SOLERAS - Solar Controlled Environment Agriculture Project. Final report, Volume 1. Project summary
Energy Technology Data Exchange (ETDEWEB)
1985-12-30
A summary of the Solar Controlled Environment Agriculture Project is presented. The design of the greenhouses include transparent double pane glass roof with channels for fluid between the panes, inner pane tinted and double pane extruded acrylic aluminized mylar shade and diffuser. Solar energy technologies provide power for water desalination, for pumping irrigation water, and for cooling and heating the controlled environment space so that crops can grow in arid lands. The project is a joint effort between the United States and Saudi Arabia. (BCS)
Energy Technology Data Exchange (ETDEWEB)
1985-01-01
Literature summarizing a study on the Saudi Arabian solar controlled environment agriculture system is presented. Specifications and performance requirements for the system components are revealed. Detailed performance and cost analyses are used to determine the optimum design. A preliminary design of an engineering field test is included. Some weather data are provided for Riyadh, Saudi Arabia. (BCS)
The Solar Connections Observatory for Planetary Environments
Oliversen, Ronald J.; Harris, Walter M.; Oegerle, William R. (Technical Monitor)
2002-01-01
The NASA Sun-Earth Connection theme roadmap calls for comparative study of how the planets, comets, and local interstellar medium (LISM) interact with the Sun and respond to solar variability. Through such a study we advance our understanding of basic physical plasma and gas dynamic processes, thus increasing our predictive capabilities for the terrestrial, planetary, and interplanetary environments where future remote and human exploration will occur. Because the other planets have lacked study initiatives comparable to the terrestrial ITM, LWS, and EOS programs, our understanding of the upper atmospheres and near space environments on these worlds is far less detailed than our knowledge of the Earth. To close this gap we propose a mission to study {\\it all) of the solar interacting bodies in our planetary system out to the heliopause with a single remote sensing space observatory, the Solar Connections Observatory for Planetary Environments (SCOPE). SCOPE consists of a binocular EUV/FUV telescope operating from a remote, driftaway orbit that provides sub-arcsecond imaging and broadband medium resolution spectro-imaging over the 55-290 nm bandpass, and high (R>10$^{5}$ resolution H Ly-$\\alpha$ emission line profile measurements of small scale planetary and wide field diffuse solar system structures. A key to the SCOPE approach is to include Earth as a primary science target. From its remote vantage point SCOPE will be able to observe auroral emission to and beyond the rotational pole. The other planets and comets will be monitored in long duration campaigns centered when possible on solar opposition when interleaved terrestrial-planet observations can be used to directly compare the response of both worlds to the same solar wind stream and UV radiation field. Using a combination of observations and MHD models, SCOPE will isolate the different controlling parameters in each planet system and gain insight into the underlying physical processes that define the
Simulated Space Environment Effects on a Candidate Solar Sail Material
Kang, Jin Ho; Bryant, Robert G.; Wilkie, W. Keats; Wadsworth, Heather M.; Craven, Paul D.; Nehls, Mary K.; Vaughn, Jason A.
2017-01-01
For long duration missions of solar sails, the sail material needs to survive harsh space environments and the degradation of the sail material controls operational lifetime. Therefore, understanding the effects of the space environment on the sail membrane is essential for mission success. In this study, we investigated the effect of simulated space environment effects of ionizing radiation, thermal aging and simulated potential damage on mechanical, thermal and optical properties of a commercial off the shelf (COTS) polyester solar sail membrane to assess the degradation mechanisms on a feasible solar sail. The solar sail membrane was exposed to high energy electrons (about 70 keV and 10 nA/cm2), and the physical properties were characterized. After about 8.3 Grad dose, the tensile modulus, tensile strength and failure strain of the sail membrane decreased by about 20 95%. The aluminum reflective layer was damaged and partially delaminated but it did not show any significant change in solar absorbance or thermal emittance. The effect on mechanical properties of a pre-cracked sample, simulating potential impact damage of the sail membrane, as well as thermal aging effects on metallized PEN (polyethylene naphthalate) film will be discussed.
A solar charge and discharge controller for wireless sensor nodes
Dang, Yibo; Shen, Shu
2018-02-01
Aiming at the energy supply problem that restricts the life of wireless sensor nodes, a solar energy charge and discharge controller suitable for wireless sensor nodes is designed in this paper. A Microcontroller is used as the core of the solar charge and discharge controller. The software of the solar charge and discharge controller adopts the C language to realize the program of the main control module. Firstly, the function of monitoring solar panel voltage and lithium battery voltage are simulated by Protel software, and the charge time is tested in cloudy and overcast outdoor environment. The results of the experiment show that our controller meets the power supply demand of wireless sensor nodes.
Interplanetary Radiation and Internal Charging Environment Models for Solar Sails
Minow, Joseph I.; Altstatt, Richard L.; NeegaardParker, Linda
2005-01-01
A Solar Sail Radiation Environment (SSRE) model has been developed for defining charged particle environments over an energy range from 0.01 keV to 1 MeV for hydrogen ions, helium ions, and electrons. The SSRE model provides the free field charged particle environment required for characterizing energy deposition per unit mass, charge deposition, and dose rate dependent conductivity processes required to evaluate radiation dose and internal (bulk) charging processes in the solar sail membrane in interplanetary space. Solar wind and energetic particle measurements from instruments aboard the Ulysses spacecraft in a solar, near-polar orbit provide the particle data over a range of heliospheric latitudes used to derive the environment that can be used for radiation and charging environments for both high inclination 0.5 AU Solar Polar Imager mission and the 1.0 AU L1 solar missions. This paper describes the techniques used to model comprehensive electron, proton, and helium spectra over the range of particle energies of significance to energy and charge deposition in thin (less than 25 micrometers) solar sail materials.
Control of Solar Energy Systems
Camacho, Eduardo F; Rubio, Francisco R; Martínez, Diego
2012-01-01
Control of Solar Energy Systems details the main solar energy systems, problems involved with their control, and how control systems can help in increasing their efficiency. After a brief introduction to the fundamental concepts associated with the use of solar energy in both photovoltaic and thermal plants, specific issues related to control of solar systems are embarked upon. Thermal energy systems are then explored in depth, as well as other solar energy applications such as solar furnaces and solar refrigeration systems. Problems of variable generation profile and of the contribution of many solar plants to the same grid system are considered with the necessary integrated and supervisory control solutions being discussed. The text includes material on: · A comparison of basic and advanced control methods for parabolic troughs from PID to nonlinear model-based control; · solar towers and solar tracking; · heliostat calibration, characterization and off...
Solar/Space Environment Data (Satellites)
National Oceanic and Atmospheric Administration, Department of Commerce — The National Oceanic and Atmospheric Administration (NOAA) monitors the geospace and solar environments using a variety of space weather sensors aboard its fleet of...
Nanostructured Solar Irradiation Control Materials for Solar Energy Conversion
Kang, Jinho; Marshall, I. A.; Torrico, M. N.; Taylor, C. R.; Ely, Jeffry; Henderson, Angel Z.; Kim, J.-W.; Sauti, G.; Gibbons, L. J.; Park, C.;
2012-01-01
Tailoring the solar absorptivity (alpha(sub s)) and thermal emissivity (epsilon(sub T)) of materials constitutes an innovative approach to solar energy control and energy conversion. Numerous ceramic and metallic materials are currently available for solar absorbance/thermal emittance control. However, conventional metal oxides and dielectric/metal/dielectric multi-coatings have limited utility due to residual shear stresses resulting from the different coefficient of thermal expansion of the layered materials. This research presents an alternate approach based on nanoparticle-filled polymers to afford mechanically durable solar-absorptive and thermally-emissive polymer nanocomposites. The alpha(sub s) and epsilon(sub T) were measured with various nano inclusions, such as carbon nanophase particles (CNPs), at different concentrations. Research has shown that adding only 5 wt% CNPs increased the alpha(sub s) and epsilon(sub T) by a factor of about 47 and 2, respectively, compared to the pristine polymer. The effect of solar irradiation control of the nanocomposite on solar energy conversion was studied. The solar irradiation control coatings increased the power generation of solar thermoelectric cells by more than 380% compared to that of a control power cell without solar irradiation control coatings.
Effects of solar electromagnetic radiation on the terrestrial environment
International Nuclear Information System (INIS)
Dickinson, R.E.
1986-01-01
The general intent of this essay is to discuss the effect of solar electromagnetic radiation on the terrestrial environment. Instead of giving a systematic approach considering all environment processes where solar emission is the primary energy source and all important materials which have been generated by solar driven processes, the author sketches an impression of the range of the effects of solar radiation on the environment by surveying a number of topics of particular current interest, in varying levels of detail. These include atmospheric chemistry, some aspects of the transfer of radiation within the atmosphere, global energy balance and climate feedbacks, especially those due to clouds, impacts of fossil fuel energy use, evolution of early life processes, photosynthesis and plant productivity as it relates to photosynthesis and the global carbon cycle. (Auth.)
Effects of solar photovoltaic technology on the environment in China.
Qi, Liqiang; Zhang, Yajuan
2017-10-01
Among the various types of renewable energy, solar photovoltaic has elicited the most attention because of its low pollution, abundant reserve, and endless supply. Solar photovoltaic technology generates both positive and negative effects on the environment. The environmental loss of 0.00666 yuan/kWh from solar photovoltaic technology is lower than that from coal-fired power generation (0.05216 yuan/kWh). The negative effects of solar photovoltaic system production include wastewater and waste gas pollutions, the representatives of which contain fluorine, chromium with wastewater and hydrogen fluoride, and silicon tetrachloride gas. Solar panels are also a source of light pollution. Improper disposal of solar cells that have reached the end of their service life harms the environment through the stench they produce and the damage they cause to the soil. So, the positive and negative effects of green energy photovoltaic power generation technology on the environment should be considered.
A Review of Solar Energy and the Built Environment
Directory of Open Access Journals (Sweden)
Raha Sulaiman
2005-12-01
Full Text Available Solar Energy has been acknowledged as a free and infinite source of energy. In Built Environment (BE, solar energy has been used since pre-historic time. Many improvements and technologies .have been developed with respect to their potential. As solar supplies free energy, the issues with regard to their development in the BE will be examined. The solar energy is used in building either in Passive Solar Design (PSD or Active Solar Design (ASD. Rapid development in BE has caused global warming effect where the heating and cooling of the building contribute to half the total energy consumption of the nation and the construction industry leading to CO2 emission level at 300 million tonnes. It is found that solar energy produces different energy performances which result from different building technique that affected the environment in various ways. Whether or not the energy performances depend on the materials used, the equipment installed in the building or the energy sources supplied to the building , the improvement and development of solar energy still continues and grows.
Robust Controller for Delays and Packet Dropout Avoidance in Solar-Power Wireless Network
Al-Azzawi, Waleed
2013-01-01
Solar Wireless Networked Control Systems (SWNCS) are a style of distributed control systems where sensors, actuators, and controllers are interconnected via a wireless communication network. This system setup has the benefit of low cost, flexibility, low weight, no wiring and simplicity of system diagnoses and maintenance. However, it also unavoidably calls some wireless network time delays and packet dropout into the design procedure. Solar lighting system offers a clean environment, therefo...
Solar charge controller in solar street light
Dong, Haibo
2014-01-01
Recently, with the rapid development of scientific technology, the conventional energy cannot meet the requirement of human beings. People are looking for the utilization of renew energy. Solar en-ergy as a new clean energy has attract the eyes of people. The applications of solar energy are popular to human society. Solar street light is a good example. This thesis will focus on a deeper research of the popular and ubiquitous solar street light in China. However, solar charge controll...
Development of Intelligent Fuzzy Controller for a Two-Axis Solar Tracking System
Directory of Open Access Journals (Sweden)
Cong-Hui Huang
2016-05-01
Full Text Available This paper proposes the development of a two-axis sun tracking solar energy system using fuzzy logic as intelligent quality policy. To achieve maximum efficiency for solar panels, it is necessary to follow the sun’s path in the sky. Therefore, the architecture for the two-axis sun tracking solar energy system uses software to control the hardware. The hardware comprises (i solar cells; (ii lead-acid batteries; (iii a gear box; (iv a stepping motor; and (v a light detection circuit, while the software comprises (i a detection system; (ii a fuzzy tracking controller; and (iii a database system. A fuzzy logic controller is designed as the software architecture of the system to decide the timing for tracking the sun. The nearest position that results in receiving direct sunlight is obtained from the database. Our system is fully automatic in a changing environment and takes into account meteorological changes and the effects of the external environment arising from a malfunction. This approach reduces the number of starting motors and results in smaller energy loss in cloudy, cloud mask, or unstable weather conditions.
Handbook of the Solar-Terrestrial Environment
Kamide, Y
2007-01-01
The Handbook of the Solar-Terrestrial Environment is a unique compendium. Recognized international leaders in their field contribute chapters on basic topics of solar physics, space plasmas and the Earth's magnetosphere, and on applied topics like the aurora, magnetospheric storms, space weather, space climatology and planetary science. This book will be of highest value as a reference for researchers working in the area of planetary and space science. However, it is also written in a style accessible to graduate students majoring in those fields.
Concentrated solar power in the built environment
Montenon, Alaric C.; Fylaktos, Nestor; Montagnino, Fabio; Paredes, Filippo; Papanicolas, Costas N.
2017-06-01
Solar concentration systems are usually deployed in large open spaces for electricity generation; they are rarely used to address the pressing energy needs of the built environment sector. Fresnel technology offers interesting and challenging CSP energy pathways suitable for the built environment, due to its relatively light weight (Heating, Ventilation, and Air Conditioning) system of a recently constructed office & laboratory building, the Novel Technologies Laboratory (NTL). The multi-generative system will support cooling, heating and hot water production feeding the system of the NTL building, as a demonstration project, part of the STS-MED program (Small Scale Thermal Solar District Units for Mediterranean Communities) financed by the European Commission under the European Neighbourhood and Partnership Instrument (ENPI), CBCMED program.
Directory of Open Access Journals (Sweden)
Mariela Edith Arboit
2014-12-01
Full Text Available The aim of this work is to advance the understanding of the solar potential of urban residential environments which, by their morphology, and the impact of urban trees, present values of irradiance very different from full solar collection. Morphological variables of urban settings and urban trees, a very distinctive feature of the Mendoza Metropolitan Area (MMA, have a fundamental impact on the feasibility of implementing strategies for solar energy utilization in urban environments. The results achieved will contribute to modify and gradually update urban and building legislation to implement higher levels of energy efficiency and minimum environmental impacts.This work proposes to study the potential of solar collection in urban environments, analyzing eleven urban configurations selected according to their building and urban morphological characteristics.Methodologically, we have monitored the global solar irradiance on vertical plane on northern facades, completely sunny and partly sunny, affected by solid masking and arboreal masking. Results obtained so far indicate that solar masking is critical for vertical surfaces, with a reduction of the available solar energy between 2% and 66% in the winter season. However, these drawbacks caused by urban trees are compensated by benefits in the warm season: controlling the intensity of the urban heat island, absorption of pollutants, cooling and humidifying the air through evapotranspiration, reducing thermal loads of buildings, occupancy of public open spaces, and an invaluable contribution to the urban aesthetic.
Design of Solar Street Lamp Control System Based on MPPT
Cui, Fengying
This paper proposes a new solar street lamp control system which is composed of photovoltaic cell, controller, battery and load. In this system controller as the key part applies the microchip to achieve many functions. According to the nonlinear output characteristics of solar cell and the influence of environment, it uses the perturbation and observation (P&O) method to realize the maximum power point tracking (MPPT) and promotes the efficiency. In order to prolong the battery life the pulse width modulation (PWM) charge mode is selected to control the battery capacity and provent the battery from the state of over-charge and over-discharge. Meanwhile the function of temperature compensation, charge and discharge protection are set to improve the running safety and stability.
The Solar Wind Environment in Time
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.
Effect of soil solarization using plastic mulch in controlling root-knot ...
African Journals Online (AJOL)
PRECIOUS
2009-12-15
Dec 15, 2009 ... effect of soil solarization using plastic mulch in controlling root-knot nematode infestation and yield of ... addition to their increased toxic effects in the soil over the .... thereby promoting conducive environment for the utiliza- ...
Application of dynamic model to predict some inside environment variables in a semi-solar greenhouse
Directory of Open Access Journals (Sweden)
Behzad Mohammadi
2018-06-01
Full Text Available Greenhouses are one of the most effective cultivation methods with a yield per cultivated area up to 10 times more than free land cultivation but the use of fossil fuels in this production field is very high. The greenhouse environment is an uncertain nonlinear system which classical modeling methods have some problems to solve it. There are many control methods, such as adaptive, feedback and intelligent control and they require a precise model. Therefore, many modeling methods have been proposed for this purpose; including physical, transfer function and black-box modeling. The objective of this paper is to modeling and experimental validation of some inside environment variables in an innovative greenhouse structure (semi-solar greenhouse. For this propose, a semi-solar greenhouse was designed and constructed at the North-West of Iran in Azerbaijan Province (38°10′N and 46°18′E with elevation of 1364 m above the sea level. The main inside environment factors include inside air temperature (Ta and inside soil temperature (Ts were collected as the experimental data samples. The dynamic heat transfer model used to estimate the temperature in two different points of semi-solar greenhouse with initial values. The results showed that dynamic model can predict the inside temperatures in two different points (Ta and Ts with RMSE, MAPE and EF about 5.3 °C, 10.2% and 0.78% and 3.45 °C, 7.7% and 0.86%, respectively. Keywords: Semi-solar greenhouse, Dynamic model, Commercial greenhouse
Solar cells: An environment-benign energy source?
International Nuclear Information System (INIS)
Alsema, E.; Van Engelenburg, B.
1993-01-01
Attention is paid to a study on the environmental aspects of solar cell production techniques and the possibility of recycling solar cell materials. In the study the following types of solar cell modules are dealt with: CdTe and CuInSe 2 , amorphous silicon, crystalline silicon, and GaAs. It appears that silicon solar cells have minor environmental effects and are controllable. However, attention should be paid to the energy consumption and the use of etching and purification materials during the production of solar cells, and the emission of heavy metals from f.e. CdTe/CIS solar cells during and after usage. Without effective recycling enough supplies of indium, selenium and tellurium cannot be guaranteed. 3 figs., 1 ill
Studies of Earth Space Environment and Sudden Disappearances of Solar Prominences
National Research Council Canada - National Science Library
Huang, Tian-Sen
2005-01-01
With the support from AFOSR's Minority University Program, we worked on research of Sun-Earth space environment, conducted daily solar observation programs, improved solar instruments, and established...
Solar field control for desalination plants
Energy Technology Data Exchange (ETDEWEB)
Roca, Lidia [Convenio Universidad de Almeria, Plataforma Solar de Almeria, Ctra. Senes s/n, 04200 Tabernas, Almeria (Spain); Berenguel, Manuel [Universidad de Almeria, Dpto. Lenguajes y Computacion, Ctra. Sacramento s/n, 04120 Almeria (Spain); Yebra, Luis; Alarcon-Padilla, Diego C. [CIEMAT, Plataforma Solar de Almeria, Ctra. Senes s/n, 04200 Tabernas, Almeria (Spain)
2008-09-15
This paper presents the development and application of a feedback linearization control strategy for a solar collector field supplying process heat to a multi-effect seawater distillation plant. Since one objective is to use as much as possible the solar resource, control techniques can be used to produce the maximum heat process in the solar field. The main purpose of the controller presented in this paper is to manipulate the water flow rate to maintain an outlet-inlet temperature gradient in the collectors, thereby ensuring continuous process heating, or in other words, continuous production of fresh water in spite of disturbances. The dynamic behaviour of this solar field was approximated by a simplified lumped-parameters nonlinear model based on differential equations, validated with real data and used in the feedback linearization control design. Experimental results in the seawater desalination plant at the Plataforma Solar de Almeria (Spain) show good agreement of the model and real data despite the approximations included. Moreover, by using feedback linearization control it is possible to track a constant gradient temperature reference in the solar field with good results. (author)
Combined Contamination and Space Environmental Effects on Solar Cells and Thermal Control Surfaces
Dever, Joyce A.; Bruckner, Eric J.; Scheiman, David A.; Stidham, Curtis R.
1994-01-01
For spacecraft in low Earth orbit (LEO), contamination can occur from thruster fuel, sputter contamination products and from products of silicone degradation. This paper describes laboratory testing in which solar cell materials and thermal control surfaces were exposed to simulated spacecraft environmental effects including contamination, atomic oxygen, ultraviolet radiation and thermal cycling. The objective of these experiments was to determine how the interaction of the natural LEO environmental effects with contaminated spacecraft surfaces impacts the performance of these materials. Optical properties of samples were measured and solar cell performance data was obtained. In general, exposure to contamination by thruster fuel resulted in degradation of solar absorptance for fused silica and various thermal control surfaces and degradation of solar cell performance. Fused silica samples which were subsequently exposed to an atomic oxygen/vacuum ultraviolet radiation environment showed reversal of this degradation. These results imply that solar cells and thermal control surfaces which are susceptible to thruster fuel contamination and which also receive atomic oxygen exposure may not undergo significant performance degradation. Materials which were exposed to only vacuum ultraviolet radiation subsequent to contamination showed slight additional degradation in solar absorptance.
Analysis of the effects of simulated synergistic LEO environment on solar panels
Allegri, G.; Corradi, S.; Marchetti, M.; Scaglione, S.
