.

  11. ANEMOS: Development of a next generation wind power forecasting system for the large-scale integration of onshore and offshore wind farms.

    Science.gov (United States)

    Kariniotakis, G.; Anemos Team

    2003-04-01

    Objectives: Accurate forecasting of the wind energy production up to two days ahead is recognized as a major contribution for reliable large-scale wind power integration. Especially, in a liberalized electricity market, prediction tools enhance the position of wind energy compared to other forms of dispatchable generation. ANEMOS, is a new 3.5 years R&D project supported by the European Commission, that resembles research organizations and end-users with an important experience on the domain. The project aims to develop advanced forecasting models that will substantially outperform current methods. Emphasis is given to situations like complex terrain, extreme weather conditions, as well as to offshore prediction for which no specific tools currently exist. The prediction models will be implemented in a software platform and installed for online operation at onshore and offshore wind farms by the end-users participating in the project. Approach: The paper presents the methodology of the project. Initially, the prediction requirements are identified according to the profiles of the end-users. The project develops prediction models based on both a physical and an alternative statistical approach. Research on physical models gives emphasis to techniques for use in complex terrain and the development of prediction tools based on CFD techniques, advanced model output statistics or high-resolution meteorological information. Statistical models (i.e. based on artificial intelligence) are developed for downscaling, power curve representation, upscaling for prediction at regional or national level, etc. A benchmarking process is set-up to evaluate the performance of the developed models and to compare them with existing ones using a number of case studies. The synergy between statistical and physical approaches is examined to identify promising areas for further improvement of forecasting accuracy. Appropriate physical and statistical prediction models are also developed for

  12. Ultra-high efficiency photovoltaic cells for large scale solar power generation.

    Science.gov (United States)

    Nakano, Yoshiaki

    2012-01-01

    The primary targets of our project are to drastically improve the photovoltaic conversion efficiency and to develop new energy storage and delivery technologies. Our approach to obtain an efficiency over 40% starts from the improvement of III-V multi-junction solar cells by introducing a novel material for each cell realizing an ideal combination of bandgaps and lattice-matching. Further improvement incorporates quantum structures such as stacked quantum wells and quantum dots, which allow higher degree of freedom in the design of the bandgap and the lattice strain. Highly controlled arrangement of either quantum dots or quantum wells permits the coupling of the wavefunctions, and thus forms intermediate bands in the bandgap of a host material, which allows multiple photon absorption theoretically leading to a conversion efficiency exceeding 50%. In addition to such improvements, microfabrication technology for the integrated high-efficiency cells and the development of novel material systems that realizes high efficiency and low cost at the same time are investigated.

  13. Were chondrites magnetized by the early solar wind?

    Science.gov (United States)

    Oran, Rona; Weiss, Benjamin P.; Cohen, Ofer

    2018-06-01

    Chondritic meteorites have been traditionally thought to be samples of undifferentiated bodies that never experienced large-scale melting. This view has been challenged by the existence of post-accretional, unidirectional natural remanent magnetization (NRM) in CV carbonaceous chondrites. The relatively young inferred NRM age [∼10 million years (My) after solar system formation] and long duration of NRM acquisition (1-106 y) have been interpreted as evidence that the magnetizing field was that of a core dynamo within the CV parent body. This would imply that CV chondrites represent the primitive crust of a partially differentiated body. However, an alternative hypothesis is that the NRM was imparted by the early solar wind. Here we demonstrate that the solar wind scenario is unlikely due to three main factors: 1) the magnitude of the early solar wind magnetic field is estimated to be limits field amplification due to pile-up of the solar wind to less than a factor of 3.5 times that of the instantaneous solar wind field, and 3) the solar wind field likely changed over timescales orders of magnitude shorter than the timescale of NRM acquisition. Using analytical arguments, numerical simulations and astronomical observations of the present-day solar wind and magnetic fields of young stars, we show that the maximum mean field the ancient solar wind could have imparted on an undifferentiated CV parent body is <3.5 nT, which is 3-4 and 3 orders of magnitude weaker than the paleointensities recorded by the CV chondrites Allende and Kaba, respectively. Therefore, the solar wind is highly unlikely to be the source of the NRM in CV chondrites. Nevertheless, future high sensitivity paleomagnetic studies of rapidly-cooled meteorites with high magnetic recording fidelity could potentially trace the evolution of the solar wind field in time.

  14. Low-Temperature Soft-Cover Deposition of Uniform Large-Scale Perovskite Films for High-Performance Solar Cells.

    Science.gov (United States)

    Ye, Fei; Tang, Wentao; Xie, Fengxian; Yin, Maoshu; He, Jinjin; Wang, Yanbo; Chen, Han; Qiang, Yinghuai; Yang, Xudong; Han, Liyuan

    2017-09-01

    Large-scale high-quality perovskite thin films are crucial to produce high-performance perovskite solar cells. However, for perovskite films fabricated by solvent-rich processes, film uniformity can be prevented by convection during thermal evaporation of the solvent. Here, a scalable low-temperature soft-cover deposition (LT-SCD) method is presented, where the thermal convection-induced defects in perovskite films are eliminated through a strategy of surface tension relaxation. Compact, homogeneous, and convection-induced-defects-free perovskite films are obtained on an area of 12 cm 2 , which enables a power conversion efficiency (PCE) of 15.5% on a solar cell with an area of 5 cm 2 . This is the highest efficiency at this large cell area. A PCE of 15.3% is also obtained on a flexible perovskite solar cell deposited on the polyethylene terephthalate substrate owing to the advantage of presented low-temperature processing. Hence, the present LT-SCD technology provides a new non-spin-coating route to the deposition of large-area uniform perovskite films for both rigid and flexible perovskite devices. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Fluid-structure interaction simulation of floating structures interacting with complex, large-scale ocean waves and atmospheric turbulence with application to floating offshore wind turbines

    Science.gov (United States)

    Calderer, Antoni; Guo, Xin; Shen, Lian; Sotiropoulos, Fotis

    2018-02-01

    We develop a numerical method for simulating coupled interactions of complex floating structures with large-scale ocean waves and atmospheric turbulence. We employ an efficient large-scale model to develop offshore wind and wave environmental conditions, which are then incorporated into a high resolution two-phase flow solver with fluid-structure interaction (FSI). The large-scale wind-wave interaction model is based on a two-fluid dynamically-coupled approach that employs a high-order spectral method for simulating the water motion and a viscous solver with undulatory boundaries for the air motion. The two-phase flow FSI solver is based on the level set method and is capable of simulating the coupled dynamic interaction of arbitrarily complex bodies with airflow and waves. The large-scale wave field solver is coupled with the near-field FSI solver with a one-way coupling approach by feeding into the latter waves via a pressure-forcing method combined with the level set method. We validate the model for both simple wave trains and three-dimensional directional waves and compare the results with experimental and theoretical solutions. Finally, we demonstrate the capabilities of the new computational framework by carrying out large-eddy simulation of a floating offshore wind turbine interacting with realistic ocean wind and waves.

  16. Wind in the Solar System

    Science.gov (United States)

    McIntosh, Gordon

    2010-01-01

    As an astronomy instructor I am always looking for commonly experienced Earthly phenomena to help my students and me understand and appreciate similar occurrences elsewhere in the solar system. Recently I wrote short "TPT" articles on frost and precipitation. The present article is on winds in the solar system. A windy day or storm might…

  17. Multicriteria GIS modeling of wind and solar farms in Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Janke, Jason R. [Metropolitan State College of Denver, Department of Earth and Atmospheric Sciences, CB 22 P.O. Box 173362-22, Denver, CO 80217-3362 (United States)

    2010-10-15

    The majority of electricity and heat in Colorado comes from coal and natural gas; however, renewable energy sources will play an integral role in the state's energy future. Colorado is the 11th windiest state and has more than 250 sunny days per year. The objectives of this research are to: 1) determine which landcover classes are affiliated with high wind and solar potential; and 2) identify areas that are suitable for wind and solar farms using multicriteria GIS modelling techniques. Renewable potential (NREL wind speed measurements at 50 m above the ground and NREL annual insolation data), landcover, population density, federal lands, and distance to roads, transmission lines, and cities were reclassified according to their suitability. Each was assigned weights based on their relative importance to one another. Superb wind classes are located in high alpine areas. Unfortunately, these areas are not suitable for large-scale wind farm development due to their inaccessibility and location within a sensitive ecosystem. Federal lands have low wind potential. According to the GIS model, ideal areas for wind farm development are located in northeastern Colorado. About 41 850 km{sup 2} of the state has model scores that are in the 90-100% range. Although annual solar radiation varies slightly, inter-mountain areas receive the most insolation. As far as federal lands, Indian reservations have the greatest solar input. The GIS model indicates that ideal areas for solar development are located in northwestern Colorado and east of Denver. Only 191 km{sup 2} of the state had model scores that were in the 90-100% range. These results suggest that the variables used in this analysis have more of an effect at eliminating non-suitable areas for large-scale solar farms; a greater area exists for suitable wind farms. However, given the statewide high insolation values with minimal variance, solar projects may be better suited for small-scale residential or commercial

  18. New Techniques Used in Modeling the 2017 Total Solar Eclipse: Energizing and Heating the Large-Scale Corona

    Science.gov (United States)

    Downs, Cooper; Mikic, Zoran; Linker, Jon A.; Caplan, Ronald M.; Lionello, Roberto; Torok, Tibor; Titov, Viacheslav; Riley, Pete; Mackay, Duncan; Upton, Lisa

    2017-08-01

    Over the past two decades, our group has used a magnetohydrodynamic (MHD) model of the corona to predict the appearance of total solar eclipses. In this presentation we detail recent innovations and new techniques applied to our prediction model for the August 21, 2017 total solar eclipse. First, we have developed a method for capturing the large-scale energized fields typical of the corona, namely the sheared/twisted fields built up through long-term processes of differential rotation and flux-emergence/cancellation. Using inferences of the location and chirality of filament channels (deduced from a magnetofrictional model driven by the evolving photospheric field produced by the Advective Flux Transport model), we tailor a customized boundary electric field profile that will emerge shear along the desired portions of polarity inversion lines (PILs) and cancel flux to create long twisted flux systems low in the corona. This method has the potential to improve the morphological shape of streamers in the low solar corona. Second, we apply, for the first time in our eclipse prediction simulations, a new wave-turbulence-dissipation (WTD) based model for coronal heating. This model has substantially fewer free parameters than previous empirical heating models, but is inherently sensitive to the 3D geometry and connectivity of the coronal field---a key property for modeling/predicting the thermal-magnetic structure of the solar corona. Overall, we will examine the effect of these considerations on white-light and EUV observables from the simulations, and present them in the context of our final 2017 eclipse prediction model.Research supported by NASA's Heliophysics Supporting Research and Living With a Star Programs.

  19. Wind-tunnel investigation of a large-scale VTOL aircraft model with wing root and wing thrust augmentors. [Ames 40 by 80 foot wind tunnel

    Science.gov (United States)

    Aoyagi, K.; Aiken, T. N.

    1979-01-01

    Tests were conducted in the Ames 40 by 80 foot wind tunnel to determine the aerodynamic characteristics of a large-scale V/STOL aircraft model with thrust augmentors. The model had a double-delta wing of aspect ratio 1.65 with augmentors located in the wing root and the wing trailing edge. The supply air for the augmentor primary nozzles was provided by the YJ-97 turbojet engine. The airflow was apportioned approximately 74 percent to the wing root augmentor and 24 percent to wing augmentor. Results were obtained at several trailing-edge flap deflections with the nozzle jet-momentum coefficients ranging from 0 to 7.9. Three-component longitudinal data are presented with the agumentor operating with and without the horizontal tail. A limited amount of six component data are also presented.

  20. An aggregate model of grid-connected, large-scale, offshore wind farm for power stability investigations-importance of windmill mechanical system

    DEFF Research Database (Denmark)

    Akhmatov, Vladislav; Knudsen, H.

    2002-01-01

    . Because the shaft system gives a soft coupling between the rotating wind turbine and the induction generator, the large-scale wind farm cannot always be reduced to one-machine equivalent and use of multi-machine equivalents will be necessary for reaching accuracy of the investigation results....... This will be in cases with irregular wind distribution over the wind farm area. The torsion mode of the shaft systems of large wind turbines is commonly in the range of 1-2 Hz and close to typical values of the electric power grid eigenfrequencies why there is a risk of oscillation between the wind turbines...... and the entire network. All these phenomena are different compared to previous experiences with modelling of conventional power plants with synchronous generators and stiff shaft systems....

  1. PHOTOIONIZATION IN THE SOLAR WIND

    Energy Technology Data Exchange (ETDEWEB)

    Landi, E.; Lepri, S. T., E-mail: elandi@umich.edu [Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)

    2015-10-20

    In this work we investigate the effects of photoionization on the charge state composition of the solar wind. Using measured solar EUV and X-ray irradiance, the Michigan Ionization Code and a model for the fast and slow solar wind, we calculate the evolution of the charge state distribution of He, C, N, O, Ne, Mg, Si, S, and Fe with and without including photoionization for both types of wind. We find that the solar radiation has significant effects on the charge state distribution of C, N, and O, causing the ionization levels of these elements to be higher than without photoionization; differences are largest for oxygen. The ions commonly observed for elements heavier than O are much less affected, except in ICMEs where Fe ions more ionized than 16+ can also be affected by the solar radiation. We also show that the commonly used O{sup 7+}/O{sup 6+} density ratio is the most sensitive to photoionization; this sensitivity also causes the value of this ratio to depend on the phase of the solar cycle. We show that the O{sup 7+}/O{sup 6+} ratio needs to be used with caution for solar wind classification and coronal temperature estimates, and recommend the C{sup 6+}/C{sup 4+} ratio for these purposes.

  2. Spatiotemporal distribution of nitrogen dioxide within and around a large-scale wind farm – a numerical case study

    Directory of Open Access Journals (Sweden)

    J. Mo

    2017-12-01

    Full Text Available As a renewable and clean energy source, wind power has become the most rapidly growing energy resource worldwide in the past decades. Wind power has been thought not to exert any negative impacts on the environment. However, since a wind farm can alter the local meteorological conditions and increase the surface roughness lengths, it may affect air pollutants passing through and over the wind farm after released from their sources and delivered to the wind farm. In the present study, we simulated the nitrogen dioxide (NO2 air concentration within and around the world's largest wind farm (Jiuquan wind farm in Gansu Province, China using a coupled meteorology and atmospheric chemistry model WRF-Chem. The results revealed an edge effect, which featured higher NO2 levels at the immediate upwind and border region of the wind farm and lower NO2 concentration within the wind farm and the immediate downwind transition area of the wind farm. A surface roughness length scheme and a wind turbine drag force scheme were employed to parameterize the wind farm in this model investigation. Modeling results show that both parameterization schemes yield higher concentration in the immediate upstream of the wind farm and lower concentration within the wind farm compared to the case without the wind farm. We infer this edge effect and the spatial distribution of air pollutants to be the result of the internal boundary layer induced by the changes in wind speed and turbulence intensity driven by the rotation of the wind turbine rotor blades and the enhancement of surface roughness length over the wind farm. The step change in the roughness length from the smooth to rough surfaces (overshooting in the upstream of the wind farm decelerates the atmospheric transport of air pollutants, leading to their accumulation. The rough to the smooth surface (undershooting in the downstream of the wind farm accelerates the atmospheric transport of air pollutants, resulting in

  3. The turbulent cascade and proton heating in the solar wind during solar minimum

    International Nuclear Information System (INIS)

    Coburn, Jesse T.; Smith, Charles W.; Vasquez, Bernard J.; Stawarz, Joshua E.; Forman, Miriam A.

    2013-01-01

    Solar wind measurements at 1 AU during the recent solar minimum and previous studies of solar maximum provide an opportunity to study the effects of the changing solar cycle on in situ heating. Our interest is to compare the levels of activity associated with turbulence and proton heating. Large-scale shears in the flow caused by transient activity are a source that drives turbulence that heats the solar wind, but as the solar cycle progresses the dynamics that drive the turbulence and heat the medium are likely to change. The application of third-moment theory to Advanced Composition Explorer (ACE) data gives the turbulent energy cascade rate which is not seen to vary with the solar cycle. Likewise, an empirical heating rate shows no significan changes in proton heating over the cycle.

  4. Financial return for government support of large-scale thin-film solar photovoltaic manufacturing in Canada

    International Nuclear Information System (INIS)

    Branker, K.; Pearce, J.M.

    2010-01-01

    As the Ontario government has recognized that solar photovoltaic (PV) energy conversion is a solution to satisfying energy demands while reducing the adverse anthropogenic impacts on the global environment that compromise social welfare, it has begun to generate policy to support financial incentives for PV. This paper provides a financial analysis for investment in a 1 GW per year turnkey amorphous silicon PV manufacturing plant. The financial benefits for both the provincial and federal governments were quantified for: (i) full construction subsidy, (ii) construction subsidy and sale, (iii) partially subsidize construction, (iv) a publicly owned plant, (v) loan guarantee for construction, and (vi) an income tax holiday. Revenues for the governments are derived from: taxation (personal, corporate, and sales), sales of panels in Ontario, and saved health, environmental and economic costs associated with offsetting coal-fired electricity. Both governments enjoyed positive cash flows from these investments in less than 12 years and in many of the scenarios both governments earned well over 8% on investments from 100 s of millions to $2.4 billion. The results showed that it is in the financial best interest of both the Ontario and Canadian federal governments to implement aggressive fiscal policy to support large-scale PV manufacturing.

  5. Solar wind temperature observations in the outer heliosphere

    Science.gov (United States)

    Gazis, P. R.; Barnes, A.; Mihalov, J. D.; Lazarus, A. J.

    1992-01-01

    The Pioneer 10, Pioneer 11, and Voyager 2 spacecraft are now at heliocentric distances of 50, 32 and 33 AU, and heliographic latitudes of 3.5 deg N, 17 deg N, and 0 deg N, respectively. Pioneer 11 and Voyager 2 are at similar celestial longitudes, while Pioneer l0 is on the opposite side of the sun. The baselines defined by these spacecraft make it possible to resolve radial, longitudinal, and latitudinal variations of solar wind parameters. The solar wind temperature decreases with increasing heliocentric distance out to a distance of 10-15 AU. At larger heliocentric distances, this gradient disappears. These high solar wind temperatures in the outer heliosphere have persisted for at least 10 years, which suggests that they are not a solar cycle effect. The solar wind temperature varied with heliographic latitude during the most recent solar minimum. The solar wind temperature at Pioneer 11 and Voyager 2 was higher than that seen at Pioneer 10 for an extended period of time, which suggests the existence of a large-scale variation of temperature with celestial longitude, but the contribution of transient phenomena is yet to be clarified.

  6. Managing Critical Weather Conditions in a Large-Scale Wind Based European Power System - The TWENTIES Project

    DEFF Research Database (Denmark)

    Detlefsen, N.; Sørensen, Poul Ejnar; Eriksen, P.

    2011-01-01

    the cut-off wind speed (typically 25 m/s). Experience has shown that a large offshore wind farm in this way can be shut down from full power to zero power in less than 5 minutes. Thus, in the planned offshore development in the North Sea, several GW of wind power could be shut down within less than one...

  7. Solar powered oxygen systems in remote health centers in Papua New Guinea: a large scale implementation effectiveness trial.

    Science.gov (United States)

    Duke, Trevor; Hwaihwanje, Ilomo; Kaupa, Magdalynn; Karubi, Jonah; Panauwe, Doreen; Sa'avu, Martin; Pulsan, Francis; Prasad, Peter; Maru, Freddy; Tenambo, Henry; Kwaramb, Ambrose; Neal, Eleanor; Graham, Hamish; Izadnegahdar, Rasa

    2017-06-01

    Pneumonia is the largest cause of child deaths in Papua New Guinea (PNG), and hypoxaemia is the major complication causing death in childhood pneumonia, and hypoxaemia is a major factor in deaths from many other common conditions, including bronchiolitis, asthma, sepsis, malaria, trauma, perinatal problems, and obstetric emergencies. A reliable source of oxygen therapy can reduce mortality from pneumonia by up to 35%. However, in low and middle income countries throughout the world, improved oxygen systems have not been implemented at large scale in remote, difficult to access health care settings, and oxygen is often unavailable at smaller rural hospitals or district health centers which serve as the first point of referral for childhood illnesses. These hospitals are hampered by lack of reliable power, staff training and other basic services. We report the methodology of a large implementation effectiveness trial involving sustainable and renewable oxygen and power systems in 36 health facilities in remote rural areas of PNG. The methodology is a before-and after evaluation involving continuous quality improvement, and a health systems approach. We describe this model of implementation as the considerations and steps involved have wider implications in health systems in other countries. The implementation steps include: defining the criteria for where such an intervention is appropriate, assessment of power supplies and power requirements, the optimal design of a solar power system, specifications for oxygen concentrators and other oxygen equipment that will function in remote environments, installation logistics in remote settings, the role of oxygen analyzers in monitoring oxygen concentrator performance, the engineering capacity required to sustain a program at scale, clinical guidelines and training on oxygen equipment and the treatment of children with severe respiratory infection and other critical illnesses, program costs, and measurement of processes and

  8. The solar wind at solar maximum: comparisons of EISCAT IPS and in situ observations

    Directory of Open Access Journals (Sweden)

    A. R. Breen

    Full Text Available The solar maximum solar wind is highly structured in latitude, longitude and in time. Coronal measurements show a very high degree of variability, with large variations that are less apparent within in situ spacecraft measurements. Interplanetary scintillation (IPS observations from EISCAT, covering distances from 20 to 100 solar radii (RS, are an ideal source of information on the inner solar wind and can be used, therefore, to cast light on its evolution with distance from the Sun. Earlier comparisons of in situ and IPS measurements under solar minimum conditions showed good large-scale agreement, particularly in the fast wind. In this study we attempt a quantitative comparison of measurements made over solar maximum by EISCAT (20–100 RS and the Wind and Ulysses spacecraft (at 215 RS and 300–1000 RS, respectively. The intervals studied were August–September 1999, May 2000, September 2000 and May 2001, the last-named being the period of the second Ulysses fast latitude scan. Both ballistic and – when possible – MHD/ballistic hybrid models were used to relate the data sets, and we compare the results obtained from these two mapping methods. The results of this study suggest that solar wind velocities measured in situ were less variable than those estimated from IPS measurements closer to the Sun, with the greatest divergence between IPS velocities and in situ measurements occurring in regions where steep longitudinal velocity gradients were seen in situ. We suggest that the interaction between streams of solar wind with different velocities leads to "smoothing" of solar wind velocities between 30–60 RS and 1 AU, and that this process continues at greater distances from the Sun.

    Key words. Interplanetary physics (solar wind plasma; sources of the solar wind; instruments and techniques

  9. How does market power affect the impact of large scale wind investment in 'energy only' wholesale electricity markets?

    International Nuclear Information System (INIS)

    Browne, Oliver; Poletti, Stephen; Young, David

    2015-01-01

    In the short run, it is well known that increasing wind penetration is likely to reduce spot market electricity prices due to the merit order effect. The long run effect is less clear because there will be a change in new capacity investment in response to the wind penetration. In this paper we examine the interaction between capacity investment, wind penetration and market power by first using a least-cost generation expansion model to simulate capacity investment with increasing amounts of wind generation, and then using a computer agent-based model to predict electricity prices in the presence of market power. We find the degree to which firms are able to exercise market power depends critically on the ratio of capacity to peak demand. For our preferred long run generation scenario we show market power increases for some periods as wind penetration increases however the merit order counteracts this with the results that prices overall remain flat. Returns to peakers increase significantly as wind penetration increases. The market power in turn leads to inefficient dispatch which is exacerbated with large amounts of wind generation. - Highlights: • Increasing investment in wind generation is analyzed using an agent based model. • In an energy only market, increased total capacity reduces market power. • Increasing wind penetration results in more market power in some periods. • Market power causes dispatch inefficiencies, which grow as wind capacity increases.

  10. Demonstrating a new framework for the comparison of environmental impacts from small- and large-scale hydropower and wind power projects.

    Science.gov (United States)

    Bakken, Tor Haakon; Aase, Anne Guri; Hagen, Dagmar; Sundt, Håkon; Barton, David N; Lujala, Päivi

    2014-07-01

    Climate change and the needed reductions in the use of fossil fuels call for the development of renewable energy sources. However, renewable energy production, such as hydropower (both small- and large-scale) and wind power have adverse impacts on the local environment by causing reductions in biodiversity and loss of habitats and species. This paper compares the environmental impacts of many small-scale hydropower plants with a few large-scale hydropower projects and one wind power farm, based on the same set of environmental parameters; land occupation, reduction in wilderness areas (INON), visibility and impacts on red-listed species. Our basis for comparison was similar energy volumes produced, without considering the quality of the energy services provided. The results show that small-scale hydropower performs less favourably in all parameters except land occupation. The land occupation of large hydropower and wind power is in the range of 45-50 m(2)/MWh, which is more than two times larger than the small-scale hydropower, where the large land occupation for large hydropower is explained by the extent of the reservoirs. On all the three other parameters small-scale hydropower performs more than two times worse than both large hydropower and wind power. Wind power compares similarly to large-scale hydropower regarding land occupation, much better on the reduction in INON areas, and in the same range regarding red-listed species. Our results demonstrate that the selected four parameters provide a basis for further development of a fair and consistent comparison of impacts between the analysed renewable technologies. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  11. Understanding non-equilibrium collisional and expansion effects in the solar wind with Parker Solar Probe

    Science.gov (United States)

    Korreck, K. E.; Klein, K. G.; Maruca, B.; Alterman, B. L.

    2017-12-01

    The evolution of the solar wind from the corona to the Earth and throughout the heliosphere is a complex interplay between local micro kinetics and large scale expansion effects. These processes in the solar wind need to be separated in order to understand and distinguish the dominant mechanism for heating and acceleration of the solar wind. With the upcoming launch in 2018 of Parker Solar Probe and the launch of Solar Orbiter after, addressing the local and global phenomena will be enabled with in situ measurements. Parker Solar Probe will go closer to the Sun than any previous mission enabling the ability to examine the solar wind at an early expansion age. This work examines the predictions for what will be seen inside of the 0.25 AU (54 solar radii) where Parker Solar Probe will take measurements and lays the groundwork for disentangling the expansion and collisional effects. In addition, methods of thermal plasma data analysis to determine the stability of the plasma in the Parker Solar Probe measurements will be discussed.

  12. Variation of the solar wind velocity following solar flares

    International Nuclear Information System (INIS)

    Huang, Y.; Lee, Y.

    1975-01-01

    By use of the superposed epoch method, changes in the solar wind velocity following solar flares have been investigated by using the solar wind velocity data obtained by Pioneer 6 and 7 and Vela 3, 4, and 5 satellites. A significant increase of the solar wind velocity has been found on the second day following importance 3 solar flares and on the third day following importance 2 solar flares. No significant increase of the solar wind velocity has been found for limb flares. (auth)

  13. Large-scale wind energy and birds in Friesland: A survey of the possible hindrance for birds of the project Windstreek: Environmental Effect Report Windstreek, Base report A

    International Nuclear Information System (INIS)

    Van den Bergh, L.M.J.; Spaans, A.L.

    1994-01-01

    For several alternative sites in the Dutch province Friesland, where it is planned to install 500 kW and 1 MW wind turbines on a large scale (the Windstreek project), the possible hindrance for breeding birds, stopping birds and migratory birds has been investigated. First an overview is given of basic data from the literature and experts in the field with regard to the possible hindrances for birds and the situation of the birds in the areas considered. Next, several criteria are used to determine which locations are the most suitable sites for placing the wind turbines. For the 500 kW wind turbines (worst case) the suitability differs strongly per site. The variation is the largest for the option of decentralized sites. Realization of 200 MW large-scale generated wind power is the least unfavourable option, regarding the effects on birds, by means of decentralized sites. The super-structure option Afsluitdijk-Waddenkust and the Project Memorandum alternative are for that matter the least favourable options. The combined alternative and the super-structure Middelzeetrechter take the in-between position. The 1MW variants of the alternatives score better than the similar 500 kW options. The hindrance for birds can be reduced further by applying two-bladed rotors instead of three-bladed rotors and to adjust the site. 20 figs., 9 tabs., 2 appendices, 42 refs

  14. Real-time impact of power balancing on power system operation with large scale integration of wind power

    DEFF Research Database (Denmark)

    Basit, Abdul; Hansen, Anca Daniela; Sørensen, Poul Ejnar

    2017-01-01

    Highly wind power integrated power system requires continuous active power regulation to tackle the power imbalances resulting from the wind power forecast errors. The active power balance is maintained in real-time with the automatic generation control and also from the control room, where...... power system model. The power system model takes the hour-ahead regulating power plan from power balancing model and the generation and power exchange capacities for the year 2020 into account. The real-time impact of power balancing in a highly wind power integrated power system is assessed...

  15. Gap Flows through Idealized Topography. Part I: Forcing by Large-Scale Winds in the Nonrotating Limit.

    Science.gov (United States)

    Gabersek, Sasa.; Durran, Dale R.

    2004-12-01

    Gap winds produced by a uniform airstream flowing over an isolated flat-top ridge cut by a straight narrow gap are investigated by numerical simulation. On the scale of the entire barrier, the proportion of the oncoming flow that passes through the gap is relatively independent of the nondimensional mountain height , even over that range of for which there is the previously documented transition from a “flow over the ridge” regime to a “flow around” regime.The kinematics and dynamics of the gap flow itself were investigated by examining mass and momentum budgets for control volumes at the entrance, central, and exit regions of the gap. These analyses suggest three basic behaviors: the linear regime (small ) in which there is essentially no enhancement of the gap flow; the mountain wave regime ( 1.5) in which vertical mass and momentum fluxes play a crucial role in creating very strong winds near the exit of the gap; and the upstream-blocking regime ( 5) in which lateral convergence generates the strongest winds near the entrance of the gap.Trajectory analysis of the flow in the strongest events, the mountain wave events, confirms the importance of net subsidence in creating high wind speeds. Neglect of vertical motion in applications of Bernoulli's equation to gap flows is shown to lead to unreasonable wind speed predictions whenever the temperature at the gap exit exceeds that at the gap entrance. The distribution of the Bernoulli function on an isentropic surface shows a correspondence between regions of high Bernoulli function and high wind speeds in the gap-exit jet similar to that previously documented for shallow-water flow.

  16. Geometry of solar corona expansion and solar wind parameters

    International Nuclear Information System (INIS)

    Krajnev, M.B.

    1980-01-01

    The character of the parameter chanqe of solar wind plasma in the region of the Earth orbit is studied. The main regularities in the parametep behaviour of solar wind (plasma velocity and density) are qualitatively explained in the framework of a model according to which solar corona expansion stronqly differs from radial expansion, that is: the solar wind current lines are focused towards helioequator during the period of low solar activity with gradual transfer to radial expansion during the years of high solar activity. It is shown that the geometry of the solar wind current tubes and its change with the solar activity cycle can not serve an explanation of the observed change of the solar wind parameters

  17. Round-the-year security analysis with bottleneck ranking for interconnected power systems with large-scale wind power

    NARCIS (Netherlands)

    Ciupuliga, A.R.; Gibescu, M.; Pelgrum, E.; Jacobs, P.G.H.; Jansen, C.P.J.; Kling, W.L.

    2010-01-01

    The ongoing liberalization process in Europe together with the growing penetration of renewable energy sources (RES), e.g. wind power, require an internationally oriented transmission planning approach that considers the increased uncertainties in terms of trade, location of generation and output of

  18. Barriers to renewable energy development: A case study of large-scale wind energy in Saskatchewan, Canada

    International Nuclear Information System (INIS)

    Richards, Garrett; Noble, Bram; Belcher, Ken

    2012-01-01

    Renewable energy is receiving increased attention as a viable alternative to non-renewable electrical generation, however, meeting global energy demands will require a more ambitious renewable energy program than is currently the case. There have been several reviews of potential technological, economic, social, or public barriers and solutions to renewable energy investment. Although important, there is also need for multi-dimensional analyses of these barriers and identification of the most significant underlying barriers if viable solutions are to be developed. In this paper we apply a theoretical framework to examine stakeholder's perceptions and understanding of the barriers to wind energy development in Saskatchewan, Canada. We identify and examine the most significant underlying barriers to investment in renewable energy and the interactions between those barriers. Results show a number of perceived barriers to wind energy investment, however, these barriers can be explained in large part by knowledge barriers, if not disagreement over whether the current level of investment in wind energy is sufficient. We show that barriers to renewable energy cannot be explained solely by technological, social, political, or economic factors in isolation, and that a multi-dimensional approach, identifying and explaining the underlying sources of these barriers, is necessary to develop viable solutions. - Highlights: ► Meeting future wind energy objectives requires an ambitious investment program. ► A framework is applied to identify and explain perceived barriers to wind energy. ► Stakeholders perceived technological and political barriers as the most significant. ► These could be explained by knowledge barriers and complacency with the status quo. ► Even with additional investment these underlying barriers will constrain progress.

  19. The transport sectors potential contribution to the flexibility in the power sector required by large-scale wind power integration

    DEFF Research Database (Denmark)

    Nørgård, Per Bromand; Lund, H.; Mathiesen, B.V.

    2007-01-01

    -scale integration of renewable energy in the power system – in specific wind power. In the plan, 20 % of the road transport is based on electricity and 20 % on bio- fuels. This, together with other initiatives allows for up to 55-60 % wind power penetration in the power system. A fleet of 0.5 mio electrical...... vehicles in Denmark in 2030 connected to the grid 50 % of the time represents an aggregated flexible power capacity of 1- 1.5 GW and an energy capacity of 10-150 GWh.......In 2006, the Danish Society of Engineers developed a visionary plan for the Danish energy system in 2030. The paper presents and qualifies selected part of the analyses, illustrating the transport sectors potential to contribute to the flexibility in the power sector, necessary for large...

  20. New grid-planning and certification approaches for the large-scale offshore-wind farm grid-connection systems

    Energy Technology Data Exchange (ETDEWEB)

    Heising, C.; Bartelt, R. [Avasition GmbH, Dortmund (Germany); Zadeh, M. Koochack; Lebioda, T.J.; Jung, J. [TenneT Offshore GmbH, Bayreuth (Germany)

    2012-07-01

    Stable operation of the offshore-wind farms (OWF) and stable grid connection under stationary and dynamic conditions are essential to achieve a stable public power supply. To reach this aim, adequate grid-planning and certification approaches are a major advantage. Within this paper, the fundamental characteristics of the offshore-wind farms and their grid-connection systems are given. The main goal of this research project is to study the stability of the offshore grid especially in terms of subharmonic stability for the likely future extension stage of the offshore grids i.e. having parallel connection of two or more HVDC links and for certain operating scenarios e.g. overload scenario. The current requirements according to the grid code are not the focus of this research project. The goal is to study and define potential additional grid code requirements, simulations, tests and grid planning methods for the future. (orig.)

  1. 77 FR 61597 - Avalon Wind, LLC; Avalon Wind 2, LLC; Catalina Solar, LLC; Catalina Solar 2, LLC; Pacific Wind...

    Science.gov (United States)

    2012-10-10

    ... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. EL12-109-000] Avalon Wind, LLC; Avalon Wind 2, LLC; Catalina Solar, LLC; Catalina Solar 2, LLC; Pacific Wind Lessee, LLC; Pacific Wind 2, LLC; Valentine Solar, LLC; EDF Renewable Development, Inc.; Notice of Petition for Declaratory...

  2. Wind power installations in Switzerland - Checklist for investors in large-scale installations; Windkraftanlagen in der Schweiz. Checkliste fuer Investoren von Grossanlagen

    Energy Technology Data Exchange (ETDEWEB)

    Ott, W.; Kaufmann, Y.; Steiner, P. [Econcept AG, Zuerich (Switzerland); Gilgen, K.; Sartoris, A. [IRAP-HSR, Institut fuer Raumentwicklung an der Hochschule fuer Technik Rapperswil, Rapperswil (Switzerland)

    2008-07-01

    This report published by the Swiss Federal Office of Energy (SFOE) takes a look at a checklist for investors in large-scale wind-power installations. The authors state that the same questions are often posed in the course of the planning and realisation of wind turbine installations. This document presents a checklist that will help achieve the following goals: Tackling the steps involved in the planning and implementation phases, increasing planning security, systematic implementation in order to reduce risks for investors and to shorten time-scales as well as the reduction of costs. Further, participative processes can be optimised by using comprehensively prepared information in order to reduce the risk of objections during project approval. The structure of the check-list is described and discussed.