2007-02-01
The effects due to the LEO environment exposure of a solar array primary structure are here presented and discussed in detail. The synergistic damaging components featuring LEO environment are high vacuum, thermal cycling, neutral gas, ultraviolet (UV) radiation and cold plasma. The synergistic effects due to these environmental elements are simulated by "on ground" tests, performed in the Space Environment Simulator (SAS) at the University of Rome "La Sapienza"; numerical simulations are performed by the Space Environment Information System (SPENVIS), developed by the European Space Agency (ESA). A "safe life" design for a solar array primary structure is developed, taking into consideration the combined damaging action of the LEO environment components; therefore results from both numerical and experimental simulations are coupled within the framework of a standard finite element method (FEM) based design. The expected durability of the solar array primary structure, made of laminated sandwich composite, is evaluated assuming that the loads exerted on the structure itself are essentially dependent on thermo-elastic stresses. The optical degradation of surface materials and the stiffness and strength degradation of structural elements are taken into account to assess the global structural durability of the solar array under characteristic operative conditions in LEO environment.
Solar journey: The significance of our galactic environment for the heliosphere and earth
Frisch, Priscilla C
2006-01-01
Humans evolved when the Sun was in the great void of the Local Bubble. The Sun entered the present environment of interstellar clouds only during the late Quaternary. Astronomical data reveal these long and short term changes in our galactic environment. Theoretical models then tell us how these changes affect interplanetary particles, planetary magnetospheres, and the Earth itself. Cosmic rays leave an isotopic signature in the paleoclimate record that helps trace the solar journey through space. "Solar Journey: The Significance of Our Galactic Environment for the Heliosphere and Earth" lays the foundation for an interdisciplinary study of the influence of interstellar material on the solar system and Earth as we travel through the Milky Way Galaxy. The solar wind bubble responds dynamically to interstellar material flowing past the Sun, regulating interstellar gas, dust, and cosmic particle fluxes in the interplanetary medium and the Earth. Cones of interstellar gas and dust focused by solar gravity, the ma...
Soil solarization for weed control in carrot
Directory of Open Access Journals (Sweden)
MARENCO RICARDO ANTONIO
2000-01-01
Full Text Available Soil solarization is a technique used for weed and plant disease control in regions with high levels of solar radiation. The effect of solarization (0, 3, 6, and 9 weeks upon weed populations, carrot (Daucus carota L. cv. Brasília yield and nematode infestation in carrot roots was studied in São Luís (2º35' S; 44º10' W, MA, Brazil, using transparent polyethylene films (100 and 150 mm of thickness. The maximum temperature at 5 cm of depth was about 10ºC warmer in solarized soil than in control plots. In the study 20 weed types were recorded. Solarization reduced weed biomass and density in about 50% of weed species, including Cyperus spp., Chamaecrista nictans var. paraguariensis (Chod & Hassl. Irwin & Barneby, Marsypianthes chamaedrys (Vahl O. Kuntze, Mitracarpus sp., Mollugo verticillata L., Sebastiania corniculata M. Arg., and Spigelia anthelmia L. Approximately 40% of species in the weed flora were not affected by soil mulching. Furthermore, seed germination of Commelina benghalensis L. was increased by soil solarization. Marketable yield of carrots was greater in solarized soil than in the unsolarized one. It was concluded that solarization for nine weeks increases carrot yield and is effective for controlling more than half of the weed species recorded. Mulching was not effective for controlling root-knot nematodes in carrot.
Dynamics and Control of a Flexible Solar Sail
Jiafu Liu; Siyuan Rong; Fan Shen; Naigang Cui
2014-01-01
Solar sail can merely make use of solar radiation pressure (SRP) force as the thrust for space missions. The attitude dynamics is obtained for the highly flexible solar sail with control vanes, sliding masses, and a gimbaled control boom. The vibration equations are derived considering the geometric nonlinearity of the sail structure subjected to the forces generated by the control vanes, solar radiation pressure (SRP), and sliding masses. Then the dynamic models for attitude/vibration contr...
A Charge Controller Design For Solar Power System
Nandar Oo; Kyaw Soe Lwin; Hla Myo Tun
2015-01-01
This paper presents the solar charge controller circuit for controlling the overcharging and discharging from solar panel. This circuit regulates the charging of the battery in a solar system by monitoring battery voltage and switching the solar or other power source off when the battery reaches a preset voltage. This circuit is low voltages disconnect circuit. A charge controller circuit can increase battery life by preventing over-charging which can cause loss of electrolyte. The flow chart...
A Charge Controller Design For Solar Power System
Directory of Open Access Journals (Sweden)
Nandar Oo
2015-08-01
Full Text Available This paper presents the solar charge controller circuit for controlling the overcharging and discharging from solar panel. This circuit regulates the charging of the battery in a solar system by monitoring battery voltage and switching the solar or other power source off when the battery reaches a preset voltage. This circuit is low voltages disconnect circuit. A charge controller circuit can increase battery life by preventing over-charging which can cause loss of electrolyte. The flow chart is also provided.
A novel GUI modeled fuzzy logic controller for a solar powered energy utilization scheme
International Nuclear Information System (INIS)
Altas, I. H.; Sharaf, A. M.
2007-01-01
Photovoltaic PVA-solar powered electrical systems comprise different components and subsystems to be controlled separately. Since the generated solar power is dependant on uncontrollable environmental conditions, it requires extra caution to design controllers that handle unpredictable events and maintain efficient load matching power. In this study, a photovoltaic (PV) solar array model is developed for Matlab/Simulink GUI environment and controlled using a fuzzy logic controller (FLC), which is also developed for GUI environment. The FLC is also used to control the DC load bus voltage at constant value as well as controlling the speed of a PMDC motor as one of the loads being fed. The FLC controller designed using the Matlab/Simuling GUI environment has flexible design criteria's so that it can easily be modified and extended for controlling different systems. The proposed FLC is used in three different parts of the PVA stand alone utilization scheme here. One of these parts is the speed control of the PMDC load, one of the other parts is controlling the DC load bus voltage, and the third part is the maximum power point (MPPT) tracking control, which is used to operate the PVA at its available maximum power as the solar insolation and ambient temperature change. This paper presents a study of a standalone Photovoltaic energy utilization system feeding a DC and AC hybrid electric load and is fully controlled by a novel and simple on-line fuzzy logic based dynamic search, detection and tracking controller that ensures maximum power point operation under excursions in Solar Insolation, Ambient temperature and electric load variations. The maximum power point MPP-Search and Detection algorithm is fully dynamic in nature and operates without any required direct measurement or forecasted PV array information about the irradiation and temperature. An added Search sensitivity measure is defined and also used in the MPP search algorithm to sense and dynamic response for
International Nuclear Information System (INIS)
Shirazi, Ali; Pintaldi, Sergio; White, Stephen D.; Morrison, Graham L.; Rosengarten, Gary; Taylor, Robert A.
2016-01-01
Highlights: • A simulation model of a solar driven absorption chiller is developed in detail. • Three control strategies were proposed in the solar loop of the plant. • Series and parallel auxiliary heater arrangements were investigated. • The results showed the auxiliary-heater in parallel outperformed the series one. • Solar fraction can be increased by 20% by implementing the proposed configuration. - Abstract: Solar-assisted cooling technology has enormous potential for air-conditioning applications since both solar energy supply and cooling energy demand are well correlated. Unfortunately, market uptake of solar cooling technologies has been slow due to the high capital cost and limited design/operational experience. In the present work, different designs and operational modes for solar heating and cooling (SHC) absorption chiller systems are investigated and compared in order to identify the preferred design strategies for these systems. Three control scenarios are proposed for the solar collector loop. The first uses a constant flow pump, while the second and third control schemes employ a variable speed pump, where the solar collector (SC) set-point temperature could be either fixed or adjusted to the required demand. Series and parallel arrangements, between the auxiliary heater and the storage tank, have been examined in detail from an energy efficiency perspective. A simulation model for different system layouts is developed in the transient system simulation environment (TRNSYS, Version 17). Simulation results revealed that the total solar fraction of the plant is increased by up to 11% when a variable speed solar loop pump is used to achieve a collector set-point temperature adjusted according to the building load demand. Another significant finding of this study is that a parallel configuration for the auxiliary heater out-performs a conventional series configuration. The yearly performance of an auxiliary heater in parallel with the storage
Controlling solar light and heat in a forest by managing shadow sources
Howard G. Halverson; James L. Smith
1974-01-01
Control of solar light and heat to develop the proper growth environment is a desirable goal in forest management. The amount of sunlight and heat reaching the surface is affected by shadows cast by nearby objects, including trees. In timbered areas, the type of forest management practiced can help develop desired microclimates. The results depend on the size and...
Directory of Open Access Journals (Sweden)
Jaw-Kuen Shiau
2015-04-01
Full Text Available This paper presents the design of a fuzzy-logic-based voltage-regulated solar power maximum power point tracking (MPPT system for applications involving hybrid power systems. The system contains a solar power system and battery as the primary and secondary power sources, respectively. The solar system alone supplies power to the electric motor and maintains the output voltage at a predetermined level when it has sufficient power. When the solar power is insufficient, the solar system is operated at its maximum power point (MPP and the battery is engaged to compensate for the insufficiency. First, a variant of the incremental conductance MPP condition was established. Under the MPP condition, the voltage-regulated MPPT system was formulated as a feedback control system, where the MPP condition and voltage regulation requirements were used as the system inputs. Next, a fuzzy controller was developed to perform the voltage-regulated MPPT function for the hybrid power system. A simulation model based on Matrix laboratory (MATLAB/SIMULINK (a block diagram environment for multi-domain simulation and model-based design and a piecewise linear electric circuit simulation (PLECS tool for controlling the dc motor velocity was developed to verify the voltage-regulated solar power MPPT system.
Solar energy: an environment friendly reliable and sustainable source
International Nuclear Information System (INIS)
Siddique, M.A.; Akhtar, W.
2011-01-01
The rapid enhancement in consumption of fossil fuels in order to meet the day-to day increasing energy requirements has blown a danger sign for all nations. Global warming effect has compelled researchers to discover other techniques of energy generation instead of traditional ways in order to reduce adverse effects on global terrain. Renewable energy resources have got attention of global entrepreneurs due to their long lasting availability and environment friendliness. Solar technology is finding increased application in both domestic and military application. This paper discusses the ideas behind the art of design of solar cells and their historical developments. It also covers the kind of techniques/ methodologies used for solar energy conversion into electrical energy with comparison between different renewable technologies and solar technology. This paper gives the brief review of world energy resources and their consumption v/s Solar energy production percentage. Researchers in the field of energy generation have impressed by the Prodigious results of Renewable Energies. Today's most of the high ranked international universities of developed countries in collaboration with government/ industries have been carrying on advance researches in the field of renewable technologies. (author)
A review on factors for maximizing solar fraction under wet climate environment in Malaysia
International Nuclear Information System (INIS)
Kadir, Mohd Zainal Abidin Ab; Rafeeu, Yaaseen
2010-01-01
Solar energy is the most promising source of clean, renewable energy and it has the greatest potential of any power source to solve the world's energy problems. However, the problem, is how best to harness this vast amount of solar energy. Nevertheless, even if highly efficient Concentrating Solar Power (CSP) could be made cheaply, there would be considerable change in solar power. This technology is expected to be more efficient and to achieve a manufacturing cost of less than $1/W near future. This paper reviews and elaborates the methodology utilized to design and fabricate the solar dish concentrator and outlines the parameters that can be used to increase the efficiency of solar fraction in parabolic dish concentrator under wet climate environment in Malaysia. The study finally provides ideas to the continually increasing ability of these technologies to concentrate and harness solar energy for electricity production and thus eliminate the growing concern over climate change and how it will hurt the region's environment, human health and economy. (author)
A review on factors for maximizing solar fraction under wet climate environment in Malaysia
Energy Technology Data Exchange (ETDEWEB)
Kadir, Mohd Zainal Abidin Ab; Rafeeu, Yaaseen [Alternative and Renewable Energy Laboratory, Institute of Advanced Technology (ITMA), Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)
2010-10-15
Solar energy is the most promising source of clean, renewable energy and it has the greatest potential of any power source to solve the world's energy problems. However, the problem, is how best to harness this vast amount of solar energy. Nevertheless, even if highly efficient Concentrating Solar Power (CSP) could be made cheaply, there would be considerable change in solar power. This technology is expected to be more efficient and to achieve a manufacturing cost of less than $1/W near future. This paper reviews and elaborates the methodology utilized to design and fabricate the solar dish concentrator and outlines the parameters that can be used to increase the efficiency of solar fraction in parabolic dish concentrator under wet climate environment in Malaysia. The study finally provides ideas to the continually increasing ability of these technologies to concentrate and harness solar energy for electricity production and thus eliminate the growing concern over climate change and how it will hurt the region's environment, human health and economy. (author)
Dynamics and Control of a Flexible Solar Sail
Directory of Open Access Journals (Sweden)
Jiafu Liu
2014-01-01
Full Text Available Solar sail can merely make use of solar radiation pressure (SRP force as the thrust for space missions. The attitude dynamics is obtained for the highly flexible solar sail with control vanes, sliding masses, and a gimbaled control boom. The vibration equations are derived considering the geometric nonlinearity of the sail structure subjected to the forces generated by the control vanes, solar radiation pressure (SRP, and sliding masses. Then the dynamic models for attitude/vibration controller design and dynamic simulation are obtained, respectively. The linear quadratic regulator (LQR based and optimal proportional-integral (PI based controllers are designed for the coupled attitude/vibration models with constant disturbance torques caused by the center-of-mass (cm/center-of-pressure (cp offset, respectively. It can be concluded from the theoretical analysis and simulation results that the optimal PI based controller performs better than the LQR based controller from the view of eliminating the steady-state errors. The responses with and without the geometrical nonlinearity are performed, and the differences are observed and analyzed. And some suggestions are also presented.
The upper atmosphere and solar-terrestrial relations - An introduction to the aerospace environment
International Nuclear Information System (INIS)
Hargreaves, J.K.
1979-01-01
A theoretical and observational overview of earth's aerospace environment is presented in this book. Emphasis is placed on the principles and observed phenomena of the neutral upper atmosphere, particularly in relation to solar activity. Topics include the structure of the ionosphere and magnetosphere, waves in the magnetosphere, solar flares and solar protons, and storms and other disturbance phenomena, while applications to communications, navigation and space technology are also discussed
Optimising position control of a solar parabolic trough
Directory of Open Access Journals (Sweden)
Puramanathan Naidoo
2011-03-01
Full Text Available In today’s climate of growing energy needs and increasing environmental concerns, alternatives to the use of non-renewable and polluting fossil fuels have to be investigated. One such alternative is solar energy. This study is based on the implementation of a mathematical computation – the PSA (Plataforma Solar de Almeria computation developed at PSA (the European Test Centre for solar energy applications – embedded in a control algorithm to locate the position of the sun. Tests were conducted on a solar parabolic trough (SPT constructed at the Solar Thermal Applications Research Laboratory of the Mangosuthu University of Technology (Durban, South Africa for optimal position control using the PSA value. The designed control algorithm embedded in an industrial Siemens S7-314 C-2PtP programmable logic controller compared the PSA computation to a measured position of the SPT to optimally rotate the SPT to a desired position with the constant movement of the sun. The two main angles of the sun relative to the position of the SPT on earth, the zenith angle and the azimuth angle, both calculated in the PSA from the vertical and horizontal planes, respectively, were applied to the control algorithm to generate an appropriate final tracking angle within a 0.007 radian (0° 24′ 3.6″ tolerance, in accordance to the construction specifications and solar collector testing standards of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE, 1991. These values, together with the longitude and latitude applicable to the geographical location of the SPT, were processed in the control software to rotate the SPT to an optimal position with respect to the position of the sun in its daily path, for solar-to-thermal conversion.
Optimal Control of Solar Heating System
Huang, Bin-Juine
2017-02-21
Forced-circulation solar heating system has been widely used in process and domestic heating applications. Additional pumping power is required to circulate the water through the collectors to absorb the solar energy. The present study intends to develop a maximum-power point tracking control (MPPT) to obtain the minimum pumping power consumption at an optimal heat collection. The net heat energy gain Qnet (= Qs − Wp/ηe) was found to be the cost function for MPPT. The step-up-step-down controller was used in the feedback design of MPPT. The field test results show that the pumping power is 89 W at Qs = 13.7 kW and IT = 892 W/m2. A very high electrical COP of the solar heating system (Qs/Wp = 153.8) is obtained.
Thomas, N. L.; Chisel, D. M.
1976-01-01
The success of a rocket-borne experiment depends not only on the pointing of the attitude control system, but on the alignment of the attitude control system to the payload. To ensure proper alignment, special optical tools and alignment techniques are required. Those that were used in the SPARCS program are described and discussed herein. These tools include theodolites, autocollimators, a 38-cm diameter solar simulator, a high-performance 1-m heliostat to provide a stable solar source during the integration of the rocket payload, a portable 75-cm sun tracker for use at the launch site, and an innovation called the Solar Alignment Prism. Using the real sun as the primary reference under field conditions, the Solar Alignment Prism facilitates the coalignment of the attitude sun sensor with the payload. The alignment techniques were developed to ensure the precise alignment of the solar payloads to the SPARCS attitude sensors during payload integration and to verify the required alignment under field conditions just prior to launch.
Lessons learned on solar powered wireless sensor network deployments in urban, desert environments
Dehwah, Ahmad H.; Mousa, Mustafa; Claudel, Christian G.
2015-01-01
The successful deployment of a large scale solar powered wireless sensor network in an urban, desert environment is a very complex task. Specific cities of such environments cause a variety of operational problems, ranging from hardware faults
Propellantless Attitude Control of Solar Sail Technology Utilizing Reflective Control Devices
Munday, Jeremy
2016-01-01
Solar sails offer an opportunity for a CubeSatscale, propellant-free spacecraft technology that enables long-term and long-distance missions not possible with traditional methods. Solar sails operate using the transfer of linear momentum from photons of sunlight reflected from the surface of the sail. To propel the spacecraft, no mechanically moving parts, thrusters, or propellant are needed. However, attitude control, or orientation, is still performed using traditional methods involving reaction wheels and propellant ejection, which severely limit mission lifetime. For example, the current state of the art solutions employed by upcoming missions couple solar sails with a state of the art propellant ejection gas system. Here, the use of the gas thruster has limited the lifetime of the mission. To solve the limited mission lifetime problem, the Propellantless Attitude Control of Solar Sail Technology Utilizing Reflective Control Devices project team is working on propellantless attitude control using thin layers of material, an optical film, electrically switchable from transparent to reflective. The technology is based on a polymer-dispersed liquid crystal (PDLC), which allows this switch upon application of a voltage. This technology removes the need for propellant, which reduces weight and cost while improving performance and lifetime.
Predictive Solar-Integrated Commercial Building Load Control
Energy Technology Data Exchange (ETDEWEB)
Glasgow, Nathan [EdgePower Inc., Aspen, CO (United States)
2017-01-31
This report is the final technical report for the Department of Energy SunShot award number EE0007180 to EdgePower Inc., for the project entitled “Predictive Solar-Integrated Commercial Building Load Control.” The goal of this project was to successfully prove that the integration of solar forecasting and building load control can reduce demand charge costs for commercial building owners with solar PV. This proof of concept Tier 0 project demonstrated its value through a pilot project at a commercial building. This final report contains a summary of the work completed through he duration of the project. Clean Power Research was a sub-recipient on the award.
Occupant Behaviour with regard to Control of the Indoor Environment
DEFF Research Database (Denmark)
Andersen, Rune Vinther
A large proportion of the world’s energy consumption is spent in an effort to maintain a comfortable and healthy indoor environment. As a consequence reductions in the energy consumed to climatise buildings are instrumental to the efforts of reducing energy related CO2 emissions and alleviating....... As a consequence, most programs are capable of accurate simulations of the physical properties of a building. However, even though the occupants’ control of the various systems in the building has a significant impact on the energy consumption and the indoor environment, only few studies have focused...... on the behaviour of their occupants. As a consequence, there is a need to investigate occupants’ interactions with building controls, such as opening of windows, adjustments of heating set-points, use of solar shading, etc. Some models of occupants’ interactions with operable windows do exist, but these are based...
Microcontroller Based Solar Charge Controller for Power Application
Mr. Vikas Khare
2012-01-01
Photovoltaic cell converts solar energy directly into electricity. This paper describes a design of microcontroller based solar charge controller for power application.[2] The work of the Paper is to charge a 12 volt battery by using a 50 watt solar panel with maximum power. This circuit regulates the charging of battery in a solar system by monitoring battery voltage and switching the solar or other power source off when the battery reached a preset value.[1] The microprocessor based charge ...
Optimal Control Design for a Solar Greenhouse
Ooteghem, van R.J.C.
2010-01-01
Abstract: An optimal climate control has been designed for a solar greenhouse to achieve optimal crop production with sustainable instead of fossil energy. The solar greenhouse extends a conventional greenhouse with an improved roof cover, ventilation with heat recovery, a heat pump, a heat
Maximum-power-point tracking control of solar heating system
Huang, Bin-Juine
2012-11-01
The present study developed a maximum-power point tracking control (MPPT) technology for solar heating system to minimize the pumping power consumption at an optimal heat collection. The net solar energy gain Q net (=Q s-W p/η e) was experimentally found to be the cost function for MPPT with maximum point. The feedback tracking control system was developed to track the optimal Q net (denoted Q max). A tracking filter which was derived from the thermal analytical model of the solar heating system was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI controller was designed for a tracking target Q max(t) with a quadratic time function. The MPPT control system was implemented using a microprocessor-based controller and the test results show good tracking performance with small tracking errors. It is seen that the average mass flow rate for the specific test periods in five different days is between 18.1 and 22.9kg/min with average pumping power between 77 and 140W, which is greatly reduced as compared to the standard flow rate at 31kg/min and pumping power 450W which is based on the flow rate 0.02kg/sm 2 defined in the ANSI/ASHRAE 93-1986 Standard and the total collector area 25.9m 2. The average net solar heat collected Q net is between 8.62 and 14.1kW depending on weather condition. The MPPT control of solar heating system has been verified to be able to minimize the pumping energy consumption with optimal solar heat collection. © 2012 Elsevier Ltd.