  3. Wind power installations in Switzerland - Checklist for investors in large-scale installations; Eoliennes en Suisse. Liste de controle pour investisseurs de grandes installations

    Energy Technology Data Exchange (ETDEWEB)

    Ott, W.; Kaufmann, Y.; Steiner, P. [Econcept AG, Zuerich (Switzerland); Gilgen, K.; Sartoris, A. [IRAP-HSR, Institut fuer Raumentwicklung an der Hochschule fuer Technik Rapperswil, Rapperswil (Switzerland)

    2008-07-01

    This report published by the Swiss Federal Office of Energy (SFOE) takes a look at a checklist for investors in large-scale wind-power installations. The authors state that the same questions are often posed in the course of the planning and realisation of wind turbine installations. This document presents a checklist that will help achieve the following goals: Tackling the steps involved in the planning and implementation phases, increasing planning security, systematic implementation in order to reduce risks for investors and to shorten time-scales as well as the reduction of costs. Further, participative processes can be optimised by using comprehensively prepared information in order to reduce the risk of objections during project approval. The structure of the check-list is described and discussed.

  4. Distributed Wind Cost Reduction: Learning from Solar

    Energy Technology Data Exchange (ETDEWEB)

    Tegen, Suzanne

    2016-02-23

    The distributed wind energy industry can learn several lessons from the solar industry regarding reducing soft costs. Suzanne Tegen presented this overview at the 2016 Distributed Wind Energy Association Business Conference in Washington, D.C., on February 23, 2016.

  5. Astrospheres and Solar-like Stellar Winds

    Directory of Open Access Journals (Sweden)

    Wood Brian E.

    2004-07-01

    Full Text Available Stellar analogs for the solar wind have proven to be frustratingly difficult to detect directly. However, these stellar winds can be studied indirectly by observing the interaction regions carved out by the collisions between these winds and the interstellar medium (ISM. These interaction regions are called "astrospheres", analogous to the "heliosphere" surrounding the Sun. The heliosphere and astrospheres contain a population of hydrogen heated by charge exchange processes that can produce enough H I Ly alpha absorption to be detectable in UV spectra of nearby stars from the Hubble Space Telescope (HST. The amount of astrospheric absorption is a diagnostic for the strength of the stellar wind, so these observations have provided the first measurements of solar-like stellar winds. Results from these stellar wind studies and their implications for our understanding of the solar wind are reviewed here. Of particular interest are results concerning the past history of the solar wind and its impact on planetary atmospheres.

  6. Solar Wind Earth Exchange Project (SWEEP)

    Science.gov (United States)

    2016-10-28

    highly charged ions of the solar wind. The main challenge in predicting the resultant photon flux in the X-ray energy bands is due to the...Newton, an X-ray astronomical observatory. We use OMNI solar wind conditions, heavy ion composition data from ACE, the Hodges neutral hydrogen model...of SWEEP was to compare theoretical models of X-ray emission in the terrestrial magnetosphere caused by the Solar Wind Charge Exchange

  7. The Large-scale Coronal Structure of the 2017 August 21 Great American Eclipse: An Assessment of Solar Surface Flux Transport Model Enabled Predictions and Observations

    Science.gov (United States)

    Nandy, Dibyendu; Bhowmik, Prantika; Yeates, Anthony R.; Panda, Suman; Tarafder, Rajashik; Dash, Soumyaranjan

    2018-01-01

    On 2017 August 21, a total solar eclipse swept across the contiguous United States, providing excellent opportunities for diagnostics of the Sun’s corona. The Sun’s coronal structure is notoriously difficult to observe except during solar eclipses; thus, theoretical models must be relied upon for inferring the underlying magnetic structure of the Sun’s outer atmosphere. These models are necessary for understanding the role of magnetic fields in the heating of the corona to a million degrees and the generation of severe space weather. Here we present a methodology for predicting the structure of the coronal field based on model forward runs of a solar surface flux transport model, whose predicted surface field is utilized to extrapolate future coronal magnetic field structures. This prescription was applied to the 2017 August 21 solar eclipse. A post-eclipse analysis shows good agreement between model simulated and observed coronal structures and their locations on the limb. We demonstrate that slow changes in the Sun’s surface magnetic field distribution driven by long-term flux emergence and its evolution governs large-scale coronal structures with a (plausibly cycle-phase dependent) dynamical memory timescale on the order of a few solar rotations, opening up the possibility for large-scale, global corona predictions at least a month in advance.

  8. Large-Scale Uncertainty and Error Analysis for Time-dependent Fluid/Structure Interactions in Wind Turbine Applications

    Energy Technology Data Exchange (ETDEWEB)

    Alonso, Juan J. [Stanford University; Iaccarino, Gianluca [Stanford University

    2013-08-25

    solution to the long-time integration problem of spectral chaos approaches; 4. A rigorous methodology to account for aleatory and epistemic uncertainties, to emphasize the most important variables via dimension reduction and dimension-adaptive refinement, and to support fusion with experimental data using Bayesian inference; 5. The application of novel methodologies to time-dependent reliability studies in wind turbine applications including a number of efforts relating to the uncertainty quantification in vertical-axis wind turbine applications. In this report, we summarize all accomplishments in the project (during the time period specified) focusing on advances in UQ algorithms and deployment efforts to the wind turbine application area. Detailed publications in each of these areas have also been completed and are available from the respective conference proceedings and journals as detailed in a later section.

  9. Results of IEA SHC Task 45: Large Scale Solar Heating and Cooling Systems. Subtask A: “Collectors and Collector Loop”

    DEFF Research Database (Denmark)

    Bava, Federico; Nielsen, Jan Erik; Knabl, Samuel

    2016-01-01

    . Within this project, subtask A had the more specific objectives of investigating ways to evaluate the influence that different operating conditions can have on the collector performance, assure proper and safe installation of large solar collector fields, and guarantee their performance and yearly energy......The IEA SHC Task 45 Large Scale Solar Heating and Cooling Systems, carried out between January 2011 and December 2014, had the main objective to assist in the development of a strong and sustainable market of large solar heating systems by focusing on high performance and reliability of systems...... output. The results of the different investigations are presented, with a particular focus on how different parameters such as tilt, flow rate and fluid type, can affect the collector efficiency. Other presented results include methods to guarantee and check the thermal performance of a solar collector...

  10. Simulation of the large-scale offshore-wind farms including HVDC-grid connections using the simulation tool VIAvento

    Energy Technology Data Exchange (ETDEWEB)

    Bartelt, R.; Heising, C.; Ni, B. [Avasition GmbH, Dortmund (Germany); Zadeh, M. Koochack; Lebioda, T.J.; Jung, J. [TenneT Offshore GmbH, Bayreuth (Germany)

    2012-07-01

    Within the framework of a research project the stability of the offshore grid especially in terms of sub-harmonic stability for the likely future extension stage of the offshore grids i.e. having parallel connection of two or more HVDC links and for certain operating scenarios e.g. overload scenario will be investigated. For this purpose, a comprehensive scenario-based assessment in time domain is unavoidable. Within this paper, the simulation tool VIAvento is briefly presented which allows for these comprehensive time-domain simulations taking the special characteristics of power-electronic assets into account. The core maxims of VIAvento are presented. Afterwards, the capability of VIAvento is demonstrated with simulation results of two wind farms linked via a HVDC grid connection system (160 converters and two HVDC stations in modular multilevel converter topology). (orig.)

  11. NEMO 2 - Be aware: Wind and solar are coming

    Energy Technology Data Exchange (ETDEWEB)

    Lund, P. [Helsinki Univ. of Technology, Otaniemi (Finland)

    1996-12-31

    Finnish research and development is well placed with respect to new renewable energy technologies in that there exists considerable expertise in specialized areas. For example, over 20 % of all power transmission equipment and generators used in wind energy systems world-wide are manufactured in Finland, while advanced instruments for monitoring wind speed are also highly regarded internationally. Moreover, unique wind technology for complex windy and freezing conditions have been developed. Finland has a 10 % share in the European photovoltaic market, and has competitive advantages in photovoltaic systems and applications, thin film solar cells, and automated electronic controlling systems. A unique solar energy storage system based on hydrogen technology demonstrates skills on overcoming the summer-winter syndrome of large-scale solar energy utilization. The annual turnover of the Finnish industries on solar and wind energy has increased from 5 million ECU in 1988 to almost 50 million ECU in 1996. The national R and D and D from 1988 onwards has played an important role in this context. Most of the research and development into new and renewable energy technologies in Finland has been carried out through the Advanced New Energy Systems and Technologies Research Programme (NEMO2) of Tekes

  12. Air emissions due to wind and solar power.

    Science.gov (United States)

    Katzenstein, Warren; Apt, Jay

    2009-01-15

    Renewables portfolio standards (RPS) encourage large-scale deployment of wind and solar electric power. Their power output varies rapidly, even when several sites are added together. In many locations, natural gas generators are the lowest cost resource available to compensate for this variability, and must ramp up and down quickly to keep the grid stable, affecting their emissions of NOx and CO2. We model a wind or solar photovoltaic plus gas system using measured 1-min time-resolved emissions and heat rate data from two types of natural gas generators, and power data from four wind plants and one solar plant. Over a wide range of renewable penetration, we find CO2 emissions achieve approximately 80% of the emissions reductions expected if the power fluctuations caused no additional emissions. Using steam injection, gas generators achieve only 30-50% of expected NOx emissions reductions, and with dry control NOx emissions increase substantially. We quantify the interaction between state RPSs and NOx constraints, finding that states with substantial RPSs could see significant upward pressure on NOx permit prices, if the gas turbines we modeled are representative of the plants used to mitigate wind and solar power variability.

  13. FY 1998 Report on development of large-scale wind power generation systems. Part 1. Operational research on large-scale wind power generation systems; 1998 nendo ogata furyoku hatsuden system kaihatsu seika hokokusho. 1. Ogata furyoku hatsuden system no unten kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The research and development project is implemented for large-scale wind power generation systems, and the FY 1998 results are reported. In the FY 1998, a slip property variable generator is actually mounted on the wind power generator, to conduct various types of demonstration tests. The reliability validation tests include microstructure examinations, fatigue tests and fatigue strength tests to predict residual strength in the blade. It is confirmed that the blade has a sufficient residual strength. The performance validation tests include continuous measurement of power outputs and wind velocities, and analysis of the output fluctuations. The power output performance during winter when the west wind prevails is higher than designed. In the tests for evaluating the characteristics of the system on which a slip property variable generator is mounted, the output smoothing effect is confirmed in a range beyond the rated output. The wind power generation system is continuously operated, to accumulate the operational data for, e.g., capacity factor, operating time rate, and system failure status. The FY 1998 results are 920,000kWh as the output and 21% as capacity factor. The other items investigate include aerodynamic noise reduction countermeasures, fatigue life of the wind turbine blades, economics of wind power generation, and dismantling and reuse of the wind turbines. (NEDO)

  14. Implementation of a large-scale solar photovoltaic system at a higher education institution in Illinois, USA

    Directory of Open Access Journals (Sweden)

    Jin H. Jo

    2017-01-01

    Full Text Available Solar energy has several environmental, economic, and educational benefits for college campuses, but it is difficult for state schools to find funding for these projects. This study shows that a solar photovoltaic (PV system on Illinois State University’s (ISU campus is technically and financially feasible. While there have been several solar feasibility studies of higher education institutions in USA, there has been a lack of in depth financial analysis. We conducted solar site assessments on five potential locations on campus, used a solar energy performance model to analyze the technical feasibility of each location, and performed a financial assessment using a professional PV financial modeling tool to compare different financing options. Our results show that three sites on campus can be used to develop a combined solar PV system of one megawatt. Both direct and third-party ownership models are financially feasible for this combined system. Our findings can be replicable as a case study for future solar PV system development on college campuses.

  15. Ensemble downscaling in coupled solar wind-magnetosphere modeling for space weather forecasting.

    Science.gov (United States)

    Owens, M J; Horbury, T S; Wicks, R T; McGregor, S L; Savani, N P; Xiong, M

    2014-06-01

    Advanced forecasting of space weather requires simulation of the whole Sun-to-Earth system, which necessitates driving magnetospheric models with the outputs from solar wind models. This presents a fundamental difficulty, as the magnetosphere is sensitive to both large-scale solar wind structures, which can be captured by solar wind models, and small-scale solar wind "noise," which is far below typical solar wind model resolution and results primarily from stochastic processes. Following similar approaches in terrestrial climate modeling, we propose statistical "downscaling" of solar wind model results prior to their use as input to a magnetospheric model. As magnetospheric response can be highly nonlinear, this is preferable to downscaling the results of magnetospheric modeling. To demonstrate the benefit of this approach, we first approximate solar wind model output by smoothing solar wind observations with an 8 h filter, then add small-scale structure back in through the addition of random noise with the observed spectral characteristics. Here we use a very simple parameterization of noise based upon the observed probability distribution functions of solar wind parameters, but more sophisticated methods will be developed in the future. An ensemble of results from the simple downscaling scheme are tested using a model-independent method and shown to add value to the magnetospheric forecast, both improving the best estimate and quantifying the uncertainty. We suggest a number of features desirable in an operational solar wind downscaling scheme. Solar wind models must be downscaled in order to drive magnetospheric models Ensemble downscaling is more effective than deterministic downscaling The magnetosphere responds nonlinearly to small-scale solar wind fluctuations.

  16. Solar wind radiation damage in lunar dust grains and the characteristics of the ancient solar wind

    International Nuclear Information System (INIS)

    Borg, J.; Chaumont, J.

    1980-01-01

    Current understanding of the exposure history of lunar dust grains to the ancient solar wind is reviewed, the work being based mostly on a Monte Carlo statistical code, describing the 'gardening' effects of the meteorite bombardment in the lunar regolith, and on analytical models, yielding the lifetimes of the grains against various types of destruction processes. Families of lunar dust grains are identified, and evidence is presented showing that lunar dust grains were not partially shielded from solar wind ions. Results of solar wind simulation experiments are used to interpret the thickness distribution of the amorphous coatings of solar wind radiation-damaged material observed on 1-micron lunar dust grains. It is argued that such distributions reflect the speed distribution of the ancient solar wind as averaged over periods of approximately 5000 years in duration, and that the ancient solar wind is less energetic than the present day solar wind

  17. Limitation of solar energy and wind energy

    International Nuclear Information System (INIS)

    White, R. S.

    2008-01-01

    Wind turbines, solar energy collectors and photovoltaic cells have been popular sources of electricity since the oil crisis in the late seventies, and they are increasingly favored by many scientists and much of the public as methods for reducing global warming. The older wind farms in California are outdated. New wind turbines have not followed, primarily because of competition from lower-cost natural gas. The Times urges increased federal and state subsidies for the wind and solar industries. The primary reason that wind and solar energies have not made inroads in the past, and will never supply more than a few percentage points of the world's electrical energy, is their unpredictable variations in time and their constant need for back-ups. The only non-carbon-dioxide-emitting generator capable of backing up wind and solar energy and replacing coal and gas generators is nuclear fission. Nuclear power may be the practical solution to global warming, after all.

  18. Application of lightweight materials in structure concept design of large-scale solar energy unmanned aerial vehicle

    Science.gov (United States)

    Zhang, Wei; Lv, Shengli; Guan, XiQi

    2017-09-01

    Carbon fiber composites and film materials can be effectively used in light aircraft structures, especially for solar unmanned aerial vehicles. The use of light materials can reduce the weight of the aircraft, but also can effectively improve the aircraft's strength and stiffness. The structure of the large aspect ratio solar energy UAV was analyzed in detail, taking Solar-impulse solar aircraft as an example. The solar energy UAV has a wing aspect ratio greater than 20, and the detailed digital model of the wing structure including beam, ribs and skin was built, also the Finite Element Method was applied to analyze the static and dynamic performance of the structure. The upper skin of the wing is covered with silicon solar cells, while the lower skin is light and transparent film. The single beam truss form of carbon fiber lightweight material is used in the wing structure. The wing beam is a box beam with rectangular cross sections. The box beam connected the front parts and after parts of the ribs together. The fuselage of the aircraft was built by space truss structure. According to the static and dynamic analysis with Finite Element method, it was found that the aircraft has a small wingtip deflection relative to the wingspan in the level flight state. The first natural frequency of the wing structure is pretty low, which is closed to the gust load.

  19. WSA-Enlil Solar Wind Prediction

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — WSA-Enlil is a large-scale, physics-based prediction model of the heliosphere, used by the Space Weather Forecast Office to provide 1-4 day advance warning of solar...

  20. Integration of 18 GW Wind Energy into the Energy Market. Practical Experiences in Germany. Experiences with large-scale integration of wind power into power systems

    International Nuclear Information System (INIS)

    Krauss, C.; Graeber, B.; Lange, M.; Focken, U.

    2006-01-01

    This work describes the integration of 18 GW of wind power into the German energy market. The focus lies on reporting practical experiences concerning the use of wind energy in Germany within the framework of the renewable energy act (EEG) and the immediate exchange of wind power between the four German grid control areas. Due to the EEG the demand for monitoring the current energy production of wind farms and for short-term predictions of wind power has significantly increased and opened a broader market for these services. In particular for trading on the intraday market ultra short term predictions in the time frame of 1 to 10 hours require different approaches than usual dayahead predictions because the large numerical meteorological models are not sufficiently optimized for very short time horizons. It is shown that for this range a combination of a statistical and a deterministic model leads to significant improvements and stable results as it unites the characteristics of the current wind power production with the synoptic-scale meteorological situation. The possible concepts of balancing the remaining differences between predicted and actual wind power generation are discussed. As wind power prediction errors and load forecasting errors are uncorrelated, benefits can arise from a combined balancing. Finally practical experiences with wind power fluctuations and large forecast errors are presented.

  1. Large scale wind energy conversion system (WECS) design and installation as affected by site wind energy characteristics, grouping arrangement, and social acceptance. [Sweden

    Energy Technology Data Exchange (ETDEWEB)

    Ljungstrom, O

    1977-01-01

    The Swedish wind energy prospecting program includes special features of determining site wind characteristics and design of WECS group stations, which are described briefly, such as applications of normalized WDP-Wind Duration Profiles, WHP-Wind Height Profiles and how these are affected by site location and terrain roughness. A set of WEC-Wind Energy Classes (1 to 4) is introduced as an aid in territorial wind energy surveys. A survey of Sweden's WEPA-Wind Energy Producing Areas--with associated distribution over WEC-2-4 is presented. In order to determine the corresponding wind energy production capacity, the problem of optimizing WECS group station design for cost effective energy production per land usage must be solved. Here, the effects of WECS unit size and spacing on specific annual energy production, TWh/km/sup 2/, yr, are analyzed with the use of specific group station models in the 40 to 100 MW capacity range, applying WECS unit sizes 50kW, 1 MW and 5 MW, studying the energy balance for typical group stations. By applying the specific productivity data for 1 to 5 MW systems, a survey of the WEPA-associated wind energy production capacity in Sweden is presented.

  2. Solar energy system with wind vane

    Science.gov (United States)

    Grip, Robert E

    2015-11-03

    A solar energy system including a pedestal defining a longitudinal axis, a frame that is supported by the pedestal and that is rotateable relative to the pedestal about the longitudinal axis, the frame including at least one solar device, and a wind vane operatively connected to the frame to urge the frame relative to the pedestal about the longitudinal axis in response to wind acting on the wind vane.

  3. Solar winds along curved magnetic field lines

    OpenAIRE

    Li, Bo; Xia, Li-Dong; Chen, Yao

    2011-01-01

    Both remote-sensing measurements using the interplanetary scintillation (IPS) technique and in situ measurements by the Ulysses spacecraft show a bimodal structure for the solar wind at solar minimum conditions. At present what makes the fast wind fast and the slow wind slow still remains to be answered. While a robust empirical correlation exists between the coronal expansion rate $f_c$ of the flow tubes and the speeds $v$ measured in situ, further data analysis suggests that $v$ depends on ...

  4. A Deeper Understanding of Stability in the Solar Wind: Applying Nyquist's Instability Criterion to Wind Faraday Cup Data

    Science.gov (United States)

    Alterman, B. L.; Klein, K. G.; Verscharen, D.; Stevens, M. L.; Kasper, J. C.

    2017-12-01

    Long duration, in situ data sets enable large-scale statistical analysis of free-energy-driven instabilities in the solar wind. The plasma beta and temperature anisotropy plane provides a well-defined parameter space in which a single-fluid plasma's stability can be represented. Because this reduced parameter space can only represent instability thresholds due to the free energy of one ion species - typically the bulk protons - the true impact of instabilities on the solar wind is under estimated. Nyquist's instability criterion allows us to systematically account for other sources of free energy including beams, drifts, and additional temperature anisotropies. Utilizing over 20 years of Wind Faraday cup and magnetic field observations, we have resolved the bulk parameters for three ion populations: the bulk protons, beam protons, and alpha particles. Applying Nyquist's criterion, we calculate the number of linearly growing modes supported by each spectrum and provide a more nuanced consideration of solar wind stability. Using collisional age measurements, we predict the stability of the solar wind close to the sun. Accounting for the free-energy from the three most common ion populations in the solar wind, our approach provides a more complete characterization of solar wind stability.

  5. Application of Satellite Solar-Induced Chlorophyll Fluorescence to Understanding Large-Scale Variations in Vegetation Phenology and Function Over Northern High Latitude Forests

    Science.gov (United States)

    Jeong, Su-Jong; Schimel, David; Frankenberg, Christian; Drewry, Darren T.; Fisher, Joshua B.; Verma, Manish; Berry, Joseph A.; Lee, Jung-Eun; Joiner, Joanna

    2016-01-01

    This study evaluates the large-scale seasonal phenology and physiology of vegetation over northern high latitude forests (40 deg - 55 deg N) during spring and fall by using remote sensing of solar-induced chlorophyll fluorescence (SIF), normalized difference vegetation index (NDVI) and observation-based estimate of gross primary productivity (GPP) from 2009 to 2011. Based on GPP phenology estimation in GPP, the growing season determined by SIF time-series is shorter in length than the growing season length determined solely using NDVI. This is mainly due to the extended period of high NDVI values, as compared to SIF, by about 46 days (+/-11 days), indicating a large-scale seasonal decoupling of physiological activity and changes in greenness in the fall. In addition to phenological timing, mean seasonal NDVI and SIF have different responses to temperature changes throughout the growing season. We observed that both NDVI and SIF linearly increased with temperature increases throughout the spring. However, in the fall, although NDVI linearly responded to temperature increases, SIF and GPP did not linearly increase with temperature increases, implying a seasonal hysteresis of SIF and GPP in response to temperature changes across boreal ecosystems throughout their growing season. Seasonal hysteresis of vegetation at large-scales is consistent with the known phenomena that light limits boreal forest ecosystem productivity in the fall. Our results suggest that continuing measurements from satellite remote sensing of both SIF and NDVI can help to understand the differences between, and information carried by, seasonal variations vegetation structure and greenness and physiology at large-scales across the critical boreal regions.

  6. Solar wind classification from a machine learning perspective

    Science.gov (United States)

    Heidrich-Meisner, V.; Wimmer-Schweingruber, R. F.

    2017-12-01

    It is a very well known fact that the ubiquitous solar wind comes in at least two varieties, the slow solar wind and the coronal hole wind. The simplified view of two solar wind types has been frequently challenged. Existing solar wind categorization schemes rely mainly on different combinations of the solar wind proton speed, the O and C charge state ratios, the Alfvén speed, the expected proton temperature and the specific proton entropy. In available solar wind classification schemes, solar wind from stream interaction regimes is often considered either as coronal hole wind or slow solar wind, although their plasma properties are different compared to "pure" coronal hole or slow solar wind. As shown in Neugebauer et al. (2016), even if only two solar wind types are assumed, available solar wind categorization schemes differ considerably for intermediate solar wind speeds. Thus, the decision boundary between the coronal hole and the slow solar wind is so far not well defined.In this situation, a machine learning approach to solar wind classification can provide an additional perspective.We apply a well-known machine learning method, k-means, to the task of solar wind classification in order to answer the following questions: (1) How many solar wind types can reliably be identified in our data set comprised of ten years of solar wind observations from the Advanced Composition Explorer (ACE)? (2) Which combinations of solar wind parameters are particularly useful for solar wind classification?Potential subtypes of slow solar wind are of particular interest because they can provide hints of respective different source regions or release mechanisms of slow solar wind.

  7. Large-scale integration of wind power into power systems as well as on transmission networks for offshore wind power plants. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    Betancourt, Uta; Ackermann, Thomas (eds.)

    2013-11-01

    This proceedings contains contributions to the followings main topics: Grid integration experiences; Flexibility and economics of integration; Voltage control issues; Offshore wind power plants; Forecasting; Grid code issues; HVDC connection issues; Frequency control issues; National grid's perspective; Power system balancing; Power system issues; New grid and generators issues; Flexibility with storage and demand side management; AC connected offshore wind power plants; Economic and market issues; Modelling issues; Offshore grid issues.

  8. Large scale electrolysers

    International Nuclear Information System (INIS)

    B Bello; M Junker

    2006-01-01

    Hydrogen production by water electrolysis represents nearly 4 % of the world hydrogen production. Future development of hydrogen vehicles will require large quantities of hydrogen. Installation of large scale hydrogen production plants will be needed. In this context, development of low cost large scale electrolysers that could use 'clean power' seems necessary. ALPHEA HYDROGEN, an European network and center of expertise on hydrogen and fuel cells, has performed for its members a study in 2005 to evaluate the potential of large scale electrolysers to produce hydrogen in the future. The different electrolysis technologies were compared. Then, a state of art of the electrolysis modules currently available was made. A review of the large scale electrolysis plants that have been installed in the world was also realized. The main projects related to large scale electrolysis were also listed. Economy of large scale electrolysers has been discussed. The influence of energy prices on the hydrogen production cost by large scale electrolysis was evaluated. (authors)

  9. Corotating pressure waves without streams in the solar wind

    International Nuclear Information System (INIS)

    Burlaga, L.F.

    1983-01-01

    Voyager 1 and 2 magnetic field and plasma data are presented which demonstrate the existence of large scale, corotating, non-linear pressure waves between 2 AU and 4 AU that are not accompanied by fast streams. The pressure waves are presumed to be generated by corotating streams near the Sun. For two of the three pressure waves that are discussed, the absence of a stream is probably a real, physical effect, viz., a consequence of deceleration of the stream by the associated compression wave. For the third pressure wave, the apparent absence of a stream may be a geometrical effect it is likely that the stream was at latitudes just above those of the spacecraft, while the associated shocks and compression wave extended over a broader range of latitudes so that they could be observed by the spacecraft. It is suggested that the development of large-scale non-linear pressure waves at the expense of the kinetic energy of streams produces a qualitative change in the solar wind in the outer heliosphere. Within a few AU the quasi-stationary solar wind structure is determined by corotating streams whose structure is determined by the boundary conditions near the Sun

  10. Solar cycle variation of cosmic ray intensity along with interplanetary and solar wind plasma parameters

    International Nuclear Information System (INIS)

    Mishra, R.K.; Tiwari, S.; Agarwal, R.

    2008-01-01

    Galactic cosmic rays are modulated at their propagation in the heliosphere by the effect of the large-scale structure of the interplanetary medium. A comparison of the variations in the cosmic ray intensity data obtained by neutron monitoring stations with those in geomagnetic disturbance, solar wind velocity (V), interplanetary magnetic field (B), and their product (V , B) near the Earth for the period 1964-2004 has been presented so as to establish a possible correlation between them. We used the hourly averaged cosmic ray counts observed with the neutron monitor in Moscow. It is noteworthy that a significant negative correlation has been observed between the interplanetary magnetic field, product (V , B) and cosmic ray intensity during the solar cycles 21 and 22. The solar wind velocity has a good positive correlation with cosmic ray intensity during solar cycle 21, whereas it shows a weak correlation during cycles 20, 22 and 23. The interplanetary magnetic field shows a weak negative correlation with cosmic rays for solar cycle 20, and a good anti-correlation for solar cycles 21-23 with the cosmic ray intensity, which, in turn, shows a good positive correlation with disturbance time index (Dst) during solar cycles 21 and 22, and a weak correlation for cycles 20 and 23. (Authors)

  11. Ultrasonic Spray-Coating of Large-Scale TiO2 Compact Layer for Efficient Flexible Perovskite Solar Cells

    Directory of Open Access Journals (Sweden)

    Peng Zhou

    2017-02-01

    Full Text Available Flexible electronics have attracted great interest in applications for the wearable devices. Flexible solar cells can be integrated into the flexible electronics as the power source for the wearable devices. In this work, an ultrasonic spray-coating method was employed to deposit TiO2 nanoparticles on polymer substrates for the fabrication of flexible perovskite solar cells (PSCs. Pre-synthesized TiO2 nanoparticles were first dispersed in ethanol to prepare the precursor solutions with different concentrations (0.5 mg/mL, 1.0 mg/mL, 2.0 mg/mL and then sprayed onto the conductive substrates to produce compact TiO2 films with different thicknesses (from 30 nm to 150 nm. The effect of the different drying processes on the quality of the compact TiO2 film was studied. In order to further improve the film quality, titanium diisopropoxide bis(acetylacetonate (TAA was added into the TiO2-ethanol solution at a mole ratio of 1.0 mol % with respect to the TiO2 content. The final prepared PSC devices showed a power conversion efficiency (PCE of 14.32% based on the indium doped tin oxide coated glass (ITO-glass substrate and 10.87% on the indium doped tin oxide coated polyethylene naphthalate (ITO-PEN flexible substrate.

  12. A Generalized Equatorial Model for the Accelerating Solar Wind

    Science.gov (United States)

    Tasnim, S.; Cairns, Iver H.; Wheatland, M. S.

    2018-02-01

    A new theoretical model for the solar wind is developed that includes the wind's acceleration, conservation of angular momentum, deviations from corotation, and nonradial velocity and magnetic field components from an inner boundary (corresponding to the onset of the solar wind) to beyond 1 AU. The model uses a solution of the time-steady isothermal equation of motion to describe the acceleration and analytically predicts the Alfvénic critical radius. We fit the model to near-Earth observations of the Wind spacecraft during the solar rotation period of 1-27 August 2010. The resulting data-driven model demonstrates the existence of noncorotating, nonradial flows and fields from the inner boundary (r = rs) outward and predicts the magnetic field B = (Br,Bϕ), velocity v = (vr,vϕ), and density n(r,ϕ,t), which vary with heliocentric distance r, heliolatitude ϕ, and time t in a Sun-centered standard inertial plane. The description applies formally only in the equatorial plane. In a frame corotating with the Sun, the transformed velocity v' and a field B' are not parallel, resulting in an electric field with a component Ez' along the z axis. The resulting E'×B'=E'×B drift lies in the equatorial plane, while the ∇B and curvature drifts are out of the plane. Together these may lead to enhanced scattering/heating of sufficiently energetic particles. The model predicts that deviations δvϕ from corotation at the inner boundary are common, with δvϕ(rs,ϕs,ts) comparable to the transverse velocities due to granulation and supergranulation motions. Abrupt changes in δvϕ(rs,ϕs,ts) are interpreted in terms of converging and diverging flows at the cell boundaries and centers, respectively. Large-scale variations in the predicted angular momentum demonstrate that the solar wind can drive vorticity and turbulence from near the Sun to 1 AU and beyond.

  13. Techno-economic analysis of large-scale integration of solar power plants in the European grid

    Energy Technology Data Exchange (ETDEWEB)

    Tielens, Pieter; Ergun, Hakan; Hertem, Dirk van [Katholieke Universiteit Leuven (Belgium). Electrical Engineering Dept.

    2012-07-01

    In this paper different options to connect large solar power plants in North Africa to the European power system are compared from a transmission system investment point of view. Three different possible DC connections from Tunisia to Italy are investigated from a cost-based perspective. In the second part of the paper, the impact of the power fluctuations from CSP and PV power plants on the frequency control is examined in a qualitative manner. It is shown that the frequency response mainly depends on the amount of PV installed and the inertia present in the grid. The results of the simulations give a first estimation of the maximum amount of PV integration in the Tunisian grid without reaching certain frequency limits after a sudden power fluctuation. (orig.)

  14. Wind and solar resource data sets

    DEFF Research Database (Denmark)

    Clifton, Andrew; Hodge, Bri-Mathias; Draxl, Caroline

    2017-01-01

    The range of resource data sets spans from static cartography showing the mean annual wind speed or solar irradiance across a region to high temporal and high spatial resolution products that provide detailed information at a potential wind or solar energy facility. These data sets are used...... to support continental-scale, national, or regional renewable energy development; facilitate prospecting by developers; and enable grid integration studies. This review first provides an introduction to the wind and solar resource data sets, then provides an overview of the common methods used...... for their creation and validation. A brief history of wind and solar resource data sets is then presented, followed by areas for future research. For further resources related to this article, please visit the WIREs website....

  15. Solar and Wind Site Screening Decision Trees

    Science.gov (United States)

    EPA and NREL created a decision tree to guide state and local governments and other stakeholders through a process for screening sites for their suitability for future redevelopment with solar photovoltaic (PV) energy and wind energy.

  16. Electrostatic Solitary Waves in the Solar Wind: Evidence for Instability at Solar Wind Current Sheets

    Science.gov (United States)

    Malaspina, David M.; Newman, David L.; Wilson, Lynn Bruce; Goetz, Keith; Kellogg, Paul J.; Kerstin, Kris

    2013-01-01

    A strong spatial association between bipolar electrostatic solitary waves (ESWs) and magnetic current sheets (CSs) in the solar wind is reported here for the first time. This association requires that the plasma instabilities (e.g., Buneman, electron two stream) which generate ESWs are preferentially localized to solar wind CSs. Distributions of CS properties (including shear angle, thickness, solar wind speed, and vector magnetic field change) are examined for differences between CSs associated with ESWs and randomly chosen CSs. Possible mechanisms for producing ESW-generating instabilities at solar wind CSs are considered, including magnetic reconnection.

  17. High-latitude Conic Current Sheets in the Solar Wind

    Energy Technology Data Exchange (ETDEWEB)

    Khabarova, Olga V.; Obridko, Vladimir N.; Kharshiladze, Alexander F. [Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation of the Russian Academy of Sciences (IZMIRAN), Moscow (Russian Federation); Malova, Helmi V. [Scobeltsyn Nuclear Physics Institute of Lomonosov Moscow State University, Moscow (Russian Federation); Kislov, Roman A.; Zelenyi, Lev M. [Space Research Centre of the Polish Academy of Sciences (CBK PAN), Warsaw (Poland); Tokumaru, Munetoshi; Fujiki, Ken’ichi [Institute for Space-Earth Environmental Research, Nagoya University (Japan); Sokół, Justyna M.; Grzedzielski, Stan [Space Research Centre of the Polish Academy of Sciences (CBK), Warsaw (Poland)

    2017-02-10

    We provide observational evidence for the existence of large-scale cylindrical (or conic-like) current sheets (CCSs) at high heliolatitudes. Long-lived CCSs were detected by Ulysses during its passages over the South Solar Pole in 1994 and 2007. The characteristic scale of these tornado-like structures is several times less than a typical width of coronal holes within which the CCSs are observed. CCS crossings are characterized by a dramatic decrease in the solar wind speed and plasma beta typical for predicted profiles of CCSs. Ulysses crossed the same CCS at different heliolatitudes at 2–3 au several times in 1994, as the CCS was declined from the rotation axis and corotated with the Sun. In 2007, a CCS was detected directly over the South Pole, and its structure was strongly highlighted by the interaction with comet McNaught. Restorations of solar coronal magnetic field lines reveal the occurrence of conic-like magnetic separators over the solar poles in both 1994 and 2007. Such separators exist only during solar minima. Interplanetary scintillation data analysis confirms the presence of long-lived low-speed regions surrounded by the typical polar high-speed solar wind in solar minima. Energetic particle flux enhancements up to several MeV/ nuc are observed at edges of the CCSs. We built simple MHD models of a CCS to illustrate its key features. The CCSs may be formed as a result of nonaxiality of the solar rotation axis and magnetic axis, as predicted by the Fisk–Parker hybrid heliospheric magnetic field model in the modification of Burger and coworkers.

  18. Wind loads on solar energy roofs

    NARCIS (Netherlands)

    Geurts, C.P.W.; Bentum, C.A. van

    2007-01-01

    This paper presents an overview of the wind loads on roofs, equipped with solar energy products, so called Active Roofs. Values given in this paper have been based on wind tunnel and full scale measurements, carried out at TNO, and on an interpretation of existing rules and guidelines. The results

  19. Performance and Feasibility Analysis of a Grid Interactive Large Scale Wind/PV Hybrid System based on Smart Grid Methodology Case Study South Part – Jordan

    Directory of Open Access Journals (Sweden)

    Qais H. Alsafasfeh

    2015-02-01

    Full Text Available Most recent research on renewable energy resources main one goal to make Jordan less dependent on imported energy with locally developed and produced solar power, this paper discussed the efficient system of Wind/ PV Hybrid System to be than main power sources for south part of Jordan, the proposed hybrid system design based on Smart Grid Methodology,  the solar energy will be installed on top roof of  electricity subscribers across the Governorate of Maan, Tafila, Karak and Aqaba and the wind energy will set in one site by this way the capital cost for project will be reduced also the  simulation result show   the feasibility  is a very competitive and feasible cost . Economics analysis of a proposed renewable energy system was made using HOMER simulation and evaluation was completed with the cost per kilowatt of EDCO company, the net present cost is $2,551,676,416, the cost of energy is 0.07kWhr with a renewable fraction of 86.6 %.

  20. Three-fluid, three-dimensional magnetohydrodynamic solar wind model with eddy viscosity and turbulent resistivity

    Energy Technology Data Exchange (ETDEWEB)

    Usmanov, Arcadi V.; Matthaeus, William H. [Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States); Goldstein, Melvyn L., E-mail: arcadi.usmanov@nasa.gov [Code 672, NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2014-06-10

    We have developed a three-fluid, three-dimensional magnetohydrodynamic solar wind model that incorporates turbulence transport, eddy viscosity, turbulent resistivity, and turbulent heating. The solar wind plasma is described as a system of co-moving solar wind protons, electrons, and interstellar pickup protons, with separate energy equations for each species. Numerical steady-state solutions of Reynolds-averaged solar wind equations coupled with turbulence transport equations for turbulence energy, cross helicity, and correlation length are obtained by the time relaxation method in the corotating with the Sun frame of reference in the region from 0.3 to 100 AU (but still inside the termination shock). The model equations include the effects of electron heat conduction, Coulomb collisions, photoionization of interstellar hydrogen atoms and their charge exchange with the solar wind protons, turbulence energy generation by pickup protons, and turbulent heating of solar wind protons and electrons. The turbulence transport model is based on the Reynolds decomposition and turbulence phenomenologies that describe the conversion of fluctuation energy into heat due to a turbulent cascade. In addition to using separate energy equations for the solar wind protons and electrons, a significant improvement over our previous work is that the turbulence model now uses an eddy viscosity approximation for the Reynolds stress tensor and the mean turbulent electric field. The approximation allows the turbulence model to account for driving of turbulence by large-scale velocity gradients. Using either a dipole approximation for the solar magnetic field or synoptic solar magnetograms from the Wilcox Solar Observatory for assigning boundary conditions at the coronal base, we apply the model to study the global structure of the solar wind and its three-dimensional properties, including embedded turbulence, heating, and acceleration throughout the heliosphere. The model results are

  1. NONLINEAR FORCE-FREE FIELD EXTRAPOLATION OF A CORONAL MAGNETIC FLUX ROPE SUPPORTING A LARGE-SCALE SOLAR FILAMENT FROM A PHOTOSPHERIC VECTOR MAGNETOGRAM

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Chaowei; Wu, S. T.; Hu, Qiang [Center for Space Plasma and Aeronomic Research, The University of Alabama in Huntsville, Huntsville, AL 35899 (United States); Feng, Xueshang, E-mail: cwjiang@spaceweather.ac.cn, E-mail: wus@uah.edu, E-mail: qh0001@uah.edu, E-mail: fengx@spaceweather.ac.cn [SIGMA Weather Group, State Key Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-05-10

    Solar filaments are commonly thought to be supported in magnetic dips, in particular, in those of magnetic flux ropes (FRs). In this Letter, based on the observed photospheric vector magnetogram, we implement a nonlinear force-free field (NLFFF) extrapolation of a coronal magnetic FR that supports a large-scale intermediate filament between an active region and a weak polarity region. This result is a first, in the sense that current NLFFF extrapolations including the presence of FRs are limited to relatively small-scale filaments that are close to sunspots and along main polarity inversion lines (PILs) with strong transverse field and magnetic shear, and the existence of an FR is usually predictable. In contrast, the present filament lies along the weak-field region (photospheric field strength ≲ 100 G), where the PIL is very fragmented due to small parasitic polarities on both sides of the PIL and the transverse field has a low signal-to-noise ratio. Thus, extrapolating a large-scale FR in such a case represents a far more difficult challenge. We demonstrate that our CESE-MHD-NLFFF code is sufficient for the challenge. The numerically reproduced magnetic dips of the extrapolated FR match observations of the filament and its barbs very well, which strongly supports the FR-dip model for filaments. The filament is stably sustained because the FR is weakly twisted and strongly confined by the overlying closed arcades.

  2. ARGO-YBJ OBSERVATION OF THE LARGE-SCALE COSMIC RAY ANISOTROPY DURING THE SOLAR MINIMUM BETWEEN CYCLES 23 AND 24

    Energy Technology Data Exchange (ETDEWEB)

    Bartoli, B.; Catalanotti, S.; Piazzoli, B. D’Ettorre; Girolamo, T. Di [Dipartimento di Fisica dell’Università di Napoli “Federico II”, Complesso Universitario di Monte Sant’Angelo, via Cinthia, I-80126 Napoli (Italy); Bernardini, P.; D’Amone, A.; Mitri, I. De [Dipartimento Matematica e Fisica ”Ennio De Giorgi”, Università del Salento, via per Arnesano, I-73100 Lecce (Italy); Bi, X. J.; Cao, Z.; Chen, S. Z.; Feng, Zhaoyang; Gou, Q. B. [Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918, 100049 Beijing (China); Chen, T. L.; Danzengluobu [Tibet University, 850000 Lhasa, Xizang (China); Cui, S. W.; Gao, W. [Hebei Normal University, 050024, Shijiazhuang Hebei (China); Dai, B. Z. [Yunnan University, 2 North Cuihu Road, 650091 Kunming, Yunnan (China); Sciascio, G. Di [Istituto Nazionale di Fisica Nucleare, Sezione di Roma Tor Vergata, via della Ricerca Scientifica 1, I-00133 Roma (Italy); Feng, C. F. [Shandong University, 250100 Jinan, Shandong (China); Feng, Zhenyong, E-mail: cuisw@ihep.ac.cn [Southwest Jiaotong University, 610031 Chengdu, Sichuan (China); Collaboration: ARGO-YBJ Collaboration; and others

    2015-08-10

    This paper reports on the measurement of the large-scale anisotropy in the distribution of cosmic-ray arrival directions using the data collected by the air shower detector ARGO-YBJ from 2008 January to 2009 December, during the minimum of solar activity between cycles 23 and 24. In this period, more than 2 × 10{sup 11} showers were recorded with energies between ∼1 and 30 TeV. The observed two-dimensional distribution of cosmic rays is characterized by two wide regions of excess and deficit, respectively, both of relative intensity ∼10{sup −3} with respect to a uniform flux, superimposed on smaller size structures. The harmonic analysis shows that the large-scale cosmic-ray relative intensity as a function of R.A. can be described by the first and second terms of a Fouries series. The high event statistics allow the study of the energy dependence of the anistropy, showing that the amplitude increases with energy, with a maximum intensity at ∼10 TeV, and then decreases while the phase slowly shifts toward lower values of R.A. with increasing energy. The ARGO-YBJ data provide accurate observations over more than a decade of energy around this feature of the anisotropy spectrum.

  3. MEASUREMENT OF LARGE-SCALE SOLAR POWER PLANT BY USING IMAGES ACQUIRED BY NON-METRIC DIGITAL CAMERA ON BOARD UAV

    Directory of Open Access Journals (Sweden)

    R. Matsuoka

    2012-07-01

    Full Text Available This paper reports an experiment conducted in order to investigate the feasibility of the deformation measurement of a large-scale solar power plant on reclaimed land by using images acquired by a non-metric digital camera on board a micro unmanned aerial vehicle (UAV. It is required that a root mean squares of errors (RMSE in height measurement should be less than 26 mm that is 1/3 of the critical limit of deformation of 78 mm off the plane of a solar panel. Images utilized in the experiment have been obtained by an Olympus PEN E-P2 digital camera on board a Microdrones md4-1000 quadrocopter. The planned forward and side overlap ratios of vertical image acquisition have been 60 % and 60 % respectively. The planned flying height of the UAV has been 20 m above the ground level and the ground resolution of an image is approximately 5.0 mm by 5.0 mm. 8 control points around the experiment area are utilized for orientation. Measurement results are evaluated by the space coordinates of 220 check points which are corner points of 55 solar panels selected from 1768 solar panels in the experiment area. Two teams engage in the experiment. One carries out orientation and measurement by using 171 images following the procedure of conventional aerial photogrammetry, and the other executes those by using 126 images in the manner of close range photogrammetry. The former fails to satisfy the required accuracy, while the RMSE in height measurement by the latter is 8.7 mm that satisfies the required accuracy. From the experiment results, we conclude that the deformation measurement of a large-scale solar power plant on reclaimed land by using images acquired by a nonmetric digital camera on board a micro UAV would be feasible if points utilized in orientation and measurement have a sufficient number of bundles in good geometry and self-calibration in orientation is carried out.

  4. Nonlinear Force-free Field Extrapolation of a Coronal Magnetic Flux Rope Supporting a Large-scale Solar Filament from a Photospheric Vector Magnetogram

    Science.gov (United States)

    Jiang, Chaowei; Wu, S. T.; Feng, Xueshang; Hu, Qiang

    2014-05-01

    Solar filaments are commonly thought to be supported in magnetic dips, in particular, in those of magnetic flux ropes (FRs). In this Letter, based on the observed photospheric vector magnetogram, we implement a nonlinear force-free field (NLFFF) extrapolation of a coronal magnetic FR that supports a large-scale intermediate filament between an active region and a weak polarity region. This result is a first, in the sense that current NLFFF extrapolations including the presence of FRs are limited to relatively small-scale filaments that are close to sunspots and along main polarity inversion lines (PILs) with strong transverse field and magnetic shear, and the existence of an FR is usually predictable. In contrast, the present filament lies along the weak-field region (photospheric field strength barbs very well, which strongly supports the FR-dip model for filaments. The filament is stably sustained because the FR is weakly twisted and strongly confined by the overlying closed arcades.

  5. The Solar Wind Environment in Time

    Science.gov (United States)

    Pognan, Quentin; Garraffo, Cecilia; Cohen, Ofer; Drake, Jeremy J.

    2018-03-01

    We use magnetograms of eight solar analogs of ages 30 Myr–3.6 Gyr obtained from Zeeman Doppler Imaging and taken from the literature, together with two solar magnetograms, to drive magnetohydrodynamical wind simulations and construct an evolutionary scenario of the solar wind environment and its angular momentum loss rate. With observed magnetograms of the radial field strength as the only variant in the wind model, we find that a power-law model fitted to the derived angular momentum loss rate against time, t, results in a spin-down relation Ω ∝ t ‑0.51, for angular speed Ω, which is remarkably consistent with the well-established Skumanich law Ω ∝ t ‑0.5. We use the model wind conditions to estimate the magnetospheric standoff distances for an Earth-like test planet situated at 1 au for each of the stellar cases, and to obtain trends of minimum and maximum wind ram pressure and average ram pressure in the solar system through time. The wind ram pressure declines with time as \\overline{{P}ram}}\\propto {t}2/3, amounting to a factor of 50 or so over the present lifetime of the solar system.

  6. Wind and solar energy incentives in Iran

    International Nuclear Information System (INIS)

    Taleghani, G.; Kazemi Karegar, H.

    2006-01-01

    Incentive have yet been viewed as a means of supporting technological developments until a new technology becomes cost competitive wind based electricity is not jet generally competitive with alternate sources of electricity such as fossil fuels. This paper presents the potential for wind and solar in Iran and shows how much electric energy is now produced by renewable power plants compared to steam and gas. The importance of renewable energy effects on Iran environment and economy is also discussed and the issue of the contribution of renewable energy for producing electricity in the future will be shown. Also this paper highlights the ability of Iran to manufacture the components of the wind turbine and solar system locally, and its effect on the price of wind turbine and solar energy

  7. Inertial-Range Reconnection in Magnetohydrodynamic Turbulence and in the Solar Wind.

    Science.gov (United States)

    Lalescu, Cristian C; Shi, Yi-Kang; Eyink, Gregory L; Drivas, Theodore D; Vishniac, Ethan T; Lazarian, Alexander

    2015-07-10

    In situ spacecraft data on the solar wind show events identified as magnetic reconnection with wide outflows and extended "X lines," 10(3)-10(4) times ion scales. To understand the role of turbulence at these scales, we make a case study of an inertial-range reconnection event in a magnetohydrodynamic simulation. We observe stochastic wandering of field lines in space, breakdown of standard magnetic flux freezing due to Richardson dispersion, and a broadened reconnection zone containing many current sheets. The coarse-grain magnetic geometry is like large-scale reconnection in the solar wind, however, with a hyperbolic flux tube or apparent X line extending over integral length scales.

  8. On Lunar Exospheric Column Densities and Solar Wind Access Beyond the Terminator from ROSAT Soft X-Ray Observations of Solar Wind Charge Exchange

    Science.gov (United States)

    Collier, Michael R.; Snowden, S. L.; Sarantos, M.; Benna, M.; Carter, J. A.; Cravens, T. E.; Farrell, W. M.; Fatemi, S.; Hills, H. Kent; Hodges, R. R.; hide

    2014-01-01

    We analyze the Rontgen satellite (ROSAT) position sensitive proportional counter soft X-ray image of the Moon taken on 29 June 1990 by examining the radial profile of the surface brightness in three wedges: two 19 deg wedges (one north and one south) 13-32 deg off the terminator toward the dark side and one wedge 38 deg wide centered on the antisolar direction. The radial profiles of both the north and the south wedges show significant limb brightening that is absent in the 38 deg wide antisolar wedge. An analysis of the soft X-ray intensity increase associated with the limb brightening shows that its magnitude is consistent with that expected due to solar wind charge exchange (SWCX) with the tenuous lunar atmosphere based on lunar exospheric models and hybrid simulation results of solar wind access beyond the terminator. Soft X-ray imaging thus can independently infer the total lunar limb column density including all species, a property that before now has not been measured, and provide a large-scale picture of the solar wind-lunar interaction. Because the SWCX signal appears to be dominated by exospheric species arising from solar wind implantation, this technique can also determine how the exosphere varies with solar wind conditions. Now, along with Mars, Venus, and Earth, the Moon represents another solar system body at which SWCX has been observed.

  9. FADING CORONAL STRUCTURE AND THE ONSET OF TURBULENCE IN THE YOUNG SOLAR WIND

    Energy Technology Data Exchange (ETDEWEB)

    DeForest, C. E. [Southwest Research Institute, 1050 Walnut Street, Boulder, CO (United States); Matthaeus, W. H. [Bartol Research Institute, University of Delaware, Newark, DE 19716 (United States); Viall, N. M. [NASA/Goddard Space Flight Center, Mail Code 671, Greenbelt, MD 20771 (United States); Cranmer, S. R. [University of Colorado, Duane E226, Boulder, CO 80305 (United States)

    2016-09-10

    Above the top of the solar corona, the young, slow solar wind transitions from low- β , magnetically structured flow dominated by radial structures to high- β , less structured flow dominated by hydrodynamics. This transition, long inferred via theory, is readily apparent in the sky region close to 10° from the Sun in processed, background-subtracted solar wind images. We present image sequences collected by the inner Heliospheric Imager instrument on board the Solar-Terrestrial Relations Observatory ( STEREO /HI1) in 2008 December, covering apparent distances from approximately 4° to 24° from the center of the Sun and spanning this transition in the large-scale morphology of the wind. We describe the observation and novel techniques to extract evolving image structure from the images, and we use those data and techniques to present and quantify the clear textural shift in the apparent structure of the corona and solar wind in this altitude range. We demonstrate that the change in apparent texture is due both to anomalous fading of the radial striae that characterize the corona and to anomalous relative brightening of locally dense puffs of solar wind that we term “flocculae.” We show that these phenomena are inconsistent with smooth radial flow, but consistent with the onset of hydrodynamic or magnetohydrodynamic instabilities leading to a turbulent cascade in the young solar wind.

  10. Fading Coronal Structure and the Onset of Turbulence in the Young Solar Wind

    Science.gov (United States)

    DeForest, C. E.; Matthaeus, W. H.; Viall, N. M.; Cranmer, S. R.

    2016-01-01

    Above the top of the solar corona, the young, slow solar wind transitions from low-beta, magnetically structured flow dominated by radial structures to high-beta, less structured flow dominated by hydrodynamics. This transition, long inferred via theory, is readily apparent in the sky region close to 10deg from the Sun in processed, background-subtracted solar wind images. We present image sequences collected by the inner Heliospheric Imager instrument on board the Solar-Terrestrial Relations Observatory (STEREO/HI1) in 2008 December, covering apparent distances from approximately 4deg to 24deg from the center of the Sun and spanning this transition in the large-scale morphology of the wind. We describe the observation and novel techniques to extract evolving image structure from the images, and we use those data and techniques to present and quantify the clear textural shift in the apparent structure of the corona and solar wind in this altitude range. We demonstrate that the change in apparent texture is due both to anomalous fading of the radial striae that characterize the corona and to anomalous relative brightening of locally dense puffs of solar wind that we term "flocculae." We show that these phenomena are inconsistent with smooth radial flow, but consistent with the onset of hydrodynamic or magnetohydrodynamic instabilities leading to a turbulent cascade in the young solar wind.

  11. Clouds blown by the solar wind

    International Nuclear Information System (INIS)

    Voiculescu, M; Condurache-Bota, S; Usoskin, I

    2013-01-01

    In this letter we investigate possible relationships between the cloud cover (CC) and the interplanetary electric field (IEF), which is modulated by the solar wind speed and the interplanetary magnetic field. We show that CC at mid–high latitudes systematically correlates with positive IEF, which has a clear energetic input into the atmosphere, but not with negative IEF, in general agreement with predictions of the global electric circuit (GEC)-related mechanism. Thus, our results suggest that mid–high latitude clouds might be affected by the solar wind via the GEC. Since IEF responds differently to solar activity than, for instance, cosmic ray flux or solar irradiance, we also show that such a study allows distinguishing one solar-driven mechanism of cloud evolution, via the GEC, from others. (letter)

  12. Ion acoustic waves in the solar wind

    International Nuclear Information System (INIS)

    Gurnett, D.A.; Frank, L.A.

    1978-01-01

    Plasma wave measurements on the Helios I and 2 spacecraft have revealed the occurrence of electric field turbulence in the solar wind at frequencies between the electron and ion plasma frequencies. Wavelength measurements with the Imp 6 spacecraft now provide strong evidence that these waves are short-wavelength ion acoustic waves which are Doppler-shifted upward in frequency by the motion of the solar wind. Comparison of the Helios results with measurements from the earth-orbiting Imp 6 and 8 spacecraft shows that the ion acoustic turbulence detected in interplanetary space has characteristics essentially identical to those of bursts of electrostatic turbulence generated by protons streaming into the solar wind from the earth's bow shock. In a few cases, enhanced ion acoustic wave intensities have been observed in direct association with abrupt increases in the anisotropy of the solar wind electron distribution. This relationship strongly suggests that the ion acoustic waves detected by Helios far from the earth are produced by an electron heat flux instability, as was suggested by Forslund. Possible related mechanisms which could explain the generation of ion acoustic waves by protons streaming into the solar wind from the earth's bow shock are also considered

  13. Solar Illumination Control of the Polar Wind

    Science.gov (United States)

    Maes, L.; Maggiolo, R.; De Keyser, J.; André, M.; Eriksson, A. I.; Haaland, S.; Li, K.; Poedts, S.

    2017-11-01

    Polar wind outflow is an important process through which the ionosphere supplies plasma to the magnetosphere. The main source of energy driving the polar wind is solar illumination of the ionosphere. As a result, many studies have found a relation between polar wind flux densities and solar EUV intensity, but less is known about their relation to the solar zenith angle at the ionospheric origin, certainly at higher altitudes. The low energy of the outflowing particles and spacecraft charging means it is very difficult to measure the polar wind at high altitudes. We take advantage of an alternative method that allows estimations of the polar wind flux densities far in the lobes. We analyze measurements made by the Cluster spacecraft at altitudes from 4 up to 20 RE. We observe a strong dependence on the solar zenith angle in the ion flux density and see that both the ion velocity and density exhibit a solar zenith angle dependence as well. We also find a seasonal variation of the flux density.

  14. Laboratory Facility for Simulating Solar Wind Sails

    International Nuclear Information System (INIS)

    Funaki, Ikkoh; Ueno, Kazuma; Oshio, Yuya; Ayabe, Tomohiro; Horisawa, Hideyuki; Yamakawa, Hiroshi

    2008-01-01

    Magnetic sail (MagSail) is a deep space propulsion system, in which an artificial magnetic cavity captures the energy of the solar wind to propel a spacecraft in the direction leaving the sun. For a scale-model experiment of the plasma flow of MagSail, we employed a magnetoplasmadynamic arcjet as a solar wind simulator. It is observed that a plasma flow from the solar wind simulator reaches a quasi-steady state of about 0.8 ms duration after a transient phase when initiating the discharge. During this initial phase of the discharge, a blast-wave was observed to develop radially in a vacuum chamber. When a solenoidal coil (MagSail scale model) is immersed into the quasi-steady flow where the velocity is 45 km/s, and the number density is 10 19 m-3, a bow shock as well as a magnetic cavity were formed in front of the coil. As a result of the interaction between the plasma flow and the magnetic cavity, the momentum of the simulated solar wind is decreased, and it is found from the thrust measurement that the solar wind momentum is transferred to the coil simulating MagSail.

  15. Solar-wind minor ions: recent observations

    International Nuclear Information System (INIS)

    Bame, S.J.

    1982-01-01

    During the years following the Solar Wind Four Conference at Burghausen our knowledge of the solar wind ion composition and dynamics has grown. There have been some surprises, and our understanding of the evolution of the solar wind has been improved. Systematic studies have shown that the minor ions generally travel with a common bulk speed and have temperatures roughly proportional to their masses. It has been determined that the 3 He ++ content varies greatly; 3 He ++ / 4 He ++ ranges from as high as 10 2 values to below 2 x 10 - 4 . In some solar wind flows which can be related to energetic coronal events, the minor ions are found in unusual ionization states containing Fe 16 + as a prominent ion, showing that the states were formed at unusually high temperatures. Unexpectedly, in a few flows substantial quantities of 4 He + have been detected, sometimes with ions identifiable as O 2 + and O 3 + . Surprisingly, in some of these examples the ionization state is mixed showing that part of the plasma escaped the corona without attaining the usual million-degree temperatures while other parts were heated more nearly in the normal manner. Additionally, detailed studies of the minor ions have increased our understanding of the coronal expansion. For example, such studies have contributed to identifying near equatorial coronal streamers as the source of solar wind flows between high speed streams

  16. Studies on improvement of tomato productivity in a large-scale greenhouse: Prediction of tomato yield based on integrated solar radiation

    International Nuclear Information System (INIS)

    Hisaeda, K.; Nishina, H.

    2007-01-01

    As there are currently many large-scale production facilities that have contracts with the large retailing companies, accurate prediction of yield is necessary. The present study developed a method to predict tomato yield accurately using the data on the outside solar radiation. The present study was conducted in a Venlo-type greenhouse (29,568 square m) at Sera Farm Co., Ltd. in Sera-cho in Hiroshima prefecture. The cultivar used for this experiment was plum tomato. The sowing took place on July 18, the planting took place on August 30, and the harvesting started on October 9, 2002. The planting density was 2.5 plants msup(-2). As the results of the analysis of correlation between the weekly tomato yield and the integrated solar radiation for the period from October 7 to July 28 (43 weeks), the highest correlation (r = 0.518) between the weekly tomato yield and the solar radiation integrated from seven to one weeks before the harvesting was observed. Further investigation by the same correlation analysis was conducted for the 25 weeks period from December 8 to May 26, during which time the effect of growing stages and air temperature were considered to be relatively small. The results showed the highest correlation (r = 0.730) between the weekly tomato yield and the solar radiation integrated from eight to one weeks before the harvesting. The tomato yield occasionally needed to be adjusted at Sera Farm. Consequently, the correlation between the three-week moving average of tomato yield and the integrated solar radiation was calculated. The results showed the highest correlation was obtained for the period from eight to one weeks before the harvesting (r = 0.860). This study therefore showed that it was possible to predict the tomato yield (y: kg.msup(-2).weeksup(-1)) using the following equation on the solar radiation integrated from eight to one weeks before the harvesting(x: MJ.msup(-2)): y = 7.50 x 10 sup(-6)x + 0.148 (rsup(2) = 0.740)

  17. Estimation of wind and solar resources in Mali

    Energy Technology Data Exchange (ETDEWEB)

    Badger, J.; Kamissoko, F.; Olander Rasmussen, M.; Larsen, Soeren; Guidon, N.; Boye Hansen, L.; Dewilde, L.; Alhousseini, M.; Noergaard, P.; Nygaard, I.

    2012-11-15

    The wind resource has been estimated for all of Mali at 7.5 km resolution using the KAMM/WAsP numerical wind atlas methodology. Three domains were used to cover entire country and three sets of wind classes used to capture change in large scale forcing over country. The final output includes generalized climate statistics for any location in Mali, giving wind direction and wind speed distribution. The modelled generalized climate statistics can be used directly in the WAsP software. The preliminary results show a wind resource, which is relatively low, but which under certain conditions may be economically feasible, i.e. at favourably exposed sites, giving enhanced winds, and where practical utilization is possible, given consideration to grid connection or replacement or augmentation of diesel-based electricity systems. The solar energy resource for Mali was assessed for the period between July 2008 and June 2011 using a remote sensing based estimate of the down-welling surface shortwave flux. The remote sensing estimates were adjusted on a month-by-month basis to account for seasonal differences between the remote sensing estimates and in situ data. Calibration was found to improve the coefficient of determination as well as decreasing the mean error both for the calibration and validation data. Compared to the results presented in the ''Renewable energy resources in Mali - preliminary mapping''-report that showed a tendency for underestimation compared to data from the NASA PPOWER/SSE database, the presented results show a very good agreement with the in situ data (after calibration) with no significant bias. Unfortunately, the NASA-database only contains data up until 2005, so a similar comparison could not be done for the time period analyzed in this study, although the agreement with the historic NASA data is still useful as reference. (LN)

  18. ENERGY DISSIPATION PROCESSES IN SOLAR WIND TURBULENCE

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y.; Wei, F. S.; Feng, X. S.; Sun, T. R.; Zuo, P. B. [SIGMA Weather Group, State Key Laboratory for Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing 100190 (China); Xu, X. J. [Space Science Institute, Macau University of Science and Technology, Macao (China); Zhang, J., E-mail: yw@spaceweather.ac.cn [School of Physics, Astronomy and Computational Sciences, George Mason University, 4400 University Drive, MSN 3F3, Fairfax, Virginia 22030 (United States)

    2015-12-15

    Turbulence is a chaotic flow regime filled by irregular flows. The dissipation of turbulence is a fundamental problem in the realm of physics. Theoretically, dissipation ultimately cannot be achieved without collisions, and so how turbulent kinetic energy is dissipated in the nearly collisionless solar wind is a challenging problem. Wave particle interactions and magnetic reconnection (MR) are two possible dissipation mechanisms, but which mechanism dominates is still a controversial topic. Here we analyze the dissipation region scaling around a solar wind MR region. We find that the MR region shows unique multifractal scaling in the dissipation range, while the ambient solar wind turbulence reveals a monofractal dissipation process for most of the time. These results provide the first observational evidences for intermittent multifractal dissipation region scaling around a MR site, and they also have significant implications for the fundamental energy dissipation process.

  19. Solar wind controlled pulsations: A review

    International Nuclear Information System (INIS)

    Odera, T.J.

    1986-01-01

    Studies of the solar wind controlled Pc 3, 4 pulsations by early and recent researchers are highlighted. The review focuses on the recent observations, which cover the time during the International Magnetospheric Study (IMS). Results from early and recent observations agree on one point, that is, that the Pc 3, 4 pulsations are influenced by three main solar wind parameters, namely, the solar wind velocity V/sub 5w/, the IMF orientation theta/sub x/B, and magnitude B. The results can be interpreted, preferably, in terms of an external origin for Pc 3, 4 pulsations. This implies, essentially, the signal model, which means that the pulsations originate in the upstream waves (in the interplanetary medium) and are transported by convection to the magnetopause, where they couple to oscillations of the magnetospheric field lines

  20. Diagnostics of the solar wind transition region

    International Nuclear Information System (INIS)

    Lotova, N.A.; Nagelis, Ya.V.; Rudnitskij, G.M.; Smirnova, T.V.; AN Latvijskoj SSR, Riga. Radioastrofizicheskaya Observatoriya; Moskovskij Gosudarstvennyj Univ.; AN SSSR, Moscow. Fizicheskij Inst.)

    1988-01-01

    Possibilities are discussed of a more complete study of hardly observable regions of the interplanetary medium, in the zone of the solar wind formation, where transition from subsonic to supersonic flow occurs at R sun . It is shown that an investigation of fine structure of the extended transonic region of the solar wind and of the sequence of changes in the parameters of the interplanetary plasma in the region of the solar wind formation with the changing distance from the Sun can be effectuated by using jointly different modifications of the occupation method. Combination of two or more modifications of this method supposes using compact radio sources of different classes and observations in two different wavelength ranges, namely at short centimeter and at meter waves

  1. WIND observations of coherent electrostatic waves in the solar wind

    Directory of Open Access Journals (Sweden)

    A. Mangeney

    1999-03-01

    Full Text Available The time domain sampler (TDS experiment on WIND measures electric and magnetic wave forms with a sampling rate which reaches 120 000 points per second. We analyse here observations made in the solar wind near the Lagrange point L1. In the range of frequencies above the proton plasma frequency fpi and smaller than or of the order of the electron plasma frequency fpe, TDS observed three kinds of electrostatic (e.s. waves: coherent wave packets of Langmuir waves with frequencies f ~ fpe, coherent wave packets with frequencies in the ion acoustic range fpi < f < fpe, and more or less isolated non-sinusoidal spikes lasting less than 1 ms. We confirm that the observed frequency of the low frequency (LF ion acoustic wave packets is dominated by the Doppler effect: the wavelengths are short, 10 to 50 electron Debye lengths λD. The electric field in the isolated electrostatic structures (IES and in the LF wave packets is more or less aligned with the solar wind magnetic field. Across the IES, which have a spatial width of the order of ~ 25λD, there is a small but finite electric potential drop, implying an average electric field generally directed away from the Sun. The IES wave forms, which have not been previously reported in the solar wind, are similar, although with a smaller amplitude, to the weak double layers observed in the auroral regions, and to the electrostatic solitary waves observed in other regions in the magnetosphere. We have also studied the solar wind conditions which favour the occurrence of the three kinds of waves: all these e.s. waves are observed more or less continuously in the whole solar wind (except in the densest regions where a parasite prevents the TDS observations. The type (wave packet or IES of the observed LF waves is mainly determined by the proton temperature and by the direction of the magnetic field, which themselves depend on the latitude of WIND with respect to the heliospheric current sheet.Key words

  2. WIND observations of coherent electrostatic waves in the solar wind

    Directory of Open Access Journals (Sweden)

    A. Mangeney

    Full Text Available The time domain sampler (TDS experiment on WIND measures electric and magnetic wave forms with a sampling rate which reaches 120 000 points per second. We analyse here observations made in the solar wind near the Lagrange point L1. In the range of frequencies above the proton plasma frequency fpi and smaller than or of the order of the electron plasma frequency fpe, TDS observed three kinds of electrostatic (e.s. waves: coherent wave packets of Langmuir waves with frequencies f ~ fpe, coherent wave packets with frequencies in the ion acoustic range fpi < f < fpe, and more or less isolated non-sinusoidal spikes lasting less than 1 ms. We confirm that the observed frequency of the low frequency (LF ion acoustic wave packets is dominated by the Doppler effect: the wavelengths are short, 10 to 50 electron Debye lengths λD. The electric field in the isolated electrostatic structures (IES and in the LF wave packets is more or less aligned with the solar wind magnetic field. Across the IES, which have a spatial width of the order of ~ 25λD, there is a small but finite electric potential drop, implying an average electric field generally directed away from the Sun. The IES wave forms, which have not been previously reported in the solar wind, are similar, although with a smaller amplitude, to the weak double layers observed in the auroral regions, and to the electrostatic solitary waves observed in other regions in the magnetosphere. We have also studied the solar wind conditions which favour the occurrence of the three kinds of waves: all these e.s. waves are observed more or less continuously in the whole solar wind (except in the densest regions where a parasite prevents the TDS observations. The type (wave packet or IES of the observed LF waves is mainly determined

  3. A study to solve the variability of wind generation through integration of large-scale hydraulic generation; Um estudo para resolver a variabilidade da geracao eolica atraves da integracao em larga escala com geracao hidraulica

    Energy Technology Data Exchange (ETDEWEB)

    Emmerik, Emanuel Leonardus van; Steinberger, Johann Michael; Aredes, Mauricio [Coordenacao dos Programas de Pos-Graduacao de Engenharia (PEE/COPPE/UFRJ), RJ (Brazil). Programa de Engenharia Eletrica

    2010-07-01

    The optimal deployment of wind generation with the hydro generation is being investigated as a viable option to assist in resolving the constraints coming ahead as a consequence of the tendency of recovery in the Brazilian Amazon basin for expansion of generating facilities. It is in the validity of this research that this work is focused. The value is shown of feasibility studies of using water power generation to offset the variability of wind generation when it is deployed on a large scale. Preliminary results are presented for the variability of wind generation at various cycles, the variability of the availability of hydropower. (author)

  4. For the definition of capacity effects of electricity generation from wind power and solar radiation

    International Nuclear Information System (INIS)

    Kaltschmitt, M.

    1996-01-01

    It is the objective of this contribution to define the calculable really available output of a fluctuating electricity generation from wind energy and solar radiation. Apart from that, the methods for determining the really available output are explained, as far as they are necessary for understanding the definitions. Exemplified on a simulated large-scale regenerative electricity generation in Germany, in addition, some defined values are calculated and discussed. (orig.) [de

  5. Combined wind and solar feed-in to the grid

    CSIR Research Space (South Africa)

    Mushwana, Crescent

    2018-05-01

    Full Text Available This presentation highlights South African wind and solar resources and presents a case study on wind and solar PV combination. It also distinguishes between traditional and new philosophies regarding energy system design and the changes...

  6. Wind/solar resource in Texas

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, V.; Starcher, K.; Gaines, H. [West Texas A& M Univ., Canyon, TX (United States)

    1997-12-31

    Data are being collected at 17 sites to delineate a baseline for the wind and solar resource across Texas. Wind data are being collected at 10, 25, and 40 m (in some cases at 50 m) to determine wind shear and power at hub heights of large turbines. Many of the sites are located in areas of predicted terrain enhancement. The typical day in a month for power and wind turbine output was calculated for selected sites and combination of sites; distributed systems. Major result to date is that there is the possibility of load matching in South Texas during the summer months, even though the average values by month indicate a low wind potential.

  7. Solar wind-magnetosphere coupling during intense magnetic storms (1978-1979)

    Science.gov (United States)

    Gonzalez, Walter D.; Gonzalez, Alicia L. C.; Tsurutani, Bruce T.; Smith, Edward J.; Tang, Frances

    1989-01-01

    The solar wind-magnetosphere coupling problem during intense magnetic storms was investigated for ten intense magnetic storm events occurring between August 16, 1978 to December 28, 1979. Particular attention was given to the dependence of the ring current energization on the ISEE-measured solar-wind parameters and the evolution of the ring current during the main phase of the intense storms. Several coupling functions were tested as energy input, and several sets of the ring current decay time-constant were searched for the best correlation with the Dst response. Results indicate that a large-scale magnetopause reconnection operates during an intense storm event and that the solar wind ram pressure plays an important role in the energization of the ring current.