Solar Radiation Model for Development and Control of Solar Energy Sources
Directory of Open Access Journals (Sweden)
Dominykas Vasarevičius
2016-06-01
Full Text Available The model of solar radiation, which takes into account direct, diffused and reflected components of solar energy, has been presented. Model is associated with geographical coordinates and local time of every day of the year. It is shown that using analytic equations for modelling the direct component, it is possible to adopt it for embedded systems with low computational power and use in solar tracking applications. Reflected and diffused components are especially useful in determining the performance of photovoltaic modules in certain location and surroundings. The statistical method for cloud layer simulation based on local meteorological data is offered. The presented method can’t be used for prediction of weather conditions but it provides patterns of solar radiation in time comparable to those measured with pyranometer. Cloud layer simulation together with total solar radiation model is a useful tool for development and analysis of maximum power point tracking controllers for PV modules.
International Nuclear Information System (INIS)
Yuge, K.; Haraguchi, T.; Nakano, Y.; Kuroda, M.; Funakoshi, T.
2002-01-01
The objective of this study is quantification of the solar radiation in the farmland located in the hilly and mountainous areas, considering the effect of the shelter adjacent to the field, such as the forest (This effect is called as the edge-effect in this study.). To evaluate the edge-effect on the solar radiation environment in the farmland, solar radiations are measured at the center and edge of the study site adjacent to the forest. The simulation model is composed, coupling with the fish-eye projection method and procedure for the separating direct and diffuse solar radiations. Using this model, the diurnal solar radiations are simulated at the center and edge of the study site. The simulation result showed good agreement with the observation. The spatial distribution of the solar radiation in an observational field is quantified by this method, considering the edge-effect. The simulation result indicated that the solar radiation environment on the field surface is affected by the shelter adjacent to the field and the field direction. (author)
Larasati, Devi
2015-01-01
The purpose of this final project is to apply the codevision AVR ATMega 8535 to process the data on the storage accumulator battery charging current from the solar panels. Value current is processed in the microcontroller is in the current detection using current sensor ACS-712. To prevent backflow from batteries to solar panels when the solar panel voltage is less than accumulator battery voltage, current flows from the solar panels through solar charge controller to the battery before. C...
Effects of soil solarization and some amendments to control ...
African Journals Online (AJOL)
SCM) (1 kg m-2), solarization + olive processing waste (SOPW) (2 kg m-2), solarization + urea (SU) (100 g m-2) and an untreated control (C). Maximum soil temperatures reached in solarized plots were 54.7 and 43.9°C and in the ...
Energy Technology Data Exchange (ETDEWEB)
Pacheco Ramirez, Jesus Horacio; Anaya Perez, Maria Elena; Benitez Baltazar, Victor Hugo [Universidad de onora, Hermosillo, Sonora (Mexico)]. E-mail: jpacheco@industrial.uson.mx; meanaya@industrial.uson.mx; vbenitez@industrial.uson.mx
2010-11-15
This work shows how artificial vision feedback can be applied to control systems. The control is applied to a solar panel in order to track the sun position. The algorithms to calculate the position of the sun and the image processing are developed in LabView. The responses obtained from the control show that it is possible to use vision for a control scheme in closed loop. [Spanish] El presente trabajo muestra la manera en la cual un sistema de control puede ser retroalimentado mediante vision artificial. El control es aplicado en un panel solar para realizar el seguimiento del sol a lo largo del dia. Los algoritmos para calcular la posicion del sol y para el tratamiento de la imagen fueron desarrollados en LabView. Las respuestas obtenidas del control muestran que es posible utilizar vision para un esquema de control en lazo cerrado.
Active control of the Chinese Giant Solar Telescope
Dai, Yichun; Yang, Dehua; Jin, Zhenyu; Liu, Zhong; Qin, Wei
2014-07-01
The Chinese Giant Solar Telescope (CGST) is the next generation solar telescope of China with diameter of 8 meter. The unique feature of CGST is that its primary is a ring, which facilitates the polarization detection and thermal control. In its present design and development phase, two primary mirror patterns are considered. For one thing, the primary mirror is expected to construct with mosaic mirror with 24 trapezoidal (or petal) segments, for another thing, a monolithic mirror is also a candidate for its primary mirror. Both of them depend on active control technique to maintain the optical quality of the ring mirror. As a solar telescope, the working conditions of the CGST are quite different from those of the stellar telescopes. To avoid the image deterioration due to the mirror seeing and dome seeing, especially in the case of the concentration of flux in a solar telescope, large aperture solar projects prefer to adopt open telescopes and open domes. In this circumstance, higher wind loads act on the primary mirror directly, which will cause position errors and figure errors of the primary with matters worse than those of the current 10-meter stellar telescopes with dome protect. Therefore, it gives new challenges to the active control capability, telescope structure design, and wind shielding design. In this paper, the study progress of active control of CGST for its mosaic and monolithic mirror are presented, and the wind effects on such two primary mirrors are also investigated.
Adaptive control of solar energy collector systems
Lemos, João M; Igreja, José M
2014-01-01
This book describes methods for adaptive control of distributed-collector solar fields: plants that collect solar energy and deliver it in thermal form. Controller design methods are presented that can overcome difficulties found in these type of plants:they are distributed-parameter systems, i.e., systems with dynamics that depend on space as well as time;their dynamics is nonlinear, with a bilinear structure;there is a significant level of uncertainty in plant knowledge.Adaptive methods form the focus of the text because of the degree of uncertainty in the knowledge of plant dynamics. Parts
Fuzzy attitude control of solar sail via linear matrix inequalities
Baculi, Joshua; Ayoubi, Mohammad A.
2017-09-01
This study presents a fuzzy tracking controller based on the Takagi-Sugeno (T-S) fuzzy model of the solar sail. First, the T-S fuzzy model is constructed by linearizing the existing nonlinear equations of motion of the solar sail. Then, the T-S fuzzy model is used to derive the state feedback controller gains for the Twin Parallel Distributed Compensation (TPDC) technique. The TPDC tracks and stabilizes the attitude of the solar sail to any desired state in the presence of parameter uncertainties and external disturbances while satisfying actuator constraints. The performance of the TPDC is compared to a PID controller that is tuned using the Ziegler-Nichols method. Numerical simulation shows the TPDC outperforms the PID controller when stabilizing the solar sail to a desired state.
Lessons learned on solar powered wireless sensor network deployments in urban, desert environments
Dehwah, Ahmad H.
2015-05-01
The successful deployment of a large scale solar powered wireless sensor network in an urban, desert environment is a very complex task. Specific cities of such environments cause a variety of operational problems, ranging from hardware faults to operational challenges, for instance due to the high variability of solar energy availability. Even a seemingly functional sensor network created in the lab does not guarantee reliable long term operation, which is absolutely necessary given the cost and difficulty of accessing sensor nodes in urban environments. As part of a larger traffic flow wireless sensor network project, we conducted several deployments in the last two years to evaluate the long-term performance of solar-powered urban wireless sensor networks in a desert area. In this article, we share our experiences in all domains of sensor network operations, from the conception of hardware to post-deployment analysis, including operational constraints that directly impact the software that can be run. We illustrate these experiences using numerous experimental results, and present multiple unexpected operational problems as well as some possible solutions to address them. We also show that current technology is far from meeting all operational constraints for these demanding applications, in which sensor networks are to operate for years to become economically appealing.
Development of an Embedded Solar Tracking System with LabVIEW Motion Control
International Nuclear Information System (INIS)
Oh, Seung Jin; Hyun, Jun Ho; Oh, Won Jong; Kim, Yeong Min; Lee, Yoon Joon; Chun, Won Gee
2010-01-01
Motion control is a sub-field of automation, in which the position and/or velocity of machines are controlled using some type of device such as a hydraulic pump, linear actuator, or an electric motor. The motion control is widely used in the packaging, printing, textile, semiconductor production, and power plants. National Instruments LabVIEW is a graphical programming language that has its roots in automation control and data acquisition. Its graphical representation, similar to a process flow diagram, was created to provide an intuitive programming environment for scientist and engineers. Crystal River Nuclear Plant engineers developed automated testing system of nuclear plant control modules in an aging nuclear power plant using LabVIEW to improve performance and reliability and reduce cost. In this study, an embedded two-axis solar tracking system was developed using LabVIEW motion control module
Solar Plus: A Holistic Approach to Distributed Solar PV
Energy Technology Data Exchange (ETDEWEB)
O' Shaughnessy, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ardani, Kristen [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cutler, Dylan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Margolis, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States)
2017-05-25
Solar 'plus' refers to an emerging approach to distributed solar photovoltaic (PV) deployment that uses energy storage and controllable devices to optimize customer economics. The solar plus approach increases customer system value through technologies such as electric batteries, smart domestic water heaters, smart air-conditioner (AC) units, and electric vehicles We use an NREL optimization model to explore the customer-side economics of solar plus under various utility rate structures and net metering rates. We explore optimal solar plus applications in five case studies with different net metering rates and rate structures. The model deploys different configurations of PV, batteries, smart domestic water heaters, and smart AC units in response to different rate structures and customer load profiles. The results indicate that solar plus improves the customer economics of PV and may mitigate some of the negative impacts of evolving rate structures on PV economics. Solar plus may become an increasingly viable model for optimizing PV customer economics in an evolving rate environment.
Solar Plus: A Holistic Approach to Distributed Solar PV
Energy Technology Data Exchange (ETDEWEB)
OShaughnessy, Eric J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Ardani, Kristen B. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cutler, Dylan S. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States)
2017-06-08
Solar 'plus' refers to an emerging approach to distributed solar photovoltaic (PV) deployment that uses energy storage and controllable devices to optimize customer economics. The solar plus approach increases customer system value through technologies such as electric batteries, smart domestic water heaters, smart air-conditioner (AC) units, and electric vehicles We use an NREL optimization model to explore the customer-side economics of solar plus under various utility rate structures and net metering rates. We explore optimal solar plus applications in five case studies with different net metering rates and rate structures. The model deploys different configurations of PV, batteries, smart domestic water heaters, and smart AC units in response to different rate structures and customer load profiles. The results indicate that solar plus improves the customer economics of PV and may mitigate some of the negative impacts of evolving rate structures on PV economics. Solar plus may become an increasingly viable model for optimizing PV customer economics in an evolving rate environment.
Energy Technology Data Exchange (ETDEWEB)
Caneppele, Fernando de Lima [Universidade Estadual Paulista (UNESP), Itapeva, SP (Brazil). Campus Experimental], E-mail: fernando@itapeva.unesp.br; Seraphim, Odivaldo Jose [Universidade Estadual Paulista (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Engenharia Rural; Gabriel Filho, Luis Roberto de Almeida [Universidade Estadual Paulista (UNESP), Tupa, SP (Brazil). Campus Experimental
2010-07-01
The work developed a methodology fuzzy and simulated its use in control of a hybrid system of electric power generation, using solar-photovoltaic and wind energy. Using this control system, we get the point of maximum energy generation and transfer all the energy generated from alternative sources, solar-photovoltaic and wind energy to charge and / or batteries. The model uses three input variables, which are: wind (wind speed), sun (solar radiation) and batteries (charge the battery bank). With these variables, the fuzzy system will play, according to the rules to be described, what is the source of power supply system, which will have priority and how the batteries are loaded. For the simulations regarding the use of fuzzy theory to control, we used the scientific computing environment MATLAB. In this environment have been analyzed and simulated all mathematical modeling, rules and other variables described in the fuzzy system. This model can be applied to implement a control system of hybrid power generation, providing the best use of renewable energy, solar and wind, so that we can extract the maximum possible energy of these alternative sources without compromising the environment. (author)
Effects of solar radiation on endurance exercise capacity in a hot environment.
Otani, Hidenori; Kaya, Mitsuharu; Tamaki, Akira; Watson, Phillip; Maughan, Ronald J
2016-04-01
The present study investigated the effects of variations in solar radiation on endurance exercise capacity and thermoregulatory responses in a hot environment. Eight male volunteers performed four cycle exercise trials at 70 % maximum oxygen uptake until exhaustion in an environmental chamber maintained at 30 °C and 50 % relative humidity. Volunteers were tested under four solar radiation conditions: 800, 500, 250 and 0 W/m(2). Exercise time to exhaustion was less on the 800 W/m(2) trial (23 ± 4 min) than on all the other trials (500 W/m(2) 30 ± 7 min; P 0.05). Mean skin temperature was higher on the 800 W/m(2) trial than the 250 and 0 W/m(2) trials (P solar radiation increases.
Reading The Sun: A Three Dimensional Visual Model of The Solar Environment During Solar Cycle 24
Carranza-fulmer, T. L.; Moldwin, M.
2014-12-01
The sun is a powerful force that has proven to our society that it has a large impact on our lives. Unfortunately, there is still a lack of awareness on how the sun is capable of affecting Earth. The over all idea of "Reading The Sun" installation is to help demonstrate how the sun impacts the Earth, by compiling various data sources from satellites (SOHO, SDO, and STERO) with solar and solar wind models (MAS and ENLIL) to create a comprehensive three dimensional display of the solar environment. It focuses on the current solar maximum of solar cycle 24 and a CME that impacted Earth's magnetic field on February 27, 2014, which triggered geomagnetic storms around the Earth's poles. The CME was an after-effect of a class X4.9 solar flare, which was released from the sun on February 25, 2014. "Reading The Sun" is a 48" x 48" x 48" hanging model of the sun with color coded open opposing magnetic field lines along with various layers of the solar atmosphere, the heliospheric current sheet, and the inner planets. At the center of the xyz axis is the sun with the open magnetic field lines and the heliospheric current sheet permeating inner planetary space. The xyz axes are color coded to represent various types of information with corresponding visual images for the viewer to be able to read the model. Along the z-axis are three colors (yellow, orange, and green) that represent the different layers of the solar atmosphere (photosphere, chromosphere, and corona) that correspond to three satellite images in various spectrums related to a CME and Solar Flare and the xy-plane shows where the inner planets are in relation to the sun. The exhibit in which "Reading The Sun "is being displayed is called, The Rotation of Language at the Wheather Again Gallery in Rockaway, New York. The intent of the exhibit is to both celebrate as well as present a cautionary tale on the ability of human language to spark and ignite the individual and collective imagination towards an experience
Solar and terrestrial physics. [effects of solar activities on earth environment
1975-01-01
The effects of solar radiation on the near space and biomental earth, the upper atmosphere, and the magnetosphere are discussed. Data obtained from the OSO satellites pertaining to the solar cycle variation of extreme ultraviolet (EUV) radiation are analyzed. The effects of solar cycle variation of the characteristics of the solar wind are examined. The fluid mechanics of shock waves and the specific relationship to the characteristics of solar shock waves are investigated. The solar and corpuscular heating of the upper atmosphere is reported based on the findings of the AEROS and NATE experiments. Seasonal variations of the upper atmosphere composition are plotted based on OGO-6 mass spectrometer data.
Solar Photovoltaic (PV) Distributed Generation Systems - Control and Protection
Yi, Zhehan
This dissertation proposes a comprehensive control, power management, and fault detection strategy for solar photovoltaic (PV) distribution generations. Battery storages are typically employed in PV systems to mitigate the power fluctuation caused by unstable solar irradiance. With AC and DC loads, a PV-battery system can be treated as a hybrid microgrid which contains both DC and AC power resources and buses. In this thesis, a control power and management system (CAPMS) for PV-battery hybrid microgrid is proposed, which provides 1) the DC and AC bus voltage and AC frequency regulating scheme and controllers designed to track set points; 2) a power flow management strategy in the hybrid microgrid to achieve system generation and demand balance in both grid-connected and islanded modes; 3) smooth transition control during grid reconnection by frequency and phase synchronization control between the main grid and microgrid. Due to the increasing demands for PV power, scales of PV systems are getting larger and fault detection in PV arrays becomes challenging. High-impedance faults, low-mismatch faults, and faults occurred in low irradiance conditions tend to be hidden due to low fault currents, particularly, when a PV maximum power point tracking (MPPT) algorithm is in-service. If remain undetected, these faults can considerably lower the output energy of solar systems, damage the panels, and potentially cause fire hazards. In this dissertation, fault detection challenges in PV arrays are analyzed in depth, considering the crossing relations among the characteristics of PV, interactions with MPPT algorithms, and the nature of solar irradiance. Two fault detection schemes are then designed as attempts to address these technical issues, which detect faults inside PV arrays accurately even under challenging circumstances, e.g., faults in low irradiance conditions or high-impedance faults. Taking advantage of multi-resolution signal decomposition (MSD), a powerful signal
Kusano, K.
2016-12-01
Project for Solar-Terrestrial Environment Prediction (PSTEP) is a Japanese nation-wide research collaboration, which was recently launched. PSTEP aims to develop a synergistic interaction between predictive and scientific studies of the solar-terrestrial environment and to establish the basis for next-generation space weather forecasting using the state-of-the-art observation systems and the physics-based models. For this project, we coordinate the four research groups, which develop (1) the integration of space weather forecast system, (2) the physics-based solar storm prediction, (3) the predictive models of magnetosphere and ionosphere dynamics, and (4) the model of solar cycle activity and its impact on climate, respectively. In this project, we will build the coordinated physics-based model to answer the fundamental questions concerning the onset of solar eruptions and the mechanism for radiation belt dynamics in the Earth's magnetosphere. In this paper, we will show the strategy of PSTEP, and discuss about the role and prospect of the physics-based space weather forecasting system being developed by PSTEP.
Automated Intelligent Monitoring and the Controlling Software System for Solar Panels
Nalamvar, Hitesh Sanzhay; Ivanov, Maksim Anatoljevich; Baydali, Sergey Anatolievich
2017-01-01
The inspection of the solar panels on a periodic basis is important to improve longevity and ensure performance of the solar system. To get the most solar potential of the photovoltaic (PV) system is possible through an intelligent monitoring & controlling system. The monitoring & controlling system has rapidly increased its popularity because of its user-friendly graphical interface for data acquisition, monitoring, controlling and measurements. In order to monitor the performance of the sys...
Cost and Performance Report: Solar-Powered Remediation and pH Control
2017-04-01
parallel, with two batteries in each series, providing a 24 V DC power supply. A solar charge controller regulated the charging of the batteries when...ER-201033) Solar -Powered Remediation and pH Control April 2017 This document has been cleared for public release; Distribution Statement A...Technol. 32:1817-1824. CB&I Federal Services. 2017. Final Report. Solar Powered Remediation and pH Control . ESTCP Project ER-201033. April. Cheng, S
Fuzzy Logic Controlled Solar Module for Driving Three- Phase Induction Motor
Afiqah Zainal, Nurul; Sooi Tat, Chan; Ajisman
2016-02-01
Renewable energy produced by solar module gives advantages for generated three- phase induction motor in remote area. But, solar module's ou tput is uncertain and complex. Fuzzy logic controller is one of controllers that can handle non-linear system and maximum power of solar module. Fuzzy logic controller used for Maximum Power Point Tracking (MPPT) technique to control Pulse-Width Modulation (PWM) for switching power electronics circuit. DC-DC boost converter used to boost up photovoltaic voltage to desired output and supply voltage source inverter which controlled by three-phase PWM generated by microcontroller. IGBT switched Voltage source inverter (VSI) produced alternating current (AC) voltage from direct current (DC) source to control speed of three-phase induction motor from boost converter output. Results showed that, the output power of solar module is optimized and controlled by using fuzzy logic controller. Besides that, the three-phase induction motor can be drive and control using VSI switching by the PWM signal generated by the fuzzy logic controller. This concluded that the non-linear system can be controlled and used in driving three-phase induction motor.
Energy Technology Data Exchange (ETDEWEB)
Ramos Berumen, Carlos; Ramirez Benitez, Juan Rafael; Lopez Perez, Manuel de Jesus; Beltran Adan, Jose; Lagunas Mendoza, Javier [Instituto de Investigaciones Electricas, Cuernavaca, Morelos (Mexico)
2010-11-15
A solar concentrator prototype of Parabolic Trough (PT) for solar process heat generation has been designed, manufactured and put into operation by the Instituto de Investigaciones Electricas. By means of a sun tracking mechanism controlled by an automatic device, the PT is moving from East to West during the day then this way the solar energy is focused continually over the lineal receiver. Such movement is reached thanks to the electronic module fitted with special software. In this paper, the design of an electronic module based on calculation algorithm of the sun position along the day and over the year which controls the PT sun tracking is presented. The main purpose of the development is to integrate a control system which is using the algorithm of low cost (it was tested in a commercial system with success). [Spanish] El Instituto de Investigaciones Electricas (IIE) ha disenado, fabricado y puesto en operacion un prototipo de concentrador solar de canal parabolico para la generacion de calor de proceso. La tecnologia termosolar a concentracion de canal parabolica mantiene el concentrador moviendose de este a oeste durante el dia, enfocando continuamente el sol en el receptor lineal, mediante un mecanismo y un control automatico que permite el seguimiento aparente del sol. Se ha desarrollado el software para el control del mecanismo de seguimiento solar. En este articulo se presenta el diseno de un modulo electronico que controla el mecanismo de seguimiento solar de un canal parabolico, el cual tiene sus bases en un algoritmo que calcula la posicion del sol durante todo el dia y a lo largo del ano. El proposito principal es integrar un sistema de control de bajo costo, que utilice el algoritmo desarrollado por el IIE, el cual fue probado con exito en un sistema comercial para el seguimiento solar de un canal parabolico.