  8. Solar wind-magnetosphere coupling during intense magnetic storms (1978--1979)

    International Nuclear Information System (INIS)

    Gonzalez, W.D.; Tsurutani, B.T.; Gonzalez, A.L.C.; Smith, E.J.; Tang, F.; Akasofu, S.

    1989-01-01

    The solar wind-magnetosphere coupling problem is investigated for the ten intense magnetic storms (Dst <-100 nT) that occurred during the 500 days (August 16, 1978 to December 28, 1979) studied by Gonzalez and Tsurutani [1987]. This investigation concentrates on the ring current energization in terms of solar wind parameters, in order to explain the | -Dst | growth observed during these storms. Thus several coupling functions are tested as energy input and several sets of the ring current decay time-constant τ are searched to find best correlations with the Dst response. From the fairly large correlation coefficients found in this study, there is strong evidence that large scale magnetopause reconnection operates during such intense storm events and that the solar wind ram pressure plays an important role in the ring current energization. Thus a ram pressure correction factor is suggested for expressions concerning the reconnection power during time intervals with large ram pressure variations

  9. Numerical simulation of wind loads on solar panels

    Science.gov (United States)

    Su, Kao-Chun; Chung, Kung-Ming; Hsu, Shu-Tsung

    2018-05-01

    Solar panels mounted on the roof of a building or ground are often vulnerable to strong wind loads. This study aims to investigate wind loads on solar panels using computational fluid dynamic (CFD). The results show good agreement with wind tunnel data, e.g. the streamwise distribution of mean surface pressure coefficient of a solar panel. Wind uplift for solar panels with four aspect ratios is evaluated. The effect of inclined angle and clearance (or height) of a solar panel is addressed. It is found that wind uplift of a solar panel increases when there is an increase in inclined angle and the clearance above ground shows an opposite effect.

  10. A large-scale solar greenhouse dryer using polycarbonate cover: Modeling and testing in a tropical environment of Lao People's Democratic Republic

    Energy Technology Data Exchange (ETDEWEB)

    Janjai, Serm; Intawee, Poolsak; Kaewkiew, Jinda; Sritus, Chanoke [Solar Energy Research Laboratory, Department of Physics, Faculty of Science, Silpakorn University, Nakhon Pathom 73000 (Thailand); Khamvongsa, Vathsana [Department of Physics, Faculty of Natural Science, National University of Laos, P O Box 7322, Vientiane (Lao People' s Democratic Republic)

    2011-03-15

    A large-scale solar greenhouse dryer with a loading capacity of 1000 kg of fruits or vegetables has been developed and tested at field levels. The dryer has a parabolic shape and the dryer is covered with polycarbonate sheets. The base of the dryer is a black concrete floor with an area of 7.5 x 20.0 m{sup 2}. Nine DC fans powered by three 50-W solar cell modules are used to ventilate the dryer. The dryer was installed at Champasak (15.13 N, 105.79 E) in Lao People's Democratic Republic (Lao PDR). It is routinely used to dry chilli, banana and coffee. To assess the experimental performances of the dryer, air temperature, air relative humidity and product moisture contents were measured. One thousand kilograms of banana with the initial moisture content of 68% (wb) was dried within 5 days, compared to 7 days required for natural sun drying with the same weather conditions. Also three hundred kilograms of chilli with the initial moisture content of 75% (wb) was dried within 3 days while the natural sun drying needed 5 days. Two hundred kilograms of coffee with the initial moisture content of 52% (wb) was dried within 2 days as compared to 4 days required for natural sun drying. The chilli, coffee and banana dried in this dryer were completely protected from insects, animals and rain. Furthermore, good quality of dried products was obtained. The payback period of the dryer is estimated to be 2.5 years. A system of partial differential equations describing heat and moisture transfer during drying of chilli, coffee and banana in the greenhouse dryer was developed. These equations were solved by using the finite different method. The simulated results agree well with the experimental data. This model can be used to provide the design data for this type of dryer in other locations. (author)

  11. Solar wind structure suggested by bimodal correlations of solar wind speed and density between the spacecraft SOHO and Wind

    Science.gov (United States)

    Ogilvie, K. W.; Coplan, M. A.; Roberts, D. A.; Ipavich, F.

    2007-08-01

    We calculate the cross-spacecraft maximum lagged-cross-correlation coefficients for 2-hour intervals of solar wind speed and density measurements made by the plasma instruments on the Solar and Heliospheric Observatory (SOHO) and Wind spacecraft over the period from 1996, the minimum of solar cycle 23, through the end of 2005. During this period, SOHO was located at L1, about 200 R E upstream from the Earth, while Wind spent most of the time in the interplanetary medium at distances of more than 100 R E from the Earth. Yearly histograms of the maximum, time-lagged correlation coefficients for both the speed and density are bimodal in shape, suggesting the existence of two distinct solar wind regimes. The larger correlation coefficients we suggest are due to structured solar wind, including discontinuities and shocks, while the smaller are likely due to Alfvénic turbulence. While further work will be required to firmly establish the physical nature of the two populations, the results of the analysis are consistent with a solar wind that consists of turbulence from quiet regions of the Sun interspersed with highly filamentary structures largely convected from regions in the inner solar corona. The bimodal appearance of the distributions is less evident in the solar wind speed than in the density correlations, consistent with the observation that the filamentary structures are convected with nearly constant speed by the time they reach 1 AU. We also find that at solar minimum the fits for the density correlations have smaller high-correlation components than at solar maximum. We interpret this as due to the presence of more relatively uniform Alfvénic regions at solar minimum than at solar maximum.

  12. The Solar Wind as a Turbulence Laboratory

    Directory of Open Access Journals (Sweden)

    Vincenzo Carbone

    2013-05-01

    Full Text Available In this review we will focus on a topic of fundamental importance for both astrophysics and plasma physics, namely the occurrence of large-amplitude low-frequency fluctuations of the fields that describe the plasma state. This subject will be treated within the context of the expanding solar wind and the most meaningful advances in this research field will be reported emphasizing the results obtained in the past decade or so. As a matter of fact, Helios inner heliosphere and Ulysses' high latitude observations, recent multi-spacecrafts measurements in the solar wind (Cluster four satellites and new numerical approaches to the problem, based on the dynamics of complex systems, brought new important insights which helped to better understand how turbulent fluctuations behave in the solar wind. In particular, numerical simulations within the realm of magnetohydrodynamic (MHD turbulence theory unraveled what kind of physical mechanisms are at the basis of turbulence generation and energy transfer across the spectral domain of the fluctuations. In other words, the advances reached in these past years in the investigation of solar wind turbulence now offer a rather complete picture of the phenomenological aspect of the problem to be tentatively presented in a rather organic way.

  13. Energy Primer: Solar, Water, Wind, and Biofuels.

    Science.gov (United States)

    Portola Inst., Inc., Menlo Park, CA.

    This is a comprehensive, fairly technical book about renewable forms of energy--solar, water, wind, and biofuels. The biofuels section covers biomass energy, agriculture, aquaculture, alcohol, methane, and wood. The focus is on small-scale systems which can be applied to the needs of the individual, small group, or community. More than one-fourth…

  14. Identifying Wind and Solar Ramping Events: Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Florita, A.; Hodge, B. M.; Orwig, K.

    2013-01-01

    Wind and solar power are playing an increasing role in the electrical grid, but their inherent power variability can augment uncertainties in power system operations. One solution to help mitigate the impacts and provide more flexibility is enhanced wind and solar power forecasting; however, its relative utility is also uncertain. Within the variability of solar and wind power, repercussions from large ramping events are of primary concern. At the same time, there is no clear definition of what constitutes a ramping event, with various criteria used in different operational areas. Here the Swinging Door Algorithm, originally used for data compression in trend logging, is applied to identify variable generation ramping events from historic operational data. The identification of ramps in a simple and automated fashion is a critical task that feeds into a larger work of 1) defining novel metrics for wind and solar power forecasting that attempt to capture the true impact of forecast errors on system operations and economics, and 2) informing various power system models in a data-driven manner for superior exploratory simulation research. Both allow inference on sensitivities and meaningful correlations, as well as the ability to quantify the value of probabilistic approaches for future use in practice.

  15. Classification of solar wind with machine learning

    NARCIS (Netherlands)

    E. Camporeale (Enrico); A. Carè (Algo); J.E. Borovsky (Joseph)

    2017-01-01

    htmlabstractWe present a four-category classification algorithm for the solar wind, based on Gaussian Process. The four categories are the ones previously adopted in Xu and Borovsky (2015): ejecta, coronal hole origin plasma, streamer belt origin plasma, and sector reversal origin plasma. The

  16. Mirror Instability in the Turbulent Solar Wind

    Czech Academy of Sciences Publication Activity Database

    Hellinger, Petr; Landi, S.; Matteini, L.; Verdini, A.; Franci, L.

    2017-01-01

    Roč. 838, č. 2 (2017), 158/1-158/7 ISSN 0004-637X Institutional support: RVO:67985815 Keywords : instabilities * solar wind * waves Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics OBOR OECD: Astronomy (including astrophysics,space science) Impact factor: 5.533, year: 2016

  17. Solar wind conditions for a quiet magnetosphere

    International Nuclear Information System (INIS)

    Kerns, K.J.; Gussenhoven, M.S.

    1990-01-01

    The conditions of the solar wind that lead to a quiet magnetosphere are determined under the assumption that the quiet or baseline magnetosphere can be identified by prolonged periods of low values of the am index. The authors analyzed solar wind data from 1978 to 1984 (7 years) during periods in which am ≤ 3 nT to identify those solar wind parameters that deviate significantly from average values. Parallel studies were also performed for prolonged periods of Kp = 0, 0+ and AE z ) show distinctive variations from average values. They independently varied these solar wind parameters and the length of time the conditions must persist to minimize am. This was done with the additional requirement that the conditions yield a reasonable number of occurrences (5% of the data set). The resulting baseline conditions are V ≤ 390 km/s; 180 degree - arctan |B y /B z | ≤ 101 degree, when b z ≤ 0 (no restriction on B z positive); B ≤ 6.5 nT; and persistence of these conditions for at least 5 hours. Minimizing the am index does not require a clear upper limit on the value of B z as might be anticipated from the work of Gussenhoven (1988) and Berthelier (1980). Apparently, this is a result of the requirement that the conditions must occur 5% of the time. When the requirement is lowered to 1% occurrence, an upper limit to B z emerges

  18. Modeling 3-D solar wind structure

    Czech Academy of Sciences Publication Activity Database

    Odstrčil, Dušan

    2003-01-01

    Roč. 32, č. 4 (2003), s. 497-506 ISSN 0273-1177 R&D Projects: GA AV ČR IAA3003003; GA AV ČR IBS1003006 Institutional research plan: CEZ:AV0Z1003909 Keywords : solar wind * modeling Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 0.483, year: 2003

  19. Wind and solar resource data sets: Wind and solar resource data sets

    Energy Technology Data Exchange (ETDEWEB)

    Clifton, Andrew [National Renewable Energy Laboratory, Golden CO USA; Hodge, Bri-Mathias [National Renewable Energy Laboratory, Golden CO USA; Power Systems Engineering Center, National Renewable Energy Laboratory, Golden CO USA; Draxl, Caroline [National Renewable Energy Laboratory, Golden CO USA; National Wind Technology Center, National Renewable Energy Laboratory, Golden CO USA; Badger, Jake [Department of Wind Energy, Danish Technical University, Copenhagen Denmark; Habte, Aron [National Renewable Energy Laboratory, Golden CO USA; Power Systems Engineering Center, National Renewable Energy Laboratory, Golden CO USA

    2017-12-05

    The range of resource data sets spans from static cartography showing the mean annual wind speed or solar irradiance across a region to high temporal and high spatial resolution products that provide detailed information at a potential wind or solar energy facility. These data sets are used to support continental-scale, national, or regional renewable energy development; facilitate prospecting by developers; and enable grid integration studies. This review first provides an introduction to the wind and solar resource data sets, then provides an overview of the common methods used for their creation and validation. A brief history of wind and solar resource data sets is then presented, followed by areas for future research.

  20. Intermittency Statistics in the Expanding Solar Wind

    Science.gov (United States)

    Cuesta, M. E.; Parashar, T. N.; Matthaeus, W. H.

    2017-12-01

    The solar wind is observed to be turbulent. One of the open questions in solar wind research is how the turbulence evolves as the solar wind expands to great distances. Some studies have focused on evolution of the outer scale but not much has been done to understand how intermittency evolves in the expanding wind beyond 1 AU (see [1,2]). We use magnetic field data from Voyager I spacecraft from 1 to 10AU to study the evolution of statistics of magnetic discontinuities. We perform various statistical tests on these discontinuities and make connections to the physical processes occurring in the expanding wind.[1] Tsurutani, Bruce T., and Edward J. Smith. "Interplanetary discontinuities: Temporal variations and the radial gradient from 1 to 8.5 AU." Journal of Geophysical Research: Space Physics 84.A6 (1979): 2773-2787.[2] Greco, A., et al. "Evidence for nonlinear development of magnetohydrodynamic scale intermittency in the inner heliosphere." The Astrophysical Journal 749.2 (2012): 105.

  1. Kinetic Physics of the Solar Corona and Solar Wind

    Directory of Open Access Journals (Sweden)

    Marsch Eckart

    2006-07-01

    Full Text Available Kinetic plasma physics of the solar corona and solar wind are reviewed with emphasis on the theoretical understanding of the in situ measurements of solar wind particles and waves, as well as on the remote-sensing observations of the solar corona made by means of ultraviolet spectroscopy and imaging. In order to explain coronal and interplanetary heating, the microphysics of the dissipation of various forms of mechanical, electric and magnetic energy at small scales (e.g., contained in plasma waves, turbulences or non-uniform flows must be addressed. We therefore scrutinise the basic assumptions underlying the classical transport theory and the related collisional heating rates, and also describe alternatives associated with wave-particle interactions. We elucidate the kinetic aspects of heating the solar corona and interplanetary plasma through Landau- and cyclotron-resonant damping of plasma waves, and analyse in detail wave absorption and micro instabilities. Important aspects (virtues and limitations of fluid models, either single- and multi-species or magnetohydrodynamic and multi-moment models, for coronal heating and solar wind acceleration are critically discussed. Also, kinetic model results which were recently obtained by numerically solving the Vlasov–Boltzmann equation in a coronal funnel and hole are presented. Promising areas and perspectives for future research are outlined finally.

  2. Statistics of counter-streaming solar wind suprathermal electrons at solar minimum: STEREO observations

    Directory of Open Access Journals (Sweden)

    B. Lavraud

    2010-01-01

    Full Text Available Previous work has shown that solar wind suprathermal electrons can display a number of features in terms of their anisotropy. Of importance is the occurrence of counter-streaming electron patterns, i.e., with "beams" both parallel and anti-parallel to the local magnetic field, which is believed to shed light on the heliospheric magnetic field topology. In the present study, we use STEREO data to obtain the statistical properties of counter-streaming suprathermal electrons (CSEs in the vicinity of corotating interaction regions (CIRs during the period March–December 2007. Because this period corresponds to a minimum of solar activity, the results are unrelated to the sampling of large-scale coronal mass ejections, which can lead to CSE owing to their closed magnetic field topology. The present study statistically confirms that CSEs are primarily the result of suprathermal electron leakage from the compressed CIR into the upstream regions with the combined occurrence of halo depletion at 90° pitch angle. The occurrence rate of CSE is found to be about 15–20% on average during the period analyzed (depending on the criteria used, but superposed epoch analysis demonstrates that CSEs are preferentially observed both before and after the passage of the stream interface (with peak occurrence rate >35% in the trailing high speed stream, as well as both inside and outside CIRs. The results quantitatively show that CSEs are common in the solar wind during solar minimum, but yet they suggest that such distributions would be much more common if pitch angle scattering were absent. We further argue that (1 the formation of shocks contributes to the occurrence of enhanced counter-streaming sunward-directed fluxes, but does not appear to be a necessary condition, and (2 that the presence of small-scale transients with closed-field topologies likely also contributes to the occurrence of counter-streaming patterns, but only in the slow solar wind prior to

  3. Electric solar wind sail mass budget model

    Directory of Open Access Journals (Sweden)

    P. Janhunen

    2013-02-01

    Full Text Available The electric solar wind sail (E-sail is a new type of propellantless propulsion system for Solar System transportation, which uses the natural solar wind to produce spacecraft propulsion. The E-sail consists of thin centrifugally stretched tethers that are kept charged by an onboard electron gun and, as such, experience Coulomb drag through the high-speed solar wind plasma stream. This paper discusses a mass breakdown and a performance model for an E-sail spacecraft that hosts a mission-specific payload of prescribed mass. In particular, the model is able to estimate the total spacecraft mass and its propulsive acceleration as a function of various design parameters such as the number of tethers and their length. A number of subsystem masses are calculated assuming existing or near-term E-sail technology. In light of the obtained performance estimates, an E-sail represents a promising propulsion system for a variety of transportation needs in the Solar System.

  4. Scale Dependence of Magnetic Helicity in the Solar Wind

    Science.gov (United States)

    Brandenburg, Axel; Subramanian, Kandaswamy; Balogh, Andre; Goldstein, Melvyn L.

    2011-01-01

    We determine the magnetic helicity, along with the magnetic energy, at high latitudes using data from the Ulysses mission. The data set spans the time period from 1993 to 1996. The basic assumption of the analysis is that the solar wind is homogeneous. Because the solar wind speed is high, we follow the approach first pioneered by Matthaeus et al. by which, under the assumption of spatial homogeneity, one can use Fourier transforms of the magnetic field time series to construct one-dimensional spectra of the magnetic energy and magnetic helicity under the assumption that the Taylor frozen-in-flow hypothesis is valid. That is a well-satisfied assumption for the data used in this study. The magnetic helicity derives from the skew-symmetric terms of the three-dimensional magnetic correlation tensor, while the symmetric terms of the tensor are used to determine the magnetic energy spectrum. Our results show a sign change of magnetic helicity at wavenumber k approximately equal to 2AU(sup -1) (or frequency nu approximately equal to 2 microHz) at distances below 2.8AU and at k approximately equal to 30AU(sup -1) (or nu approximately equal to 25 microHz) at larger distances. At small scales the magnetic helicity is positive at northern heliographic latitudes and negative at southern latitudes. The positive magnetic helicity at small scales is argued to be the result of turbulent diffusion reversing the sign relative to what is seen at small scales at the solar surface. Furthermore, the magnetic helicity declines toward solar minimum in 1996. The magnetic helicity flux integrated separately over one hemisphere amounts to about 10(sup 45) Mx(sup 2) cycle(sup -1) at large scales and to a three times lower value at smaller scales.

  5. The solar noise barrier project : 2. The effect of street art on performance of a large scale luminescent solar concentrator prototype

    NARCIS (Netherlands)

    Debije, M.G.; Tzikas, C.; Rajkumar, V.A.; de Jong, M.

    2017-01-01

    Noise barriers have been used worldwide to reduce the impact of sound generated from traffic on nearby areas. A common feature to appear on these noise barriers are all manner of graffiti and street art. In this work we describe the relative performance of a large area luminescent solar concentrator

  6. The solar noise barrier project: 1. Effect of incident light orientation on the performance of a large-scale luminescent solar concentrator noise barrier

    NARCIS (Netherlands)

    Kanellis, M.; de Jong, M.; Slooff, L.H.; Debije, M.G.

    2017-01-01

    In this work we describe the relative performance of the largest luminescent solar concentrator (LSC) constructed to date. Comparisons are made for performance of North/South and East/West facing panels during a sunny day. It is shown that the East/West panels display much more varied performance

  7. Large scale reflood test

    International Nuclear Information System (INIS)

    Hirano, Kemmei; Murao, Yoshio

    1980-01-01

    The large-scale reflood test with a view to ensuring the safety of light water reactors was started in fiscal 1976 based on the special account act for power source development promotion measures by the entrustment from the Science and Technology Agency. Thereafter, to establish the safety of PWRs in loss-of-coolant accidents by joint international efforts, the Japan-West Germany-U.S. research cooperation program was started in April, 1980. Thereupon, the large-scale reflood test is now included in this program. It consists of two tests using a cylindrical core testing apparatus for examining the overall system effect and a plate core testing apparatus for testing individual effects. Each apparatus is composed of the mock-ups of pressure vessel, primary loop, containment vessel and ECCS. The testing method, the test results and the research cooperation program are described. (J.P.N.)

  8. Wind and IMP 8 Solar Wind, Magnetosheath and Shock Data

    Science.gov (United States)

    2004-01-01

    The purpose of this project was to provide the community access to magnetosheath data near Earth. We provided 27 years of IMP 8 magnetosheath proton velocities, densities, and temperatures with our best (usually 1-min.) time resolution. IMP 8 crosses the magnetosheath twice each 125 day orbit, and we provided magnetosheath data for the roughly 27 years of data for which magnetometer data are also available (which are needed to reliably pick boundaries). We provided this 27 years of IMP 8 magnetosheath data to the NSSDC; this data is now integrated with the IMP 8 solar wind data with flags indicating whether each data point is in the solar wind, magnetosheath, or at the boundary between the two regions. The plasma speed, density, and temperature are provided for each magnetosheath point. These data are also available on the MIT web site ftp://space .mit.edu/pub/plasma/imp/www/imp.html. We provide ASCII time-ordered rows of data giving the observation time, the spacecraft position in GSE, the velocity is GSE, the density and temperature for protons. We also have analyzed and archived on our web site the Wind magnetosheath plasma parameters. These consist of ascii files of the proton and alpha densities, speeds, and thermal speeds. These data are available at ftp://space.mit.edu/pub/plasma/wind/sheath These are the two products promised in the work statement and they have been completed in full.

  9. FY 1998 Report on development of large-scale wind power generation systems. Feasibility study on development of new technologies for wind power generation (Study on the development of wind power generation); 1998 nendo ogata furyoku hatsuden system kaihatsu. Furyoku hatsuden shingijutsu kaihatsu kanosei chosa (furyoku hatsuden gijutsu ni kansuru kaihatsu doko chosa)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This survey is designed to analyze, e.g., current status of large-scale wind power generation devices/system technologies and development trends worldwide, and to make predictions about future developments, in an effort to contribute to advancements in new technology for wind power generation systems in Japan. The international R and D cooperation programs promoted by IEA and EU have helped the participants produce a number of good results at lower costs. The European countries have developed the wind power generation industries in each area, promoted by the governmental subsidy policies, and are leading the world. The system is becoming larger, from around an average unit capacity of 250kW in the beginning of the 90's to 600kW now, reducing the cost by the scale merit. The improved computer capacity has made it possible to more easily analyze the complicated rotor aerodynamics, structural dynamics, wind characteristics and other factors related to wind power generation systems. The future R and D directions will include world standards for large-scale wind turbines, advancements in wind farm technologies, offshore wind power generation systems, advancement in design technologies, and new concepts for wind power turbine designs, e.g., floating wind turbine. (NEDO)

  10. Solar and wind exergy potentials for Mars

    International Nuclear Information System (INIS)

    Delgado-Bonal, Alfonso; Martín-Torres, F. Javier; Vázquez-Martín, Sandra; Zorzano, María-Paz

    2016-01-01

    The energy requirements of the planetary exploration spacecrafts constrain the lifetime of the missions, their mobility and capabilities, and the number of instruments onboard. They are limiting factors in planetary exploration. Several missions to the surface of Mars have proven the feasibility and success of solar panels as energy source. The analysis of the exergy efficiency of the solar radiation has been carried out successfully on Earth, however, to date, there is not an extensive research regarding the thermodynamic exergy efficiency of in-situ renewable energy sources on Mars. In this paper, we analyse the obtainable energy (exergy) from solar radiation under Martian conditions. For this analysis we have used the surface environmental variables on Mars measured in-situ by the Rover Environmental Monitoring Station onboard the Curiosity rover and from satellite by the Thermal Emission Spectrometer instrument onboard the Mars Global Surveyor satellite mission. We evaluate the exergy efficiency from solar radiation on a global spatial scale using orbital data for a Martian year; and in a one single location in Mars (the Gale crater) but with an appreciable temporal resolution (1 h). Also, we analyse the wind energy as an alternative source of energy for Mars exploration and compare the results with those obtained on Earth. We study the viability of solar and wind energy station for the future exploration of Mars, showing that a small square solar cell of 0.30 m length could maintain a meteorological station on Mars. We conclude that the low density of the atmosphere of Mars is responsible of the low thermal exergy efficiency of solar panels. It also makes the use of wind energy uneffective. Finally, we provide insights for the development of new solar cells on Mars. - Highlights: • We analyse the exergy of solar radiation under Martian environment • Real data from in-situ instruments is used to determine the maximum efficiency of radiation • Wind

  11. News from heat-pump research - Large-scale heat pumps, components, heat pumps and solar heating; News aus der Waermepumpen-Forschung - Gross-Waermepumpen, Komponenten, Waermepumpe und Solar

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-06-15

    These proceedings summarise the presentations made at the 16{sup th} annual meeting held by the Swiss Federal Office of Energy's Heat Pump Research Program in Burgdorf, Switzerland. The proceedings include contributions on large-scale heat pumps, components and the activities of the heat pump promotion society. A summary of targets and trends in energy research in general is presented and an overview of the heat pump market in 2009 and future perspectives is given. International work within the framework of the International Energy Agency's heat pump group is reviewed, including solar - heat pump combinations. Field-monitoring and the analysis of large-scale heat pumps are discussed and the importance of the use of correct concepts in such installations is stressed. Large-scale heat pumps with carbon dioxide as working fluid are looked at, as are output-regulated air/water heat pumps. Efficient system solutions with heat pumps used both to heat and to cool are discussed. Deep geothermal probes and the potential offered by geothermal probes using carbon dioxide as a working fluid are discussed. The proceedings are rounded off with a list of useful addresses.

  12. Western Wind and Solar Integration Study Phase 3A: Low Levels of Synchronous Generation

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Nicholas W. [GE Energy Management, Atlanta, GA (United States); Leonardi, Bruno [GE Energy Management, Atlanta, GA (United States); D' Aquila, Robert [GE Energy Management, Atlanta, GA (United States); Clark, Kara [National Renewable Energy Lab. (NREL), Golden, CO (United States)

    2015-11-17

    The stability of the North American electric power grids under conditions of high penetrations of wind and solar is a significant concern and possible impediment to reaching renewable energy goals. The 33% wind and solar annual energy penetration considered in this study results in substantial changes to the characteristics of the bulk power system. This includes different power flow patterns, different commitment and dispatch of existing synchronous generation, and different dynamic behavior from wind and solar generation. The Western Wind and Solar Integration Study (WWSIS), sponsored by the U.S. Department of Energy, is one of the largest regional solar and wind integration studies to date. In multiple phases, it has explored different aspects of the question: Can we integrate large amounts of wind and solar energy into the electric power system of the West? The work reported here focused on the impact of low levels of synchronous generation on the transient stability performance in one part of the region in which wind generation has displaced synchronous thermal generation under highly stressed, weak system conditions. It is essentially an extension of WWSIS-3. Transient stability, the ability of the power system to maintain synchronism among all elements following disturbances, is a major constraint on operations in many grids, including the western U.S. and Texas systems. These constraints primarily concern the performance of the large-scale bulk power system. But grid-wide stability concerns with high penetrations of wind and solar are still not thoroughly understood. This work focuses on 'traditional' fundamental frequency stability issues, such as maintaining synchronism, frequency, and voltage. The objectives of this study are to better understand the implications of low levels of synchronous generation and a weak grid on overall system performance by: 1) Investigating the Western Interconnection under conditions of both high renewable

  13. Solar wind velocity and geomagnetic moment variations

    International Nuclear Information System (INIS)

    Kalinin, Yu.D.; Rozanova, T.S.

    1982-01-01

    The mean year values of the solar wind velocity have been calculated from the mean-year values of a geomagnetic activity index am according to the Svalgard equation of regression for the pe-- riod from 1930 to 1960. For the same years the values of the geomagnetic moment M and separately of its ''inner'' (causes of which'' are inside the Earth) and ''external'' (causes of which are outside the Earth) parts have been calculated from the mean year data of 12 magnetic observatories. The proof of the presence of the 11-year variation in the moment M has been obtained. It is concluded that the 11-year variations in M result from the variations of the solar wind velocity

  14. Mirror Instability in the Turbulent Solar Wind

    Czech Academy of Sciences Publication Activity Database

    Hellinger, Petr; Landi, S.; Matteini, L.; Verdini, A.; Franci, L.

    2017-01-01

    Roč. 838, č. 2 (2017), č. článku 158. ISSN 0004-637X Institutional support: RVO:68378289 Keywords : instabilities * solar wind * turbulence * waves Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 5.533, year: 2016 http://iopscience.iop.org/article/10.3847/1538-4357/aa67e0

  15. The Solar Wind as a Turbulence Laboratory

    Directory of Open Access Journals (Sweden)

    Bruno Roberto

    2005-09-01

    Full Text Available In this review we will focus on a topic of fundamental importance for both plasma physics and astrophysics, namely the occurrence of large-amplitude low-frequency fluctuations of the fields that describe the plasma state. This subject will be treated within the context of the expanding solar wind and the most meaningful advances in this research field will be reported emphasizing the results obtained in the past decade or so. As a matter of fact, Ulysses’ high latitude observations and new numerical approaches to the problem, based on the dynamics of complex systems, brought new important insights which helped to better understand how turbulent fluctuations behave in the solar wind. In particular, numerical simulations within the realm of magnetohydrodynamic (MHD turbulence theory unraveled what kind of physical mechanisms are at the basis of turbulence generation and energy transfer across the spectral domain of the fluctuations. In other words, the advances reached in these past years in the investigation of solar wind turbulence now offer a rather complete picture of the phenomenological aspect of the problem to be tentatively presented in a rather organic way.

  16. Kinetic Properties of the Neutral Solar Wind

    International Nuclear Information System (INIS)

    Florinski, V.; Heerikhuisen, J.

    2017-01-01

    Charge-exchange collisions between the solar wind protons and interstellar hydrogen produce a distinctive population of neutral hydrogen streaming radially at nearly the solar-wind speed. This tenuous population, known as the neutral solar wind (NSW) is thought to play a key role in the appearance of the Interplanetary Boundary EXplorer ribbon, a bright circular band in the sky that is the source of neutral hydrogen with energies near 1 keV. According to the leading model of the ribbon, the velocity distribution of NSW hydrogen is imparted on the pickup ions (PUIs) generated via charge exchange with the interstellar protons beyond the heliopause, and in this way controls the stability of the resulting ring distribution of PUIs against hydromagnetic wave generation. In this paper, we examine the velocity distributions of the NSW atoms in the heliosphere and the outer heliosheath regions by following the phase-space trajectories of the Boltzmann equation. It is demonstrated that these distributions are highly anisotropic, with the parallel (radial) temperature greatly exceeding the perpendicular temperature. Ions picked up near 90° from the anisotropic NSW would form a stable ring distribution capable of generating the ribbon flux. We also discuss a second population of neutrals born in charge transfer collisions with interstellar PUIs, the so-called neutralized pickup ion (NPI) component. Their high thermal velocities translate into large parallel velocity spread of the daughter ribbon PUIs, which would adversely affect plasma stability in local interstellar space.

  17. Kinetic Properties of the Neutral Solar Wind

    Science.gov (United States)

    Florinski, V.; Heerikhuisen, J.

    2017-03-01

    Charge-exchange collisions between the solar wind protons and interstellar hydrogen produce a distinctive population of neutral hydrogen streaming radially at nearly the solar-wind speed. This tenuous population, known as the neutral solar wind (NSW) is thought to play a key role in the appearance of the Interplanetary Boundary EXplorer ribbon, a bright circular band in the sky that is the source of neutral hydrogen with energies near 1 keV. According to the leading model of the ribbon, the velocity distribution of NSW hydrogen is imparted on the pickup ions (PUIs) generated via charge exchange with the interstellar protons beyond the heliopause, and in this way controls the stability of the resulting ring distribution of PUIs against hydromagnetic wave generation. In this paper, we examine the velocity distributions of the NSW atoms in the heliosphere and the outer heliosheath regions by following the phase-space trajectories of the Boltzmann equation. It is demonstrated that these distributions are highly anisotropic, with the parallel (radial) temperature greatly exceeding the perpendicular temperature. Ions picked up near 90° from the anisotropic NSW would form a stable ring distribution capable of generating the ribbon flux. We also discuss a second population of neutrals born in charge transfer collisions with interstellar PUIs, the so-called neutralized pickup ion (NPI) component. Their high thermal velocities translate into large parallel velocity spread of the daughter ribbon PUIs, which would adversely affect plasma stability in local interstellar space.

  18. Solar Wind Charge Exchange During Geomagnetic Storms

    Science.gov (United States)

    Robertson, Ina P.; Cravens, Thomas E.; Sibeck, David G.; Collier, Michael R.; Kuntz, K. D.

    2012-01-01

    On March 31st. 2001, a coronal mass ejection pushed the subsolar magnetopause to the vicinity of geosynchronous orbit at 6.6 RE. The NASA/GSFC Community Coordinated Modeling Center (CCMe) employed a global magnetohydrodynamic (MHD) model to simulate the solar wind-magnetosphere interaction during the peak of this geomagnetic storm. Robertson et aL then modeled the expected 50ft X-ray emission due to solar wind charge exchange with geocoronal neutrals in the dayside cusp and magnetosheath. The locations of the bow shock, magnetopause and cusps were clearly evident in their simulations. Another geomagnetic storm took place on July 14, 2000 (Bastille Day). We again modeled X-ray emission due to solar wind charge exchange, but this time as observed from a moving spacecraft. This paper discusses the impact of spacecraft location on observed X-ray emission and the degree to which the locations of the bow shock and magnetopause can be detected in images.

  19. Large scale model testing

    International Nuclear Information System (INIS)

    Brumovsky, M.; Filip, R.; Polachova, H.; Stepanek, S.

    1989-01-01

    Fracture mechanics and fatigue calculations for WWER reactor pressure vessels were checked by large scale model testing performed using large testing machine ZZ 8000 (with a maximum load of 80 MN) at the SKODA WORKS. The results are described from testing the material resistance to fracture (non-ductile). The testing included the base materials and welded joints. The rated specimen thickness was 150 mm with defects of a depth between 15 and 100 mm. The results are also presented of nozzles of 850 mm inner diameter in a scale of 1:3; static, cyclic, and dynamic tests were performed without and with surface defects (15, 30 and 45 mm deep). During cyclic tests the crack growth rate in the elastic-plastic region was also determined. (author). 6 figs., 2 tabs., 5 refs

  20. Large scale development of wind power. Consequences for the national grid and the need for load balancing; Storskalig utbyggnad av vindkraft. Konsekvenser foer stamnaetet och behovet av reglerkraft

    Energy Technology Data Exchange (ETDEWEB)

    2008-06-15

    Wind power is expected to growth rapidly in Sweden. The existing certificate system gives economic incentives for development of 17 TWh from renewable energy sources until 2016, compared to the 2002 level. The Swedish Energy Agency estimates that 9 TWh wind power will be built by 2020, given the present certificate system. However, a new planning goal of 30 TWh wind energy by 2020 has been proposed by the Agency. It is very important for Svenska Kraftnaet to follow the development in order to take the right actions to adapt the national grid to the increased share of wind power. The total increased need for balancing power is estimated to be: 1 400-1 800 MW for 10 TWh added wind power, and 4 300-5 300 MW for 30 TWh. About 15% of the increased balancing need must be assigned to automatically frequency regulating generation. The rest can be made up of sources that can be regulated on a minute- or hour-scale. The planned wind power risks to replace generation with regulating capacity, and it is important to continuously analyze if and how this happens, and which the consequences will be for the balancing capacity. The socio-economic effects for the national grid include increased investment cost and increased costs foe balancing and regulating. Massive expansion in North Sweden is the most costly alternative, with a capitalized cost estimated to 25 000 MSEK (about 4 000 MUSD) at an expansion of 30 TWh wind power. This can be compared to the estimated investment cost for the wind power expansion of 150 000 MSEK

  1. Large-scale integration of off-shore wind power and regulation strategies of cogeneration plants in the Danish electricity system

    DEFF Research Database (Denmark)

    Østergaard, Poul Alberg

    2005-01-01

    The article analyses how the amount of a small-scale CHP plants and heat pumps and the regulation strategies of these affect the quantity of off-shore wind power that may be integrated into Danish electricity supply......The article analyses how the amount of a small-scale CHP plants and heat pumps and the regulation strategies of these affect the quantity of off-shore wind power that may be integrated into Danish electricity supply...

  2. On the Origins of the Intercorrelations Between Solar Wind Variables

    Science.gov (United States)

    Borovsky, Joseph E.

    2018-01-01

    It is well known that the time variations of the diverse solar wind variables at 1 AU (e.g., solar wind speed, density, proton temperature, electron temperature, magnetic field strength, specific entropy, heavy-ion charge-state densities, and electron strahl intensity) are highly intercorrelated with each other. In correlation studies of the driving of the Earth's magnetosphere-ionosphere-thermosphere system by the solar wind, these solar wind intercorrelations make determining cause and effect very difficult. In this report analyses of solar wind spacecraft measurements and compressible-fluid computer simulations are used to study the origins of the solar wind intercorrelations. Two causes are found: (1) synchronized changes in the values of the solar wind variables as the plasma types of the solar wind are switched by solar rotation and (2) dynamic interactions (compressions and rarefactions) in the solar wind between the Sun and the Earth. These findings provide an incremental increase in the understanding of how the Sun-Earth system operates.

  3. ISOTOPIC MASS FRACTIONATION OF SOLAR WIND: EVIDENCE FROM FAST AND SLOW SOLAR WIND COLLECTED BY THE GENESIS MISSION

    International Nuclear Information System (INIS)

    Heber, Veronika S.; Baur, Heinrich; Wieler, Rainer; Bochsler, Peter; McKeegan, Kevin D.; Neugebauer, Marcia; Reisenfeld, Daniel B.; Wiens, Roger C.

    2012-01-01

    NASA's Genesis space mission returned samples of solar wind collected over ∼2.3 years. We present elemental and isotopic compositions of He, Ne, and Ar analyzed in diamond-like carbon targets from the slow and fast solar wind collectors to investigate isotopic fractionation processes during solar wind formation. The solar wind provides information on the isotopic composition for most volatile elements for the solar atmosphere, the bulk Sun and hence, on the solar nebula from which it formed 4.6 Ga ago. Our data reveal a heavy isotope depletion in the slow solar wind compared to the fast wind composition by 63.1 ± 2.1 per mille for He, 4.2 ± 0.5 per mille amu –1 for Ne and 2.6 ± 0.5 per mille amu –1 for Ar. The three Ne isotopes suggest that isotopic fractionation processes between fast and slow solar wind are mass dependent. The He/H ratios of the collected slow and fast solar wind samples are 0.0344 and 0.0406, respectively. The inefficient Coulomb drag model reproduces the measured isotopic fractionation between fast and slow wind. Therefore, we apply this model to infer the photospheric isotopic composition of He, Ne, and Ar from our solar wind data. We also compare the isotopic composition of oxygen and nitrogen measured in the solar wind with values of early solar system condensates, probably representing solar nebula composition. We interpret the differences between these samples as being due to isotopic fractionation during solar wind formation. For both elements, the magnitude and sign of the observed differences are in good agreement with the values predicted by the inefficient Coulomb drag model.

  4. ISOTOPIC MASS FRACTIONATION OF SOLAR WIND: EVIDENCE FROM FAST AND SLOW SOLAR WIND COLLECTED BY THE GENESIS MISSION

    Energy Technology Data Exchange (ETDEWEB)

    Heber, Veronika S.; Baur, Heinrich; Wieler, Rainer [Institute for Geochemistry and Petrology, ETH Zurich, Clausiusstrasse 25, CH-8092 Zurich (Switzerland); Bochsler, Peter [Physikalisches Institut, Universitaet Bern, Sidlerstasse 5, CH-3012 Bern (Switzerland); McKeegan, Kevin D. [Department of Earth and Space Sciences, University of California Los Angeles, 595 Charles Young Drive East, Box 951567, Los Angeles, CA 90095-1567 (United States); Neugebauer, Marcia [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721-0092 (United States); Reisenfeld, Daniel B. [Department of Physics and Astronomy, University of Montana, Missoula, MT 59812 (United States); Wiens, Roger C., E-mail: heber@ess.ucla.edu [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States)

    2012-11-10

    NASA's Genesis space mission returned samples of solar wind collected over {approx}2.3 years. We present elemental and isotopic compositions of He, Ne, and Ar analyzed in diamond-like carbon targets from the slow and fast solar wind collectors to investigate isotopic fractionation processes during solar wind formation. The solar wind provides information on the isotopic composition for most volatile elements for the solar atmosphere, the bulk Sun and hence, on the solar nebula from which it formed 4.6 Ga ago. Our data reveal a heavy isotope depletion in the slow solar wind compared to the fast wind composition by 63.1 {+-} 2.1 per mille for He, 4.2 {+-} 0.5 per mille amu{sup -1} for Ne and 2.6 {+-} 0.5 per mille amu{sup -1} for Ar. The three Ne isotopes suggest that isotopic fractionation processes between fast and slow solar wind are mass dependent. The He/H ratios of the collected slow and fast solar wind samples are 0.0344 and 0.0406, respectively. The inefficient Coulomb drag model reproduces the measured isotopic fractionation between fast and slow wind. Therefore, we apply this model to infer the photospheric isotopic composition of He, Ne, and Ar from our solar wind data. We also compare the isotopic composition of oxygen and nitrogen measured in the solar wind with values of early solar system condensates, probably representing solar nebula composition. We interpret the differences between these samples as being due to isotopic fractionation during solar wind formation. For both elements, the magnitude and sign of the observed differences are in good agreement with the values predicted by the inefficient Coulomb drag model.

  5. Solar wind acceleration in coronal holes

    International Nuclear Information System (INIS)

    Kopp, R.A.

    1978-01-01

    Past attempts to explain the large solar wind velocities in high speed streams by theoretical models of the expansion have invoked either extended nonthermal heating of the corona, heat flux inhibition, or direct addition of momentum to the expanding coronal plasma. Several workers have shown that inhibiting the heat flux at low coronal densities is probably not adequate to explain quantitatively the observed plasma velocities in high speed streams. It stressed that, in order to account for both these large plasma velocities and the low densities found in coronal holes (from which most high speed streams are believed to emanate), extended heating by itself will not suffice. One needs a nonthermal mechanism to provide the bulk acceleration of the high wind plasma close to the sun, and the most likely candidate at present is direct addition of the momentum carried by outward-propagating waves to the expanding corona. Some form of momentum addition appears to be absolutely necessary if one hopes to build quantitatively self-consistent models of coronal holes and high speed solar wind streams

  6. Morphology of Pseudostreamers and Solar Wind Properties

    Science.gov (United States)

    Panasenco, Olga; Velli, Marco

    2016-05-01

    The solar dynamo and photospheric convection lead to three main types of structures extending from the solar surface into the corona - active regions, solar filaments (prominences when observed at the limb) and coronal holes. These structures exist over a wide range of scales, and are interlinked with each other in evolution and dynamics. Active regions can form clusters of magnetic activity and the strongest overlie sunspots. In the decay of active regions, the boundaries separating opposite magnetic polarities (neutral lines) develop the specific structures called filament channels above which filaments form. In the presence of flux imbalance decaying active regions can also give birth to lower latitude coronal holes. The accumulation of magnetic flux at coronal hole boundaries also creates the conditions for filament formation: polar crown filaments are permanently present at the boundaries of the polar coronal holes. Middle-latitude and equatorial coronal holes - the result of active region evolution - can create pseudostreamers (PSs) if other coronal holes of the same polarity are present. While helmet streamers form between open fields of opposite polarities, the pseudostreamer, characterized by a smaller coronal imprint, typically shows a more prominent straight ray or stalk extending from the corona. The pseudostreamer base at photospheric heights is multipolar; often one observes tripolar magnetic configurations with two neutral lines - where filaments can form - separating the coronal holes. Here we discuss the specific role of filament channels on pseudostreamer topology and on solar wind properties. 1D numerical analysis of PSs shows that the properties of the solar wind from around PSs depend on the presence/absence of filament channels, number of channels and chirality at the PS base low in the corona.

  7. Large scale tracking algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Hansen, Ross L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Love, Joshua Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Melgaard, David Kennett [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Karelitz, David B. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Pitts, Todd Alan [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Zollweg, Joshua David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Anderson, Dylan Z. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Nandy, Prabal [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Whitlow, Gary L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bender, Daniel A. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Byrne, Raymond Harry [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-01-01

    Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

  8. A NEW THREE-DIMENSIONAL SOLAR WIND MODEL IN SPHERICAL COORDINATES WITH A SIX-COMPONENT GRID

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Xueshang; Zhang, Man; Zhou, Yufen, E-mail: fengx@spaceweather.ac.cn [SIGMA Weather Group, State Key Laboratory for Space Weather, Center for Space Science and Applied Research, Chinese Academy of Sciences, Beijing 100190 (China)

    2014-09-01

    In this paper, we introduce a new three-dimensional magnetohydrodynamics numerical model to simulate the steady state ambient solar wind from the solar surface to 215 R {sub s} or beyond, and the model adopts a splitting finite-volume scheme based on a six-component grid system in spherical coordinates. By splitting the magnetohydrodynamics equations into a fluid part and a magnetic part, a finite volume method can be used for the fluid part and a constrained-transport method able to maintain the divergence-free constraint on the magnetic field can be used for the magnetic induction part. This new second-order model in space and time is validated when modeling the large-scale structure of the solar wind. The numerical results for Carrington rotation 2064 show its ability to produce structured solar wind in agreement with observations.

  9. Boosting the adoption and the reliability of renewable energy sources: Mitigating the large-scale wind power intermittency through vehicle to grid technology

    International Nuclear Information System (INIS)

    Zhao, Yang; Noori, Mehdi; Tatari, Omer

    2017-01-01

    The integration of wind energy in the electricity sector and the adoption of electric vehicles in the transportation sector both have the potential to significantly reduce greenhouse gas emissions individually as well as in tandem with Vehicle-to-Grid technology. This study aims to evaluate the greenhouse gas emission savings of mitigating intermittency resulting from the introduction of wind power through Vehicle-to-Grid technologies, as well as the extent to which the marginal electricity consumption from charging an electric vehicle fleet may weaken this overall environmental benefit. To this end, the comparisons are conducted in seven independent system operator regions. The results indicate that, in most cases, the emission savings of a combination of wind power and Vehicle-to-Grid technology outweighs the additional emissions from marginal electricity generation for electric vehicles. In addition, the fluctuations in newly-integrated wind power could be balanced in the future using EVs and V2G technology, provided that a moderate portion of EV owners is willing to provide V2G services. On the other hand, such a combination is not favorable if the Vehicle-to-Grid service participation rate is less than 5% of all electric vehicle owners within a particular region. - Highlights: • The environmental benefit of vehicle to grid systems as grid stabilizer is analyzed. • Emission savings of vehicle to grid and impacts of electric vehicles are compared. • Seven independent system operator regions are studied. • Uncertainty and sensitivity analysis are performed through a Monte Carlo Simulation.

  10. The sun, the solar wind, and the heliosphere

    CERN Document Server

    Miralles, Mari Paz

    2011-01-01

    This volume presents a concise, up-to-date overview of current research on the observations, theoretical interpretations, and empirical and physical descriptions of the Sun, the Solar Wind, and the Heliosphere, from the solar interior outward to the planets.

  11. Coulomb collisions in the solar wind

    Science.gov (United States)

    Klein, L. W.; Ogilvie, K. W.; Burlaga, L. F.

    1985-01-01

    A major improvement of the present investigation over previous studies of the subject is related to the use of helium temperatures obtained from helium ion measurements uncontaminated by the high-velocity tail of the proton distribution. More observations, covering a large parameter range, were employed, and the effects of interspecies drift were taken into account. It is shown in a more definite way than has been done previously, that Coulomb collisions provide the most important mechanism bringing about equilibrium between helium and protons in the solar wind. Other mechanisms may play some part in restricted regions, but Coulomb collisions are dominant on the macroscale.

  12. Simulation experiments and solar wind sputtering

    International Nuclear Information System (INIS)

    Griffith, J.E.; Papanastassiou, D.A.; Russell, W.A.; Tombrello, T.A.; Weller, R.A.

    1978-01-01

    In order to isolate the role played by solar wind sputtering from other lunar surface phenomena a number of simulation experiments were performed, including isotope abundance measurements of Ca sputtered from terrestrial fluorite and plagioclase by 50-keV and 130-keV 14 N beams, measurement of the energy distribution of U atoms sputtered with 80-keV 40 Ar, and measurement of the fraction of sputtered U atoms which stick on the surfaces used to collect these atoms. 10 references

  13. Genesis Solar Wind Science Canister Components Curated as Potential Solar Wind Collectors and Reference Contamination Sources

    Science.gov (United States)

    Allton, J. H.; Gonzalez, C. P.; Allums, K. K.

    2016-01-01

    The Genesis mission collected solar wind for 27 months at Earth-Sun L1 on both passive and active collectors carried inside of a Science Canister, which was cleaned and assembled in an ISO Class 4 cleanroom prior to launch. The primary passive collectors, 271 individual hexagons and 30 half-hexagons of semiconductor materials, are described in. Since the hard landing reduced the 301 passive collectors to many thousand smaller fragments, characterization and posting in the online catalog remains a work in progress, with about 19% of the total area characterized to date. Other passive collectors, surfaces of opportunity, have been added to the online catalog. For species needing to be concentrated for precise measurement (e.g. oxygen and nitrogen isotopes) an energy-independent parabolic ion mirror focused ions onto a 6.2 cm diameter target. The target materials, as recovered after landing, are described in. The online catalog of these solar wind collectors, a work in progress, can be found at: http://curator.jsc.nasa.gov/gencatalog/index.cfm This paper describes the next step, the cataloging of pieces of the Science Canister, which were surfaces exposed to the solar wind or component materials adjacent to solar wind collectors which may have contributed contamination.

  14. FY 1998 Report on development of large-scale wind power generation systems. Feasibility study on development of new technologies for wind power generation (Study on the development of wind power generation systems for small-scale power grids); 1998 nendo ogata furyoku hatsuden system kaihatsu seika hokokusho. Furyoku hatsuden shingijutsu kaihatsu kanosei chosa (shokibo keito ni okeru furyoku hatsuden system ni kansuru chosa)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This survey includes the characteristics of small-scale power grids, feasibility studies on introduction of wind turbines in these grids, and statuses of application of wind turbines to isolated islands or the like in the advanced countries, in order to promote introduction of wind power generation systems in isolated islands or the like. It is concluded that small-capacity wind power generation systems can be possibly introduced in the intermediate- to large-scale grids in isolated islands, 1,500kW or larger in capacity, in the Tokyo, Kyushu and Okinawa Electric Power Companies' areas. A scheduled steamer ship for isolated islands can carry up to 10 ton track, and introduction of a small-scale wind turbine is more advantageous viewed from the transportation cost. Some foreign countries have the sites which have achieved a high percentage of grid connection of wind power units by stabilizing wind conditions and connecting them to the main high-voltage grids in different manners from those adopted in Japan. For developing wind turbine bodies, most of the foreign countries surveyed are concentrating their efforts on development and manufacture of large-size units, paying little attention on development of small-size wind turbines for isolated islands. For the future prospects, the promising concepts include adoption of wind turbines small in capacity and easy to transport and assemble, and hybrid systems combined with power storage units. (NEDO)

  15. FY 1998 Report on development of large-scale wind power generation systems. Feasibility study on development of new technologies for wind power generation (Study on the development of wind power generation systems for small-scale power grids); 1998 nendo ogata furyoku hatsuden system kaihatsu seika hokokusho. Furyoku hatsuden shingijutsu kaihatsu kanosei chosa (shokibo keito ni okeru furyoku hatsuden system ni kansuru chosa)

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    This survey includes the characteristics of small-scale power grids, feasibility studies on introduction of wind turbines in these grids, and statuses of application of wind turbines to isolated islands or the like in the advanced countries, in order to promote introduction of wind power generation systems in isolated islands or the like. It is concluded that small-capacity wind power generation systems can be possibly introduced in the intermediate- to large-scale grids in isolated islands, 1,500kW or larger in capacity, in the Tokyo, Kyushu and Okinawa Electric Power Companies' areas. A scheduled steamer ship for isolated islands can carry up to 10 ton track, and introduction of a small-scale wind turbine is more advantageous viewed from the transportation cost. Some foreign countries have the sites which have achieved a high percentage of grid connection of wind power units by stabilizing wind conditions and connecting them to the main high-voltage grids in different manners from those adopted in Japan. For developing wind turbine bodies, most of the foreign countries surveyed are concentrating their efforts on development and manufacture of large-size units, paying little attention on development of small-size wind turbines for isolated islands. For the future prospects, the promising concepts include adoption of wind turbines small in capacity and easy to transport and assemble, and hybrid systems combined with power storage units. (NEDO)

  16. The solar wind and the earth

    International Nuclear Information System (INIS)

    Akasofu, I.; Kamide, Y.

    1987-01-01

    The sun constantly emits an enormous amount of radiation into space. This energy emission consists of three modes. Almost all the energy is emitted in the form of familiar sunlight but sun also emits X-rays, extreme ultraviolet (EUV), and UV radiation, which is absorbed above the earth's stratosphere, as a second mode of solar energy. The sun has made another important mode of energy emission in which the energy is carried out by charged particles. These particles have a bery wide range of energies, from less than 1 keV to more than 1 GeV. Because of this wide range, it is convenient to group them into two components: particles, with energies greater than 10 keV and the lower-energy particles. The former are generally referred to as solar portions or solar cosmic rays; their emission is associated with active features on the sun. Low-energy particles constitute plasma which is called the solar wind

  17. The 3-D solar radioastronomy and the structure of the corona and the solar wind. [solar probes of solar activity

    Science.gov (United States)

    Steinberg, J. L.; Caroubalos, C.

    1976-01-01

    The mechanism causing solar radio bursts (1 and 111) is examined. It is proposed that a nonthermal energy source is responsible for the bursts; nonthermal energy is converted into electromagnetic energy. The advantages are examined for an out-of-the-ecliptic solar probe mission, which is proposed as a means of stereoscopically viewing solar radio bursts, solar magnetic fields, coronal structure, and the solar wind.

  18. Large-scale Wind Turbine Blade Redesign Based on Reverse Engineering%大型风能发电机组叶片反求再设计

    Institute of Scientific and Technical Information of China (English)

    陶庆; 孙文磊

    2015-01-01

    叶片的外形设计和翼型的选择等都能影响风机性能和产能效率。提出一种大型风能发电机组叶片反求再设计的原理和方法,通过对大型风能发电机组叶片反求测量、大型风能发电机组叶片逆向CAD建模,寻找几何特征,探索制约叶片形状的基本因素,确定叶片截面参数计算公式,利用所开发的叶片翼型自动生成系统,完成了叶片的再设计,并得到了实际应用。%The large⁃scale wind turbine blade contour design and the choice of wing section affect the wind turbine performance and energy efficiency. A redesign principle and method for large⁃scale wind turbine blade was presented which was based on the analy⁃sis of blade CAD model from reverse engineering, looking for geometric features, exploring basic constraint factors on blade shape, and determining parameters of blade cross section calculation formula. Blade design was completed using this self⁃developed blade aerofoil automatic generation system. The results show that the redesign meets the production requirements.

  19. Estimating the Quantity of Wind and Solar Required To Displace Storage-Induced Emissions.

    Science.gov (United States)

    Hittinger, Eric; Azevedo, Inês M L

    2017-11-07

    The variable and nondispatchable nature of wind and solar generation has been driving interest in energy storage as an enabling low-carbon technology that can help spur large-scale adoption of renewables. However, prior work has shown that adding energy storage alone for energy arbitrage in electricity systems across the U.S. routinely increases system emissions. While adding wind or solar reduces electricity system emissions, the emissions effect of both renewable generation and energy storage varies by location. In this work, we apply a marginal emissions approach to determine the net system CO 2 emissions of colocated or electrically proximate wind/storage and solar/storage facilities across the U.S. and determine the amount of renewable energy required to offset the CO 2 emissions resulting from operation of new energy storage. We find that it takes between 0.03 MW (Montana) and 4 MW (Michigan) of wind and between 0.25 MW (Alabama) and 17 MW (Michigan) of solar to offset the emissions from a 25 MW/100 MWh storage device, depending on location and operational mode. Systems with a realistic combination of renewables and storage will result in net emissions reductions compared with a grid without those systems, but the anticipated reductions are lower than a renewable-only addition.

  20. Program of solar wind data analysis utilizing data from Pioneer 6, Mariner 5 and explorer 35

    Science.gov (United States)

    Siscoe, G. L.

    1972-01-01

    A combined data analysis and theoretical program aimed at interpreting and utilizing solar wind data obtained from Pioneer 6, Mariner 5, and Explorer 35 has been completed. A theoretical model of the radial dependence of large scale solar wind inhomogeneities was developed and used to map solar wind variations measured by Explorer 35 to various heliocentric distances and to the orbits of Mercury, Venus, and Mars. The model was also used to determine power spectra velocity, density and temperature variations of 20 R sub s from spectra obtained from the Mariner 5 data at an average heliocentric distance of 180 R sub s. Five stream-stream interaction events in the Pioneer 6 data were analyzed which confirmed the picture of a spiral compression ridge interfacing the two streams and the associated east-west deflections of the solar wind flow. Magnetopause crossings observed in Explorer 35 plasma data were used to develop statics on boundary motions at lunar distance. A study of the geomagnetic disturbance field asymmetry was performed and a model of disturbance field from a partial ring current was developed.

  1. Solar wind structure out of the ecliptic plane over solar cycles

    Science.gov (United States)

    Sokol, J. M.; Bzowski, M.; Tokumaru, M.

    2017-12-01

    Sun constantly emits a stream of plasma known as solar wind. Ground-based observations of the solar wind speed through the interplanetary scintillations (IPS) of radio flux from distant point sources and in-situ measurements by Ulysses mission revealed that the solar wind flow has different characteristics depending on the latitude. This latitudinal structure evolves with the cycle of solar activity. The knowledge on the evolution of solar wind structure is important for understanding the interaction between the interstellar medium surrounding the Sun and the solar wind, which is responsible for creation of the heliosphere. The solar wind structure must be taken into account in interpretation of most of the observations of heliospheric energetic neutral atoms, interstellar neutral atoms, pickup ions, and heliospheric backscatter glow. The information on the solar wind structure is not any longer available from direct measurements after the termination of Ulysses mission and the only source of the solar wind out of the ecliptic plane is the IPS observations. However, the solar wind structure obtained from this method contains inevitable gaps in the time- and heliolatitude coverage. Sokół et al 2015 used the solar wind speed data out of the ecliptic plane retrieved from the IPS observations performed by Institute for Space-Earth Environmental Research (Nagoya University, Japan) and developed a methodology to construct a model of evolution of solar wind speed and density from 1985 to 2013 that fills the data gaps. In this paper we will present a refined model of the solar wind speed and density structure as a function of heliographic latitude updated by the most recent data from IPS observations. And we will discuss methods of extrapolation of the solar wind structure out of the ecliptic plane for the past solar cycles, when the data were not available, as well as forecasting for few years upward.

  2. EVIDENCE FOR NEWLY INITIATED RECONNECTION IN THE SOLAR WIND AT 1 AU

    International Nuclear Information System (INIS)

    Xu, Xiaojun; Ma, Yonghui; Wong, Hon-Cheng; Wang, Yi; Zuo, Pingbing; Wei, Fengsi; Feng, Xueshang; Zhou, Meng; Deng, Xiaohua

    2015-01-01

    We report the first evidence for a large-scale reconnection exhaust newly initiated in the solar wind using observations from three spacecraft: ACE, Wind, and ARTEMIS P2. We identified a well-structured X-line exhaust using measurements from ARTEMIS P2 in the downstream solar wind. However, in the upstream solar wind, ACE detected the same current sheet that corresponds to the exhaust identified by ARTEMIS P2 data without showing any reconnection signals. We cannot find any reconnection signals from Wind located between ACE and ARTEMIS P2. Within the exhaust, a magnetic island is identified, which is not consistent with the quasi-steady feature as previously reported and provides further evidence that the reconnection is newly initiated. Our observations show that the entering of energetic particles, probably from Earth's bow shock, makes the crucial difference between the non-reconnecting current sheet and the exhaust. Since no obvious driving factors are responsible for the reconnection initiation, we infer that these energetic particles probably play an important role in the reconnection initiation. Theoretical analysis also shows support for this potential mechanism

  3. Reliability Assessment Considering the Coordination of Wind Power, Solar Energy and Energy Storage

    Institute of Scientific and Technical Information of China (English)

    WANG Haiying; BAI Xiaomin; XU Jing

    2012-01-01

    Large-scale integration of wind power and solar photovoltaic (PV) power in an electric grid can result in a high operating risk due to their randomness and intermi- ttency. Energy storage (ES) can be used to coordinate with them to reduce this risk by improving supply continuity. It is therefore important to evaluate the reliability benefits of systems consist of wind power, solar photovoltaic power and energy storage. The objective of this paper is to evaluate how the parameters such as the capacity and characteristics of ES and the configuration of a hybrid generation system (HGS) affect the system adequacy based on the sequential Monte Carlo approach.

  4. The study of large-scale wind turbine blade redesign system%大型风能发电机组叶片再设计系统研究

    Institute of Scientific and Technical Information of China (English)

    陶庆; 孙文磊

    2015-01-01

    The large-scale wind turbine blade contour design and the choice of wing section are the core technolo-gy in wind power generation;both of them could affect the wind turbine performance and the energy efficiency. This paper presents the redesign principles and methods for large-scale wind turbine blade,based on the analysis of blade CAD model from reverse engineering,looking for geometric features,exploring basic constraint factors on blade shape,and determining parameters of blade cross section calculation formula.Blade design has been com-pleted by using this self-developed blade airfoil automatic generation system.The results showed that the redesign meets all the production requirements.%叶片的外形设计和翼型的选择是影响风力机性能和产能效率最为核心的技术。提出了一种大型风能发电机组叶片再设计的原理和方法,对叶片模型进行剖析,寻找几何特征,探索制约叶片形状的基本因素,确定叶片截面参数计算公式,利用所开发的叶片翼型自动生成系统,完成了叶片的再设计,并得到了实际应用。结果表明:这种再设计方法满足产品设计需求。

  5. Indirect solar wind geothermal: Alternative energy sources 4, volume 4

    Science.gov (United States)

    Veziroglu, T. N.

    The utilities are obliged to provide electricity in a reliable and cost effective manner. Some unique problems posed by large scale wind turbines as an electricity source have to be considered. A value model is presented which is based upon the fuel displacement capability and the capacity displacement capability of wind turbines. The amount of fossil fuels which is saved by wind turbines depends on the forecasted wind power output, the actual power output fluctuations of the wind turbines and on system operation. The highly controversial capacity credit of wind turbines is discussed under the aspect of system reliability. It is shown that calculations of the capacity credit should be based upon detailed investigations with regard to the time dependence of the hourly wind power output.

  6. Nearly incompressible fluids: Hydrodynamics and large scale inhomogeneity

    International Nuclear Information System (INIS)

    Hunana, P.; Zank, G. P.; Shaikh, D.

    2006-01-01

    A system of hydrodynamic equations in the presence of large-scale inhomogeneities for a high plasma beta solar wind is derived. The theory is derived under the assumption of low turbulent Mach number and is developed for the flows where the usual incompressible description is not satisfactory and a full compressible treatment is too complex for any analytical studies. When the effects of compressibility are incorporated only weakly, a new description, referred to as 'nearly incompressible hydrodynamics', is obtained. The nearly incompressible theory, was originally applied to homogeneous flows. However, large-scale gradients in density, pressure, temperature, etc., are typical in the solar wind and it was unclear how inhomogeneities would affect the usual incompressible and nearly incompressible descriptions. In the homogeneous case, the lowest order expansion of the fully compressible equations leads to the usual incompressible equations, followed at higher orders by the nearly incompressible equations, as introduced by Zank and Matthaeus. With this work we show that the inclusion of large-scale inhomogeneities (in this case time-independent and radially symmetric background solar wind) modifies the leading-order incompressible description of solar wind flow. We find, for example, that the divergence of velocity fluctuations is nonsolenoidal and that density fluctuations can be described to leading order as a passive scalar. Locally (for small lengthscales), this system of equations converges to the usual incompressible equations and we therefore use the term 'locally incompressible' to describe the equations. This term should be distinguished from the term 'nearly incompressible', which is reserved for higher-order corrections. Furthermore, we find that density fluctuations scale with Mach number linearly, in contrast to the original homogeneous nearly incompressible theory, in which density fluctuations scale with the square of Mach number. Inhomogeneous nearly

  7. Self-organization of large-scale ULF electromagnetic wave structures in their interaction with nonuniform zonal winds in the ionospheric E region

    International Nuclear Information System (INIS)

    Aburjania, G. D.; Chargazia, Kh. Z.

    2011-01-01

    A study is made of the generation and subsequent linear and nonlinear evolution of ultralow-frequency planetary electromagnetic waves in the E region of a dissipative ionosphere in the presence of a nonuniform zonal wind (a sheared flow). Hall currents flowing in the E region and such permanent global factors as the spatial nonuniformity of the geomagnetic field and of the normal component of the Earth’s angular velocity give rise to fast and slow planetary-scale electromagnetic waves. The efficiency of the linear amplification of planetary electromagnetic waves in their interaction with a nonuniform zonal wind is analyzed. When there are sheared flows, the operators of linear problems are non-self-conjugate and the corresponding eigenfunctions are nonorthogonal, so the canonical modal approach is poorly suited for studying such motions and it is necessary to utilize the so-called nonmodal mathematical analysis. It is shown that, in the linear evolutionary stage, planetary electromagnetic waves efficiently extract energy from the sheared flow, thereby substantially increasing their amplitude and, accordingly, energy. The criterion for instability of a sheared flow in an ionospheric medium is derived. As the shear instability develops and the perturbation amplitude grows, a nonlinear self-localization mechanism comes into play and the process ends with the self-organization of nonlinear, highly localized, solitary vortex structures. The system thus acquires a new degree of freedom, thereby providing a new way for the perturbation to evolve in a medium with a sheared flow. Depending on the shape of the sheared flow velocity profile, nonlinear structures can be either purely monopole vortices or vortex streets against the background of the zonal wind. The accumulation of such vortices can lead to a strongly turbulent state in an ionospheric medium.

  8. Characteristics of Solar Wind Density Depletions During Solar Cycles 23 and 24

    Directory of Open Access Journals (Sweden)

    Keunchan Park

    2017-06-01

    Full Text Available Solar wind density depletions are phenomena that solar wind density is rapidly decreased and keep the state. They are generally believed to be caused by the interplanetary (IP shocks. However, there are other cases that are hardly associated with IP shocks. We set up a hypothesis for this phenomenon and analyze this study. We have collected the solar wind parameters such as density, speed and interplanetary magnetic field (IMF data related to the solar wind density depletion events during the period from 1996 to 2013 that are obtained with the advanced composition explorer (ACE and the Wind satellite. We also calculate two pressures (magnetic, dynamic and analyze the relation with density depletion. As a result, we found total 53 events and the most these phenomena’s sources caused by IP shock are interplanetary coronal mass ejection (ICME. We also found that solar wind density depletions are scarcely related with IP shock’s parameters. The solar wind density is correlated with solar wind dynamic pressure within density depletion. However, the solar wind density has an little anti-correlation with IMF strength during all events of solar wind density depletion, regardless of the presence of IP shocks. Additionally, In 47 events of IP shocks, we find 6 events that show a feature of blast wave. The quantities of IP shocks are weaker than blast wave from the Sun, they are declined in a short time after increasing rapidly. We thus argue that IMF strength or dynamic pressure are an important factor in understanding the nature of solar wind density depletion. Since IMF strength and solar wind speed varies with solar cycle, we will also investigate the characteristics of solar wind density depletion events in different phases of solar cycle as an additional clue to their physical nature.

  9. The problem of intermittency of renewable energies: solar and wind energy

    International Nuclear Information System (INIS)

    Livet, Frederic

    2011-01-01

    As solar and wind energies are to be intensively developed but are intermittent, more or less regular and unpredictable, the author first discusses methods which are presently used to manage this intermittency in various European countries. He also discusses the various methods which are proposed to compensate this intermittency: hydraulic storage, hydrogen-based storage, batteries, and large scale interconnections. He gives and comments cost assessments of the various proposed methods and of capacities. He shows that various measures which are discussed at the European level to promote renewable energies and to promote electricity exchanges will in fact result in a three times higher price of electricity for individuals

  10. The solar wind in the third dimension

    International Nuclear Information System (INIS)

    Neugebauer, M.

    1996-01-01

    For many years, solar-wind physicists have been using plasma and field data acquired near the ecliptic plane together with data on the scintillation of radio sources and remote sensing of structures in the solar corona to estimate the properties of the high-latitude solar wind. Because of the highly successful Ulysses mission, the moment of truth is now here. This paper summarizes the principal agreements and differences between the Ulysses observations and expectations. The speed of the high-latitude solar wind was even greater than anticipated. The strength of the radial component of the interplanetary magnetic field was found to be independent of latitude. The tilt of the heliospheric current sheet caused reverse corotating shocks to be observed to higher latitudes than forward corotating shocks. The energetic particles accelerated in these shocks were detected well poleward of the latitudes at which Ulysses observed the interaction regions themselves. As anticipated, there was a strong flux of outward propagating Alfven waves throughout the polar flow. Those waves were probably largely responsible for the smaller-than-anticipated increase of galactic cosmic rays with increasing latitude. As expected, the charge state or ionization temperature of heavy ions was lower in the polar flow than in low-latitude interstream flows. What was not anticipated was the correlation of elemental abundances with ionization temperatures; the Ulysses data revealed a connection between the first ionization time in the upper chromosphere and the final ionization state in the corona. As expected, transient events were detected to ∼60 deg. latitude, but the properties of those high latitude transient flows held some surprises. At high latitudes, the speeds of the transient interplanetary plasma clouds were approximately the same as the speed of the ambient plasma and the expansion of the clouds drove forward and reverse shock pairs that had never been seen at low latitudes. At high

  11. Solar Wind Associated with Near Equatorial Coronal Hole M ...

    Indian Academy of Sciences (India)

    2015-05-25

    May 25, 2015 ... coronal hole and solar wind. For both the wavelength bands, we also com- pute coronal hole radiative energy near the earth and it is found to be of similar order as that of solar wind energy. However, for the wavelength. 193 Å, owing to almost similar magnitudes of energy emitted by coronal hole and ...

  12. Large Scale Automatic Analysis and Classification of Roof Surfaces for the Installation of Solar Panels Using a Multi-Sensor Aerial Platform

    Directory of Open Access Journals (Sweden)

    Luis López-Fernández

    2015-09-01

    Full Text Available A low-cost multi-sensor aerial platform, aerial trike, equipped with visible and thermographic sensors is used for the acquisition of all the data needed for the automatic analysis and classification of roof surfaces regarding their suitability to harbor solar panels. The geometry of a georeferenced 3D point cloud generated from visible images using photogrammetric and computer vision algorithms, and the temperatures measured on thermographic images are decisive to evaluate the areas, tilts, orientations and the existence of obstacles to locate the optimal zones inside each roof surface for the installation of solar panels. This information is complemented with the estimation of the solar irradiation received by each surface. This way, large areas may be efficiently analyzed obtaining as final result the optimal locations for the placement of solar panels as well as the information necessary (location, orientation, tilt, area and solar irradiation to estimate the productivity of a solar panel from its technical characteristics.