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
Imprints to the terrestrial environment at galactic arm crossings of the solar system
Fahr, H. J.; Fichtner, H.; Scherer, K.; Stawicki, O.
At its itinerary through our milky way galaxy the solar system moves through highly variable interstellar environments. Due to its orbital revolution around the galactic center, the solar system also crosses periodically the spiral arms of our galactic plane and thereby expe riences pronounced enviromental changes. Gas densities, magnetic fields and galactic cosmic ray intensities are substantially higher there compared to interarm conditions. Here we present theoretical calculations describing the SN-averaged galactic cosmic ray spectrum for regions inside and outside of galactic arms which then allow to predict how periodic passages of the solar system through galactic arms should be reflected by enhanced particle irradiations of the earth`s atmosphere and by correlated terrestrial Be-10 production rates.
Comparison of sensorless dimming control based on building modeling and solar power generation
International Nuclear Information System (INIS)
Lee, Naeun; Kim, Jonghun; Jang, Cheolyong; Sung, Yoondong; Jeong, Hakgeun
2015-01-01
Artificial lighting in office buildings accounts for about 30% of the total building energy consumption. Lighting energy is important to reduce building energy consumption since artificial lighting typically has a relatively large energy conversion factor. Therefore, previous studies have proposed a dimming control using daylight. When applied dimming control, method based on building modeling does not need illuminance sensors. Thus, it can be applied to existing buildings that do not have illuminance sensors. However, this method does not accurately reflect real-time weather conditions. On the other hand, solar power generation from a PV (photovoltaic) panel reflects real-time weather conditions. The PV panel as the sensor improves the accuracy of dimming control by reflecting disturbance. Therefore, we compared and analyzed two types of sensorless dimming controls: those based on the building modeling and those that based on solar power generation using PV panels. In terms of energy savings, we found that a dimming control based on building modeling is more effective than that based on solar power generation by about 6%. However, dimming control based on solar power generation minimizes the inconvenience to occupants and can also react to changes in solar radiation entering the building caused by dirty window. - Highlights: • We conducted sensorless dimming control based on solar power generation. • Dimming controls using building modeling and solar power generation were compared. • The real time weather conditions can be considered by using solar power generation. • Dimming control using solar power generation minimizes inconvenience to occupants
Degradation of Solar Array Components in a Combined UV/VUV High Temperature Test Environment
Directory of Open Access Journals (Sweden)
Nömayr Christel
2017-01-01
A design verification test under UV/VUV conditions of sun exposed materials and technologies on component level is presented which forms part of the overall verification and qualification of the solar array design of the MTM and MPO. The test concentrates on the self-contamination aspects and the resulting performance losses of the solar array under high intensity and elevated temperature environment representative for the photovoltaic assembly (PVA.
Fuzzy Logic Controlled Solar Module for Driving Three- Phase Induction Motor
International Nuclear Information System (INIS)
Zainal, Nurul Afiqah; Tat, Chan Sooi; Ajisman
2016-01-01
Renewable energy produced by solar module gives advantages for generated three- phase induction motor in remote area. But, solar module's output is uncertain and complex. Fuzzy logic controller is one of controllers that can handle non-linear system and maximum power of solar module. Fuzzy logic controller used for Maximum Power Point Tracking (MPPT) technique to control Pulse-Width Modulation (PWM) for switching power electronics circuit. DC-DC boost converter used to boost up photovoltaic voltage to desired output and supply voltage source inverter which controlled by three-phase PWM generated by microcontroller. IGBT switched Voltage source inverter (VSI) produced alternating current (AC) voltage from direct current (DC) source to control speed of three-phase induction motor from boost converter output. Results showed that, the output power of solar module is optimized and controlled by using fuzzy logic controller. Besides that, the three-phase induction motor can be drive and control using VSI switching by the PWM signal generated by the fuzzy logic controller. This concluded that the non-linear system can be controlled and used in driving three-phase induction motor. (paper)
Evolving Robot Controllers for Structured Environments Through Environment Decomposition
DEFF Research Database (Denmark)
Moreno, Rodrigo; Faiña, Andres; Støy, Kasper
2015-01-01
In this paper we aim to develop a controller that allows a robot to traverse an structured environment. The approach we use is to decompose the environment into simple sub-environments that we use as basis for evolving the controller. Specifically, we decompose a narrow corridor environment...... environments and that the order in which the decomposed sub-environments are presented in sequence impacts the performance of the evolutionary algorithm....
Three-Axis Attitude Control of Solar Sails Utilising Reflectivity Control Devices
Theodorou, Theodoros
Solar sails are spacecraft that utilise the Solar Radiation Pressure, the force generated by impinging photons, to propel themselves. Conventional actuators are not suitable for controlling the attitude of solar sails therefore specific attitude control methods have been devised to tackle this. One of these methods is to change the centre of pressure with respect to the center of mass thus creating a torque. Reflectivity Control Devices (RCDs) have been proposed and successfully used to change the centre of pressure. Current methods that utilise RCDs have control authority over two axis only with no ability to control the torque about the normal of the sail surface. This thesis extends the state of the art and demonstrates 3-axis control by generating arbitrary torque vectors within a convex polyhedron. Two different RCD materials are considered, transmission and diffusion technologies both compatible with the proposed concept. A number of metrics have been developed which facilitate the comparison of different sail configurations. One of these metics is the sun map which is a graphic representation of the sun angles for which control authority is maintained. An iterative design process is presented which makes use of the metrics developed and aids in the design of a sail which meets the mission requirements and constraints. Moreover, the effects of different parameters on the performance of the proposed control concept are discussed. For example it is shown that by alternating the angle between the edge and middle RCDs the control authority increases. The concept's scalability has been investigated and a hybrid control scheme has been devised which makes use of both RCDs and reaction wheels. The RCDs are complemented by the reaction wheels to achieve higher slew rates while in turn the RCDs desaturate the reaction wheels. Finally, a number of simulations are conducted to verify the validity of the proposed concept.
Radiation Environments for Future Human Exploration Throughout the Solar System.
Schwadron, N.; Gorby, M.; Linker, J.; Riley, P.; Torok, T.; Downs, C.; Spence, H. E.; Desai, M. I.; Mikic, Z.; Joyce, C. J.; Kozarev, K. A.; Townsend, L. W.; Wimmer-Schweingruber, R. F.
2016-12-01
mission durations. If the heliospheric magnetic field continues to weaken over time, as is likely, then allowable mission durations will decrease correspondingly. Thus, we examine the rapidly changing radiation environment and its implications for human exploration destinations throughout the inner solar system.
Energy Technology Data Exchange (ETDEWEB)
Rodriguez Viqueira, Manuel; Fuentes Freixanet Victor [Universidad Autonoma Metropolitana, Mexico, D.F. (Mexico)
2000-07-01
This paper is a reflection on the tradition and evolution of the use of solar control systems as a solution to the architectonic problem that arises from the solar radiation excess in the inhabitable spaces and its comfort conditions. The study has been structured from a historical-geographic vision of the architecture, showing the universality and the rationality of the solutions before certain environmental and climatologic conditions. That allows to arrive to the conclusion that similar architectonic solutions, as much in the functional aspect as in which refers to the use of the materials, that might not be related among them, and be independent in the space and time. To seat at the shade of a tree in a warm and sunned day, we quickly associated it to the pleasantness sensation, be this in a climate: dry, humid or template. This is the way we must conceive the solar control, as a tool for the bioclimatic design where we look for an increasing of the comfort sensation, in the architectonic spaces, with an optimization of the energy resources. In general terms the solar control devices, (of solarization) can be grouped in those of architectonic type, that is to say, those that are integrated and comprise the same architecture, and those non-architectonic, that is to say, those that do not comprise in it in a direct way. On the basis of this characterization we will enunciate the main devices of each one of the typologies or groups. [Spanish] Este trabajo es una reflexion sobre la tradicion y evolucion del uso de dispositivos de control solar como solucion al problema arquitectonico que surge del exceso de radiacion solar en los espacios habitables y las condiciones de confort en los mismos. El estudio se ha estructurado a partir de una vision historico-geografica de la arquitectura, mostrando la universalidad y la racionalidad de las soluciones ante determinadas condiciones ambientales y climatologicas. Lo que permite llegar a la conclusion de que soluciones
Solar control window film: report and manual
Energy Technology Data Exchange (ETDEWEB)
1980-01-01
A method has been developed by which the energy and energy cost savings associated with application of solar control film to windows of commercial and institutional buildings can be calculated. This method has been prepared as a separate, self-contained user's manual. It is simple and essentially non-technical, based on Toronto conditions, and is sufficiently accurate to provide a basis for economic feasibility analysis. The report explains the method in depth and compares it to alternate methods developed by the solar film industry. Variables which affect film performance, the savings that result, and limitations on the use of solar film as an energy conserving method are discussed. 8 refs., 2 figs., 1 tab.
Process development for high-efficiency silicon solar cells
Energy Technology Data Exchange (ETDEWEB)
Gee, J.M.; Basore, P.A.; Buck, M.E.; Ruby, D.S.; Schubert, W.K.; Silva, B.L.; Tingley, J.W.
1991-12-31
Fabrication of high-efficiency silicon solar cells in an industrial environment requires a different optimization than in a laboratory environment. Strategies are presented for process development of high-efficiency silicon solar cells, with a goal of simplifying technology transfer into an industrial setting. The strategies emphasize the use of statistical experimental design for process optimization, and the use of baseline processes and cells for process monitoring and quality control. 8 refs.
PSO based PI controller design for a solar charger system.
Yau, Her-Terng; Lin, Chih-Jer; Liang, Qin-Cheng
2013-01-01
Due to global energy crisis and severe environmental pollution, the photovoltaic (PV) system has become one of the most important renewable energy sources. Many previous studies on solar charger integrated system only focus on load charge control or switching Maximum Power Point Tracking (MPPT) and charge control modes. This study used two-stage system, which allows the overall portable solar energy charging system to implement MPPT and optimal charge control of Li-ion battery simultaneously. First, this study designs a DC/DC boost converter of solar power generation, which uses variable step size incremental conductance method (VSINC) to enable the solar cell to track the maximum power point at any time. The voltage was exported from the DC/DC boost converter to the DC/DC buck converter, so that the voltage dropped to proper voltage for charging the battery. The charging system uses constant current/constant voltage (CC/CV) method to charge the lithium battery. In order to obtain the optimum PI charge controller parameters, this study used intelligent algorithm to determine the optimum parameters. According to the simulation and experimental results, the control parameters resulted from PSO have better performance than genetic algorithms (GAs).
PSO Based PI Controller Design for a Solar Charger System
Directory of Open Access Journals (Sweden)
Her-Terng Yau
2013-01-01
Full Text Available Due to global energy crisis and severe environmental pollution, the photovoltaic (PV system has become one of the most important renewable energy sources. Many previous studies on solar charger integrated system only focus on load charge control or switching Maximum Power Point Tracking (MPPT and charge control modes. This study used two-stage system, which allows the overall portable solar energy charging system to implement MPPT and optimal charge control of Li-ion battery simultaneously. First, this study designs a DC/DC boost converter of solar power generation, which uses variable step size incremental conductance method (VSINC to enable the solar cell to track the maximum power point at any time. The voltage was exported from the DC/DC boost converter to the DC/DC buck converter, so that the voltage dropped to proper voltage for charging the battery. The charging system uses constant current/constant voltage (CC/CV method to charge the lithium battery. In order to obtain the optimum PI charge controller parameters, this study used intelligent algorithm to determine the optimum parameters. According to the simulation and experimental results, the control parameters resulted from PSO have better performance than genetic algorithms (GAs.
Survey of occupant behaviour and control of indoor environment in Danish dwellings
DEFF Research Database (Denmark)
Andersen, Rune Vinther; Toftum, Jørn; Andersen, Klaus Kaae
2009-01-01
separately by means of multiple logistic regression in order to quantify factors influencing occupants’ behaviour. The window opening behaviour was strongly related to the outdoor temperature. The perception of the environment and factors concerning the dwelling also impacted the window opening behaviour......Repeated surveys of occupant control of the indoor environment were carried out in Danish dwellings from September to October 2006 and again from February to March 2007. The summer survey comprised 933 respondents and the winter survey 636 respondents. The surveys were carried out by sending out....... The proportion of dwellings with the heating turned on was strongly related to the outdoor temperature and the presence of a wood burning stove. The solar radiation, dwelling ownership conditions and the perception of the indoor environment also affected the use of heating. The results of the statistical...
Carrier population control and surface passivation in solar cells
Cuevas, Andres
2018-05-02
Controlling the concentration of charge carriers near the surface is essential for solar cells. It permits to form regions with selective conductivity for either electrons or holes and it also helps to reduce the rate at which they recombine. Chemical passivation of the surfaces is equally important, and it can be combined with population control to implement carrier-selective, passivating contacts for solar cells. This paper discusses different approaches to suppress surface recombination and to manipulate the concentration of carriers by means of doping, work function and charge. It also describes some of the many surface-passivating contacts that are being developed for silicon solar cells, restricted to experiments performed by the authors.
Sherif, A.; El-Zafarany, A.; Arafa, R.
2012-01-01
In hot arid desert environments, the solar radiation passing through windows increases the cooling loads and the energy consumption of buildings. Shading of windows can reduce these loads. Unlike the woven solar screens, wooden solar screens have a
PSO Based PI Controller Design for a Solar Charger System
Yau, Her-Terng; Lin, Chih-Jer; Liang, Qin-Cheng
2013-01-01
Due to global energy crisis and severe environmental pollution, the photovoltaic (PV) system has become one of the most important renewable energy sources. Many previous studies on solar charger integrated system only focus on load charge control or switching Maximum Power Point Tracking (MPPT) and charge control modes. This study used two-stage system, which allows the overall portable solar energy charging system to implement MPPT and optimal charge control of Li-ion battery simultaneously....
Energy Technology Data Exchange (ETDEWEB)
Martinez Cirre, C. R.
2008-07-01
This work presents several different approaches to hierarchical control algorithms designed for a parabolic-trough solar collector field to demonstrate the possibility of maximizing hypothetical profit possible from this type of plant by improving and increasing plant automation. This study was developed in the current world power supply scenario, posing the possibility of using renewable energies (among which is solar thermal power), which the author is interested in contributing to advancing through research on improved plant operation control. The design was made for the ACUREX distributed solar collector field at the Plataforma Solar de Almeria. The control structures implemented to improve production in the solar collector field are based on a simple two-layered hierarchical control. One regulation layer (Layer 1) in which two proposals have been implemented: a control scheme developed using the feedback linearization technique and another proposal consisting on parallel deed forward control with an I-PD (Integral-Proportional Derivative) control. three proposals were implemented in the top layer (Layer 2) for generating the setpoint, the first one based on a physical model, the second one based on a fuzzy model, and the last uses the physical model and an optimization function for finding the optimum setpoint. (Author)
Time scaling internal state predictive control of a solar plant
Energy Technology Data Exchange (ETDEWEB)
Silva, R.N. [DEE-FCT/UNL, Caparica (Portugal); Rato, L.M. [INESC-ID/University, Evora (Portugal); Lemos, J.M. [INESC-ID/IST, Lisboa (Portugal)
2003-12-01
The control of a distributed collector solar field is addressed in this work, exploiting the plant's transport characteristic. The plant is modeled by a hyperbolic type partial differential equation (PDE) where the transport speed is the manipulated flow, i.e. the controller output. The model has an external distributed source, which is the solar radiation captured along the collector, approximated to depend only of time. From the solution of the PDE, a linear discrete state space model is obtained by using time-scaling and the redefinition of the control input. This method allows overcoming the dependency of the time constants with the operating point. A model-based predictive adaptive controller is derived with the internal temperature distribution estimated with a state observer. Experimental results at the solar power plant are presented, illustrating the advantages of the approach under consideration. (author)
Transformers For Extreme Environments
National Aeronautics and Space Administration — Imagine a revolutionary way to remotely control the environment surrounding one or more roving vehicles exploring remote and unexplored areas of the Solar System,...
International Nuclear Information System (INIS)
Sammarone, D.G.
1978-01-01
Disclosed is a system for controlling the environment of an enclosed area in nuclear reactor installations. The system permits the changing of the environment from nitrogen to air, or from air to nitrogen, without the release of any radioactivity or process gas to the outside atmosphere
Development of greenhouse solar systems for bulk tobacco curing and plant production
Energy Technology Data Exchange (ETDEWEB)
Huang, B.K.; Bowers, C.G. Jr.
1986-12-01
Among many farm crops, bright leaf tobacco is the most energy- and labor-intensive crop. The greenhouse solar system (solar bulk-curing/greenhouse system, or solar barn) was developed to provide multiple-use facilities for year-round solar energy utilization to save fossil fuels in tobacco curing and plant production and to facilitate the total mechanization of tobacco culture. Two types of full-size greenhouse solar systems, the load-supporting wall design and the shell design, both utilizing the thermal envelope concept, were designed and constructed for solar bulk-curing of tobacco, growing transplants and horticultural crops under controlled environment, and aiding automation of transplanting operations. Full-scale field tests of solar bulk curing showed that the fuel savings were consistantly improved from 37% in 1975 to 51% in 1978 for this solar bulk-curing system as compared with a conventional bulk-curing barn as a control. The feasibility of the system to save energy by using solar energy as a first priority source was significantly demonstrated. Three-year greenhouse and field tests showed that high germination rate of 95-97% with excellent emergence frequency was obtained for tobacco seeds under the controlled environment provided by the greenhouse solar system. In general, the containerized transplants from greenhouse solar system significantly exceeded the conventional bare-root transplants in growth, leaf-quality and yield. 9 figs., 3 tabs., 10 refs.
Virtualization in control system environment
International Nuclear Information System (INIS)
Shen, L.R.; Liu, D.K.; Wan, T.M.
2012-01-01
In large scale distributed control system, there are lots of common service composed an environment for the entire control system, such as the server system for the common software base library, application server, archive server and so on. This paper gives a description of a virtualization realization for control system environment including the virtualization for server, storage, network system and application for the control system. With a virtualization instance of the EPICS based control system environment that was built by the VMware vSphere v4, we tested the whole functionality of this virtualization environment in the SSRF control system, including the common server of the NFS, NIS, NTP, Boot and EPICS base and extension library tools, we also have applied virtualization to application servers such as the Archive, Alarm, EPICS gateway and all of the network based IOC. Specially, we test the high availability and VMotion for EPICS asynchronous IOC successful under the different VLAN configuration of the current SSRF control system network. (authors)
Solar shading control strategy for office buildings in cold climate
DEFF Research Database (Denmark)
Røseth Karlsen, Line; Heiselberg, Per Kvols; Bryn, Ida
2016-01-01
Highlights •Solar shading control strategy for office buildings in cold climate is developed. •Satisfying energy and indoor environmental performance is confirmed. •Importance of integrated evaluations when selecting shading strategy is illustrated.......Highlights •Solar shading control strategy for office buildings in cold climate is developed. •Satisfying energy and indoor environmental performance is confirmed. •Importance of integrated evaluations when selecting shading strategy is illustrated....
Automated Intelligent Monitoring and the Controlling Software System for Solar Panels
Nalamwar, H. S.; Ivanov, M. A.; Baidali, S. A.
2017-01-01
The inspection of the solar panels on a periodic basis is important to improve longevity and ensure performance of the solar system. To get the most solar potential of the photovoltaic (PV) system is possible through an intelligent monitoring & controlling system. The monitoring & controlling system has rapidly increased its popularity because of its user-friendly graphical interface for data acquisition, monitoring, controlling and measurements. In order to monitor the performance of the system especially for renewable energy source application such as solar photovoltaic (PV), data-acquisition systems had been used to collect all the data regarding the installed system. In this paper the development of a smart automated monitoring & controlling system for the solar panel is described, the core idea is based on IoT (the Internet of Things). The measurements of data are made using sensors, block management data acquisition modules, and a software system. Then, all the real-time data collection of the electrical output parameters of the PV plant such as voltage, current and generated electricity is displayed and stored in the block management. The proposed system is smart enough to make suggestions if the panel is not working properly, to display errors, to remind about maintenance of the system through email or SMS, and to rotate panels according to a sun position using the Ephemeral table that stored in the system. The advantages of the system are the performance of the solar panel system which can be monitored and analyzed.
Periodic orbits of solar sail equipped with reflectance control device in Earth-Moon system
Yuan, Jianping; Gao, Chen; Zhang, Junhua
2018-02-01
In this paper, families of Lyapunov and halo orbits are presented with a solar sail equipped with a reflectance control device in the Earth-Moon system. System dynamical model is established considering solar sail acceleration, and four solar sail steering laws and two initial Sun-sail configurations are introduced. The initial natural periodic orbits with suitable periods are firstly identified. Subsequently, families of solar sail Lyapunov and halo orbits around the L1 and L2 points are designed with fixed solar sail characteristic acceleration and varying reflectivity rate and pitching angle by the combination of the modified differential correction method and continuation approach. The linear stabilities of solar sail periodic orbits are investigated, and a nonlinear sliding model controller is designed for station keeping. In addition, orbit transfer between the same family of solar sail orbits is investigated preliminarily to showcase reflectance control device solar sail maneuver capability.