  13. Alfvénic fluctuations in "newborn"' polar solar wind

    Directory of Open Access Journals (Sweden)

    B. Bavassano

    2005-06-01

    Full Text Available The 3-D structure of the solar wind is strongly dependent upon the Sun's activity cycle. At low solar activity a bimodal structure is dominant, with a fast and uniform flow at the high latitudes, and slow and variable flows at low latitudes. Around solar maximum, in sharp contrast, variable flows are observed at all latitudes. This last kind of pattern, however, is a relatively short-lived feature, and quite soon after solar maximum the polar wind tends to regain its role. The plasma parameter distributions for these newborn polar flows appear very similar to those typically observed in polar wind at low solar activity. The point addressed here is about polar wind fluctuations. As is well known, the low-solar-activity polar wind is characterized by a strong flow of Alfvénic fluctuations. Does this hold for the new polar flows too? An answer to this question is given here through a comparative statistical analysis on parameters such as total energy, cross helicity, and residual energy, that are of general use to describe the Alfvénic character of fluctuations. Our results indicate that the main features of the Alfvénic fluctuations observed in low-solar-activity polar wind have been quickly recovered in the new polar flows developed shortly after solar maximum. Keywords. Interplanetary physics (MHD waves and turbulence; Sources of the solar wind – Space plasma physics (Turbulence

  14. Quasar Feedback in the Ultraluminous Infrared Galaxy F11119+3257: Connecting the Accretion Disk Wind with the Large-scale Molecular Outflow

    Science.gov (United States)

    Veilleux, S.; Bolatto, A.; Tombesi, F.; Meléndez, M.; Sturm, E.; González-Alfonso, E.; Fischer, J.; Rupke, D. S. N.

    2017-07-01

    In Tombesi et al., we reported the first direct evidence for a quasar accretion disk wind driving a massive (>100 M ⊙ yr-1) molecular outflow. The target was F11119+3257, an ultraluminous infrared galaxy (ULIRG) with unambiguous type 1 quasar optical broad emission lines. The energetics of the accretion disk wind and molecular outflow were found to be consistent with the predictions of quasar feedback models where the molecular outflow is driven by a hot energy-conserving bubble inflated by the inner quasar accretion disk wind. However, this conclusion was uncertain because the mass outflow rate, momentum flux, and mechanical power of the outflowing molecular gas were estimated from the optically thick OH 119 μm transition profile observed with Herschel. Here, we independently confirm the presence of the molecular outflow in F11119+3257, based on the detection of ˜±1000 km s-1 blue- and redshifted wings in the CO(1-0) emission line profile derived from deep ALMA observations obtained in the compact array configuration (˜2.″8 resolution). The broad CO(1-0) line emission appears to be spatially extended on a scale of at least ˜7 kpc from the center. Mass outflow rate, momentum flux, and mechanical power of (80-200) {R}7-1 M ⊙ yr-1, (1.5-3.0) {R}7-1 L AGN/c, and (0.15-0.40)% {R}7-1 {L}{AGN}, respectively, are inferred from these data, assuming a CO-to-H2 conversion factor appropriate for a ULIRG (R 7 is the radius of the outflow normalized to 7 kpc, and L AGN is the AGN luminosity). These rates are time-averaged over a flow timescale of 7 × 106 yr. They are similar to the OH-based rates time-averaged over a flow timescale of 4 × 105 yr, but about a factor of 4 smaller than the local (“instantaneous” ≲105 yr) OH-based estimates cited in Tombesi et al. The implications of these new results are discussed in the context of time-variable quasar-mode feedback and galaxy evolution. The need for an energy-conserving bubble to explain the molecular outflow

  15. Evidence for large-scale winds from starburst galaxies. I. The nature of the ionized gas in M82 and NGC 253

    International Nuclear Information System (INIS)

    Mccarthy, P.J.; Van breugel, W.; Heckman, T.; Maryland Univ., College Park)

    1987-01-01

    The results of long-slit spectroscopy and narrow-band imaging of M82 and NGC 253, the two nearest examples of FIR luminous galaxies believed to be undergoing intense bursts of star formation, are presented. The profile of the gas pressure in the emission-line filaments in M82 is derived and found to be in good agreement with the model of Chevalier and Clegg (1985) of a supernovae-driven wind from a starburst nucleus. Lower quality data from NGC 253 support the same interpretation. Analysis of the emission-line ratios suggests that the line-emitting gas may be heated by low-velocity shocks, although photoionization from dilute UV radiation from unusually hot stars in the central starburst may also be important. 56 references

  16. The Western Wind and Solar Integration Study Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Lew, Debra [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brinkman, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ibanez, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Florita, A. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Heaney, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hodge, B. -M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hummon, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Stark, G. [National Renewable Energy Lab. (NREL), Golden, CO (United States); King, J. [RePPAE; Lefton, S. A. [Intertek-APTECH, Houston, TX (United States); Kumar, N. [Intertek-APTECH, Houston, TX (United States); Agan, D. [Intertek-APTECH, Houston, TX (United States); Jordan, G. [GE Energy, Fairfield, CT (United States); Venkataraman, S. [GE Energy, Fairfield, CT (United States)

    2013-09-01

    The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding wind and solar affects the operation of the other power plants and adding high penetrations can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 of the Western Wind and Solar Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of wind and solar on the fossil-fueled fleet. This built on Phase 1, one of the largest wind and solar integration studies ever conducted, which examined operational impacts of high wind and solar penetrations in the West(GE Energy 2010).

  17. The Western Wind and Solar Integration Study Phase 2

    Energy Technology Data Exchange (ETDEWEB)

    Lew, D.; Brinkman, G.; Ibanez, E.; Hodge, B. M.; Hummon, M.; Florita, A.; Heaney, M.

    2013-09-01

    The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding wind and solar affects the operation of the other power plants and adding high penetrations can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 of the Western Wind and Solar Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of wind and solar on the fossil-fueled fleet. This built on Phase 1, one of the largest wind and solar integration studies ever conducted, which examined operational impacts of high wind and solar penetrations in the West.

  18. The model of unshocked deceleration of the solar wind

    International Nuclear Information System (INIS)

    Gidalevich, E.Ya.

    1977-01-01

    The motion of the Sun relative to the interstellar gas is considered as an hydrodynamic flow in a point-source field. Interstellar gas has been found to undergo considerable compaction as it is braked in the solar gravitational field. Solar-wind braking due to ion charge exchange processes on interstellar hydrogen atoms is discussed. It is shown that tangible solar-wind braking occurs at a distance of about 3x1O 14 cm from the Sun in the apex direction. In the opposite direction solar wind propagates freely

  19. Innovations in Wind and Solar PV Financing

    Energy Technology Data Exchange (ETDEWEB)

    Cory, K.; Coughlin, J.; Jenkin, T.; Pater, J.; Swezey, B.

    2008-02-01

    There is growing national interest in renewable energy development based on the economic, environmental, and security benefits that these resources provide. Historically, greater development of our domestic renewable energy resources has faced a number of hurdles, primarily related to cost, regulation, and financing. With the recent sustained increase in the costs and associated volatility of fossil fuels, the economics of renewable energy technologies have become increasingly attractive to investors, both large and small. As a result, new entrants are investing in renewable energy and new business models are emerging. This study surveys some of the current issues related to wind and solar photovoltaic (PV) energy project financing in the electric power industry, and identifies both barriers to and opportunities for increased investment.

  20. Suprathermal protons in the interplanetary solar wind

    Science.gov (United States)

    Goodrich, C. C.; Lazarus, A. J.

    1976-01-01

    Using the Mariner 5 solar wind plasma and magnetic field data, we present observations of field-aligned suprathermal proton velocity distributions having pronounced high-energy shoulders. These observations, similar to the interpenetrating stream observations of Feldman et al. (1974), are clear evidence that such proton distributions are interplanetary rather than bow shock associated phenomena. Large Alfven speed is found to be a requirement for the occurrence of suprathermal proton distribution; further, we find the proportion of particles in the shoulder to be limited by the magnitude of the Alfven speed. It is suggested that this last result could indicate that the proton thermal anisotropy is limited at times by wave-particle interactions

  1. Dst Prediction Based on Solar Wind Parameters

    Directory of Open Access Journals (Sweden)

    Yoon-Kyung Park

    2009-12-01

    Full Text Available We reevaluate the Burton equation (Burton et al. 1975 of predicting Dst index using high quality hourly solar wind data supplied by the ACE satellite for the period from 1998 to 2006. Sixty magnetic storms with monotonously decreasing main phase are selected. In order to determine the injection term (Q and the decay time (tau of the equation, we examine the relationships between Dst* and VB_s, Delta Dst* and VB_s, and Delta Dst* and Dst* during the magnetic storms. For this analysis, we take into account one hour of the propagation time from the ACE satellite to the magnetopause, and a half hour of the response time of the magnetosphere/ring current to the solar wind forcing. The injection term is found to be Q({nT}/h=-3.56VB_s for VB_s>0.5mV/m and Q({nT}/h=0 for VB_s leq0.5mV/m. The tau (hour is estimated as 0.060 Dst* + 16.65 for Dst*>-175nT and 6.15 hours for Dst* leq -175nT. Based on these empirical relationships, we predict the 60 magnetic storms and find that the correlation coefficient between the observed and predicted Dst* is 0.88. To evaluate the performance of our prediction scheme, the 60 magnetic storms are predicted again using the models by Burton et al. (1975 and O'Brien & McPherron (2000a. The correlation coefficients thus obtained are 0.85, the same value for both of the two models. In this respect, our model is slightly improved over the other two models as far as the correlation coefficients is concerned. Particularly our model does a better job than the other two models in predicting intense magnetic storms (Dst* lesssim -200nT.

  2. ATU/Fort Hood Solar Total Energy Military Large-Scale Experiment (LSE-1): system design and support activities. Final report, November 23, 1976-November 30, 1977

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    The ATU/Fort Hood Solar Total Energy System will include a concentrating solar collector field of several acres. During periods of direct insolation, a heat-transfer fluid will be circulated through the collector field and thus heated to 500 to 600/sup 0/F. Some of the fluid will be circulated through a steam generator to drive a turbine-generator set; additional fluid will be stored in insulated tanks for use when solar energy is not available. The electrical output will satisfy a portion of the electrical load at Fort Hood's 87,000 Troop Housing Complex. Heat extracted from the turbine exhaust in the form of hot water will be used for space heating, absorption air conditioning, and domestic water heating at the 87,000 Complex. Storage tanks for the hot water are also included. The systems analysis and program support activities include studies of solar availability and energy requirements at Fort Hood, investigation of interfacing LSE-1 with existing energy systems at the 87,000 Complex, and preliminary studies of environmental, health, and safety considerations. An extensive survey of available concentrating solar collectors and modifications to a computerized system simulation model for LSE-1 use are also reported. Important program support activities are military liaison and information dissemination. The engineering test program reported involved completion of the Solar Engineering Test Module (SETM) and extensive performance testing of a single module of the linear-focusing collector.

  3. Extended neutral atmosphere effect on solar wind interaction with nonmagnetic bodies of the solar system

    International Nuclear Information System (INIS)

    Breus, T.K.; Krymskij, A.M.; Mitnitskij, V.Ya.

    1987-01-01

    Numeric modelling of the Venus flow-around by the solar wind with regard to stream loading by heavy ions, produced under photoionization of the Venus neutral oxygen corona, is conducted. It is shown, that this effect can account for a whole number of peculiarities related to the solar wind interaction with the planet which have not been clearly explained yet, namely, shock wave position, solar wind stream and magnetic field characteristics behind the front

  4. Wind tunnel and CFD modelling of wind pressures on solar energy systems on flat roofs

    NARCIS (Netherlands)

    Bronkhorst, A.J.; Franke, J.; Geurts, C.P.W.; Bentum, van C.A.; Grepinet, F.

    2010-01-01

    Design of solar energy mounting systems requires more knowledge on the wind patterns around these systems. To obtain more insight in the flow patterns, which cause the pressure distributions on the solar energy systems, a wind tunnel test and Computational Fluid Dynamics analysis have been

  5. Electrifying Greece with solar and wind energy

    Directory of Open Access Journals (Sweden)

    Mentis Dimitris

    2014-01-01

    Full Text Available Ensuring energy security, reducing GHG emissions and boosting the competitiveness of a country’s economy by attracting investments and technical knowhow are of paramount importance considering the targets of “20-20-20” set by the European community. Being the cradle of civilization, Greece appears today as a country caught in a prolonged hard economic and social crisis, the way out of which its citizens are looking forward as well as the entire European Union. Establishment of the leading renewable energy sources like solar and wind in Greece will not only increase the independence of its own electrification but will also provide with a foundation for developing the market of international trade of “green” energy. This paper initially highlights the current status of photovoltaics and wind turbines in Greece. Furthermore, this study evaluates whether a higher penetration of the above mentioned green energy sources would have positive impact in the economy of the country or not and in what extent they could decline the CO2 emissions until 2020, comparing to the corresponding levels in 2010.

  6. Spectral analysis of turbulence propagation mechanisms in solar wind and tokamaks plasmas

    International Nuclear Information System (INIS)

    Dong, Yue

    2014-01-01

    This thesis takes part in the study of spectral transfers in the turbulence of magnetized plasmas. We will be interested in turbulence in solar wind and tokamaks. Spacecraft measures, first principle simulations and simple dynamical systems will be used to understand the mechanisms behind spectral anisotropy and spectral transfers in these plasmas. The first part of this manuscript will introduce the common context of solar wind and tokamaks, what is specific to each of them and present some notions needed to understand the work presented here. The second part deals with turbulence in the solar wind. We will present first an observational study on the spectral variability of solar wind turbulence. Starting from the study of Grappin et al. (1990, 1991) on Helios mission data, we bring a new analysis taking into account a correct evaluation of large scale spectral break, provided by the higher frequency data of the Wind mission. This considerably modifies the result on the spectral index distribution of the magnetic and kinetic energy. A second observational study is presented on solar wind turbulence anisotropy using autocorrelation functions. Following the work of Matthaeus et al. (1990); Dasso et al. (2005), we bring a new insight on this statistical, in particular the question of normalisation choices used to build the autocorrelation function, and its consequence on the measured anisotropy. This allows us to bring a new element in the debate on the measured anisotropy depending on the choice of the referential either based on local or global mean magnetic field. Finally, we study for the first time in 3D the effects of the transverse expansion of solar wind on its turbulence. This work is based on a theoretical and numerical scheme developed by Grappin et al. (1993); Grappin and Velli (1996), but never used in 3D. Our main results deal with the evolution of spectral and polarization anisotropy due to the competition between non-linear and linear (Alfven coupling

  7. CONDITIONED ANALYSIS OF HIGH-LATITUDE SOLAR WIND INTERMITTENCY

    International Nuclear Information System (INIS)

    D'Amicis, R.; Consolini, G.; Bavassano, B.; Bruno, R.

    2012-01-01

    The solar wind is a turbulent medium displaying intermittency. Its intermittent features have been widely documented and studied, showing how the intermittent character is different in fast and slow wind. In this paper, a statistical conditioned analysis of the solar wind intermittency for a period of high-latitude fast solar wind is presented. In particular, the intermittent features are investigated as a function of the Alfvénic degree of fluctuations at a given scale. The results show that the main contribution to solar wind intermittency is due to non-Alfvénic structures, while Alfvénic increments are found to be characterized by a smaller level of intermittency than the previous ones. Furthermore, the lifetime statistics of Alfvénic periods are discussed in terms of a multiscale texture of randomly oriented flux tubes.

  8. Electro-spray deposition of a mesoporous TiO2 charge collection layer: toward large scale and continuous production of high efficiency perovskite solar cells.

    Science.gov (United States)

    Kim, Min-cheol; Kim, Byeong Jo; Yoon, Jungjin; Lee, Jin-wook; Suh, Dongchul; Park, Nam-gyu; Choi, Mansoo; Jung, Hyun Suk

    2015-12-28

    The spin-coating method, which is widely used for thin film device fabrication, is incapable of large-area deposition or being performed continuously. In perovskite hybrid solar cells using CH(3)NH(3)PbI(3) (MAPbI(3)), large-area deposition is essential for their potential use in mass production. Prior to replacing all the spin-coating process for fabrication of perovskite solar cells, herein, a mesoporous TiO(2) electron-collection layer is fabricated by using the electro-spray deposition (ESD) system. Moreover, impedance spectroscopy and transient photocurrent and photovoltage measurements reveal that the electro-sprayed mesoscopic TiO(2) film facilitates charge collection from the perovskite. The series resistance of the perovskite solar cell is also reduced owing to the highly porous nature of, and the low density of point defects in, the film. An optimized power conversion efficiency of 15.11% is achieved under an illumination of 1 sun; this efficiency is higher than that (13.67%) of the perovskite solar cell with the conventional spin-coated TiO(2) films. Furthermore, the large-area coating capability of the ESD process is verified through the coating of uniform 10 × 10 cm(2) TiO(2) films. This study clearly shows that ESD constitutes therefore a viable alternative for the fabrication of high-throughput, large-area perovskite solar cells.

  9. Charge States of Krypton and Xenon in the Solar Wind

    Science.gov (United States)

    Bochsler, Peter; Fludra, Andrzej; Giunta, Alessandra

    2017-09-01

    We calculate charge state distributions of Kr and Xe in a model for two different types of solar wind using the effective ionization and recombination rates provided from the OPEN_ADAS data base. The charge states of heavy elements in the solar wind are essential for estimating the efficiency of Coulomb drag in the inner corona. We find that xenon ions experience particularly low Coulomb drag from protons in the inner corona, comparable to the notoriously weak drag of protons on helium ions. It has been found long ago that helium in the solar wind can be strongly depleted near interplanetary current sheets, whereas coronal mass ejecta are sometimes strongly enriched in helium. We argue that if the extraordinary variability of the helium abundance in the solar wind is due to inefficient Coulomb drag, the xenon abundance must vary strongly. In fact, a secular decrease of the solar wind xenon abundance relative to the other heavier noble gases (Ne, Ar, Kr) has been postulated based on a comparison of noble gases in recently irradiated and ancient samples of ilmenite in the lunar regolith. We conclude that decreasing solar activity and decreasing frequency of coronal mass ejections over the solar lifetime might be responsible for a secularly decreasing abundance of xenon in the solar wind.

  10. Large-scale data analytics

    CERN Document Server

    Gkoulalas-Divanis, Aris

    2014-01-01

    Provides cutting-edge research in large-scale data analytics from diverse scientific areas Surveys varied subject areas and reports on individual results of research in the field Shares many tips and insights into large-scale data analytics from authors and editors with long-term experience and specialization in the field

  11. Fruitful symbiosis: Why an export bundled with wind energy is the most feasible option for North African concentrated solar power

    International Nuclear Information System (INIS)

    Kost, Christoph; Pfluger, Benjamin; Eichhammer, Wolfgang; Ragwitz, Mario

    2011-01-01

    The idea of generating electricity in North Africa using concentrating solar thermal power (CSP) has been around for some time now but has recently gained momentum through the Mediterranean Solar Plan (MSP) and the formation of the Desertec Industrial Initiative. This paper argues that while the large-scale deployment of CSP in North Africa does not seem economically attractive for either European or African institutions or countries on their own at present, combining domestic use and electricity exports could be profitable for both parties. A detailed economic portfolio covering both solar and wind power plants can achieve competitive price levels, which would accelerate the diffusion of solar technology in North Africa. This portfolio could be financed partially by exporting electricity from solar thermal plants in North Africa via HVDC interconnections to European consumers. Sharing the costs in this way makes it possible to generate solar electricity for the domestic market at a reasonable cost. Some of the electricity produced from the solar power plants and wind parks in North Africa is sold on European energy markets in the form of a long-term contracted solar-wind portfolio, which would qualify for support from the financial incentive schemes of the European Member States (e.g. feed-in tariffs). This transfer of green electricity could help to meet the targets for energy from renewable energy sources (RES) in the EU Member States as the new EU Directive of 2009 opened the European electricity market to imports from third states. - Research highlights: → This paper describes a feasible approach to financing a larger deployment of CSP in North Africa. → The proposed portfolio includes local consumption and electricity export to Europe. → Bundling wind with solar power as a business model for exporting solar electricity. → Prices of the solar-wind mix are competitive with other renewable energy sources. → Scenario outlook for the North African CSP

  12. Fruitful symbiosis: Why an export bundled with wind energy is the most feasible option for North African concentrated solar power

    Energy Technology Data Exchange (ETDEWEB)

    Kost, Christoph, E-mail: christoph.kost@ise.fraunhofer.de [Fraunhofer Institute for Solar Energy Systems ISE, Heidenhofstrasse 2, 79110 Freiburg (Germany); Pfluger, Benjamin, E-mail: benjamin.pfluger@isi.fraunhofer.de [Fraunhofer Institute for Systems and Innovation Research ISI, Breslauer Strasse 48, 76139 Karlsruhe (Germany); Eichhammer, Wolfgang, E-mail: wolfgang.eichhammer@isi.fraunhofer.de [Fraunhofer Institute for Systems and Innovation Research ISI, Breslauer Strasse 48, 76139 Karlsruhe (Germany); Ragwitz, Mario, E-mail: mario.ragwitz@isi.fraunhofer.de [Fraunhofer Institute for Systems and Innovation Research ISI, Breslauer Strasse 48, 76139 Karlsruhe (Germany)

    2011-11-15

    The idea of generating electricity in North Africa using concentrating solar thermal power (CSP) has been around for some time now but has recently gained momentum through the Mediterranean Solar Plan (MSP) and the formation of the Desertec Industrial Initiative. This paper argues that while the large-scale deployment of CSP in North Africa does not seem economically attractive for either European or African institutions or countries on their own at present, combining domestic use and electricity exports could be profitable for both parties. A detailed economic portfolio covering both solar and wind power plants can achieve competitive price levels, which would accelerate the diffusion of solar technology in North Africa. This portfolio could be financed partially by exporting electricity from solar thermal plants in North Africa via HVDC interconnections to European consumers. Sharing the costs in this way makes it possible to generate solar electricity for the domestic market at a reasonable cost. Some of the electricity produced from the solar power plants and wind parks in North Africa is sold on European energy markets in the form of a long-term contracted solar-wind portfolio, which would qualify for support from the financial incentive schemes of the European Member States (e.g. feed-in tariffs). This transfer of green electricity could help to meet the targets for energy from renewable energy sources (RES) in the EU Member States as the new EU Directive of 2009 opened the European electricity market to imports from third states. - Research Highlights: > This paper describes a feasible approach to financing a larger deployment of CSP in North Africa. > The proposed portfolio includes local consumption and electricity export to Europe. > Bundling wind with solar power as a business model for exporting solar electricity. > Prices of the solar-wind mix are competitive with other renewable energy sources. > Scenario outlook for the North African CSP market in

  13. Solar heating of air used for the drying at medium and large scale, of forestry, fishery, agriculture, cattle and industrial products

    International Nuclear Information System (INIS)

    Gutierrez, F.

    1991-01-01

    The drying process and/or preservation of grains is improved through the previous heating of air. In many cases it is enough to raise the temperature only a few degrees (from 10 to 15 Centigrade), in order to increase their capacity to absorb dampness. This can be done using very simple solar captors. A massive use of solar energy in the drying process of products, by means of hot air, can only be done with very expensive equipment. For this reason, it is recommended the use of lower thermic heaters, which will have a lower cost too. (Author)

  14. Weather-power station. Solar energy, wind energy, water energy

    Energy Technology Data Exchange (ETDEWEB)

    Schatta, M

    1975-10-02

    A combined power station is described, which enables one to convert solar energy and wind energy into other forms of energy. The plant consists of a water-filled boiler, in which solar energy heats the water by concentration, solar cells, and finally wind rotors, which transform wind energy into electrical energy. The transformed energy is partly available as steam heat, partly as mechanical or electrical energy. The plant can be used for supplying heating systems or electrolysis equipment. Finally, by incorporating suitable motors, a mobile version of the system can be produced.

  15. Wind and Solar Curtailment: International Experience and Practices

    DEFF Research Database (Denmark)

    Lew, Debra; Bird, Lori; Milligan, Michael

    2013-01-01

    High penetrations of wind and solar generation on power systems are resulting in increasing curtailment. Wind and solar integration studies predict increased curtailment as penetration levels grow. This paper examines experiences with curtailment on bulk power systems internationally. It discusses...... how much curtailment is occurring, how it is occurring, why it is occurring, and what is being done to reduce curtailment. This summary is produced as part of the International Energy Agency Wind Task 25 on Design and Operation of Power Systems with Large Amounts of Wind Power....

  16. The structure and origin of magnetic clouds in the solar wind

    Directory of Open Access Journals (Sweden)

    V. Bothmer

    Full Text Available Plasma and magnetic field data from the Helios 1/2 spacecraft have been used to investigate the structure of magnetic clouds (MCs in the inner heliosphere. 46 MCs were identified in the Helios data for the period 1974–1981 between 0.3 and 1 AU. 85% of the MCs were associated with fast-forward interplanetary shock waves, supporting the close association between MCs and SMEs (solar mass ejections. Seven MCs were identified as direct consequences of Helios-directed SMEs, and the passage of MCs agreed with that of interplanetary plasma clouds (IPCs identified as white-light brightness enhancements in the Helios photometer data. The total (plasma and magnetic field pressure in MCs was higher and the plasma-β lower than in the surrounding solar wind. Minimum variance analysis (MVA showed that MCs can best be described as large-scale quasi-cylindrical magnetic flux tubes. The axes of the flux tubes usually had a small inclination to the ecliptic plane, with their azimuthal direction close to the east-west direction. The large-scale flux tube model for MCs was validated by the analysis of multi-spacecraft observations. MCs were observed over a range of up to ~60° in solar longitude in the ecliptic having the same magnetic configuration. The Helios observations further showed that over-expansion is a common feature of MCs. From a combined study of Helios, Voyager and IMP data we found that the radial diameter of MCs increases between 0.3 and 4.2 AU proportional to the distance, R, from the Sun as R0.8 (R in AU. The density decrease inside MCs was found to be proportional to R–2.4, thus being stronger compared to the average solar wind. Four different magnetic configurations, as expected from the flux-tube concept, for MCs have been observed in situ by the Helios probes. MCs with left- and right-handed magnetic helicity occurred with about equal frequencies during 1974–1981, but surprisingly, the majority (74% of the MCs had

  17. Different magnetospheric modes: solar wind driving and coupling efficiency

    Directory of Open Access Journals (Sweden)

    N. Partamies

    2009-11-01

    Full Text Available This study describes a systematic statistical comparison of isolated non-storm substorms, steady magnetospheric convection (SMC intervals and sawtooth events. The number of events is approximately the same in each group and the data are taken from about the same years to avoid biasing by different solar cycle phase. The very same superposed epoch analysis is performed for each event group to show the characteristics of ground-based indices (AL, PCN, PC potential, particle injection at the geostationary orbit and the solar wind and IMF parameters. We show that the monthly occurrence of sawtooth events and isolated non-stormtime substorms closely follows maxima of the geomagnetic activity at (or close to the equinoxes. The most strongly solar wind driven event type, sawtooth events, is the least efficient in coupling the solar wind energy to the auroral ionosphere, while SMC periods are associated with the highest coupling ratio (AL/EY. Furthermore, solar wind speed seems to play a key role in determining the type of activity in the magnetosphere. Slow solar wind is capable of maintaining steady convection. During fast solar wind streams the magnetosphere responds with loading–unloading cycles, represented by substorms during moderately active conditions and sawtooth events (or other storm-time activations during geomagnetically active conditions.

  18. Transient flows of the solar wind associated with small-scale solar activity in solar minimum

    Science.gov (United States)

    Slemzin, Vladimir; Veselovsky, Igor; Kuzin, Sergey; Gburek, Szymon; Ulyanov, Artyom; Kirichenko, Alexey; Shugay, Yulia; Goryaev, Farid

    The data obtained by the modern high sensitive EUV-XUV telescopes and photometers such as CORONAS-Photon/TESIS and SPHINX, STEREO/EUVI, PROBA2/SWAP, SDO/AIA provide good possibilities for studying small-scale solar activity (SSA), which is supposed to play an important role in heating of the corona and producing transient flows of the solar wind. During the recent unusually weak solar minimum, a large number of SSA events, such as week solar flares, small CMEs and CME-like flows were observed and recorded in the databases of flares (STEREO, SWAP, SPHINX) and CMEs (LASCO, CACTUS). On the other hand, the solar wind data obtained in this period by ACE, Wind, STEREO contain signatures of transient ICME-like structures which have shorter duration (<10h), weaker magnetic field strength (<10 nT) and lower proton temperature than usual ICMEs. To verify the assumption that ICME-like transients may be associated with the SSA events we investigated the number of weak flares of C-class and lower detected by SPHINX in 2009 and STEREO/EUVI in 2010. The flares were classified on temperature and emission measure using the diagnostic means of SPHINX and Hinode/EIS and were confronted with the parameters of the solar wind (velocity, density, ion composition and temperature, magnetic field, pitch angle distribution of the suprathermal electrons). The outflows of plasma associated with the flares were identified by their coronal signatures - CMEs (only in few cases) and dimmings. It was found that the mean parameters of the solar wind projected to the source surface for the times of the studied flares were typical for the ICME-like transients. The results support the suggestion that weak flares can be indicators of sources of transient plasma flows contributing to the slow solar wind at solar minimum, although these flows may be too weak to be considered as separate CMEs and ICMEs. The research leading to these results has received funding from the European Union’s Seventh Programme

  19. FY 1998 Report on development of large-scale wind power generation systems. Research of wind turbines for storm worthy and easy construction; 1998 nendo ogata furyoku hatsuden system kaihatsu. Taikyofu kensetsu yoigata fusha ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The research and development statuses in various countries are surveyed, to have useful information to draw the future R and D directions for wind turbines resistant to storms and easy construction. Greece has sites suitable for wind power generation in mountainous districts, and is developing the systems while taking the characteristic weather conditions into consideration. The country provides information regarding aerodynamic/structural design methods for wind turbine blades applicable to turbulent wind generated by complex terrain, and wind assessment and analyses in complex terrain. In India, on-the-spot surveys are made at the cyclone-attacked wind farms. One of the areas on which the USA is putting emphasis is development of small-size wind turbines and wind-diesel hybrid systems for developing countries and independent grid systems in remote areas. Australia is constructing wind-diesel hybrid systems to be connected to a number of independent grid systems in its western area. In Europe, information is collected for the advanced aerodynamic analysis, construction of offshore wind turbines, and production engineering and facilities for blades and other components from Vestas and N.E.G. Micon as the leading wind turbine makers. (NEDO)

  20. Large scale PV plants - also in Denmark. Project report

    Energy Technology Data Exchange (ETDEWEB)

    Ahm, P [PA Energy, Malling (Denmark); Vedde, J [SiCon. Silicon and PV consulting, Birkeroed (Denmark)

    2011-04-15

    Large scale PV (LPV) plants, plants with a capacity of more than 200 kW, has since 2007 constituted an increasing share of the global PV installations. In 2009 large scale PV plants with cumulative power more that 1,3 GWp were connected to the grid. The necessary design data for LPV plants in Denmark are available or can be found, although irradiance data could be improved. There seems to be very few institutional barriers for LPV projects, but as so far no real LPV projects have been processed, these findings have to be regarded as preliminary. The fast growing number of very large scale solar thermal plants for district heating applications supports these findings. It has further been investigated, how to optimize the lay-out of LPV plants. Under the Danish irradiance conditions with several winter months with very low solar height PV installations on flat surfaces will have to balance the requirements of physical space - and cost, and the loss of electricity production due to shadowing effects. The potential for LPV plants in Denmark are found in three main categories: PV installations on flat roof of large commercial buildings, PV installations on other large scale infrastructure such as noise barriers and ground mounted PV installations. The technical potential for all three categories is found to be significant and in the range of 50 - 250 km2. In terms of energy harvest PV plants will under Danish conditions exhibit an overall efficiency of about 10 % in conversion of the energy content of the light compared to about 0,3 % for biomass. The theoretical ground area needed to produce the present annual electricity consumption of Denmark at 33-35 TWh is about 300 km2 The Danish grid codes and the electricity safety regulations mention very little about PV and nothing about LPV plants. It is expected that LPV plants will be treated similarly to big wind turbines. A number of LPV plant scenarios have been investigated in detail based on real commercial offers and

  1. CORONAL SOURCES, ELEMENTAL FRACTIONATION, AND RELEASE MECHANISMS OF HEAVY ION DROPOUTS IN THE SOLAR WIND

    Energy Technology Data Exchange (ETDEWEB)

    Weberg, Micah J. [PhD Candidate in Space Science, Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, 2134A Space Research Building, 2455 Hayward Street, Ann Arbor, MI 48109-2143, USA. (United States); Lepri, Susan T. [Associate Professor, Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, 2429 Space Research Building, 2455 Hayward Street, Ann Arbor, MI 48109-2143, USA. (United States); Zurbuchen, Thomas H., E-mail: mjweberg@umich.edu, E-mail: slepri@umich.edu, E-mail: thomasz@umich.edu [Professor, Space Science and Aerospace Engineering, Associate Dean for Entrepreneurship Senior Counselor of Entrepreneurship Education, Department of Atmospheric, Oceanic, and Space Sciences, University of Michigan, 2431 Space Research Building, 2455 Hayward Street, Ann Arbor, MI 48109-2143, USA. (United States)

    2015-03-10

    The elemental abundances of heavy ions (masses larger than He) in the solar wind provide information about physical processes occurring in the corona. Additionally, the charge state distributions of these heavy ions are sensitive to the temperature profiles of their respective source regions in the corona. Heavy ion dropouts are a relatively new class of solar wind events identified by both elemental and ionic charge state distributions. We have shown that their origins lie in large, closed coronal loops where processes such as gravitational settling dominate and can cause a mass-dependent fractionation pattern. In this study we consider and attempt to answer three fundamental questions concerning heavy ion dropouts: (1) 'where are the source loops located in the large-scale corona?'; (2) 'how does the interplay between coronal processes influence the end elemental abundances?'; and (3) 'what are the most probable release mechanisms'? We begin by analyzing the temporal and spatial variability of heavy ion dropouts and their correlation with heliospheric plasma and magnetic structures. Next we investigate the ordering of the elements inside dropouts with respect to mass, ionic charge state, and first ionization potential. Finally, we discuss these results in the context of the prevailing solar wind theories and the processes they posit that may be responsible for the release of coronal plasma into interplanetary space.

  2. CORONAL SOURCES, ELEMENTAL FRACTIONATION, AND RELEASE MECHANISMS OF HEAVY ION DROPOUTS IN THE SOLAR WIND

    International Nuclear Information System (INIS)

    Weberg, Micah J.; Lepri, Susan T.; Zurbuchen, Thomas H.

    2015-01-01

    The elemental abundances of heavy ions (masses larger than He) in the solar wind provide information about physical processes occurring in the corona. Additionally, the charge state distributions of these heavy ions are sensitive to the temperature profiles of their respective source regions in the corona. Heavy ion dropouts are a relatively new class of solar wind events identified by both elemental and ionic charge state distributions. We have shown that their origins lie in large, closed coronal loops where processes such as gravitational settling dominate and can cause a mass-dependent fractionation pattern. In this study we consider and attempt to answer three fundamental questions concerning heavy ion dropouts: (1) 'where are the source loops located in the large-scale corona?'; (2) 'how does the interplay between coronal processes influence the end elemental abundances?'; and (3) 'what are the most probable release mechanisms'? We begin by analyzing the temporal and spatial variability of heavy ion dropouts and their correlation with heliospheric plasma and magnetic structures. Next we investigate the ordering of the elements inside dropouts with respect to mass, ionic charge state, and first ionization potential. Finally, we discuss these results in the context of the prevailing solar wind theories and the processes they posit that may be responsible for the release of coronal plasma into interplanetary space

  3. Prospects for large scale electricity storage in Denmark

    DEFF Research Database (Denmark)

    Krog Ekman, Claus; Jensen, Søren Højgaard

    2010-01-01

    In a future power systems with additional wind power capacity there will be an increased need for large scale power management as well as reliable balancing and reserve capabilities. Different technologies for large scale electricity storage provide solutions to the different challenges arising w...

  4. Small Footprint Solar/Wind-powered CASTNET System Dataset

    Data.gov (United States)

    U.S. Environmental Protection Agency — In this Research Effort “Small Footprint Solar/Wind-Powered CASTNET System” there are two data sets. One data set contains atmospheric concentration measurements, at...