Control and Modelling of Seawater Desalination Using Solar Technology
Energy Technology Data Exchange (ETDEWEB)
Roca, L.; Yebra, L. J.; Berenguel, M.; Alarcon, D. C.
2006-07-01
Desalination plants play a fundamental role in fighting the shortage of fresh water in places with plentiful seawater resources. This paper briefly describes a solar desalination system designed, erected and operated in the AQUASOL project at the Plataforma Solar de Almeria (PSA), consisting basically of a CPC (Compound Parabolic Concentrator) solar collector field, two water storage tanks, a multi-effect distillation plant (MED) and a Double Effect Absorption Heat Pump (DEAHP). These subsystems have been modeled to estimate system behaviour and develop control techniques for maintaining optimal operating conditions. (Author)
Impact of Manually Controlled Solar Shades on Indoor Visual Comfort
Directory of Open Access Journals (Sweden)
Jian Yao
2016-07-01
Full Text Available Daylight plays a significant role in sustainable building design. The purpose of this paper was to investigate the impact of manual solar shades on indoor visual comfort. A developed stochastic model for manual solar shades was modeled in Building Controls Virtual Test Bed, which was coupled with EnergyPlus for co-simulation. Movable solar shades were compared with two unshaded windows. Results show that movable solar shades have more than half of the working hours with a comfortable illuminance level, which is about twice higher than low-e windows, with a less significant daylight illuminance fluctuation. For glare protection, movable solar shades increase comfortable visual conditions by about 20% compared to low-e windows. Moreover, the intolerable glare perception could be reduced by more than 20% for movable solar shades.
Energy Technology Data Exchange (ETDEWEB)
Camacho, E.F.; Rubio, F.R. [Universidad de Sevilla, Escuela Superior de Ingenieros, Departamento de Ingenieria de Sistemas y Automatica, Camino de Los Descubrimientos s/n, E-41092, Sevilla (Spain); Berenguel, M. [Universidad de Almeria, Departamento de Lenguajes y Computacion, Area de Ingenieria de Sistemas y Automatica, Carretera Sacramento s/n, E-04120 La Canada, Almeria (Spain); Valenzuela, L. [Plataforma Solar de Almeria - CIEMAT, Carretera Senes s/n, P.O. Box 22, E-04200 Tabernas, Almeria (Spain)
2007-10-15
This article presents a survey of the different automatic control techniques that have been applied to control the outlet temperature of solar plants with distributed collectors during the last 25 years. Different aspects of the control problem involved in this kind of plants are treated, from modeling and simulation approaches to the different basic control schemes developed and successfully applied in real solar plants. A classification of the modeling and control approaches is used to explain the main features of each strategy. (author)
Energy Technology Data Exchange (ETDEWEB)
Gijon Rivera, M. A.; Alvarez Garcia, G.; Xaman Villasenor, J. [Centro Nacional de Investigacion y Desarrollo Tecnologico, CENIDET-DGEST-SEP, Cuernavaca, Morelos (Mexico)]. E-mail: gaby@cenidet.edu.mx; I. Beausoleil-Morrison [Department of Mechanical and Aerospace Engineering, Carleton University, Ottawa (Canada)]. E-mail: ibeausol@mae.carleton.ca
2010-11-15
The use of solar passive strategies in buildings with large glazed areas such as new solar control coatings in windows are becoming more important and helpful recently, mainly because those developments can help to reduce heat gains and/or losses through transparent materials, reduce energy consumption, and improving the environment inside buildings. This paper presents an assessment of thermal performance in an office building with a SnS-Cu{sub x}S solar control coating and its influence on indoor conditions. The simulations consider climates of Mexico city and Ottawa as a good representation of two extremely conditions to asses the thermal behaviour inside offices, energy consumption, costs for air conditioning, and the influence of interior heat transfer coefficient correlations on energy consumption. The results are shown with and without the solar control coating adhered in a clear glass and in a double window configuration. The case of the system glass-film is the worst configuration as result of the high temperatures in the internal surface impacting the air point temperature and increasing the energy consumption. In general, the double glass configuration presents the best conditions, showing higher benefits for the case in Mexico City than the case of Ottawa. [Spanish] Resulta importante implementar estrategias pasivas en estudios de edificaciones con grandes areas de ventanas, como es la implementacion de nuevos materiales de control solar en vidrios que ayudan a reducir las ganancias y/o perdidas de calor a traves de los materiales transparentes, y asi reducir el consumo de energia y mejorar las condiciones del confort interior de los edificios. Este estudio realiza una evaluacion del funcionamiento termico de una pelicula selectiva de SnS-Cu{sub x}S que permite algunas ventajas termicas y opticas en el ambiente interno. Las simulaciones dinamicas consideran climas de la Ciudad de Mexico y Ottawa , con resultados que muestran las condiciones de confort
Performance Analysis of Fractional-Order PID Controller for a Parabolic Distributed Solar Collector
Elmetennani, Shahrazed; N'Doye, Ibrahima; Salama, Khaled N.; Laleg-Kirati, Taous-Meriem
2017-01-01
This paper studies the performance of a fractional-order proportional integral derivative (FOPID) controller designed for parabolic distributed solar collectors. The control problem addressed in concentrated solar collectors aims at forcing
Performance Analysis of Fractional-Order PID Controller for a Parabolic Distributed Solar Collector
Elmetennani, Shahrazed
2017-09-01
This paper studies the performance of a fractional-order proportional integral derivative (FOPID) controller designed for parabolic distributed solar collectors. The control problem addressed in concentrated solar collectors aims at forcing the produced heat to follow a desired reference despite the unevenly varying solar irradiance. In addition to the unpredictable variations of the energy source, the parabolic solar collectors are subject to inhomogeneous distributed efficiency parameters affecting the heat production. The FOPID controller is well known for its simplicity with better tuning flexibility along with robustness with respect to disturbances. Thus, we propose a control strategy based on FOPID to achieve the control objectives. First, the FOPID controller is designed based on a linear approximate model describing the system dynamics under nominal working conditions. Then, the FOPID gains and differentiation orders are optimally tuned in order to fulfill the robustness design specifications by solving a nonlinear optimization problem. Numerical simulations are carried out to evaluate the performance of the proposed FOPID controller. A comparison to the robust integer order PID is also provided. Robustness tests are performed for the nominal model to show the effectiveness of the FOPID. Furthermore, the proposed FOPID is numerically tested to control the distributed solar collector under real working conditions.
Green, Nelson W.; Dawson, Stephen F.
2015-01-01
NASA is currently considering a mission to investigate the moons of Jupiter. When designing a spacecraft for this type of mission, there are a number of engineering challenges, especially if the mission chooses to utilize solar arrays to provide the spacecraft power. In order for solar arrays to be feasible for the mission, their total mass needed to fit within the total budget for the mission, which strongly suggested the use of carbon composite facesheets on an aluminum core for the panel structure. While these composite structures are a good functional substitution for the metallic materials they replace, they present unique challenges when interacting with the harsh Jovian space environment. As a composite material, they are composed of more than one material and can show different base properties depending in differing conditions. Looking at the electrical properties, in an Earth-based environment the carbon component of the composite dominates the response of the material to external stimulus. Under these conditions, the structures strongly resembles a conductor. In the Jovian environment, with temperatures reaching 50K and under the bombardment from energetic electrons, the non-conducting pre-preg binding materials may come to the forefront and change the perceived response. Before selecting solar arrays as the baseline power source for a mission to Jupiter, the response of the carbon composites to energetic electrons while held at cryogenic temperatures needed to be determined. A series of tests were devised to exam the response of a sample solar array panel composed of an M55J carbon weave layup with an RS-3 pre-preg binder. Test coupons were fabricated and exposed to electrons ranging from 10 keV to 100 keV, at 1 nA/cm2, while being held at cryogenic temperatures. While under electron bombardment, electrical discharges were observed and recorded with the majority of discharges occurring with electron energies of 25 keV. A decrease in temperature to liquid
DEFF Research Database (Denmark)
Perers, Bengt; Furbo, Simon; Fan, Jianhua
2011-01-01
Solar Combi systems still need quite a lot of auxiliary energy especially in small systems without seasonal storage possibilities. The control of the auxiliary energy input both in time and power is important to utilize as much as possible of the solar energy available from the collectors and also...... energy sources. It can be either direct electric heating elements or a heat pump upgrading ambient energy in the air, ground, solar collector or waste heat from the house. The paper describes system modeling and simulation results. Advanced laboratory experiments are also starting now with three...
Observer-Based Bilinear Control of First-Order Hyperbolic PDEs: Application to the Solar Collector
Mechhoud, Sarra
2015-12-18
In this paper, we investigate the problem of bilinear control of a solar collector plant using the available boundary and solar irradiance measurements. The solar collector is described by a first-order 1D hyperbolic partial differential equation where the pump volumetric flow rate acts as the plant control input. By combining a boundary state observer and an internal energy-based control law, a nonlinear observer based feedback controller is proposed. With a feed-forward control term, the effect of the solar radiation is cancelled. Using the Lyapunov approach we prove that the proposed control guarantees the global exponential stability of both the plant and the tracking error. Simulation results are provided to illustrate the performance of the proposed method.
Orphee, Juan; Heaton, Andrew; Diedrich, Ben; Stiltner, Brandon C.
2018-01-01
A novel mechanism, the Active Mass Translator (AMT), has been developed for the NASA Near Earth Asteroid (NEA) Scout mission to autonomously manage the spacecraft momentum. The NEA Scout CubeSat will launch as a secondary payload onboard Exploration Mission 1 of the Space Launch System. To accomplish its mission, the CubeSat will be propelled by an 86 square-meter solar sail during its two-year journey to reach asteroid 1991VG. NEA Scout's primary attitude control system uses reaction wheels for holding attitude and performing slew maneuvers, while a cold gas reaction control system performs the initial detumble and early trajectory correction maneuvers. The AMT control system requirements, feedback architecture, and control performance will be presented. The AMT reduces the amount of reaction control propellant needed for momentum management and allows for smaller capacity reaction wheels suitable for the limited 6U spacecraft volume. The reduced spacecraft mass allows higher in-space solar sail acceleration, thus reducing time-of-flight. The reduced time-of-flight opens the range of possible missions, which is limited by the lifetime of typical non-radiation tolerant CubeSat avionics exposed to the deep-space environment.
Dynamics and control of a solar collector system for near Earth object deflection
International Nuclear Information System (INIS)
Gong Shenping; Li Junfeng; Gao Yunfeng
2011-01-01
A solar collector system is a possible method using solar energy to deflect Earth-threatening near-Earth objects. We investigate the dynamics and control of a solar collector system including a main collector (MC) and secondary collector (SC). The MC is used to collect the sunlight to its focal point, where the SC is placed and directs the collected light to an asteroid. Both the relative position and attitude of the two collectors should be accurately controlled to achieve the desired optical path. First, the dynamical equation of the relative motion of the two collectors in the vicinity of the asteroid is modeled. Secondly, the nonlinear sliding-mode method is employed to design a control law to achieve the desired configuration of the two collectors. Finally, the deflection capability of this solar collector system is compared with those of the gravitational tractor and solar sail gravitational tractor. The results show that the solar collector is much more efficient with respect to deflection capability.
Solar tracking control tower; Steuerungstechnik folgt der Sonne
Energy Technology Data Exchange (ETDEWEB)
Leu, Andreas [Jetter AG, Ludwigsburg (Germany). Bereich technisches Marketing und Seminare
2010-11-15
The ''Gemue-Dome'' building at Waldzimmern is a unique industrial building. The research, development and innovation center has a rotary control tower equipped with solar cells which automatically tracks the sun. This automation task was a challenge for the control and power supply sections. (orig.)
Modeling and Control of DC/DC Boost Converter using K-Factor Control for MPPT of Solar PV System
DEFF Research Database (Denmark)
Vangari, Adithya; Haribabu, Divyanagalakshmi; Sakamuri, Jayachandra N.
2015-01-01
This paper is focused on the design of a controller for the DC/DC boost converter using K factor control, which is based on modified PI control method, for maximum power point tracking (MPPT) of solar PV system. A mathematical model for boost converter based on small signal averaging approach...... is presented. Design of the passive elements of the boost converter as per the system specifications is also illustrated. The performance of the proposed K factor control method is verified with the simulations for MPPT on solar PV system at different atmospheric conditions. A new circuit based model for solar...... PV array, which includes the effect of solar insolation and temperature on PV array output, for the application in power system transient simulations, is also presented. The performance of the PV array model is verified with simulations at different atmospheric conditions. A 160W PV module from BP...
Solar Dynamic Power System Stability Analysis and Control
Momoh, James A.; Wang, Yanchun
1996-01-01
The objective of this research is to conduct dynamic analysis, control design, and control performance test of solar power system. Solar power system consists of generation system and distribution network system. A bench mark system is used in this research, which includes a generator with excitation system and governor, an ac/dc converter, six DDCU's and forty-eight loads. A detailed model is used for modeling generator. Excitation system is represented by a third order model. DDCU is represented by a seventh order system. The load is modeled by the combination of constant power and constant impedance. Eigen-analysis and eigen-sensitivity analysis are used for system dynamic analysis. The effects of excitation system, governor, ac/dc converter control, and the type of load on system stability are discussed. In order to improve system transient stability, nonlinear ac/dc converter control is introduced. The direct linearization method is used for control design. The dynamic analysis results show that these controls affect system stability in different ways. The parameter coordination of controllers are recommended based on the dynamic analysis. It is concluded from the present studies that system stability is improved by the coordination of control parameters and the nonlinear ac/dc converter control stabilize system oscillation caused by the load change and system fault efficiently.
Quasi-adaptive fuzzy heating control of solar buildings
Energy Technology Data Exchange (ETDEWEB)
Gouda, M.M. [Faculty of Industrial Education, Cairo (Egypt); Danaher, S. [University of Northumbria, Newcastle upon Tyne, (United Kingdom). School of Engineering; Underwood, C.P. [University of Northumbria, Newcastle upon Tyne (United Kingdom). School of Built Environment and Sustainable Cities Research Institute
2006-12-15
Significant progress has been made on maximising passive solar heat gains to building spaces in winter. Control of the space heating in these applications is complicated due to the lagging influence of the useful solar heat gain coupled with the wide range of construction materials and heating system choices. Additionally, and in common with most building control applications, there is a need to develop control solutions that permit simple and transparent set-up and commissioning procedures. This paper addresses the development and testing of a quasi-adaptive fuzzy logic control method that addresses these issues. The controller is developed in two steps. A feed-forward neural network is used to predict the internal air temperature, in which a singular value decomposition (SVD) algorithm is used to remove the highly correlated data from the inputs of the neural network to reduce the network structure. The fuzzy controller is then designed to have two inputs: the first input being the error between the set-point temperature and the internal air temperature and the second the predicted future internal air temperature. The controller was implemented in real-time using a test cell with controlled ventilation and a modulating electric heating system. Results, compared with validated simulations of conventionally controlled heating, confirm that the proposed controller achieves superior tracking and reduced overheating when compared with the conventional method of control. (author)
Energy Technology Data Exchange (ETDEWEB)
Mejia D, David; Morillon G, David; Rodriguez V, Luis [Universidad Nacional Autonoma de Mexico (Mexico)
2001-09-01
In this article the evaluation of the solar heat gains through the transparent parts of a building (houses of social interest) is presented; with the purpose of determining the heat gains through windows during summer time and under the following conditions: without solar protection, with the use of eaves, solar breakers and, finally, with the use of both elements. With the determined percentage of the diminution of heat gains, the considered potential of energy saving in air conditioning was obtained that would be available if the houses were constructed with solar control. [Spanish] En este articulo se presenta la evaluacion de las ganancias de calor solar a traves de las partes transparentes de un edificio (viviendas de interes social); con el objeto de determinar las ganancias de calor a traves de ventanas para la epoca de verano y bajo las siguientes condiciones: sin proteccion solar, con el empleo de aleros, con quiebrasoles y, finalmente, con el empleo de ambos elementos. Con el porcentaje determinado de la disminucion de ganancias de calor, se obtuvo el potencial estimado de ahorro de energia en aire acondicionado que se tendria si las viviendas se construyen con control solar.
Design and realization of an autonomous solar system
Gaga, A.; Diouri, O.; Es-sbai, N.; Errahimi, F.
2017-03-01
The aim of this work is the design and realization of an autonomous solar system, with MPPT control, a regulator charge/discharge of batteries, an H-bridge multi-level inverter with acquisition system and supervising based on a microcontroller. The proposed approach is based on developing a software platform in the LabVIEW environment which gives the system a flexible structure for controlling, monitoring and supervising the whole system in real time while providing power maximization and best quality of energy conversion from DC to AC power. The reliability of the proposed solar system is validated by the simulation results on PowerSim and experimental results achieved with a solar panel, a Lead acid battery, solar regulator and an H-bridge cascaded topology of single-phase inverter.
Directory of Open Access Journals (Sweden)
Onur Ozdal Mengi
2018-01-01
Full Text Available Investigations were presented in order to eliminate the reactive power on microgrid loads fed by an off-grid and mid-power photovoltaic solar energy system (PVSES with a static synchronous compensator (STATCOM device. The electric network is specifically characterized by P-Q loads, ambient temperature, and widely variable solar radiation levels. Two main innovations are developed. Firstly, the STATCOM apparatus is a 5-level H-bridge inverter with capacitances as load and must totally compensates the reactive power in the network load. Secondly, this compensation is controlled by a set of fractional PI (PIλ and model predictive control (MPC hybrid. The efficiencies of these controllers were compared with classical PI controllers. Large simulations, without and with reactive power compensation, in steady and transient states, are carried out to underline the merits of the presented works, by performing in the MATLAB-Simulink environment.
Reactor Start-up and Control Methodologies: Consideration of the Space Radiation Environment
International Nuclear Information System (INIS)
Bragg-Sitton, Shannon M.; Holloway, James Paul
2004-01-01
The use of fission energy in space power and propulsion systems offers considerable advantages over chemical propulsion. Fission provides over six orders of magnitude higher energy density, which translates to higher vehicle specific impulse and lower specific mass. These characteristics enable the accomplishment of ambitious space exploration missions. The natural radiation environment in space provides an external source of protons and high energy, high Z particles that can result in the production of secondary neutrons through interactions in reactor structures. Initial investigation using MCNPX 2.5.b for proton transport through the SAFE-400 reactor indicates a secondary neutron net current of 1.4x107 n/s at the core-reflector interface, with an incoming current of 3.4x106 n/s due to neutrons produced in the Be reflector alone. This neutron population could provide a reliable startup source for a space reactor. Additionally, this source must be considered in developing a reliable control strategy during reactor startup, steady-state operation, and power transients. An autonomous control system is developed and analyzed for application during reactor startup, accounting for fluctuations in the radiation environment that result from changes in vehicle location (altitude, latitude, position in solar system) or due to temporal variations in the radiation field, as may occur in the case of solar flares. One proposed application of a nuclear electric propulsion vehicle is in a tour of the Jovian system, where the time required for communication to Earth is significant. Hence, it is important that a reactor control system be designed with feedback mechanisms to automatically adjust to changes in reactor temperatures, power levels, etc., maintaining nominal operation without user intervention. This paper will evaluate the potential use of secondary neutrons produced by proton interactions in the reactor vessel as a startup source for a space reactor and will present a
Optimal control design for a solar greenhouse
Ooteghem, van R.J.C.
2007-01-01
The research of this thesis was part of a larger project aiming at the design of a greenhouse and an associated climate control that achieves optimal crop production with sustainable instead of fossil energy. This so called solar greenhouse design extends a conventional greenhouse with an improved
Management of solar energy in microgrids using IoT-based dependable control
Phung, Manh Duong; De La Villefromoy, Michel; Ha, Quang
2017-01-01
Solar energy generation requires efficient monitoring and management in moving towards technologies for net-zero energy buildings. This paper presents a dependable control system based on the Internet of Things (IoT) to control and manage the energy flow of renewable energy collected by solar panels within a microgrid. Data for optimal control include not only measurements from local sensors but also meteorological information retrieved in real-time from online sources. For system fault toler...
Fuzzy logic controller implementation for a solar air-conditioning system
International Nuclear Information System (INIS)
Lygouras, J.N.; Botsaris, P.N.; Vourvoulakis, J.; Kodogiannis, V.
2007-01-01
The implementation of a variable structure fuzzy logic controller for a solar powered air conditioning system and its advantages are investigated in this paper. Two DC motors are used to drive the generator pump and the feed pump of the solar air-conditioner. Two different control schemes for the DC motors rotational speed adjustment are implemented and tested: the first one is a pure fuzzy controller, its output being the control signal for the DC motor driver. A 7 x 7 fuzzy matrix assigns the controller output with respect to the error value and the derivative of the error. The second scheme is a two-level controller. The lower level is a conventional PID controller, and the higher level is a fuzzy controller acting over the parameters of the low level controller. Step response of the two control loops are presented as experimental results. The contribution of this design is that in the control system, the fuzzy logic is implemented through software in a common, inexpensive, 16-bit microcontroller, which does not have special abilities for fuzzy control
Fuzzy logic controller implementation for a solar air-conditioning system
Energy Technology Data Exchange (ETDEWEB)
Lygouras, J.N.; Vourvoulakis, J. [Laboratory of Electronics, School of Electrical and Computer Engineering, Democritus University of Thrace, Vas. Sofias 12, 67100 Xanthi (Greece); Botsaris, P.N. [Laboratory of Materials, Processes and Mechanical Design, School of Production and Management Engineering, Democritus University of Thrace 67100 Xanthi (Greece); Kodogiannis, V. [Centre for Systems Analysis, School of Computer Science, University of Westminster, London, HA1 3TP (United Kingdom)
2007-12-15
The implementation of a variable structure fuzzy logic controller for a solar powered air conditioning system and its advantages are investigated in this paper. Two DC motors are used to drive the generator pump and the feed pump of the solar air-conditioner. Two different control schemes for the DC motors rotational speed adjustment are implemented and tested: the first one is a pure fuzzy controller, its output being the control signal for the DC motor driver. A 7 x 7 fuzzy matrix assigns the controller output with respect to the error value and the derivative of the error. The second scheme is a two-level controller. The lower level is a conventional PID controller, and the higher level is a fuzzy controller acting over the parameters of the low level controller. Step response of the two control loops are presented as experimental results. The contribution of this design is that in the control system, the fuzzy logic is implemented through software in a common, inexpensive, 16-bit microcontroller, which does not have special abilities for fuzzy control. (author)
CONTROL ENVIRONMENT IN KOSOVO PUBLIC INSTITUTIONS
Directory of Open Access Journals (Sweden)
Shaqir M. REXHEPI
2015-06-01
Full Text Available The study on how is Internal Control System developed in public institutions is of a special importance for modalities, forms and the manner of the application of relevant strategies for the functioning of internal control environment in public institutions. In this paper, there is treated the existing situation of internal control system environment of public finances and its implementation in public sector. For internal control system environment in public finances to function effectively, there should exist a coherent control environment which includes responsibilities for financial management from managers of Publicly Owned Enterprises and with complete functioning of internal audit, which exists in the function of development to add value. In Kosovo public institutions, this framework is offered by legislation and by institutional mechanism for the implementation of legislation according to these parameters.
Directory of Open Access Journals (Sweden)
Alfredo G M Gámez López
2011-02-01
Full Text Available En el artículo se realiza un análisis de dos sensores que se aplican en energías renovables (eólica y solar,obteniéndose una ley de control óptima. Para las fuentes energéticas elegidas se proponen técnicas de altafrecuencia de conmutación y eficiencia. Para la validación de los resultados se emplean técnicas desimulación digital In this article we make an analysis of two sensors applied in renewable energies (wind and solar,obtaining an ideal law of control. For the chosen energetic sources there appear technologies of highfrequency of commutation and of high efficiency. Technologies of digital simulation validate the results.
Environment-oriented life cycle analysis of bulk materials, applied in solar cell systems
International Nuclear Information System (INIS)
Geelen, H.
1994-04-01
In the solar cell technology several bulk materials (glass, steel, aluminium, concrete, copper, zinc and synthetic materials) are applied intensively. By means of a life cycle analysis (LCA) the environmental effects and bottlenecks of the use of these materials is investigated in this report. Also attention is paid to the options to reduce the environmental effects of photovoltaic (PV) systems by changing processes and/or by redesign of the PV systems. Two systems are studied: solar cells, integrated in pitched roofs, and solar cells on the ground in solar cell arrays. The study is focused on the use of bulk materials in the solar module, the cables and the supporting construction. After brief introductions on the environment-oriented LCA method, the standard construction of PV modules and the principles of solar cells, an overview is given of the present and future material input for the above-mentioned PV-systems. Next, attention is paid to the energy consumption and the most important emissions of the production of the bulk materials. Based on these data three environmental effect scores of the PV systems are calculated and analyzed: the energy consumption, the greenhouse effect or global warming equivalent, and the acidifying effect or acidification equivalent. Also a fourth effect, for which the so-called environmental indicator human toxicity is defined, is described. By means of this indicator the hazardous effects for the public health can be indicated. The sum of the four indicators is a measure for the environmental profile of the roof PV-system and the ground PV-array system. Recommendations are given by which the systems and their environmental profiles can be improved. 29 figs., 50 tabs., 5 appendices, refs
Radiation hard solar cell and array
International Nuclear Information System (INIS)
Russell, R.L.
1975-01-01
A power generating solar cell for a spacecraft solar array is hardened against transient response to nuclear radiation while permitting normal operation of the cell in a solar radiation environment by shunting the cell with a second solar cell whose contacts are reversed relative to the power cell to form a cell module, exposing the power cell only to the solar radiation in a solar radiation environment to produce an electrical output at the module terminals, and exposing both cells to the nuclear radiation in a nuclear radiation environment so that the radiation induced currents generated by the cells suppress one another
Implementation of Maximum Power Point Tracking (MPPT) Solar Charge Controller using Arduino
Abdelilah, B.; Mouna, A.; KouiderM’Sirdi, N.; El Hossain, A.
2018-05-01
the platform Arduino with a number of sensors standard can be used as components of an electronic system for acquiring measures and controls. This paper presents the design of a low-cost and effective solar charge controller. This system includes several elements such as the solar panel converter DC/DC, battery, circuit MPPT using Microcontroller, sensors, and the MPPT algorithm. The MPPT (Maximum Power Point Tracker) algorithm has been implemented using an Arduino Nano with the preferred program. The voltage and current of the Panel are taken where the program implemented will work and using this algorithm that MPP will be reached. This paper provides details on the solar charge control device at the maximum power point. The results include the change of the duty cycle with the change in load and thus mean the variation of the buck converter output voltage and current controlled by the MPPT algorithm.
Solar thermal energy conversion to electrical power
International Nuclear Information System (INIS)
Trinh, Anh-Khoi; González, Ivan; Fournier, Luc; Pelletier, Rémi; Sandoval V, Juan C.; Lesage, Frédéric J.
2014-01-01
The conversion of solar energy to electricity currently relies primarily on the photovoltaic effect in which photon bombardment of photovoltaic cells drives an electromotive force within the material. Alternatively, recent studies have investigated the potential of converting solar radiation to electricity by way of the Seebeck effect in which charge carrier mobility is generated by an asymmetric thermal differential. The present study builds upon these latest advancements in the state-of-the-art of thermoelectric system management by combining solar evacuated tube technology with commercially available Bismuth Telluride semiconductor modules. The target heat source is solar radiation and the target heat sink is thermal convection into the ambient air relying on wind aided forced convection. These sources of energy are reproduced in a laboratory controlled environment in order to maintain a thermal dipole across a thermoelectric module. The apparatus is then tested in a natural environment. The novelty of the present work lies in a net thermoelectric power gain for ambient environment applications and an experimental validation of theoretical electrical characteristics relative to a varying electrical load. - Highlights: • Solar radiation maintains a thermal tension which drives an electromotive force. • Voltage, current and electric power are reported and discussed. • Theoretical optimal thermoelectric conversion predictions are presented. • Theory is validated with experimentally measured data
Energy Technology Data Exchange (ETDEWEB)
Souza Mendes, Alfredo de
1986-12-31
This study was concerned to concept, to project and to build a parabolic solar collector as a generation source of thermic energy to the conventional drying of wood, jointed to a drying environment and to evaluate its efficiency. In this sense, prototypes of a solar collector and a conventional dry kiln were built. The collector with linear focus, was provided with a solar photoelectric tracking system. The dry kiln had semiautomatic control of temperature and a capacity to dry 0,3 m deg 3 of wood. All the steps of the construction of the system are presented with details. (author). 14 figs., 8 tabs., 73 refs
The Development of Monitoring and Control System of the Low PV/T Solar System
Okhorzina Alena; Bikbulatov Alexander; Yurchenko Alexey; Bernhard Norbert; Aldoshina Oksana
2016-01-01
The article presents an autonomous PV/T solar installation. Installing converts solar energy into electricity and heat. The description of its components and elements that enhance its effectiveness shows. The description of the control program and control of the installation is given. The control system provides for tracking the sun and cooling the photovoltaic module.
International Nuclear Information System (INIS)
Sidek, M.H.M.; Azis, N.; Hasan, W.Z.W.; Ab Kadir, M.Z.A.; Shafie, S.; Radzi, M.A.M.
2017-01-01
This paper presents a study on an automated positioning open-loop dual-axis solar tracking system. The solar tracker was designed and fabricated using standard cylindrical aluminium hollow and Polyuthrene (PE). The control system of the solar tracker was governed by Micro Controller Unit (MCU) with auxiliary devices which includes encoder and Global Positioning System (GPS). The sun path trajectory algorithm utilizing the astronomical equation and GPS information was also embedded in the system. The power generation performance of the dual-axis solar tracking system was compared with the fixed-tilted Photovoltaic (PV) system. It is found that the solar tracker is able to position itself automatically based on sun path trajectory algorithm with an accuracy of ±0.5°. The embedded Proportional Integral Derivative (PID) positioning system improves the tracking of elevation and azimuth angles with minimum energy consumption. It is reveals that the proposed solar tracker is able generate 26.9% and 12.8% higher power than fixed-tilted PV system on a clear and heavy overcast conditions respectively. Overall, the open-loop dual-axis solar tracker can be deployed automatically at any location on the earth with minimal configurations and is suitable for mobile solar tracking system. - Highlights: • Self-positioning dual-axis solar tracking system. • Precise control of elevation and azimuth angle. • Sun path trajectory based on astronomical equation and GPS. • Can achieve up to 26.9% higher power than fixed-tilted PV system under clear weather condition.
New fuzzy approximate model for indirect adaptive control of distributed solar collectors
Elmetennani, Shahrazed
2014-06-01
This paper studies the problem of controlling a parabolic solar collectors, which consists of forcing the outlet oil temperature to track a set reference despite possible environmental disturbances. An approximate model is proposed to simplify the controller design. The presented controller is an indirect adaptive law designed on the fuzzy model with soft-sensing of the solar irradiance intensity. The proposed approximate model allows the achievement of a simple low dimensional set of nonlinear ordinary differential equations that reproduces the dynamical behavior of the system taking into account its infinite dimension. Stability of the closed loop system is ensured by resorting to Lyapunov Control functions for an indirect adaptive controller.
New fuzzy approximate model for indirect adaptive control of distributed solar collectors
Elmetennani, Shahrazed; Laleg-Kirati, Taous-Meriem
2014-01-01
This paper studies the problem of controlling a parabolic solar collectors, which consists of forcing the outlet oil temperature to track a set reference despite possible environmental disturbances. An approximate model is proposed to simplify the controller design. The presented controller is an indirect adaptive law designed on the fuzzy model with soft-sensing of the solar irradiance intensity. The proposed approximate model allows the achievement of a simple low dimensional set of nonlinear ordinary differential equations that reproduces the dynamical behavior of the system taking into account its infinite dimension. Stability of the closed loop system is ensured by resorting to Lyapunov Control functions for an indirect adaptive controller.
International Nuclear Information System (INIS)
Yao, Jian
2014-01-01
Highlights: • Driving factor for adjustment of manually controlled solar shades was determined. • A stochastic model for manual solar shades was constructed using Markov method. • Co-simulation with Energyplus was carried out in BCVTB. • External shading even manually controlled should be used prior to LOW-E windows. • Previous studies on manual solar shades may overestimate energy savings. - Abstract: Solar shading devices play a significant role in reducing building energy consumption and maintaining a comfortable indoor condition. In this paper, a typical office building with internal roller shades in hot summer and cold winter zone was selected to determine the driving factor of control behavior of manual solar shades. Solar radiation was determined as the major factor in driving solar shading adjustment based on field measurements and logit analysis and then a stochastic model for manually adjusted solar shades was constructed by using Markov method. This model was used in BCVTB for further co-simulation with Energyplus to determine the impact of the control behavior of solar shades on energy performance. The results show that manually adjusted solar shades, whatever located inside or outside, have a relatively high energy saving performance than clear-pane windows while only external shades perform better than regularly used LOW-E windows. Simulation also indicates that using an ideal assumption of solar shade adjustment as most studies do in building simulation may lead to an overestimation of energy saving by about 16–30%. There is a need to improve occupants’ actions on shades to more effectively respond to outdoor conditions in order to lower energy consumption, and this improvement can be easily achieved by using simple strategies as a guide to control manual solar shades
Application of synchronous grid-connected controller in the wind-solar-storage micro grid
Li, Hua; Ren, Yongfeng; Li, Le; Luo, Zhenpeng
2016-01-01
Recently, there has been an increasing interest in using distributed generators (DG) not only to inject power into the grid, but also to enhance the power quality. In this study, a space voltage pulse width modulation (SVPWM) control method is proposed for a synchronous grid-connected controller in a wind-solar-storage micro grid. This method is based on the appropriate topology of the synchronous controller. The wind-solar-storage micro grid is controlled to reconnect to the grid synchronous...
Lefers, Ryan
2017-12-01
Controlled environment agriculture allows the production of fresh food indoors from global locations and contexts where it would not otherwise be possible. Growers in extreme climates and urban areas produce food locally indoors, saving thousands of food import miles and capitalizing upon the demand for fresh, tasty, and nutritious food. However, the growing of food, both indoors and outdoors, consumes huge quantities of water - as much as 70-80% of global fresh water supplies. The utilization of liquid desiccants in a closed indoor agriculture cycle provides the possibility of capturing plant-transpired water vapor. The regeneration/desalination of these liquid desiccants offers the potential to recover fresh water for irrigation and also to re-concentrate the desiccants for continued dehumidification. Through the utilization of solar thermal energy, the process can be completed with a very small to zero grid-energy footprint. The primary research in this dissertation focused on two areas: the dehumidification of indoor environments utilizing liquid desiccants inside membrane contactors and the regeneration of these desiccants using membrane distillation. Triple-bore PVDF hollow fiber membranes yielded dehumidification permeance rates around 0.25-0.31 g m-2 h-1 Pa-1 in lab-scale trials. A vacuum membrane distillation unit utilizing PVDF fibers yielded a flux of 2.8-7.0 kg m-2 hr-1. When the membrane contactor dehumidification system was applied in a bench scale controlled environment agriculture setup, the relative humidity levels responded dynamically to both plant transpiration and dehumidification rates, reaching dynamic equilibrium levels during day and night cycles. In addition, recovered fresh water from distillation was successfully applied for irrigation of crops and concentrated desiccants were successfully reused for dehumidification. If applied in practice, the liquid desiccant system for controlled environment agriculture offers the potential to reduce
International Nuclear Information System (INIS)
Jiang, Jian-ping; Li, Dong-xu
2010-01-01
The decentralized robust vibration control with collocated piezoelectric actuator and strain sensor pairs is considered in this paper for spacecraft solar panel structures. Each actuator is driven individually by the output of the corresponding sensor so that only local feedback control is implemented, with each actuator, sensor and controller operating independently. Firstly, an optimal placement method for the location of the collocated piezoelectric actuator and strain gauge sensor pairs is developed based on the degree of observability and controllability indices for solar panel structures. Secondly, a decentralized robust H ∞ controller is designed to suppress the vibration induced by external disturbance. Finally, a numerical comparison between centralized and decentralized control systems is performed in order to investigate their effectiveness to suppress vibration of the smart solar panel. The simulation results show that the vibration can be significantly suppressed with permitted actuator voltages by the controllers. The decentralized control system almost has the same disturbance attenuation level as the centralized control system with a bit higher control voltages. More importantly, the decentralized controller composed of four three-order systems is a better practical implementation than a high-order centralized controller is
Recent Advances in Heliogyro Solar Sail Structural Dynamics, Stability, and Control Research
Wilkie, W. Keats; Warren, Jerry E.; Horta, Lucas G.; Lyle, Karen H.; Juang, Jer-Nan; Gibbs, S. Chad; Dowell, Earl H.; Guerrant, Daniel V.; Lawrence, Dale
2015-01-01
Results from recent NASA sponsored research on the structural dynamics, stability, and control characteristics of heliogyro solar sails are summarized. Specific areas under investigation include coupled nonlinear finite element analysis of heliogyro membrane blade with solar radiation pressure effects, system identification of spinning membrane structures, and solarelastic stability analysis of heliogyro solar sails, including stability during blade deployment. Recent results from terrestrial 1-g blade dynamics and control experiments on "rope ladder" membrane blade analogs, and small-scale in vacuo system identification experiments with hanging and spinning high-aspect ratio membranes will also be presented. A low-cost, rideshare payload heliogyro technology demonstration mission concept is used as a mission context for these heliogyro structural dynamics and solarelasticity investigations, and is also described. Blade torsional dynamic response and control are also shown to be significantly improved through the use of edge stiffening structural features or inclusion of modest tip masses to increase centrifugal stiffening of the blade structure. An output-only system identification procedure suitable for on-orbit blade dynamics investigations is also developed and validated using ground tests of spinning sub-scale heliogyro blade models. Overall, analytical and experimental investigations to date indicate no intractable stability or control issues for the heliogyro solar sail concept.
Panasenco, O.; Velli, M.; Panasenco, A.; Lionello, R.
2017-12-01
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 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 conditions for filament formation: polar crown filaments are permanently present at the boundaries of the polar coronal holes. Mid-latitude and equatorial coronal holes - the result of active region evolution - can create pseudostreamers 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 pseudostreamers 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 thepseudostreamer base low in the corona. We review and model possible coronal magnetic configurations and solar wind plasma properties at different distances from the solar surface that
Tada, H. Y.; Carter, J. R., Jr.; Anspaugh, B. E.; Downing, R. G.
1982-01-01
The handbook to predict the degradation of solar cell electrical performance in any given space radiation environment is presented. Solar cell theory, cell manufacturing and how they are modeled mathematically are described. The interaction of energetic charged particles radiation with solar cells is discussed and the concept of 1 MeV equivalent electron fluence is introduced. The space radiation environment is described and methods of calculating equivalent fluences for the space environment are developed. A computer program was written to perform the equivalent fluence calculations and a FORTRAN listing of the program is included. Data detailing the degradation of solar cell electrical parameters as a function of 1 MeV electron fluence are presented.
Solar Dynamics Observatory Guidance, Navigation, and Control System Overview
Morgenstern, Wendy M.; Bourkland, Kristin L.; Hsu, Oscar C.; Liu, Kuo-Chia; Mason, Paul A. C.; O'Donnell, James R., Jr.; Russo, Angela M.; Starin, Scott R.; Vess, Melissa F.
2011-01-01
that solar radiation pressure is a large torque disturbance, and the momentum buildup from this disturbance and the GEO altitude drives the ACS to use thrusters to manage vehicle momentum. The demanding data capture budget for the mission, however, requires SDO to avoid frequent thruster maneuvers, while concerns about on-orbit jitter restrict the maximum desired wheel speeds desired from the RWAs. The plan for on-orbit wheel speed and momentum management will be discussed as well as what is now being done in operation after the jitter environment was characterized. The SDO ACS hardware complement is single-fault tolerant. Two main processors carry virtually identical copies of the command and data handling and ACS software, and two identical attitude control electronics (ACE) boxes carry Coldfire processors with contingency ACS software and other hardware interface cards; the ACE structure allows reaction wheels to be commanded by the Sun-pointing Safehold independent of the Mil Std 1553 data bus. The sixteen Adcole CSSs are grouped into primary and backup sets of eight sensors, each set providing the ability to calculate a sun vector. Each set of eight eyes provides full 4 -steradian coverage. The Adcole DSS comprises an optics head and a separate electronics box providing a 1553 data interface. The electronics box is mounted inside the Faraday cage created by the spacecraft bus module. The DSS head with its 32- deg square FOV is mounted on the instrument module with its boresight along the spacecraft X axis, nearly aligned with the Sun during observations. Adcole has designed the DSS calibration parameters so that the accuracy is 0.24 arcminutes within 10 deg of the boresight, and diminishes to 3 arcminutes as the Sun moves towards the edges of its FOV . This DSS calibration scheme provides higher accuracy attitude determination over the range of the instrument calibration maneuvers.
Radiation monitoring in the NPP environment, control of radioactivity in NPP-environment system
International Nuclear Information System (INIS)
Egorov, Yu.A.
1987-01-01
Problems of radiation monitoring and control of the NPP-environment system (NPPES) are considered. Radiation control system at the NPP and in the environment provides for the control of the NPP, considered as the source of radioactive releases in the environment and for the environmental radiation climate control. It is shown, that the radiation control of the NPP-environment system must be based on the ecological normalization principles of the NPP environmental impacts. Ecological normalization should be individual for the NPP region of each ecosystem. The necessity to organize and conduct radiation ecological monitoring in the NPP regions is pointed out. Radiation ecological monitoring will provide for both environmental current radiation control and information for mathematical models, used in the NPPES radiation control
Small-Scale Flat Plate Collectors for Solar Thermal Scavenging in Low Conductivity Environments
Directory of Open Access Journals (Sweden)
Emmanuel Ogbonnaya
2017-01-01
Full Text Available There is great opportunity to develop power supplies for autonomous application on the small scale. For example, remote environmental sensors may be powered through the harvesting of ambient thermal energy and heating of a thermoelectric generator. This work investigates a small-scale (centimeters solar thermal collector designed for this application. The absorber is coated with a unique selective coating and then studied in a low pressure environment to increase performance. A numerical model that is used to predict the performance of the collector plate is developed. This is validated based on benchtop testing of a fabricated collector plate in a low-pressure enclosure. Model results indicate that simulated solar input of about 800 W/m2 results in a collector plate temperature of 298 K in ambient conditions and up to 388 K in vacuum. The model also predicts the various losses in W/m2 K from the plate to the surroundings. Plate temperature is validated through the experimental work showing that the model is useful to the future design of these small-scale solar thermal energy collectors.
A neural network controller for hydronic heating systems of solar buildings.