  5. Saturn radio emission and the solar wind - Voyager-2 studies

    International Nuclear Information System (INIS)

    Desch, M.D.; Rucker, H.O.; Observatorium Lustbuhel, Graz, Austria)

    1985-01-01

    Voyager 2 data from the Plasma Science experiment, the Magnetometer experiment and the Planetary Radio Astronomy experiment were used to analyze the relationship between parameters of the solar wind/interplanetary medium and the nonthermal Saturn radiation. Solar wind and interplanetary magnetic field properties were combined to form quantities known to be important in controlling terrestrial magnetospheric processes. The Voyager 2 data set used in this investigation consists of 237 days of Saturn preencounter measurements. However, due to the immersion of Saturn and the Voyager 2 spacecraft into the extended Jupiter magnetic tail, substantial periods of the time series were lacking solar wind data. To cope with this problem a superposed epoch method (CHREE analysis) was used. The results indicate the superiority of the quantities containing the solar wind density in stimulating the radio emission of Saturn - a result found earlier using Voyager 1 data - and the minor importance of quantities incorporating the interplanetary magnetic field. 10 references

  6. Western Wind and Solar Integration Study: Phase 2 (Presentation)

    Energy Technology Data Exchange (ETDEWEB)

    Lew, D.; Brinkman, G.; Ibanez, E.; Lefton, S.; Kumar, N.; Venkataraman, S.; Jordan, G.

    2013-09-01

    This presentation summarizes the scope and results of the Western Wind and Solar Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.

  7. FY 1998 Report on development of large-scale wind power generation systems. Part 2. Operational research on large-scale wind power generation systems; 1998 nendo ogata furyoku hatsuden system kaihatsu seika hokokusho. 2. Ogata furyoku hatsuden system no unten kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The on-the-spot surveys are conducted and related information is collected for current status of wind power generators connected to power grid systems and simulation techniques therefor in the USA and European countries. In Denmark, the grid system to which wind power generators are connected is a 10kV radiation type system, by which these generators are connected to general consumers. Power quality is investigated by the programs developed by DEFU (Danske Elvarkers Forening Udredning). The German's Norderland Wind Park has the largest capacity in Europe with 35 units of 1.5MW generators. They are connected to a 110kV grind system via ISOREE to control disturbances to the commercial grid system. The USA, used to have the world largest wind power generation capacity, is now plays second fiddle to Germany whose capacity has now exceeded 2,000MW. The country is now seeing the second rush for construction of wind power generators, planning to have a new capacity of 570MW in 1998. Information is also collected from other countries or organizations, including the Netherlands, WREC, Italy and Spain. (NEDO)

  8. FY 1998 Report on development of large-scale wind power generation systems. Part 2. Operational research on large-scale wind power generation systems; 1998 nendo ogata furyoku hatsuden system kaihatsu seika hokokusho. 2. Ogata furyoku hatsuden system no unten kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    The on-the-spot surveys are conducted and related information is collected for current status of wind power generators connected to power grid systems and simulation techniques therefor in the USA and European countries. In Denmark, the grid system to which wind power generators are connected is a 10kV radiation type system, by which these generators are connected to general consumers. Power quality is investigated by the programs developed by DEFU (Danske Elvarkers Forening Udredning). The German's Norderland Wind Park has the largest capacity in Europe with 35 units of 1.5MW generators. They are connected to a 110kV grind system via ISOREE to control disturbances to the commercial grid system. The USA, used to have the world largest wind power generation capacity, is now plays second fiddle to Germany whose capacity has now exceeded 2,000MW. The country is now seeing the second rush for construction of wind power generators, planning to have a new capacity of 570MW in 1998. Information is also collected from other countries or organizations, including the Netherlands, WREC, Italy and Spain. (NEDO)

  9. Analysis of ISEE-3/ICE solar wind data

    Science.gov (United States)

    Coplan, Michael A.

    1989-01-01

    Under the grant that ended November 11, 1988 work was accomplished in a number of areas, as follows: (1) Analysis of solar wind data; (2) Analysis of Giacobini/Zinner encounter data; (3) Investigation of solar wind and magnetospheric electron velocity distributions; and (4) Experimental investigation of the electronic structure of clusters. Reprints and preprints of publications resulting from this work are included in the appendices.

  10. Electron heat flux instabilities in the solar wind

    International Nuclear Information System (INIS)

    Gary, S.P.; Feldman, W.C.; Forslund, D.W.; Montgomery, M.D.

    1975-01-01

    There are at least three plasma instabilities associated with the electron heat flux in the solar wind. This letter reports the study of the unstable fast magnetosonic, Alfven and whistler modes via a computer code which solves the full electromagnetic, linear, Vlasov dispersion relation. Linear theory demonstrates that both the magnetosonic and Alfven instabilities are candidates for turbulent limitation of the heat flux in the solar wind at 1 A.U

  11. Economic viability of wind and solar energy for industrial use

    International Nuclear Information System (INIS)

    Lashkari, Z.F.

    1994-01-01

    Non conventional energy sources have begun to move from fringes of technological possibility towards commercial viability. Out of the four sources, i e. solar, wind, biogas and minimicro hydel the first two viz. wind and solar energy are of relevance for industries in western region of India. This has to be seen in the context of developments in technology and hence economics both worldwide and in India. (author)

  12. On Electron-Scale Whistler Turbulence in the Solar Wind

    Science.gov (United States)

    Narita, Y.; Nakamura, R.; Baumjohann, W.; Glassmeier, K.-H.; Motschmann, U.; Giles, B.; Magnes, W.; Fischer, D.; Torbert, R. B.; Russell, C. T.

    2016-01-01

    For the first time, the dispersion relation for turbulence magnetic field fluctuations in the solar wind is determined directly on small scales of the order of the electron inertial length, using four-point magnetometer observations from the Magnetospheric Multiscale mission. The data are analyzed using the high-resolution adaptive wave telescope technique. Small-scale solar wind turbulence is primarily composed of highly obliquely propagating waves, with dispersion consistent with that of the whistler mode.

  13. Potential for Development of Solar and Wind Resource in Bhutan

    Energy Technology Data Exchange (ETDEWEB)

    Gilman, P.; Cowlin, S.; Heimiller, D.

    2009-09-01

    With support from the U.S. Agency for International Development (USAID), the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) produced maps and data of the wind and solar resources in Bhutan. The solar resource data show that Bhutan has an adequate resource for flat-plate collectors, with annual average values of global horizontal solar radiation ranging from 4.0 to 5.5 kWh/m2-day (4.0 to 5.5 peak sun hours per day). The information provided in this report may be of use to energy planners in Bhutan involved in developing energy policy or planning wind and solar projects, and to energy analysts around the world interested in gaining an understanding of Bhutan's wind and solar energy potential.

  14. The Character of the Solar Wind, Surface Interactions, and Water

    Science.gov (United States)

    Farrell, William M.

    2011-01-01

    We discuss the key characteristics of the proton-rich solar wind and describe how it may interact with the lunar surface. We suggest that solar wind can be both a source and loss of water/OH related volatiles, and review models showing both possibilities. Energy from the Sun in the form of radiation and solar wind plasma are in constant interaction with the lunar surface. As such, there is a solar-lunar energy connection, where solar energy and matter are continually bombarding the lunar surface, acting at the largest scale to erode the surface at 0.2 Angstroms per year via ion sputtering [1]. Figure 1 illustrates this dynamically Sun-Moon system.

  15. Large-scale grid management

    International Nuclear Information System (INIS)

    Langdal, Bjoern Inge; Eggen, Arnt Ove

    2003-01-01

    The network companies in the Norwegian electricity industry now have to establish a large-scale network management, a concept essentially characterized by (1) broader focus (Broad Band, Multi Utility,...) and (2) bigger units with large networks and more customers. Research done by SINTEF Energy Research shows so far that the approaches within large-scale network management may be structured according to three main challenges: centralization, decentralization and out sourcing. The article is part of a planned series

  16. Diamagnetic effect in the foremoon solar wind observed by Kaguya

    Science.gov (United States)

    Nishino, Masaki N.; Saito, Yoshifumi; Tsunakawa, Hideo; Miyake, Yohei; Harada, Yuki; Yokota, Shoichiro; Takahashi, Futoshi; Matsushima, Masaki; Shibuya, Hidetoshi; Shimizu, Hisayoshi

    2017-04-01

    Direct interaction between the lunar surface and incident solar wind is one of the crucial phenomena of the planetary plasma sciences. Recent observations by lunar orbiters revealed that strength of the interplanetary magnetic field (IMF) at spacecraft altitude often increases over crustal magnetic fields on the dayside. In addition, variations of the IMF on the lunar night side have been reported in the viewpoint of diamagnetic effect around the lunar wake. However, few studies have been performed for the IMF over non-magnetized regions on the dayside. Here we show an event where strength of the IMF decreases at 100 km altitude on the lunar dayside (i.e. in the foremoon solar wind) when the IMF is almost parallel to the incident solar wind flow, comparing the upstream solar wind data from ACE with Kaguya magnetometer data. The lunar surface below the Kaguya orbit is not magnetized (or very weakly magnetized), and the sunward-travelling protons show signatures of those back-scattered at the lunar surface. We find that the decrease in the magnetic pressure is compensated by the thermal pressure of the back-scattered protons. In other words, the IMF strength in the foremoon solar wind decreases by diamagnetic effect of sunward-travelling protons back-scattered at the lunar dayside surface. Such an effect would be prominent in the high-beta solar wind, and may be ubiquitous in the environment where planetary surface directly interacts with surrounding space plasma.

  17. Implications of the Deep Minimum for Slow Solar Wind Origin

    Science.gov (United States)

    Antiochos, S. K.; Mikic, Z.; Lionello, R.; Titov, V. S.; Linker, J. A.

    2009-12-01

    The origin of the slow solar wind has long been one of the most important problems in solar/heliospheric physics. Two observational constraints make this problem especially challenging. First, the slow wind has the composition of the closed-field corona, unlike the fast wind that originates on open field lines. Second, the slow wind has substantial angular extent, of order 30 degrees, which is much larger than the widths observed for streamer stalks or the widths expected theoretically for a dynamic heliospheric current sheet. We propose that the slow wind originates from an intricate network of narrow (possibly singular) open-field corridors that emanate from the polar coronal hole regions. Using topological arguments, we show that these corridors must be ubiquitous in the solar corona. The total solar eclipse in August 2008, near the lowest point of the Deep Minimum, affords an ideal opportunity to test this theory by using the ultra-high resolution Predictive Science's (PSI) eclipse model for the corona and wind. Analysis of the PSI eclipse model demonstrates that the extent and scales of the open-field corridors can account for both the angular width of the slow wind and its closed-field composition. We discuss the implications of our slow wind theory for the structure of the corona and heliosphere at the Deep Minimum and describe further observational and theoretical tests. This work has been supported by the NASA HTP, SR&T, and LWS programs.

  18. Large-Scale PV Module Manufacturing Using Ultra-Thin Polycrystalline Silicon Solar Cells: Final Subcontract Report, 1 April 2002--28 February 2006

    Energy Technology Data Exchange (ETDEWEB)

    Wohlgemuth, J.; Narayanan, M.

    2006-07-01

    The major objectives of this program were to continue advances of BP Solar polycrystalline silicon manufacturing technology. The Program included work in the following areas. (1) Efforts in the casting area to increase ingot size, improve ingot material quality, and improve handling of silicon feedstock as it is loaded into the casting stations. (2) Developing wire saws to slice 100-..mu..m-thick silicon wafers on 290-..mu..m-centers. (3) Developing equipment for demounting and subsequent handling of very thin silicon wafers. (4) Developing cell processes using 100-..mu..m-thick silicon wafers that produce encapsulated cells with efficiencies of at least 15.4% at an overall yield exceeding 95%. (5) Expanding existing in-line manufacturing data reporting systems to provide active process control. (6) Establishing a 50-MW (annual nominal capacity) green-field Mega-plant factory model template based on this new thin polycrystalline silicon technology. (7) Facilitating an increase in the silicon feedstock industry's production capacity for lower-cost solar-grade silicon feedstock..

  19. Large-Scale PV Module Manufacturing Using Ultra-Thin Polycrystalline Silicon Solar Cells: Annual Subcontract Report, 1 April 2002--30 September 2003 (Revised)

    Energy Technology Data Exchange (ETDEWEB)

    Wohlgemuth, J.; Shea, S. P.

    2004-04-01

    The goal of BP Solar's Crystalline PVMaT program is to improve the present polycrystalline silicon manufacturing facility to reduce cost, improve efficiency, and increase production capacity. Key components of the program are: increasing ingot size; improving ingot material quality; improving material handling; developing wire saws to slice 100 ..mu..m thick silicon wafers on 200 ..mu..m centers; developing equipment for demounting and subsequent handling of very thin silicon wafers; developing cell processes using 100 ..mu..m thick silicon wafers that produce encapsulated cells with efficiencies of at least 15.4% at an overall yield exceeding 95%; expanding existing in-line manufacturing data reporting systems to provide active process control; establishing a 50 MW (annual nominal capacity) green-field Mega plant factory model template based on this new thin polycrystalline silicon technology; and facilitating an increase in the silicon feedstock industry's production capacity for lower-cost solar-grade silicon feedstock.

  20. Large-Scale PV Module Manufacturing Using Ultra-Thin Polycrystalline Silicon Solar Cells: Annual Subcontract Report, 1 October 2003--30 September 2004

    Energy Technology Data Exchange (ETDEWEB)

    Wohlgemuth, J.; Narayanan, M.

    2005-03-01

    The major objectives of this program are to continue the advancement of BP Solar polycrystalline silicon manufacturing technology. The program includes work in the following areas: Efforts in the casting area to increase ingot size, improve ingot material quality, and improve handling of silicon feedstock as it is loaded into the casting stations; developing wire saws to slice 100- m-thick silicon wafers on 290- m centers; developing equipment for demounting and subsequent handling of very thin silicon wafers; developing cell processes using 100- m-thick silicon wafers that produce encapsulated cells with efficiencies of at least 15.4% at an overall yield exceeding 95%; expanding existing in-line manufacturing data reporting systems to provide active process control; establishing a 50-MW (annual nominal capacity) green-field Mega-plant factory model template based on this new thin polycrystalline silicon technology; facilitating an increase in the silicon feedstock industry's production capacity for lower-cost solar-grade silicon feedstock.

  1. Aggregated Representation of Distribution Networks for Large-Scale Transmission Network Simulations

    DEFF Research Database (Denmark)

    Göksu, Ömer; Altin, Müfit; Sørensen, Poul Ejnar

    2014-01-01

    As a common practice of large-scale transmission network analysis the distribution networks have been represented as aggregated loads. However, with increasing share of distributed generation, especially wind and solar power, in the distribution networks, it became necessary to include...... the distributed generation within those analysis. In this paper a practical methodology to obtain aggregated behaviour of the distributed generation is proposed. The methodology, which is based on the use of the IEC standard wind turbine models, is applied on a benchmark distribution network via simulations....

  2. CONTROLLING INFLUENCE OF MAGNETIC FIELD ON SOLAR WIND OUTFLOW: AN INVESTIGATION USING CURRENT SHEET SOURCE SURFACE MODEL

    Energy Technology Data Exchange (ETDEWEB)

    Poduval, B., E-mail: bpoduval@spacescience.org [Space Science Institute, Boulder, CO 80303 (United States)

    2016-08-10

    This Letter presents the results of an investigation into the controlling influence of large-scale magnetic field of the Sun in determining the solar wind outflow using two magnetostatic coronal models: current sheet source surface (CSSS) and potential field source surface. For this, we made use of the Wang and Sheeley inverse correlation between magnetic flux expansion rate (FTE) and observed solar wind speed (SWS) at 1 au. During the period of study, extended over solar cycle 23 and beginning of solar cycle 24, we found that the coefficients of the fitted quadratic equation representing the FTE–SWS inverse relation exhibited significant temporal variation, implying the changing pattern of the influence of FTE on SWS over time. A particularly noteworthy feature is an anomaly in the behavior of the fitted coefficients during the extended minimum, 2008–2010 (CRs 2073–2092), which is considered due to the particularly complex nature of the solar magnetic field during this period. However, this variation was significant only for the CSSS model, though not a systematic dependence on the phase of the solar cycle. Further, we noticed that the CSSS model demonstrated better solar wind prediction during the period of study, which we attribute to the treatment of volume and sheet currents throughout the corona and the more accurate tracing of footpoint locations resulting from the geometry of the model.

  3. FY 1998 Report on development of large-scale wind power generation systems. Research on the future prospects of wind power generation systems; 1998 nendo ogata furyoku hatsuden system kaihatsu. Furyoku hatsuden system no shorai tenbo ni kansuru chosa kenkyu

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-03-01

    Current status of wind power generation in Japan and situations in foreign countries ahead of Japan are surveyed, in order to clarify the prospects for the future diffusion and expansion of wind power generation systems in Japan. The surveyed trends of wind power generation in Japan include those related to mandatory laws and regulations, e.g., the Electricity Enterprises Act, introductory and operation situations in local autonomies and electric power companies, and R and D efforts by academic and research organizations. The surveyed wind power generation situations in foreign countries include trends of international standardization for wind power generation, and global situations of introducing these systems. The on-the-spot oversea surveys include location/wind conditions in Greece's islands, cyclone-caused damages in India, World Renewable Energy Congress in Perth and advanced technologies in Europe for wind power generation systems, and the survey results are reported in detail. The surveyed R and D projects in Japan include the basic technological R and D plans (draft) for, e.g., wind power generation systems for isolated islands. (NEDO)

  4. A survey of solar wind conditions at 5 AU: A tool for interpreting solar wind-magnetosphere interactions at Jupiter

    Directory of Open Access Journals (Sweden)

    Robert Wilkes Ebert

    2014-09-01

    Full Text Available We examine Ulysses solar wind and interplanetary magnetic field (IMF observations at 5 AU for two ~13 month intervals during the rising and declining phases of solar cycle 23 and the predicted response of the Jovian magnetosphere during these times. The declining phase solar wind, composed primarily of corotating interaction regions and high-speed streams, was, on average, faster, hotter, less dense, and more Alfvénic relative to the rising phase solar wind, composed mainly of slow wind and interplanetary coronal mass ejections. Interestingly, none of solar wind and IMF distributions reported here were bimodal, a feature used to explain the bimodal distribution of bow shock and magnetopause standoff distances observed at Jupiter. Instead, many of these distributions had extended, non-Gaussian tails that resulted in large standard deviations and much larger mean over median values. The distribution of predicted Jupiter bow shock and magnetopause standoff distances during these intervals were also not bimodal, the mean/median values being larger during the declining phase by ~1 – 4%. These results provide data-derived solar wind and IMF boundary conditions at 5 AU for models aimed at studying solar wind-magnetosphere interactions at Jupiter and can support the science investigations of upcoming Jupiter system missions. Here, we provide expectations for Juno, which is scheduled to arrive at Jupiter in July 2016. Accounting for the long-term decline in solar wind dynamic pressure reported by McComas et al. (2013, Jupiter’s bow shock and magnetopause is expected to be at least 8 – 12% further from Jupiter, if these trends continue.

  5. A survey of solar wind conditions at 5 AU: a tool for interpreting solar wind-magnetosphere interactions at Jupiter

    Energy Technology Data Exchange (ETDEWEB)

    Ebert, Robert W. [Space Science and Engineering Division, Southwest Research Institute, San Antonio, TX (United States); Bagenal, Fran [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO (United States); McComas, David J. [Space Science and Engineering Division, Southwest Research Institute, San Antonio, TX (United States); Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX (United States); Fowler, Christopher M., E-mail: rebert@swri.edu [Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, CO (United States)

    2014-09-19

    We examine Ulysses solar wind and interplanetary magnetic field (IMF) observations at 5 AU for two ~13 month intervals during the rising and declining phases of solar cycle 23 and the predicted response of the Jovian magnetosphere during these times. The declining phase solar wind, composed primarily of corotating interaction regions and high-speed streams, was, on average, faster, hotter, less dense, and more Alfvénic relative to the rising phase solar wind, composed mainly of slow wind and interplanetary coronal mass ejections. Interestingly, none of solar wind and IMF distributions reported here were bimodal, a feature used to explain the bimodal distribution of bow shock and magnetopause standoff distances observed at Jupiter. Instead, many of these distributions had extended, non-Gaussian tails that resulted in large standard deviations and much larger mean over median values. The distribution of predicted Jupiter bow shock and magnetopause standoff distances during these intervals were also not bimodal, the mean/median values being larger during the declining phase by ~1–4%. These results provide data-derived solar wind and IMF boundary conditions at 5 AU for models aimed at studying solar wind-magnetosphere interactions at Jupiter and can support the science investigations of upcoming Jupiter system missions. Here, we provide expectations for Juno, which is scheduled to arrive at Jupiter in July 2016. Accounting for the long-term decline in solar wind dynamic pressure reported by McComas et al. (2013a), Jupiter's bow shock and magnetopause is expected to be at least 8–12% further from Jupiter, if these trends continue.

  6. Observation of solar wind with radio-star scintillation

    International Nuclear Information System (INIS)

    Watanabe, Takashi

    1974-01-01

    Large solar flares occurred in groups in early August 1972, and many interesting phenomena were observed. The solar wind condition during this period, obtained by scintillation observation, is reviewed. The velocity of solar wind has been determined from the observation of interplanetary space scintillation at Toyokawa, Fujigamine and Sugadaira. Four to ten radio wave sources were observed for ten minutes at each southing every day. Strong earth magnetic storm and the Forbush decrease of cosmic ray were observed during the period from August 3rd to 7th. Pioneer 9 observed a solar wind having the maximum velocity as high as 1,100 km/sec, and HEOS-II observed a solar wind having the velocity close to 2,000 km/sec. On the other hand, according to the scintillation of 3C-48 and 3C-144, the velocity of solar wind passing in the interplanetary space on the westside of the earth was only 300 to 400 km/sec. Therefore it is considered that the condition of solar wind on the east side of the earth differs from that on the west side of the earth. Pioneer 9 observed the pass of a shock wave on August 9th. With all radio wave sources, high velocity solar wind was observed and Pioneer 6 positioned on the west side of the earth also observed it. The thickness of this shock wave is at least 0.3 AU. Discussion is made on the cause for the difference between the asymmetric shock wave in the direction of south-west and symmetrical shock wave. The former may be blast wave, and the latter may be piston driven shock wave and the like. (Iwakiri, K.)

  7. Simulation study of solar wind push on a charged wire: basis of solar wind electric sail propulsion

    Directory of Open Access Journals (Sweden)

    P. Janhunen

    2007-03-01

    Full Text Available One possibility for propellantless propulsion in space is to use the momentum flux of the solar wind. A way to set up a solar wind sail is to have a set of thin long wires which are kept at high positive potential by an onboard electron gun so that the wires repel and deflect incident solar wind protons. The efficiency of this so-called electric sail depends on how large force a given solar wind exerts on a wire segment and how large electron current the wire segment draws from the solar wind plasma when kept at a given potential. We use 1-D and 2-D electrostatic plasma simulations to calculate the force and present a semitheoretical formula which captures the simulation results. We find that under average solar wind conditions at 1 AU the force per unit length is (5±1×10−8 N/m for 15 kV potential and that the electron current is accurately given by the well-known orbital motion limited (OML theory cylindrical Langmuir probe formula. Although the force may appear small, an analysis shows that because of the very low weight of a thin wire per unit length, quite high final speeds (over 50 km/s could be achieved by an electric sailing spacecraft using today's flight-proved components. It is possible that artificial electron heating of the plasma in the interaction region could increase the propulsive effect even further.

  8. Simulation study of solar wind push on a charged wire: basis of solar wind electric sail propulsion

    Directory of Open Access Journals (Sweden)

    P. Janhunen

    2007-03-01

    Full Text Available One possibility for propellantless propulsion in space is to use the momentum flux of the solar wind. A way to set up a solar wind sail is to have a set of thin long wires which are kept at high positive potential by an onboard electron gun so that the wires repel and deflect incident solar wind protons. The efficiency of this so-called electric sail depends on how large force a given solar wind exerts on a wire segment and how large electron current the wire segment draws from the solar wind plasma when kept at a given potential. We use 1-D and 2-D electrostatic plasma simulations to calculate the force and present a semitheoretical formula which captures the simulation results. We find that under average solar wind conditions at 1 AU the force per unit length is (5±1×10−8 N/m for 15 kV potential and that the electron current is accurately given by the well-known orbital motion limited (OML theory cylindrical Langmuir probe formula. Although the force may appear small, an analysis shows that because of the very low weight of a thin wire per unit length, quite high final speeds (over 50 km/s could be achieved by an electric sailing spacecraft using today's flight-proved components. It is possible that artificial electron heating of the plasma in the interaction region could increase the propulsive effect even further.

  9. The Solar Wind Source Cycle: Relationship to Dynamo Behavior

    Science.gov (United States)

    Luhmann, J. G.; Li, Y.; Lee, C. O.; Jian, L. K.; Petrie, G. J. D.; Arge, C. N.

    2017-12-01

    Solar cycle trends of interest include the evolving properties of the solar wind, the heliospheric medium through which the Sun's plasmas and fields interact with Earth and the planets -including the evolution of CME/ICMEs enroute. Solar wind sources include the coronal holes-the open field regions that constantly evolve with solar magnetic fields as the cycle progresses, and the streamers between them. The recent cycle has been notably important in demonstrating that not all solar cycles are alike when it comes to contributions from these sources, including in the case of ecliptic solar wind. In particular, it has modified our appreciation of the low latitude coronal hole and streamer sources because of their relative prevalence. One way to understand the basic relationship between these source differences and what is happening inside the Sun and on its surface is to use observation-based models like the PFSS model to evaluate the evolution of the coronal field geometry. Although the accuracy of these models is compromised around solar maximum by lack of global surface field information and the sometimes non-potential evolution of the field related to more frequent and widespread emergence of active regions, they still approximate the character of the coronal field state. We use these models to compare the inferred recent cycle coronal holes and streamer belt sources of solar wind with past cycle counterparts. The results illustrate how (still) hemispherically asymmetric weak polar fields maintain a complex mix of low-to-mid latitude solar wind sources throughout the latest cycle, with a related marked asymmetry in the hemispheric distribution of the ecliptic wind sources. This is likely to be repeated until the polar field strength significantly increases relative to the fields at low latitudes, and the latter symmetrize.

  10. Preferred solar wind emitting longitudes on the sun

    International Nuclear Information System (INIS)

    Gosling, J.T.; Asbridge, J.R.; Bame, S.J.; Feldman, W.C.

    1977-01-01

    During the 11 1/2-year period from July 1964 through December 1975, high- and low-speed solar wind flows originated from preferred solar longitudes. The preferred longitude effect was most pronounced from 1970 onward but was also evident in the years preceding 1970. The most pronounced modulation in average solar wind speed with longitude (approximately 20%) was obtained when it was assumed that the synodic rotation period of the sun is 27.025 days. Some deep internal structure in the sun must ultmately be responsible for these long-lived longitudinal effects, which appear to rotate rigidly with the sun

  11. The Yaglom law in the expanding solar wind

    International Nuclear Information System (INIS)

    Gogoberidze, G.; Perri, S.; Carbone, V.

    2013-01-01

    We study the Yaglom law, which relates the mixed third-order structure function to the average dissipation rate of turbulence, in a uniformly expanding solar wind by using the two-scale expansion model of magnetohydrodynamic (MHD) turbulence. We show that due to the expansion of the solar wind, two new terms appear in the Yaglom law. The first term is related to the decay of the turbulent energy by nonlinear interactions, whereas the second term is related to the non-zero cross-correlation of the Elsässer fields. Using magnetic field and plasma data from WIND and Helios 2 spacecrafts, we show that at lower frequencies in the inertial range of MHD turbulence the new terms become comparable to Yaglom's third-order mixed moment, and therefore they cannot be neglected in the evaluation of the energy cascade rate in the solar wind.

  12. Quantifying the Impacts of Large Scale Integration of Renewables in Indian Power Sector

    Science.gov (United States)

    Kumar, P.; Mishra, T.; Banerjee, R.

    2017-12-01

    India's power sector is responsible for nearly 37 percent of India's greenhouse gas emissions. For a fast emerging economy like India whose population and energy consumption are poised to rise rapidly in the coming decades, renewable energy can play a vital role in decarbonizing power sector. In this context, India has targeted 33-35 percent emission intensity reduction (with respect to 2005 levels) along with large scale renewable energy targets (100GW solar, 60GW wind, and 10GW biomass energy by 2022) in INDCs submitted at Paris agreement. But large scale integration of renewable energy is a complex process which faces a number of problems like capital intensiveness, matching intermittent loads with least storage capacity and reliability. In this context, this study attempts to assess the technical feasibility of integrating renewables into Indian electricity mix by 2022 and analyze its implications on power sector operations. This study uses TIMES, a bottom up energy optimization model with unit commitment and dispatch features. We model coal and gas fired units discretely with region-wise representation of wind and solar resources. The dispatch features are used for operational analysis of power plant units under ramp rate and minimum generation constraints. The study analyzes India's electricity sector transition for the year 2022 with three scenarios. The base case scenario (no RE addition) along with INDC scenario (with 100GW solar, 60GW wind, 10GW biomass) and low RE scenario (50GW solar, 30GW wind) have been created to analyze the implications of large scale integration of variable renewable energy. The results provide us insights on trade-offs involved in achieving mitigation targets and investment decisions involved. The study also examines operational reliability and flexibility requirements of the system for integrating renewables.

  13. The magnetosphere under weak solar wind forcing

    Directory of Open Access Journals (Sweden)

    C. J. Farrugia

    2007-02-01

    Full Text Available The Earth's magnetosphere was very strongly disturbed during the passage of the strong shock and the following interacting ejecta on 21–25 October 2001. These disturbances included two intense storms (Dst*≈−250 and −180 nT, respectively. The cessation of this activity at the start of 24 October ushered in a peculiar state of the magnetosphere which lasted for about 28 h and which we discuss in this paper. The interplanetary field was dominated by the sunward component [B=(4.29±0.77, −0.30±0.71, 0.49±0.45 nT]. We analyze global indicators of geomagnetic disturbances, polar cap precipitation, ground magnetometer records, and ionospheric convection as obtained from SuperDARN radars. The state of the magnetosphere is characterized by the following features: (i generally weak and patchy (in time low-latitude dayside reconnection or reconnection poleward of the cusps; (ii absence of substorms; (iii a monotonic recovery from the previous storm activity (Dst corrected for magnetopause currents decreasing from ~−65 to ~−35 nT, giving an unforced decreased of ~1.1 nT/h; (iv the probable absence of viscous-type interaction originating from the Kelvin-Helmholtz (KH instability; (v a cross-polar cap potential of just 20–30 kV; (vi a persistent, polar cap region containing (vii very weak, and sometimes absent, electron precipitation and no systematic inter-hemisphere asymmetry. Whereas we therefore infer the presence of a moderate amount of open flux, the convection is generally weak and patchy, which we ascribe to the lack of solar wind driver. This magnetospheric state approaches that predicted by Cowley and Lockwood (1992 but has never yet been observed.

  14. A model for the origin of solar wind stream interfaces

    International Nuclear Information System (INIS)

    Hundhausen, A.J.; Burlaga, L.F.

    1975-01-01

    The basic variations in solar wind properties that have been observed at 'stream interfaces' near 1 AU are explained by a gas dynamic model in which a radially propagating stream, produced by a temperature variation in the solar envelope, steepens nonlinearly while moving through interplanetary space. The region thus identified with the stream interface separates the ambient solar wind from the fresh hot material originally in the stream. However, the interface regions given by the present model are thicker than most stream interfaces observed in the solar wind, a fact suggesting that some additional physical process may be important in determining that thickness. Variations in the density, speed, or Alfven pressure alone appear not to produce streams with such an interface

  15. SOLAR WIND HEAVY IONS OVER SOLAR CYCLE 23: ACE/SWICS MEASUREMENTS

    International Nuclear Information System (INIS)

    Lepri, S. T.; Landi, E.; Zurbuchen, T. H.

    2013-01-01

    Solar wind plasma and compositional properties reflect the physical properties of the corona and its evolution over time. Studies comparing the previous solar minimum with the most recent, unusual solar minimum indicate that significant environmental changes are occurring globally on the Sun. For example, the magnetic field decreased 30% between the last two solar minima, and the ionic charge states of O have been reported to change toward lower values in the fast wind. In this work, we systematically and comprehensively analyze the compositional changes of the solar wind during cycle 23 from 2000 to 2010 while the Sun moved from solar maximum to solar minimum. We find a systematic change of C, O, Si, and Fe ionic charge states toward lower ionization distributions. We also discuss long-term changes in elemental abundances and show that there is a ∼50% decrease of heavy ion abundances (He, C, O, Si, and Fe) relative to H as the Sun went from solar maximum to solar minimum. During this time, the relative abundances in the slow wind remain organized by their first ionization potential. We discuss these results and their implications for models of the evolution of the solar atmosphere, and for the identification of the fast and slow wind themselves.

  16. Large scale structure and baryogenesis

    International Nuclear Information System (INIS)

    Kirilova, D.P.; Chizhov, M.V.

    2001-08-01

    We discuss a possible connection between the large scale structure formation and the baryogenesis in the universe. An update review of the observational indications for the presence of a very large scale 120h -1 Mpc in the distribution of the visible matter of the universe is provided. The possibility to generate a periodic distribution with the characteristic scale 120h -1 Mpc through a mechanism producing quasi-periodic baryon density perturbations during inflationary stage, is discussed. The evolution of the baryon charge density distribution is explored in the framework of a low temperature boson condensate baryogenesis scenario. Both the observed very large scale of a the visible matter distribution in the universe and the observed baryon asymmetry value could naturally appear as a result of the evolution of a complex scalar field condensate, formed at the inflationary stage. Moreover, for some model's parameters a natural separation of matter superclusters from antimatter ones can be achieved. (author)

  17. Conductive solar wind models in rapidly diverging flow geometries

    International Nuclear Information System (INIS)

    Holzer, T.E.; Leer, E.

    1980-01-01

    A detailed parameter study of conductive models of the solar wind has been carried out, extending the previous similar studies of Durney (1972) and Durney and Hundhausen (1974) by considering collisionless inhibition of thermal conduction, rapidly diverging flow geometries, and the structure of solutions for the entire n 0 -T 0 plane (n 0 and T 0 are the coronal base density and temperature). Primary emphasis is placed on understanding the complex effects of the physical processes operative in conductive solar wind models. There are five points of particular interest that have arisen from the study: (1) neither collisionless inhibition of thermal conduction nor rapidly diverging flow geometries can significantly increase the solar wind speed at 1 AU; (2) there exists a firm upper limit on the coronal base temperature consistent with observed values of the coronal base pressure and solar wind mass flux density; (3) the principal effect of rapidly diverging flow geometries is a decrease in the solar wind mass flux density at 1 AU and an increase in the mass flux density at the coronal base; (4) collisionless inhibition of thermal conduction can lead to a solar wind flow speed that either increases or decreases with increasing coronal base density (n 0 ) and temperature (T 0 , depending on the region of the n 0 -T 0 plane considered; (5) there is a region of the n 0 -T/sub o/ plane at high coronal base densities where low-speed, high-mass-flux, transonic solar wind flows exist: a region not previously considered

  18. Meteoric ions in the corona and solar wind

    International Nuclear Information System (INIS)

    Lemaire, J.