Argiriou, Athanassios A; Bellas-Velidis, Ioannis; Kummert, Michaël; André, Philippe
2004-04-01
An artificial neural network (ANN)-based controller for hydronic heating plants of buildings is presented. The controller has forecasting capabilities: it includes a meteorological module, forecasting the ambient temperature and solar irradiance, an indoor temperature predictor module, a supply temperature predictor module and an optimizing module for the water supply temperature. All ANN modules are based on the Feed Forward Back Propagation (FFBP) model. The operation of the controller has been tested experimentally, on a real-scale office building during real operating conditions. The operation results were compared to those of a conventional controller. The performance was also assessed via numerical simulation. The detailed thermal simulation tool for solar systems and buildings TRNSYS was used. Both experimental and numerical results showed that the expected percentage of energy savings with respect to a conventional controller is of about 15% under North European weather conditions.
Steam and soil solarization were investigated for control of the root-knot nematode Meloidogyne arenaria in two years of field trials on a commercial flower farm in Florida. The objective was to determine if pre-plant steam treatments in combination with solarization, or solarization alone effective...
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
Control of Solar Power Plants Connected Grid with Simple Calculation Method on Residential Homes
Kananda, Kiki; Nazir, Refdinal
2017-12-01
One of the most compatible renewable energy in all regions to apply is solar energy. Solar power plants can be built connected to existing or stand-alone power grids. In assisting the residential electricity in which there is a power grid, then a small scale solar energy power plants is very appropriate. However, the general constraint of solar energy power plants is still low in terms of efficiency. Therefore, this study will explain how to control the power of solar power plants more optimally, which is expected to reactive power to zero to raise efficiency. This is a continuation of previous research using Newton Rapshon control method. In this study we introduce a simple method by using ordinary mathematical calculations of solar-related equations. In this model, 10 PV modules type of ND T060M1 with a 60 Wp capacity are used. The calculations performed using MATLAB Simulink provide excellent value. For PCC voltage values obtained a stable quantity of approximately 220 V. At a maximum irradiation condition of 1000 W / m2, the reactive power value of Q solar generating system maximum 20.48 Var and maximum active power of 417.5 W. In the condition of lower irradiation, value of reactive power Q almost close to zero 0.77Var. This simple mathematical method can provide excellent quality control power values.
Energy Technology Data Exchange (ETDEWEB)
Moerk, M. [Bodensee-Stiftung, Radolfzell (Germany)
2006-07-01
Summary: The swimming classroom is a particular environmental education programme. Since 2002 school classes are taught aboard the solar ferry Helio at the Lower Lake Constance. Schoolboys and girls as well as teachers have the opportunity to enlarge their knowledge about Lake Constance, its natural environment and the solar ferry Helio. They also get informed about photovoltaic systems, water pollution control and environment-friendly tourism in the Lake Constance region. Solar ferry is most suitable for nature and adventure pedagogy as well as experimental instruction. School classes and advanced training groups can easily carry out a comprehensive programme aboard the Helio and experience nature and solar technology cruising on the lake. Issues are - Energy/Photovoltaic - Limnology - Life in and on the water - Water pollution control - Geography/Landscape development. (orig.)
Simultaneous control of multiple instruments at the Advanced Technology Solar Telescope
Johansson, Erik M.; Goodrich, Bret
2012-09-01
The Advanced Technology Solar Telescope (ATST) is a 4-meter solar observatory under construction at Haleakala, Hawaii. The simultaneous use of multiple instruments is one of the unique capabilities that makes the ATST a premier ground based solar observatory. Control of the instrument suite is accomplished by the Instrument Control System (ICS), a layer of software between the Observatory Control System (OCS) and the instruments. The ICS presents a single narrow interface to the OCS and provides a standard interface for the instruments to be controlled. It is built upon the ATST Common Services Framework (CSF), an infrastructure for the implementation of a distributed control system. The ICS responds to OCS commands and events, coordinating and distributing them to the various instruments while monitoring their progress and reporting the status back to the OCS. The ICS requires no specific knowledge about the instruments. All information about the instruments used in an experiment is passed by the OCS to the ICS, which extracts and forwards the parameters to the appropriate instrument controllers. The instruments participating in an experiment define the active instrument set. A subset of those instruments must complete their observing activities in order for the experiment to be considered complete and are referred to as the must-complete instrument set. In addition, instruments may participate in eavesdrop mode, outside of the control of the ICS. All instrument controllers use the same standard narrow interface, which allows new instruments to be added without having to modify the interface or any existing instrument controllers.
Directory of Open Access Journals (Sweden)
Robert Samosir
2017-12-01
Full Text Available Electrical energy has become a basic need for human being. In some remote areas however electricity is unreachable and poses a taboo subject and cannot be enjoyed by local people such as in Tigaraja Village Sub-District of Tigadolok Regency of Simalungun. The sun is a renewable energy that it is beneficial for power plant use. With PLTS solar energy can be changed into the sun through the solar panel. Battery Charge Regulator BCR operates stabilizing voltage from solar panel to battery. The battery will save electrical power to be distributed for household consumption. Since battery power has direct current however Inverter operates changing its direct current into alternating current. To optimize absorption of solar energy a servo motor is used to make solar panel moving by following the suns path. Arduino Uno as direct control of solar panel using solar sensor gives current for servo motor. Then the servo motor can move in reverse and forward. Therefore Household goods like water pumps lamps and televisions have been worked when people come home from their work.
2016-06-01
iii Approved for public release; distribution is unlimited MICROGRID CONTROL STRATEGY UTLIZING THERMAL ENERGY STORAGE WITH RENEWABLE SOLAR AND WIND... control tracks increasing power generation in the morning. The batteries require a large amount of electrical power to charge every morning, as charge ...is 37 lost throughout the night. This causes the solar panels to output their maximum power generation. The MPPT control records when power
Nanoparticle-doped Polymer Foils for Use in Solar Control Glazing
Smith, G. B.; Deller, C. A.; Swift, P. D.; Gentle, A.; Garrett, P. D.; Fisher, W. K.
2002-04-01
Since nanoparticles can provide spectrally selective absorption without scattering they can be used to dope polymers for use in windows, to provide a clear view while strongly attenuating both solar heat gain and UV, at lower cost than alternative technologies. The underlying physics and how it influences the choice and concentration of nanoparticle materials is outlined. Spectral data, visible and solar transmittance, and solar heat gain coefficient are measured for clear polymers and some laminated glass, in which the polymer layer is doped with conducting oxide nanoparticles. Simple models are shown to apply making general optical design straightforward. Use with clear glass and tinted glass is considered and performance shown to match existing solar control alternatives. A potential for widespread adoption in buildings and cars is clearly demonstrated, and scopes for further improvements are identified, so that ultimately both cost and performance are superior.
Nanoparticle-doped Polymer Foils for Use in Solar Control Glazing
International Nuclear Information System (INIS)
Smith, G.B.; Deller, C.A.; Swift, P.D.; Gentle, A.; Garrett, P.D.; Fisher, W.K.
2002-01-01
Since nanoparticles can provide spectrally selective absorption without scattering they can be used to dope polymers for use in windows, to provide a clear view while strongly attenuating both solar heat gain and UV, at lower cost than alternative technologies. The underlying physics and how it influences the choice and concentration of nanoparticle materials is outlined. Spectral data, visible and solar transmittance, and solar heat gain coefficient are measured for clear polymers and some laminated glass, in which the polymer layer is doped with conducting oxide nanoparticles. Simple models are shown to apply making general optical design straightforward. Use with clear glass and tinted glass is considered and performance shown to match existing solar control alternatives. A potential for widespread adoption in buildings and cars is clearly demonstrated, and scopes for further improvements are identified, so that ultimately both cost and performance are superior
Energy Technology Data Exchange (ETDEWEB)
Arboit, M.; Fernandez Llano, J.C.; Rosa, C. de [Instituto de Ciencias Humanas, Sociales y Ambientales (INCIHUSA - CONICET), R and D Unit, Laboratorio de Ambiente Humano y Vivienda (LAHV), Adrian Ruiz Leal s/n, Parque General San Martin 5500, Mendoza (Argentina); Diblasi, A. [Facultad de Ciencias Economicas, UNCuyo, Centro Universitario (5500) Mendoza (Argentina)
2008-08-15
Energy use in the built environment is globally recognized as a key issue for sustainable urban development. In tempered-cold arid regions with a generous solar resource, adequate design and technology can substantially reduce the energy demand for space and water heating in urban buildings. This study assessed the solar potential of low-density urban environments in the city of Mendoza, Argentina. The results of the study will be used to develop technical guidelines for urban and energy planning agencies and professionals involved in the production of habitat. The study included the following successive steps: (i) selection of a representative sample of analysis units (city blocks); (ii) selection of a series of urban and building variables; (iii) definition of indicators accounting for solar masking, building's potential use of the solar radiation on the whole urban area, and availability of adequate collecting areas to satisfy high percentages of the energy demand in low-density urban environments; and (iv) insolation of potential collectors simulated by a graphic-computational model developed in the R and D unit. Only the results for solar space heating are presented in this paper. The results, direct and statistical, indicate that it is technically feasible to meet the target solar fractions. At the same time, by means of the solar recycling of existing building stocks, it is possible to considerably reduce the environmental impacts due to the extraction of materials from, and the disposal of solid wastes into, the ecosystem. (author)
Technology Of Controlled-Environment Agriculture
Bubenheim, David L.; Bates, Maynard E.
1995-01-01
Report discusses controlled-environment agriculture (CEA) for commercial production of organisms, whether plants or animals. Practiced in greenhouses to produce food on nonarable lands. Describes conceptual regenerative system that incorporates biological, physical, and chemical processes to support humans in extraterrestrial environments.
International Nuclear Information System (INIS)
Dyer, C.S.; Truscott, P.R.; Peerless, C.L.; Watson, C.J.; Evans, H.E.; Knight, P.; Cosby, M.; Underwood, C.; Cousins, T.; Noulty, R.; Maag, C.
1999-01-01
Flight data obtained between 1990 and 1997 from the Cosmic Radiation Environment Monitors CREAM and CREDO carried on UoSAT-3, Space Shuttle, STRV-1a (Space Technology Research Vehicle) and APEX (Advanced Photovoltaic and Electronics Experiment Spacecraft) provide coverage over half a solar cycle. The modulation of cosmic rays and evolution of the South Atlantic Anomaly are observed, the former comprising a factor of three increase at high latitudes and the latter a general increase accompanied by a north-westward drift. Comparison of particle fluxes and linear energy transfer (LET) spectra is made with improved environment and radiation transport calculations which account for shield distributions and secondary particles. While there is an encouraging convergence between predictions and observations, significant improvements are still required, particularly in the treatment of locally produced secondary particles. Solar-particle events during this time period have LET spectra significantly below the October 1989 event which has been proposed as a worst case model
Variable structure TITO fuzzy-logic controller implementation for a solar air-conditioning system
Energy Technology Data Exchange (ETDEWEB)
Lygouras, J.N.; Pachidis, Th. [Laboratory of Electronics, School of Electrical and Computer Engineering, Democritus University of Thrace, GR-67100 Xanthi (Greece); Kodogiannis, V.S. [Centre for Systems Analysis, School of Computer Science, University of Westminster, London HA1 3TP (United Kingdom); Tarchanidis, K.N. [Department of Petroleum Technology, Technological Education Institute of Kavala, GR-65404, Kavala (Greece); Koukourlis, C.S. [Laboratory of Telecommunications, School of Electrical and Computer Engineering, Democritus University of Thrace, GR-67100 Xanthi (Greece)
2008-04-15
The design and implementation of a Two-Input/Two-Output (TITO) variable structure fuzzy-logic controller for a solar-powered air-conditioning system is described in this paper. Two DC motors are used to drive the generator pump and the feed pump of the solar air-conditioner. The first affects the temperature in the generator of the solar air-conditioner, while the second, the pressure in the power loop. The difficulty of Multi-Input/Multi-Output (MIMO) systems control is how to overcome the coupling effects among each degree of freedom. First, a traditional fuzzy-controller has been designed, its output being one of the components of the control signal for each DC motor driver. Secondly, according to the characteristics of the system's dynamics coupling, an appropriate coupling fuzzy-controller (CFC) is incorporated into a traditional fuzzy-controller (TFC) to compensate for the dynamic coupling among each degree of freedom. This control strategy simplifies the implementation problem of fuzzy control, but can also improve the control performance. This mixed fuzzy controller (MFC) can effectively improve the coupling effects of the systems, and this control strategy is easy to design and implement. Experimental results from the implemented system are presented. (author)
Shape control of slack space reflectors using modulated solar pressure.
Borggräfe, Andreas; Heiligers, Jeannette; Ceriotti, Matteo; McInnes, Colin R
2015-07-08
The static deflection profile of a large spin-stabilized space reflector because of solar radiation pressure acting on its surface is investigated. Such a spacecraft consists of a thin reflective circular film, which is deployed from a supporting hoop structure in an untensioned, slack manner. This paper investigates the use of a variable reflectivity distribution across the surface to control the solar pressure force and hence the deflected shape. In this first analysis, the film material is modelled as one-dimensional slack radial strings with no resistance to bending or transverse shear, which enables a semi-analytic derivation of the nominal deflection profile. An inverse method is then used to find the reflectivity distribution that generates a specific, for example, parabolic deflection shape of the strings. Applying these results to a parabolic reflector, short focal distances can be obtained when large slack lengths of the film are employed. The development of such optically controlled reflector films enables future key mission applications such as solar power collection, radio-frequency antennae and optical telescopes.
Humic Acid Degradation via Solar Photo-Fenton Process in Aqueous Environment
Directory of Open Access Journals (Sweden)
Seyed Ali Sajjadi
2015-08-01
Full Text Available Control of mutagenic and carcinogenic disinfection by-products, particularly Trihalomethanes (THMs and Halo Acetic Acids (HAAs in water treatment process is critical, due to their adverse effects on human health. Generally, reducing the toxicity of these by-products hinges on prior removal of the precursor materials, such as Humic Acid (HA in drinking water. This study was conducted to investigate the role of some parameters that could affect the removal of HA, including HA (5 and 10 ppm and H2O2 (20, 40, 60, and 80 ppm initial concentrations, Iron (II, sulfate heptahydrate dosage (4, 8, 12, and 16 ppm, pH (2, 3, 4 and 5, Oxidation time (5, 10, 15 and 30 min, and Sunlight levels (322±13 kWm-2. To accelerate the process of HA removal, the Solar Photo-Fenton (SPF process was employed by direct irradiation of converged sunlight in a Parabolic Trough Collectors (PTC, with 3m2 effective area. HA levels were measured via quantifying Dissolved Organic Carbon (DOC concentrations by means of a TOC Analyzer method. The results showed that the SPF process is under control of the Fe & H2O2 ratio, the Fe2+ dosage and especially the pH quantity. In optimal condition, (pH: 4, oxidation time: 30min, initial HA levels: 50 ppm, H2O2 concentrations: 20 ppm Fe+2 levels: 4 ppm, the study found more than 98% DOC removal. In conclusion, the SPF, as an economically effective technique, could be applied for the removal of HA in aqueous environments.
Carrier population control and surface passivation in solar cells
Cuevas, Andres; Wan, Yimao; Yan, Di; Samundsett, Christian; Allen, Thomas; Zhang, Xinyu; Cui, Jie; Bullock, James
2018-01-01
Controlling the concentration of charge carriers near the surface is essential for solar cells. It permits to form regions with selective conductivity for either electrons or holes and it also helps to reduce the rate at which they recombine
EXPERIMENTAL INVESTIGATION OF SOLAR POND PERFORMANCE IN KARABUK ENVIRONMENT
Directory of Open Access Journals (Sweden)
Mehmet ÖZKAYMAK
2004-01-01
Full Text Available The solar energy, one of the alternative energy sources, can be economically and cheaply and efficiently collected with solar ponds. In this study, varying concentrations of sodium carbonate dilution in the solar pond in terms of heat storage performance has been examined. Experiment apparatus has been located Zonguldak Karaelmas University Karabük Technical Education Faculty. Five experiments with different density levels have been done and the changes in the temperature and density have been presented graphically within the solar pond. The experiments show that the temperature difference between the bottom and top level of solar pond is max. 21 °C and the highest temperature in lower convective zone (LCZ has been measured as 49 °C.
Influence of solar activity and environment on 10Be in recent natural archives
International Nuclear Information System (INIS)
Berggren, Ann-Marie
2009-01-01
Understanding the link between the Sun and climate is vital in the current incidence of global climate change, and 10 Be in natural archives constitutes an excellent tracer for this purpose. As cosmic rays enter the atmosphere, cosmogenic isotopes like 10 Be and 14 C are formed. Variations in solar activity modulate the amount of incoming cosmic rays, and thereby cosmogenic isotope production. Atmospherically produced 10 Be enters natural archives such as sediments and glaciers by wet and dry deposition within about a year of production. 10 Be from natural archives therefore provides information on past solar activity, and because these archives also contain climate information, solar activity and climate can be linked. One remaining question is to what degree 10 Be in natural archives reflects production, and to what extent the local and regional environment overprints the production signal. To explore this, 10 Be was measured at annual resolution over the last 600 years in a Greenland ice core. Measurement potentials for these samples benefited from the development of a new laboratory method of co-precipitating 10 Be with niobium. To diversify geographic location and archive media type, a pioneer study of measuring 10 Be with annual resolution in varved lake sediments from Finland was conducted, with samples from the entire 20th century. Pathways of 10 Be into lake sediments are more complex than into glacial ice, inferring that contemporary atmospheric conditions may not be recorded. Here, it is shown for the first time that tracing the 11-year solar cycle through lake sediment 10 Be variations is possible. Results also show that on an annual basis, 10 Be deposition in ice and sediment archives is affected by local environmental conditions. On a slightly longer timescale, however, diverse 10 Be records exhibit similar trends and a negative correlation with solar activity. Cyclic variability of 10 Be deposition persisted throughout past grand solar minima, when
Directory of Open Access Journals (Sweden)
mehdi Nasr Esfahani
2017-01-01
Full Text Available Introduction. Sugar beet cyst nematode, Heterodera schachtii Schmidt is the major disease of sugar beet worldwide, causing considerable damages, and even death of the plants, in the infested fields. There are several suggested methods of controls, which may have its own difficulties to be taken into consideration. To avoid the use of nematicides, and reduced the risk of chemical hazards in the environment, any sorts of nonchemical management is incorrigible. However, any method of management must be safe, large scale application and economical. Thus, in this manuscript, polyethylene sheaths were used to solarize and or disinfection of the infested soils to H. schachtii. And, also, the incorporation of the farm yards manure was taken into consideration too. Therefore, the field experiments were carried out in infected sugar beet growing regions, where there was a heavy infestation to the sugar beet nematodes, Isfahan province, Iran, to determine the effects of soil solarization alone and or along with undecomposed farm yard manure on sugar beet cyst nematode, H. schachtii. Material and Methods. Transparent Polyethylene sheaths of 2microns were used to solarize and or disinfection of the infested soils to H. schachtii. The fresh farm yards manure for 40 tons per hector for the incorporation was taken into consideration. The field experiments were carried out in infected sugar beet growing regions, where, there was a heavy infestation to the sugar beet nematodes, Jey and Ghahab of Isfahan, Isfahan province, Iran, for determination of the effects of soil solarization alone and or along with undecomposed farm yard manure on sugar beet cyst nematode, H. schachtii. Treatments were consisted of soil solarization with transparent polyethylene sheets, fresh yard manure, integration of soil solarization with farm yard manure and untreated, control and or ckecks in a randomized block design in three replications each in an infested field conditions, in the
Maximum-power-point tracking control of solar heating system
Huang, Bin-Juine; Ton, Wei-Zhe; Wu, Chen-Chun; Ko, Hua-Wei; Chang, Hsien-Shun; Yen, Rue-Her; Wang, Jiunn-Cherng
2012-01-01
was used to determine the instantaneous tracking target Q max(t). The system transfer-function model of solar heating system was also derived experimentally using a step response test and used in the design of tracking feedback control system. The PI
PID Testing Method Suitable for Process Control of Solar Cells Mass Production
Directory of Open Access Journals (Sweden)
Xianfang Gou
2015-01-01
Full Text Available Voltage bias of several hundred volts which are applied between solar cells and module frames may lead to significant power losses, so-called potential-induced degradation (PID, in normal photovoltaic (PV installations system. Modules and minimodules are used to conduct PID test of solar cells. The test procedure is time consuming and of high cost, which cannot be used as process monitoring method during solar cells fabrication. In this paper, three kinds of test including minimodule, Rsh, and V-Q test are conducted on solar cells or wafers with SiNx of different refractive index. All comparisons between test results of Rsh, V-Q, and minimodule tests have shown equal results. It is shown that Rsh test can be used as quality inspection of solar cells and V-Q test of coated wafer can be used as process control of solar cells.
International Nuclear Information System (INIS)
Kruisheer, N.
1992-01-01
In five brief articles product information is given on solar energy applications with special attention to the Netherlands. After an introduction on solar energy availability in the Netherlands the developments in solar boiler techniques are dealt with. Solar water heaters have advantages for the environment, and government subsidies stimulate different uses of such water heaters. Also the developments of solar cells show good prospects, not only for developing countries, but also for the industrialized countries. In brief the developments in solar energy storage and the connection of solar equipment to the grid are discussed. Finally attention is paid to the applications of passive solar energy in the housing construction, the use of transparent thermal insulation and the developments of translucent materials. 18 figs., 18 ills
Heliostat-field gain-scheduling control applied to a two-step solar hydrogen production plant
International Nuclear Information System (INIS)
Roca, Lidia; Calle, Alberto de la; Yebra, Luis J.