    1990-01-01

    The total mass of refractory material of interplanetary origin penetrating and evaporated in the meltosphere surrounding the sun has been inferred from observations of meteoroids and fireballs falling in earth's atmosphere. The amount of iron atoms deposited this way in the solar corona is of the order of 3000 t/s or larger. The measured flux of outflowing solar wind iron ions is equal to 2200 t/s. The close agreement of both fluxes is evidence that a significant fraction of iron ions observed in the solar wind and in the corona must be of meteoric origin. A similar accord is also obtained for silicon ions. The mean velocity of meteoroid ions formed in the solar corona is equal to the free-fall velocity: i.e., independent of their atomic mass as the thermal speed of heavy ion measured in low-density solar wind streams at 1 AU. Furthermore, the heavy ions of meteoric origin escape out of the corona with a larger bulk velocity than the protons which are mainly of solar origin. These differences of heavy ion and proton bulk velocities are also observed in the solar wind. 52 refs

  19. Large-scale offshore wind farms in Denmark. Update of ''Future offshore sites for wind turbines 2025''; Stor-skala havmoelleparker i Danmark. Opdatering af fremtidens havmoelleplaceringer

    Energy Technology Data Exchange (ETDEWEB)

    2011-04-15

    This updating of the ''Future offshore sites for wind turbines 2025'', is made by the Offshore Wind Farm Committee and adjusts primarily the existing sites in relation to a updated data basis. The sites are adjusted within the already identified areas, and no new areas are therefore included. In addition to an update of the underlying data base, including the revised sailing routes, the new Natura 2000 sites and mineral resources, there are now further collected knowledge about the seabed in the designated areas. Moreover, the underlying assumptions for construction costs and grid connection updated, which has resulted in a revised socio-economic priority of the areas. The Offshore Wind Farm Committee's report confirms that the placement of the 600 MW Kriegers Flak Offshore Wind Farm in the Baltic Sea is the best location for Denmark's next major offshore wind farm. Kriegers Flak Offshore Wind Farm is already included in the Government's energy strategy. (LN)

  20. Aerodynamic characteristics of a large-scale semispan model with a swept wing and an augmented jet flap with hypermixing nozzles. [Ames 40- by 80-Foot Wind Tunnel and Static Test Facility

    Science.gov (United States)

    Aiken, T. N.; Falarski, M. D.; Koenin, D. G.

    1979-01-01

    The aerodynamic characteristics of the augmentor wing concept with hypermixing primary nozzles were investigated. A large-scale semispan model in the Ames 40- by 80-Foot Wind Tunnel and Static Test Facility was used. The trailing edge, augmentor flap system occupied 65% of the span and consisted of two fixed pivot flaps. The nozzle system consisted of hypermixing, lobe primary nozzles, and BLC slot nozzles at the forward inlet, both sides and ends of the throat, and at the aft flap. The entire wing leading edge was fitted with a 10% chord slat and a blowing slot. Outboard of the flap was a blown aileron. The model was tested statically and at forward speed. Primary parameters and their ranges included angle of attack from -12 to 32 degrees, flap angles of 20, 30, 45, 60 and 70 degrees, and deflection and diffuser area ratios from 1.16 to 2.22. Thrust coefficients ranged from 0 to 2.73, while nozzle pressure ratios varied from 1.0 to 2.34. Reynolds number per foot varied from 0 to 1.4 million. Analysis of the data indicated a maximum static, gross augmentation of 1.53 at a flap angle of 45 degrees. Analysis also indicated that the configuration was an efficient powered lift device and that the net thrust was comparable with augmentor wings of similar static performance. Performance at forward speed was best at a diffuser area ratio of 1.37.

  1. Mirror Instability in the Turbulent Solar Wind

    Energy Technology Data Exchange (ETDEWEB)

    Hellinger, Petr [Astronomical Institute, CAS, Bocni II/1401,CZ-14100 Prague (Czech Republic); Landi, Simone; Verdini, Andrea; Franci, Luca [Dipartimento di Fisica e Astronomia, Università degli Studi di Firenze Largo E. Fermi 2, I-50125 Firenze (Italy); Matteini, Lorenzo, E-mail: petr.hellinger@asu.cas.cz [Department of Physics, Imperial College London, London SW7 2AZ (United Kingdom)

    2017-04-01

    The relationship between a decaying strong turbulence and the mirror instability in a slowly expanding plasma is investigated using two-dimensional hybrid expanding box simulations. We impose an initial ambient magnetic field perpendicular to the simulation box, and we start with a spectrum of large-scale, linearly polarized, random-phase Alfvénic fluctuations that have energy equipartition between kinetic and magnetic fluctuations and a vanishing correlation between the two fields. A turbulent cascade rapidly develops, magnetic field fluctuations exhibit a Kolmogorov-like power-law spectrum at large scales and a steeper spectrum at sub-ion scales. The imposed expansion (taking a strictly transverse ambient magnetic field) leads to the generation of an important perpendicular proton temperature anisotropy that eventually drives the mirror instability. This instability generates large-amplitude, nonpropagating, compressible, pressure-balanced magnetic structures in a form of magnetic enhancements/humps that reduce the perpendicular temperature anisotropy.

  2. Solar-wind predictions for the Parker Solar Probe orbit. Near-Sun extrapolations derived from an empirical solar-wind model based on Helios and OMNI observations

    Science.gov (United States)

    Venzmer, M. S.; Bothmer, V.

    2018-03-01

    Context. The Parker Solar Probe (PSP; formerly Solar Probe Plus) mission will be humanitys first in situ exploration of the solar corona with closest perihelia at 9.86 solar radii (R⊙) distance to the Sun. It will help answer hitherto unresolved questions on the heating of the solar corona and the source and acceleration of the solar wind and solar energetic particles. The scope of this study is to model the solar-wind environment for PSPs unprecedented distances in its prime mission phase during the years 2018 to 2025. The study is performed within the Coronagraphic German And US SolarProbePlus Survey (CGAUSS) which is the German contribution to the PSP mission as part of the Wide-field Imager for Solar PRobe. Aim. We present an empirical solar-wind model for the inner heliosphere which is derived from OMNI and Helios data. The German-US space probes Helios 1 and Helios 2 flew in the 1970s and observed solar wind in the ecliptic within heliocentric distances of 0.29 au to 0.98 au. The OMNI database consists of multi-spacecraft intercalibrated in situ data obtained near 1 au over more than five solar cycles. The international sunspot number (SSN) and its predictions are used to derive dependencies of the major solar-wind parameters on solar activity and to forecast their properties for the PSP mission. Methods: The frequency distributions for the solar-wind key parameters, magnetic field strength, proton velocity, density, and temperature, are represented by lognormal functions. In addition, we consider the velocity distributions bi-componental shape, consisting of a slower and a faster part. Functional relations to solar activity are compiled with use of the OMNI data by correlating and fitting the frequency distributions with the SSN. Further, based on the combined data set from both Helios probes, the parameters frequency distributions are fitted with respect to solar distance to obtain power law dependencies. Thus an empirical solar-wind model for the inner

  3. Development of large scale wind energy conservation system. Development of control techniques for assembly-type wind power generating systems; Ogata furyoku hatsuden system no kaihatsu. Shugogata furyoku hatsuden system no seigyo gijutsu no kaihatsu

    Energy Technology Data Exchange (ETDEWEB)

    Takita, M [New Energy and Industrial Technology Development Organization, Tokyo (Japan)

    1994-12-01

    Described herein are the results of the FY1994 research program for development of control techniques for assembly-type wind power generating systems. The study on optimum system configuration produces 50 to 100kW wind power units for screening small-size wind power plant types, and, at the same time, surveys performance of commercial units and experiences of 9 makers capable of producing the above units. As a result, 3 MICON`s units (output: 100kW, active YAW control, monopole tower, maximum wind speed: 60m/s) are selected. The study on optimum operational techniques integrates 2 medium-size power units into a power line, showing a service factor of 30.2% on the annual average, monthly varying in a range from 11.8 to 45.0%. These units, installed in Miyako Island, were attacked by 3 typhoons of wind velocity of 25m/s or higher in 1994, and the only damage recorded is that of the anemoscope/anemometer. It is found that No.1 unit is located at a better geographical point than the No.2 unit, to produce a higher output. 3 figs., 3 tabs.

  4. Solar wind and its interaction with the Earth magnetosphere

    International Nuclear Information System (INIS)

    Grib, S.A.

    1978-01-01

    A critical review is given regarding the research of the stationary and non-stationary interaction of the solar wind with the Earth magnetosphere. Highlighted is the significance of the interplanetary magnetic field in the non-stationary movement of the solar wind flux. The problem of the solar wind shock waves interaction with the ''bow wave-Earth's magnetosphere'' system is being solved. Considered are the secondary phenomena, as a result of which the depression-type wave occurs, that lowers the pressure on the Earth's maanetosphere. The law, governing the movement of the magnetosphere subsolar point during the abrupt start of a geomagnetic storm has been discovered. Stationary circumvention of the magnetosphere by the solar wind flux is well described by the gas dynamic theory of the hypersonic flux. Non-stationary interaction of the solar wind shock waves with the magnetosphere is magnetohydrodynamic. It is pointed out, that the problems under consideration are important for the forecasting of strong geomagnetic perturbations on the basis of cosmic observations

  5. Effect of Alfvenic fluctuations on the solar wind

    International Nuclear Information System (INIS)

    Chien, T.H.

    1974-01-01

    The major source of microscale fluctuations in the interplanetary medium due to the outwardly propagating Alfven waves is considered. The effect of the Alfven waves on the supersonic expansion of the solar wind is studied under the assumption that the motion of the interplanetary medium can be resolved physically into a comparatively smooth and slowly varying mesoscale flow and field with very irregular disordered incompressible microscale Alfvenic fluctuations superposed on it. The important features of the solar wind such as heat conduction flux, spiral interplanetary magnetic field, and proton thermal anisotropy are included in the theory. For inviscid, steady state, spherically symmetrical model of the solar wind, the two-fluid formulation of the background mesoscale MHD equations is obtained. The results show that during the expansion process, fluctuation energy is converted into the kinetic energy of the solar wind. Due to the presence of the Alfvenic fluctuations, the velocity of the solar wind is about 5 percent higher than that without considering the fluctuations. (U.S.)

  6. Wave-trains in the solar wind. III

    International Nuclear Information System (INIS)

    Richter, A.K.

    1975-01-01

    Applying an Alfven-Wave-Extended-QRH-approximation and the method of characteristics, the equations of motion for outwardly propagating Alfven waves are solved analytically for three different cases of an azimuthal dependence of the background solar wind, (a) for a pure fast-slow stream configuration, (b) for the situation where the high-speed stream originates from a diverging magnetic field, and (c) for the case of (b) and an initially decreasing density configuration ('coronal hole'). The reaction of these waves on the background state as well as mode-mode coupling effects are neglected. These three solar wind models are discussed shortly. For the superimposed Alfven waves it is found, on an average, that there is a strong azimuthal dependence of all relevant parameters which, correlated with the azimuthal distributions of the solar wind variables, leads to good agreements with observations. The signature of high-speed streams and these correlations could clearly indicate solar wind streams originating from 'coronal holes'. Contrary to the purely radial solar wind, where outwardly propagating Alfven waves are exclusively refracted towards the radial direction, a refraction nearly perpendicular to the direction of the interplanetary magnetic field in the compression region and closely towards the magnetic field direction down the trailing edge and in the low-speed regime is found. (Auth.)

  7. LONG-TERM TRENDS IN THE SOLAR WIND PROTON MEASUREMENTS

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Heather A.; McComas, David J. [Southwest Research Institute, San Antonio, TX (United States); DeForest, Craig E. [Southwest Research Institute, Boulder, CO (United States)

    2016-11-20

    We examine the long-term time evolution (1965–2015) of the relationships between solar wind proton temperature ( T {sub p}) and speed ( V {sub p}) and between the proton density ( n {sub p}) and speed using OMNI solar wind observations taken near Earth. We find a long-term decrease in the proton temperature–speed ( T {sub p}– V {sub p}) slope that lasted from 1972 to 2010, but has been trending upward since 2010. Since the solar wind proton density–speed ( n {sub p}– V {sub p}) relationship is not linear like the T {sub p}– V {sub p} relationship, we perform power-law fits for n {sub p}– V {sub p}. The exponent (steepness in the n {sub p}– V {sub p} relationship) is correlated with the solar cycle. This exponent has a stronger correlation with current sheet tilt angle than with sunspot number because the sunspot number maxima vary considerably from cycle to cycle and the tilt angle maxima do not. To understand this finding, we examined the average n {sub p} for different speed ranges, and found that for the slow wind n {sub p} is highly correlated with the sunspot number, with a lag of approximately four years. The fast wind n {sub p} variation was less, but in phase with the cycle. This phase difference may contribute to the n {sub p}– V {sub p} exponent correlation with the solar cycle. These long-term trends are important since empirical formulas based on fits to T {sub p} and V {sub p} data are commonly used to identify interplanetary coronal mass ejections, but these formulas do not include any time dependence. Changes in the solar wind density over a solar cycle will create corresponding changes in the near-Earth space environment and the overall extent of the heliosphere.

  8. A study of the solar wind deceleration in the Earth's foreshock region

    Science.gov (United States)

    Zhang, T.-L.; Schwingenschuh, K.; Russell, C. T.

    1995-01-01

    Previous observations have shown that the solar wind is decelerated and deflected in the earth's upstream region populated by long-period waves. This deceleration is corelated with the 'diffuse' but not with the 'reflected' ion population. The speed of the solar wind may decrease tens of km/s in the foreshock region. The solar wind dynamic pressure exerted on the magnetopause may vary due to the fluctuation of the solar wind speed and density in the foreshock region. In this study, we examine this solar wind deceleration and determine how the solar wind deceleration varies in the foreshock region.

  9. A hybrid reconfigurable solar and wind energy system

    Science.gov (United States)

    Gadkari, Sagar A.

    We study the feasibility of a novel hybrid solar-wind hybrid system that shares most of its infrastructure and components. During periods of clear sunny days the system will generate electricity from the sun using a parabolic concentrator. The concentrator is formed by individual mirror elements and focuses the light onto high intensity vertical multi-junction (VMJ) cells. During periods of high wind speeds and at night, the same concentrator setup will be reconfigured to channel the wind into a wind turbine which will be used to harness wind energy. In this study we report on the feasibility of this type of solar/wind hybrid energy system. The key mechanisms; optics, cooling mechanism of VMJ cells and air flow through the system were investigated using simulation tools. The results from these simulations, along with a simple economic analysis giving the levelized cost of energy for such a system are presented. An iterative method of design refinement based on the simulation results was used to work towards a prototype design. The levelized cost of the system achieved in the economic analysis shows the system to be a good alternative for a grid isolated site and could be used as a standalone system in regions of lower demand. The new approach to solar wind hybrid system reported herein will pave way for newer generation of hybrid systems that share common infrastructure in addition to the storage and distribution of energy.

  10. Weakest solar wind of the space age and the current 'MINI' solar maximum

    International Nuclear Information System (INIS)

    McComas, D. J.; Angold, N.; Elliott, H. A.; Livadiotis, G.; Schwadron, N. A.; Smith, C. W.; Skoug, R. M.

    2013-01-01

    The last solar minimum, which extended into 2009, was especially deep and prolonged. Since then, sunspot activity has gone through a very small peak while the heliospheric current sheet achieved large tilt angles similar to prior solar maxima. The solar wind fluid properties and interplanetary magnetic field (IMF) have declined through the prolonged solar minimum and continued to be low through the current mini solar maximum. Compared to values typically observed from the mid-1970s through the mid-1990s, the following proton parameters are lower on average from 2009 through day 79 of 2013: solar wind speed and beta (∼11%), temperature (∼40%), thermal pressure (∼55%), mass flux (∼34%), momentum flux or dynamic pressure (∼41%), energy flux (∼48%), IMF magnitude (∼31%), and radial component of the IMF (∼38%). These results have important implications for the solar wind's interaction with planetary magnetospheres and the heliosphere's interaction with the local interstellar medium, with the proton dynamic pressure remaining near the lowest values observed in the space age: ∼1.4 nPa, compared to ∼2.4 nPa typically observed from the mid-1970s through the mid-1990s. The combination of lower magnetic flux emergence from the Sun (carried out in the solar wind as the IMF) and associated low power in the solar wind points to the causal relationship between them. Our results indicate that the low solar wind output is driven by an internal trend in the Sun that is longer than the ∼11 yr solar cycle, and they suggest that this current weak solar maximum is driven by the same trend.

  11. Magnetic storm generation by large-scale complex structure Sheath/ICME

    Science.gov (United States)

    Grigorenko, E. E.; Yermolaev, Y. I.; Lodkina, I. G.; Yermolaev, M. Y.; Riazantseva, M.; Borodkova, N. L.

    2017-12-01

    We study temporal profiles of interplanetary plasma and magnetic field parameters as well as magnetospheric indices. We use our catalog of large-scale solar wind phenomena for 1976-2000 interval (see the catalog for 1976-2016 in web-side ftp://ftp.iki.rssi.ru/pub/omni/ prepared on basis of OMNI database (Yermolaev et al., 2009)) and the double superposed epoch analysis method (Yermolaev et al., 2010). Our analysis showed (Yermolaev et al., 2015) that average profiles of Dst and Dst* indices decrease in Sheath interval (magnetic storm activity increases) and increase in ICME interval. This profile coincides with inverted distribution of storm numbers in both intervals (Yermolaev et al., 2017). This behavior is explained by following reasons. (1) IMF magnitude in Sheath is higher than in Ejecta and closed to value in MC. (2) Sheath has 1.5 higher efficiency of storm generation than ICME (Nikolaeva et al., 2015). The most part of so-called CME-induced storms are really Sheath-induced storms and this fact should be taken into account during Space Weather prediction. The work was in part supported by the Russian Science Foundation, grant 16-12-10062. References. 1. Nikolaeva N.S., Y. I. Yermolaev and I. G. Lodkina (2015), Modeling of the corrected Dst* index temporal profile on the main phase of the magnetic storms generated by different types of solar wind, Cosmic Res., 53(2), 119-127 2. Yermolaev Yu. I., N. S. Nikolaeva, I. G. Lodkina and M. Yu. Yermolaev (2009), Catalog of Large-Scale Solar Wind Phenomena during 1976-2000, Cosmic Res., , 47(2), 81-94 3. Yermolaev, Y. I., N. S. Nikolaeva, I. G. Lodkina, and M. Y. Yermolaev (2010), Specific interplanetary conditions for CIR-induced, Sheath-induced, and ICME-induced geomagnetic storms obtained by double superposed epoch analysis, Ann. Geophys., 28, 2177-2186 4. Yermolaev Yu. I., I. G. Lodkina, N. S. Nikolaeva and M. Yu. Yermolaev (2015), Dynamics of large-scale solar wind streams obtained by the double superposed epoch

  12. Magnetic Pumping as a Source of Particle Heating and Power-law Distributions in the Solar Wind

    Science.gov (United States)

    Lichko, E.; Egedal, J.; Daughton, W.; Kasper, J.

    2017-12-01

    Based on the rate of expansion of the solar wind, the plasma should cool rapidly as a function of distance to the Sun. Observations show this is not the case. In this work, a magnetic pumping model is developed as a possible explanation for the heating and the generation of power-law distribution functions observed in the solar wind plasma. Most previous studies in this area focus on the role that the dissipation of turbulent energy on microscopic kinetic scales plays in the overall heating of the plasma. However, with magnetic pumping, particles are energized by the largest-scale turbulent fluctuations, thus bypassing the energy cascade. In contrast to other models, we include the pressure anisotropy term, providing a channel for the large-scale fluctuations to heat the plasma directly. A complete set of coupled differential equations describing the evolution, and energization, of the distribution function are derived, as well as an approximate closed-form solution. Numerical simulations using the VPIC kinetic code are applied to verify the model’s analytical predictions. The results of the model for realistic solar wind scenario are computed, where thermal streaming of particles are important for generating a phase shift between the magnetic perturbations and the pressure anisotropy. In turn, averaged over a pump cycle, the phase shift permits mechanical work to be converted directly to heat in the plasma. The results of this scenario show that magnetic pumping may account for a significant portion of the solar wind energization.

  13. BRITE-Constellation high-precision time-dependent photometry of the early O-type supergiant ζ Puppis unveils the photospheric drivers of its small- and large-scale wind structures

    Science.gov (United States)

    Ramiaramanantsoa, Tahina; Moffat, Anthony F. J.; Harmon, Robert; Ignace, Richard; St-Louis, Nicole; Vanbeveren, Dany; Shenar, Tomer; Pablo, Herbert; Richardson, Noel D.; Howarth, Ian D.; Stevens, Ian R.; Piaulet, Caroline; St-Jean, Lucas; Eversberg, Thomas; Pigulski, Andrzej; Popowicz, Adam; Kuschnig, Rainer; Zocłońska, Elżbieta; Buysschaert, Bram; Handler, Gerald; Weiss, Werner W.; Wade, Gregg A.; Rucinski, Slavek M.; Zwintz, Konstanze; Luckas, Paul; Heathcote, Bernard; Cacella, Paulo; Powles, Jonathan; Locke, Malcolm; Bohlsen, Terry; Chené, André-Nicolas; Miszalski, Brent; Waldron, Wayne L.; Kotze, Marissa M.; Kotze, Enrico J.; Böhm, Torsten

    2018-02-01

    From 5.5 months of dual-band optical photometric monitoring at the 1 mmag level, BRITE-Constellation has revealed two simultaneous types of variability in the O4I(n)fp star ζ Puppis: one single periodic non-sinusoidal component superimposed on a stochastic component. The monoperiodic component is the 1.78-d signal previously detected by Coriolis/Solar Mass Ejection Imager, but this time along with a prominent first harmonic. The shape of this signal changes over time, a behaviour that is incompatible with stellar oscillations but consistent with rotational modulation arising from evolving bright surface inhomogeneities. By means of a constrained non-linear light-curve inversion algorithm, we mapped the locations of the bright surface spots and traced their evolution. Our simultaneous ground-based multisite spectroscopic monitoring of the star unveiled cyclical modulation of its He II λ4686 wind emission line with the 1.78-d rotation period, showing signatures of corotating interaction regions that turn out to be driven by the bright photospheric spots observed by BRITE. Traces of wind clumps are also observed in the He II λ4686 line and are correlated with the amplitudes of the stochastic component of the light variations probed by BRITE at the photosphere, suggesting that the BRITE observations additionally unveiled the photospheric drivers of wind clumps in ζ Pup and that the clumping phenomenon starts at the very base of the wind. The origins of both the bright surface inhomogeneities and the stochastic light variations remain unknown, but a subsurface convective zone might play an important role in the generation of these two types of photospheric variability.

  14. Distribution and solar wind control of compressional solar wind-magnetic anomaly interactions observed at the Moon by ARTEMIS

    Science.gov (United States)

    Halekas, J. S.; Poppe, A. R.; Lue, C.; Farrell, W. M.; McFadden, J. P.

    2017-06-01

    A statistical investigation of 5 years of observations from the two-probe Acceleration, Reconnection, Turbulence, and Electrodynamics of Moon's Interaction with the Sun (ARTEMIS) mission reveals that strong compressional interactions occur infrequently at high altitudes near the ecliptic but can form in a wide range of solar wind conditions and can occur up to two lunar radii downstream from the lunar limb. The compressional events, some of which may represent small-scale collisionless shocks ("limb shocks"), occur in both steady and variable interplanetary magnetic field (IMF) conditions, with those forming in steady IMF well organized by the location of lunar remanent crustal magnetization. The events observed by ARTEMIS have similarities to ion foreshock phenomena, and those observed in variable IMF conditions may result from either local lunar interactions or distant terrestrial foreshock interactions. Observed velocity deflections associated with compressional events are always outward from the lunar wake, regardless of location and solar wind conditions. However, events for which the observed velocity deflection is parallel to the upstream motional electric field form in distinctly different solar wind conditions and locations than events with antiparallel deflections. Consideration of the momentum transfer between incoming and reflected solar wind populations helps explain the observed characteristics of the different groups of events.Plain Language SummaryWe survey the environment around the Moon to determine when and where strong amplifications in the charged particle density and magnetic field strength occur. These structures may be some of the smallest shock waves in the solar system, and learning about their formation informs us about the interaction of charged particles with small-scale magnetic fields throughout the solar system and beyond. We find that these compressions occur in an extended region downstream from the lunar dawn and dusk regions and

  15. Ulysses solar wind plasma observations at high southerly latitudes.

    Science.gov (United States)

    Phillips, J L; Bame, S J; Feldman, W C; Gosling, J T; Hammond, C M; McComas, D J; Goldstein, B E; Neugebauer, M; Scime, E E; Suess, S T

    1995-05-19

    Solar wind plasma observations made by the Ulysses spacecraft through -80.2 degrees solar latitude and continuing equatorward to -40.1 degrees are summarized. Recurrent high-speed streams and corotating interaction regions dominated at middle latitudes. The speed of the solar wind was typically 700 to 800 kilometers per second poleward of -35 degrees . Corotating reverse shocks persisted farther south than did forward shocks because of the tilt of the heliomagnetic streamer belt. Sporadic coronal mass ejections were seen as far south as -60.5 degrees . Proton temperature was higher and the electron strahl was broader at higher latitudes. The high-latitude wind contained compressional, pressure-balanced, and Alfvénic structures.

  16. Coupling of the solar wind to measures of magnetic activity

    International Nuclear Information System (INIS)

    McPherron, R.L.; Fay, R.A.; Garrity, C.R.; Bargatze, L.F.; Baker, D.N.; Clauer, C.R.; Searls, C.

    1984-01-01

    The technique of linear prediction filtering has been used to generate empirical response functions relating the solar wind electric field to the most frequently used magnetic indices, AL, AU, Dst and ASYM. Two datasets, one from 1967-1968 and one from 1973-1974, provided the information needed to calculate the empirical response functions. These functions have been convolved with solar wind observations obtained during the IMS to predict the indices. These predictions are compared with the observed indices during two, three-day intervals studied extensively by participants in the CDAW-6 workshop. Differences between the observed and predicted indices are discussed in terms of the linear assumption and in terms of physical processes other than direct solar wind-magnetosphere interaction

  17. Solar wind power electric plant on Vis (Croatia)

    International Nuclear Information System (INIS)

    1998-01-01

    A project of a solar photovoltaic electric power plant presented by the Republic of Croatia at the meeting of the E.P.I.A. Mission for photovoltaic technology of the Mediterranean countries, aroused a great interest of the representatives of the invited countries. However, the interest within Croatia in the project has disappeared although E.P.I.A. offered a financing of two thirds of costs. There are attempts to construct 1800 kw wind-driven generators at the same location not taking into consideration a possibility of building a hybrid solar-wind-power electric plant. The chance that the solar part is completely of domestic origin is not accepted but the preference is given to the building of imported wind-driven generators. (orig.)

  18. Effects of electrons on the solar wind proton temperature anisotropy

    International Nuclear Information System (INIS)

    Michno, M. J.; Lazar, M.; Schlickeiser, R.; Yoon, P. H.

    2014-01-01

    Among the kinetic microinstabilities, the firehose instability is one of the most efficient mechanisms to restrict the unlimited increase of temperature anisotropy in the direction of an ambient magnetic field as predicted by adiabatic expansion of collision-poor solar wind. Indeed, the solar wind proton temperature anisotropy detected near 1 AU shows that it is constrained by the marginal firehose condition. Of the two types of firehose instabilities, namely, parallel and oblique, the literature suggests that the solar wind data conform more closely to the marginal oblique firehose condition. In the present work, however, it is shown that the parallel firehose instability threshold is markedly influenced by the presence of anisotropic electrons, such that under some circumstances, the cumulative effects of both electron and proton anisotropies could describe the observation without considering the oblique firehose mode.

  19. Average properties of cosmic ray diffusion in solar wind streams

    International Nuclear Information System (INIS)

    Morfill, G.; Richter, A.K.; Scholer, M.

    1979-01-01

    Applying a superposed epoch analysis to the Mariner 5 plasma and magnetic field observations of 13 corotating high speed solar wind streams, we obtain the average azimuthal distribution of all relevant parameters of the background interplanetary medium, as well as those of superimposed Alfven waves. Using these measurements in model calculations allows us to determine the radial and azimuthal variation of the background and fluctuation parameters between 1 and 5 AU, and thus to calculate the cosmic ray diffusion coefficient kappa from the plasma and field properties. The calculation of kappa assumes that quasi-linear wave-particle interaction theory is applicable, and that the Alfven waves responsible for the scattering are propagating in the azimuthally varying solar wind according to geometrical optics. The consequences of these calculations regarding the occurrence of solar wind stream associated Forbush decreases are discussed

  20. THE NEW HORIZONS SOLAR WIND AROUND PLUTO (SWAP) OBSERVATIONS OF THE SOLAR WIND FROM 11–33 au

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, H. A.; McComas, D. J.; Valek, P.; Weidner, S.; Livadiotis, G. [Southwest Research Institute, 6220 Culebra Road, San Antonio, TX 78238 (United States); Nicolaou, G., E-mail: helliott@swri.edu [Swedish Institute of Space Physics, Box 812, SE-98128, Kiruna (Sweden)

    2016-04-15

    The Solar Wind Around Pluto (SWAP) instrument on National Aeronautics and Space Administration's New Horizons Pluto mission has collected solar wind observations en route from Earth to Pluto, and these observations continue beyond Pluto. Few missions have explored the solar wind in the outer heliosphere making this dataset a critical addition to the field. We created a forward model of SWAP count rates, which includes a comprehensive instrument response function based on laboratory and flight calibrations. By fitting the count rates with this model, the proton density (n), speed (V), and temperature (T) parameters are determined. Comparisons between SWAP parameters and both propagated 1 au observations and prior Voyager 2 observations indicate consistency in both the range and mean wind values. These comparisons as well as our additional findings confirm that small and midsized solar wind structures are worn down with increasing distance due to dynamic interaction of parcels of wind with different speed. For instance, the T–V relationship steepens, as the range in V is limited more than the range in T with distance. At times the T–V correlation clearly breaks down beyond 20 au, which may indicate wind currently expanding and cooling may have an elevated T reflecting prior heating and compression in the inner heliosphere. The power of wind parameters at shorter periodicities decreases with distance as the longer periodicities strengthen. The solar rotation periodicity is present in temperature beyond 20 au indicating the observed parcel temperature may reflect not only current heating or cooling, but also heating occurring closer to the Sun.

  1. THE NEW HORIZONS SOLAR WIND AROUND PLUTO (SWAP) OBSERVATIONS OF THE SOLAR WIND FROM 11–33 au

    International Nuclear Information System (INIS)

    Elliott, H. A.; McComas, D. J.; Valek, P.; Weidner, S.; Livadiotis, G.; Nicolaou, G.

    2016-01-01

    The Solar Wind Around Pluto (SWAP) instrument on National Aeronautics and Space Administration's New Horizons Pluto mission has collected solar wind observations en route from Earth to Pluto, and these observations continue beyond Pluto. Few missions have explored the solar wind in the outer heliosphere making this dataset a critical addition to the field. We created a forward model of SWAP count rates, which includes a comprehensive instrument response function based on laboratory and flight calibrations. By fitting the count rates with this model, the proton density (n), speed (V), and temperature (T) parameters are determined. Comparisons between SWAP parameters and both propagated 1 au observations and prior Voyager 2 observations indicate consistency in both the range and mean wind values. These comparisons as well as our additional findings confirm that small and midsized solar wind structures are worn down with increasing distance due to dynamic interaction of parcels of wind with different speed. For instance, the T–V relationship steepens, as the range in V is limited more than the range in T with distance. At times the T–V correlation clearly breaks down beyond 20 au, which may indicate wind currently expanding and cooling may have an elevated T reflecting prior heating and compression in the inner heliosphere. The power of wind parameters at shorter periodicities decreases with distance as the longer periodicities strengthen. The solar rotation periodicity is present in temperature beyond 20 au indicating the observed parcel temperature may reflect not only current heating or cooling, but also heating occurring closer to the Sun

  2. Magnetic fields in the solar system planets, moons and solar wind interactions

    CERN Document Server

    Wicht, Johannes; Gilder, Stuart; Holschneider, Matthias

    2018-01-01

    This book addresses and reviews many of the still little understood questions related to the processes underlying planetary magnetic fields and their interaction with the solar wind. With focus on research carried out within the German Priority Program ”PlanetMag”, it also provides an overview of the most recent research in the field. Magnetic fields play an important role in making a planet habitable by protecting the environment from the solar wind. Without the geomagnetic field, for example, life on Earth as we know it would not be possible. And results from recent space missions to Mars and Venus strongly indicate that planetary magnetic fields play a vital role in preventing atmospheric erosion by the solar wind. However, very little is known about the underlying interaction between the solar wind and a planet’s magnetic field. The book takes a synergistic interdisciplinary approach that combines newly developed tools for data acquisition and analysis, computer simulations of planetary interiors an...

  3. Agua Caliente Wind/Solar Project at Whitewater Ranch

    Energy Technology Data Exchange (ETDEWEB)

    Hooks, Todd [Agua Caliente Band of Cahuilla Indians, Palm Springs, CA (United States); Stewart, Royce [Red Mountain Energy Partners, Sante Fe, NM (United States)

    2014-12-16

    Agua Caliente Band of Cahuilla Indians (ACBCI) was awarded a grant by the Department of Energy (DOE) to study the feasibility of a wind and/or solar renewable energy project at the Whitewater Ranch (WWR) property of ACBCI. Red Mountain Energy Partners (RMEP) was engaged to conduct the study. The ACBCI tribal lands in the Coachella Valley have very rich renewable energy resources. The tribe has undertaken several studies to more fully understand the options available to them if they were to move forward with one or more renewable energy projects. With respect to the resources, the WWR property clearly has excellent wind and solar resources. The DOE National Renewable Energy Laboratory (NREL) has continued to upgrade and refine their library of resource maps. The newer, more precise maps quantify the resources as among the best in the world. The wind and solar technology available for deployment is also being improved. Both are reducing their costs to the point of being at or below the costs of fossil fuels. Technologies for energy storage and microgrids are also improving quickly and present additional ways to increase the wind and/or solar energy retained for later use with the network management flexibility to provide power to the appropriate locations when needed. As a result, renewable resources continue to gain more market share. The transitioning to renewables as the major resources for power will take some time as the conversion is complex and can have negative impacts if not managed well. While the economics for wind and solar systems continue to improve, the robustness of the WWR site was validated by the repeated queries of developers to place wind and/or solar there. The robust resources and improving technologies portends toward WWR land as a renewable energy site. The business case, however, is not so clear, especially when the potential investment portfolio for ACBCI has several very beneficial and profitable alternatives.

  4. Kinetic Properties of Solar Wind Silicon and Iron Ions

    Science.gov (United States)

    Janitzek, N. P.; Berger, L.; Drews, C.; Wimmer-Schweingruber, R. F.

    2017-12-01

    Heavy ions with atomic numbers Z>2 account for less than one percent of the solar wind ions. However, serving as test particles with differing mass and charge, they provide a unique experimental approach to major questions of solar and fundamental plasma physics such as coronal heating, the origin and acceleration of the solar wind and wave-particle interaction in magnetized plasma. Yet the low relative abundances of the heavy ions pose substantial challenges to the instrumentation measuring these species with reliable statistics and sufficient time resolution. As a consequence the numbers of independent measurements and studies are small. The Charge Time-Of-Flight (CTOF) mass spectrometer as part of the Charge, ELement and Isotope Analysis System (CELIAS) onboard the SOlar and Heliospheric Observatory (SOHO) is a linear time-of-flight mass spectrometer which was operated at Lagrangian point L1 in 1996 for a few months only, before it suffered an instrument failure. Despite its short operation time, the CTOF sensor measured solar wind heavy ions with excellent charge state separation, an unprecedented cadence of 5 minutes and very high counting statistics, exceeding similar state-of-the-art instruments by a factor of ten. In contrast to earlier CTOF studies which were based on reduced onboard post-processed data, in our current studies we use raw Pulse Height Analysis (PHA) data providing a significantly increased mass, mass-per-charge and velocity resolution. Focussing on silicon and iron ion measurements, we present an overview of our findings on (1) short time behavior of heavy ion 1D radial velocity distribution functions, (2) differential streaming between heavy ions and solar wind bulk protons, (3) kinetic temperatures of heavy ions. Finally, we compare the CTOF results with measurements of the Solar Wind Ion Composition Spectrometer (SWICS) instrument onboard the Advanced Composition Explorer (ACE).

  5. Electric field in the magnetotail depending on the geomagnetic activity level and intensity Esub(y) in the solar wind

    International Nuclear Information System (INIS)

    Pudovkin, M.I.; Osipov, V.V.; Shukhtina, M.A.; Zajtseva, S.A.; AN SSSR, Vladivostok. Dal'nevostochnyh Nauchnyj Tsentr)

    1982-01-01

    The value of the large-scale electric field in the near magnetotail on AE-index variations delay in relation to interplanetary electric field variations is estimated. It is obtained that the electric field value in a tail increases with magnetic activity level. The solar wind electric field under strong magnetic disturbance penetrates into the magnetosphere practically without weakening and is essentially weakened in magneto-quit conditions. Calculated values of the electric field magnitude in the magnetotail (0.01-1mBm) are in agreement with those obtained earlier [ru