2013-01-01
Highlights: ► A control system is proposed for a solar reactor system which produces hydrogen. ► The controller chooses which heliostats from the solar field must be focused. ► A gain scheduling scheme is included to deal with different system dynamics. ► The scheme is tested and tunned in simulation. ► Real experiments show the promising results of this work. -- Abstract: This article describes a temperature control structure designed for the interior of a solar hydrogen reactor based on a two-step ferrite-redox technology. Until now, this temperature has been controlled by manual selection of the heliostats to be focused on the receiver targets. However, the strong system dependency on operating conditions suggests that the procedure be automated in order to ensure the desired setpoint change response. The aims are to maintain the desired temperatures and to make the setpoint switch as fast as possible, keeping plant conditions within the margins of safety. The scheme proposed includes a procedure for selecting the heliostats to be focused on the reactor by using a simple model of the solar field and a gain scheduling control system which changes the control tuning parameters to deal with the varying dynamics observed during the process. Real experiments show the promising results of this work.
Flexible Access Control for Dynamic Collaborative Environments
Dekker, M.A.C.
2009-01-01
Access control is used in computer systems to control access to confidential data. In this thesis we focus on access control for dynamic collaborative environments where multiple users and systems access and exchange data in an ad hoc manner. In such environments it is difficult to protect
Simulation of closed loop controlled boost converter for solar installation
Directory of Open Access Journals (Sweden)
Kalirasu Athimulam
2010-01-01
Full Text Available With the shortage of the energy and ever increasing of the oil price, research on the renewable and green energy sources, especially the solar arrays and the fuel cells, becomes more and more important. How to achieve high stepup and high efficiency DC/DC converters is the major consideration in the renewable power applications due to the low voltage of PV arrays and fuel cells. In this paper digital simulation of closed loop controlled boost converter for solar installation is presented. Circuit models for open loop and closed loop controlled systems are developed using the blocks of simulink. The simulation results are compared with the theoretical results. This converter has advantages like improved power factor, fast response and reduced hardware. .
Controlled Environment Specimen Transfer
DEFF Research Database (Denmark)
Damsgaard, Christian Danvad; Zandbergen, Henny W.; Hansen, Thomas Willum
2014-01-01
an environmental transmission electron microscope to an in situ X-ray diffractometer through a dedicated transmission electron microscope specimen transfer holder, capable of sealing the specimen in a gaseous environment at elevated temperatures. Two catalyst material systems have been investigated; Cu/ZnO/Al2O3...... transferred in a reactive environment to the environmental transmission electron microscope where further analysis on the local scale were conducted. The Co/Al2O3 catalyst was reduced in the environmental microscope and successfully kept reduced outside the microscope in a reactive environment. The in situ......Specimen transfer under controlled environment conditions, such as temperature, pressure, and gas composition, is necessary to conduct successive complementary in situ characterization of materials sensitive to ambient conditions. The in situ transfer concept is introduced by linking...
Solar Power Station Output Inverter Control Design
Directory of Open Access Journals (Sweden)
J. Bauer
2011-04-01
Full Text Available The photovoltaic applications spreads in these days fast, therefore they also undergo great development. Because the amount of the energy obtained from the panel depends on the surrounding conditions, as intensity of the sun exposure or the temperature of the solar array, the converter must be connected to the panel output. The Solar system equipped with inverter can supply small loads like notebooks, mobile chargers etc. in the places where the supplying network is not present. Or the system can be used as a generator and it shall deliver energy to the supply network. Each type of the application has different requirements on the converter and its control algorithm. But for all of them the one thing is common – the maximal efficiency. The paper focuses on design and simulation of the low power inverter that acts as output part of the whole converter. In the paper the design of the control algorithm of the inverter for both types of inverter application – for islanding mode and for operation on the supply grid – is discussed. Attention is also paid to the design of the output filter that should reduce negative side effects of the converter on the supply network.
Energy Technology Data Exchange (ETDEWEB)
None
1981-03-01
Solar heating and cooling of a 40,000 square foot manufacturing building, sales offices and the solar computer control center/display room are described. Information on system description, test data, major problems and resolutions, performance, operation and maintenance manual, manufacturer's literature and as-built drawings are provided also. The solar system is composed of 6000 square feet of Sunworks double glazed flat plate collectors, external above ground storage subsystem, controls, ARKLA absorption chiller, heat recovery and a cooling tower.
Pluto's interaction with its space environment: Solar wind, energetic particles, and dust.
Bagenal, F; Horányi, M; McComas, D J; McNutt, R L; Elliott, H A; Hill, M E; Brown, L E; Delamere, P A; Kollmann, P; Krimigis, S M; Kusterer, M; Lisse, C M; Mitchell, D G; Piquette, M; Poppe, A R; Strobel, D F; Szalay, J R; Valek, P; Vandegriff, J; Weidner, S; Zirnstein, E J; Stern, S A; Ennico, K; Olkin, C B; Weaver, H A; Young, L A
2016-03-18
The New Horizons spacecraft carried three instruments that measured the space environment near Pluto as it flew by on 14 July 2015. The Solar Wind Around Pluto (SWAP) instrument revealed an interaction region confined sunward of Pluto to within about 6 Pluto radii. The region's surprisingly small size is consistent with a reduced atmospheric escape rate, as well as a particularly high solar wind flux. Observations from the Pluto Energetic Particle Spectrometer Science Investigation (PEPSSI) instrument suggest that ions are accelerated and/or deflected around Pluto. In the wake of the interaction region, PEPSSI observed suprathermal particle fluxes equal to about 1/10 of the flux in the interplanetary medium and increasing with distance downstream. The Venetia Burney Student Dust Counter, which measures grains with radii larger than 1.4 micrometers, detected one candidate impact in ±5 days around New Horizons' closest approach, indicating an upper limit of <4.6 kilometers(-3) for the dust density in the Pluto system. Copyright © 2016, American Association for the Advancement of Science.
Energy Technology Data Exchange (ETDEWEB)
Camacho, E.F.; Rubio, F.R. [Universidad de Sevilla, Escuela Superior de Ingenieros, Departamento de Ingenieria de Sistemas y Automatica, Camino de Los Descubrimientos s/n, E-41092 Sevilla (Spain); Berenguel, M. [Universidad de Almeria, Departamento de Lenguajes y Computacion, Area de Ingenieria de Sistemas y Automatica, Carretera Sacramento s/n, E-04120 La Canada, Almeria (Spain); Valenzuela, L. [Plataforma Solar de Almeria - CIEMAT, Carretera Senes s/n, P.O. Box 22, E-04200 Tabernas (Almeria) (Spain)
2007-10-15
This article presents a survey of the different advanced automatic control techniques that have been applied to control the outlet temperature of solar plants with distributed collectors during the last 25 years. A classification of the modeling and control approaches described in the first part of this survey is used to explain the main features of each strategy. The treated strategies range from classical advanced control strategies to those with few industrial applications. (author)
Denker, Carsten; Kuckein, Christoph; Verma, Meetu; González Manrique, Sergio J.; Diercke, Andrea; Enke, Harry; Klar, Jochen; Balthasar, Horst; Louis, Rohan E.; Dineva, Ekaterina
2018-05-01
In high-resolution solar physics, the volume and complexity of photometric, spectroscopic, and polarimetric ground-based data significantly increased in the last decade, reaching data acquisition rates of terabytes per hour. This is driven by the desire to capture fast processes on the Sun and the necessity for short exposure times “freezing” the atmospheric seeing, thus enabling ex post facto image restoration. Consequently, large-format and high-cadence detectors are nowadays used in solar observations to facilitate image restoration. Based on our experience during the “early science” phase with the 1.5 m GREGOR solar telescope (2014–2015) and the subsequent transition to routine observations in 2016, we describe data collection and data management tailored toward image restoration and imaging spectroscopy. We outline our approaches regarding data processing, analysis, and archiving for two of GREGOR’s post-focus instruments (see http://gregor.aip.de), i.e., the GREGOR Fabry–Pérot Interferometer (GFPI) and the newly installed High-Resolution Fast Imager (HiFI). The heterogeneous and complex nature of multidimensional data arising from high-resolution solar observations provides an intriguing but also a challenging example for “big data” in astronomy. The big data challenge has two aspects: (1) establishing a workflow for publishing the data for the whole community and beyond and (2) creating a collaborative research environment (CRE), where computationally intense data and postprocessing tools are colocated and collaborative work is enabled for scientists of multiple institutes. This requires either collaboration with a data center or frameworks and databases capable of dealing with huge data sets based on virtual observatory (VO) and other community standards and procedures.
TransFormers for Ensuring Long-Term Operations in Lunar Extreme Environments
Mantovani, J. G.; Stoica, A.; Alkalai, L.; Wilcox, B.; Quadrelli, M.
2016-01-01
"Surviving Extreme Space Environments" (EE) is one of NASA's Space Technology Grand Challenges. Power generation and thermal control are the key survival ingredients that allow a robotic explorer to cope with the EE using resources available to it, for example, by harvesting the local solar energy or by utilizing an onboard radioisotope thermoelectric generator (RTG). TransFormers (TFs) are a new technology concept designed to transform a localized area within a harsh extreme environment into a survivable micro-environment by projecting energy to the precise location where robots or humans operate. For example, TFs placed at a location on the rim of Shackleton Crater, which is illuminated by solar radiation for most of the year, would be able to reflect solar energy onto robots operating in the dark cold crater. TFs utilize a shape transformation mechanism to un-fold from a compact volume to a large reflective surface, and to control how much-and where-the energy is projected, and by adjusting for the changing position of the sun. TFs would enable in-situ resource utilization (ISRU) activities within locations of high interest that would normally be unreachable because of their extreme environment
Adaptive control for solar energy based DC microgrid system development
Zhang, Qinhao
During the upgrading of current electric power grid, it is expected to develop smarter, more robust and more reliable power systems integrated with distributed generations. To realize these objectives, traditional control techniques are no longer effective in either stabilizing systems or delivering optimal and robust performances. Therefore, development of advanced control methods has received increasing attention in power engineering. This work addresses two specific problems in the control of solar panel based microgrid systems. First, a new control scheme is proposed for the microgrid systems to achieve optimal energy conversion ratio in the solar panels. The control system can optimize the efficiency of the maximum power point tracking (MPPT) algorithm by implementing two layers of adaptive control. Such a hierarchical control architecture has greatly improved the system performance, which is validated through both mathematical analysis and computer simulation. Second, in the development of the microgrid transmission system, the issues related to the tele-communication delay and constant power load (CPL)'s negative incremental impedance are investigated. A reference model based method is proposed for pole and zero placements that address the challenges of the time delay and CPL in closed-loop control. The effectiveness of the proposed modeling and control design methods are demonstrated in a simulation testbed. Practical aspects of the proposed methods for general microgrid systems are also discussed.
Control of particle precipitation by energy transfer from solar wind
Bremer, J.; Gernandt, H.
1985-12-01
The energy transfer function (epsilon), introduced by Perreault and Akasofu (1978), appears to be well suited for the description of the long-term control of the particle precipitation by interplanetary parameters. An investigation was conducted with the objective to test this control in more detail. This investigation included the calculation of hourly epsilon values on the basis of satellite-measured solar wind and IMF (interplanetary magnetic field) data. The results were compared with corresponding geomagnetic and ionospheric data. The ionospheric data had been obtained by three GDR (German Democratic Republic) teams during the 21st, 22nd, and 23rd Soviet Antarctic Expeditions in the time period from 1976 to 1979. It was found that, in high latitudes, the properties of the solar wind exercise a pronounced degree of control on the precipitation of energetic particles into the atmosphere, taking into account a time delay of about one hour due to the occurrence of magnetospheric storage processes.
Hong, Seung Chan; Lee, Gunhee; Ha, Kyungyeon; Yoon, Jungjin; Ahn, Namyoung; Cho, Woohyung; Park, Mincheol; Choi, Mansoo
2017-03-08
Herein, we developed a novel electrospray coating system for continuous fabrication of perovskite solar cells with high performance. Our system can systemically control the size of CH 3 NH 3 PbI 3 precursor droplets by modulating the applied electrical potential, shown to be a crucial factor for the formation of perovskite films. As a result, we have obtained pinhole-free and large grain-sized perovskite solar cells, yielding the best PCE of 13.27% with little photocurrent hysteresis. Furthermore, the average PCE through the continuous coating process was 11.56 ± 0.52%. Our system demonstrates not only the high reproducibility but also a new way to commercialize high-quality perovskite solar cells.
Attractive manifold-based adaptive solar attitude control of satellites in elliptic orbits
Lee, Keum W.; Singh, Sahjendra N.
2011-01-01
The paper presents a novel noncertainty-equivalent adaptive (NCEA) control system for the pitch attitude control of satellites in elliptic orbits using solar radiation pressure (SRP). The satellite is equipped with two identical solar flaps to produce control moments. The adaptive law is based on the attractive manifold design using filtered signals for synthesis, which is a modification of the immersion and invariance (I&I) method. The control system has a modular controller-estimator structure and has separate tunable gains. A special feature of this NCEA law is that the trajectories of the satellite converge to a manifold in an extended state space, and the adaptive law recovers the performance of a deterministic controller. This recovery of performance cannot be obtained with certainty-equivalent adaptive (CEA) laws. Simulation results are presented which show that the NCEA law accomplishes precise attitude control of the satellite in an elliptic orbit, despite large parameter uncertainties.
Xu, Haiyuan; Zhong, Sihua; Zhuang, Yufeng; Shen, Wenzhong
2017-11-14
Nanoscale inverted pyramid structures (NIPs) have always been regarded as one of the most paramount light management schemes to achieve the extraordinary performance in various devices, especially in solar cells, due to their outstanding antireflection ability with relative lower surface enhancement ratio. However, the current approaches to fabricating the NIPs are complicated and not cost-effective for the massive cell production in the photovoltaic industry. Here, controllable NIPs are fabricated on crystalline silicon (c-Si) wafers by Ag catalyzed chemical etching and alkaline modification, which is a preferable all-solution-processed method. Through applying the NIPs to c-Si solar cells and optimizing the cell design, we have successfully achieved highly efficient NIPs textured solar cells with the champion efficiency of 20.5%. Importantly, the NIPs textured solar cells are further demonstrated to possess the quasi-omnidirectional property over the broad sunlight incident angles of approximately 0°-60°. Moreover, the NIPs are theoretically revealed to offer light trapping advantage for ultrathin c-Si solar cells. Hence, the NIPs formed by the controllable method exhibit a great potential to be used in the future photovoltaic industry as surface texture. © 2017 IOP Publishing Ltd.
Energy Technology Data Exchange (ETDEWEB)
Qazalbash, A.A.; Iqbal, T.; Shafiq, M.Z. [National Univ. of Sciences and Technology, Rawalpindi (Pakistan). Dept. of Electrical Engineering
2007-07-01
Photovoltaic (PV) solar arrays are particularly useful for electrical power generation in remote, off-grid areas in developing countries. However, PV arrays offer a small power to area ratio, resulting in the need for more PV arrays which increases the cost of the system. In order to improve the profitability of PV arrays, the power extraction from available PV array systems must be maximized. This paper presented an analysis, modeling and implementation of an efficient solar charge controller. It was shown that the maximum power of a photovoltaic system depends largely on temperature and insolation. A perturb and observe algorithm was used for maximum power point tracking (MPPT). MPPT maximizes the efficiency of a solar PV system. A solar charge controller determines the optimal values of output current and voltage of converters to maximize power output for battery charging. In order to improve performance and implement the perturb and observe algorithm, the authors designed a fuzzy rule-based system in which a solar charge controller worked with a PWM controlled DC-DC converter for battery charging. The system was implemented on a low-cost PIC microcontroller. Results were better than conventional techniques in power efficiency. Swift maximum power point tracking was obtained. 13 refs., 1 tab., 11 figs.
Optimal design and control of solar driven air gap membrane distillation desalination systems
International Nuclear Information System (INIS)
Chen, Yih-Hang; Li, Yu-Wei; Chang, Hsuan
2012-01-01
Highlights: ► Air gap membrane distillation unit was used in the desalination plants. ► Aspen Custom Molder was used to simulate each unit of desalination plants. ► Design parameters were investigated to obtain the minimum total annual cost. ► The control structure was proposed to operate desalination plants all day long. -- Abstract: A solar heated membrane distillation desalination system is constructed of solar collectors and membrane distillation devices for increasing pure water productivity. This technically and economically feasible system is designed to use indirect solar heat to drive membrane distillation processes to overcome the unstable supply of solar radiation from sunrise to sunset. The solar heated membrane distillation desalination system in the present study consisted of hot water storage devices, heat exchangers, air gap membrane distillation units, and solar collectors. Aspen Custom Molder (ACM) software was used to model and simulate each unit and establish the cost function of a desalination plant. From Design degree of freedom (DOF) analysis, ten design parameters were investigated to obtain the minimum total annual cost (TAC) with fixed pure water production rate. For a given solar energy density profile of typical summer weather, the minimal TAC per 1 m 3 pure water production can be found at 500 W/m 2 by varying the solar energy intensity. Therefore, we proposed two modes for controlling the optimal design condition of the desalination plant; day and night. In order to widen the operability range of the plant, the sensitivity analysis was used to retrofit the original design point to lower the effluent temperature from the solar collector by increasing the hot water recycled stream. The simulation results show that the pure water production can be maintained at a very stable level whether in sunny or cloudy weather.
Control of Power and Voltage of Solar Grid Connected
Allah, Boucetta Abd; Djamel, Labed
2016-01-01
Renewable energy is high on International agendas. Currently, grid-connected photovoltaic systems are a popular technology to convert solar energy into electricity. Control of power injected into the grid, maximum power point, high efficiency, and low total harmonic distortion of the currents injected into the grid are the requirements for inverter connection into the grid. Consequently, the performance of the inverters connected to the grid depends largely on the control strategy applied. In...
Energy Technology Data Exchange (ETDEWEB)
Adam, Mario; Lohmann, Sandra [Fachhochschule Duesseldorf (Germany). E2 - Erneuerbare Energien und Energieeffizienz
2011-05-15
The research project 'Solar cooling in the Hardware-in-the-Loop-Test' is funded by the BMBF and deals with the modeling of a pilot plant for solar cooling with the 17.5 kW absorption chiller of Yazaki in the simulation environment of MATLAB/ Simulink with the toolboxes Stateflow and CARNOT. Dynamic simulations and parameter variations according to the work-efficient methodology of design of experiments are used to select meaningful system configurations, control strategies and dimensioning of the components. The results of these simulations will be presented and a view of the use of acquired knowledge for the planned laboratory field tests on a hardware-in-the-loop test stand will be given. (orig.)
An Open Source Low-Cost Wireless Control System for a Forced Circulation Solar Plant.
Salamone, Francesco; Belussi, Lorenzo; Danza, Ludovico; Ghellere, Matteo; Meroni, Italo
2015-11-05
The article describes the design phase, development and practical application of a low-cost control system for a forced circulation solar plant in an outdoor test cell located near Milan. Such a system provides for the use of an electric pump for the circulation of heat transfer fluid connecting the solar thermal panel to the storage tank. The running plant temperatures are the fundamental parameter to evaluate the system performance such as proper operation, and the control and management system has to consider these parameters. A solar energy-powered wireless-based smart object was developed, able to monitor the running temperatures of a solar thermal system and aimed at moving beyond standard monitoring approaches to achieve a low-cost and customizable device, even in terms of installation in different environmental conditions. To this end, two types of communications were used: the first is a low-cost communication based on the ZigBee protocol used for control purposes, so that it can be customized according to specific needs, while the second is based on a Bluetooth protocol used for data display.
An Open Source Low-Cost Wireless Control System for a Forced Circulation Solar Plant
Directory of Open Access Journals (Sweden)
Francesco Salamone
2015-11-01
Full Text Available The article describes the design phase, development and practical application of a low-cost control system for a forced circulation solar plant in an outdoor test cell located near Milan. Such a system provides for the use of an electric pump for the circulation of heat transfer fluid connecting the solar thermal panel to the storage tank. The running plant temperatures are the fundamental parameter to evaluate the system performance such as proper operation, and the control and management system has to consider these parameters. A solar energy-powered wireless-based smart object was developed, able to monitor the running temperatures of a solar thermal system and aimed at moving beyond standard monitoring approaches to achieve a low-cost and customizable device, even in terms of installation in different environmental conditions. To this end, two types of communications were used: the first is a low-cost communication based on the ZigBee protocol used for control purposes, so that it can be customized according to specific needs, while the second is based on a Bluetooth protocol used for data display.
Visual operations control in administrative environments
Energy Technology Data Exchange (ETDEWEB)
Carson, M.L.; Levine, L.O.
1995-03-01
When asked what comes to mind when they think of ``controlling work`` in the office, people may respond with ``overbearing boss,`` ``no autonomy,`` or ``Theory X management.`` The idea of controlling work in white collar or administrative environments can have a negative connotation. However, office life is often chaotic and miserable precisely because the work processes are out of control, and managers must spend their time looking over people`s shoulders and fighting fires. While management styles and structures vary, the need for control of work processes does not. Workers in many environments are being reorganized into self-managed work teams. These teams are expected to manage their own work through increased autonomy and empowerment. However, even empowered work teams must manage their work processes because of process variation. The amount of incoming jobs vary with both expected (seasonal) and unexpected demand. The mixture of job types vary over time, changing the need for certain skills or knowledge. And illness and turnover affect the availability of workers with needed skills and knowledge. Clearly, there is still a need to control work, whether the authority for controlling work is vested in one person or many. Visual control concepts provide simple, inexpensive, and flexible mechanisms for managing processes in work teams and continuous improvement administrative environments.
Thermal performance of a double pane window with a solar control coating for warm climate of Mexico
International Nuclear Information System (INIS)
Xamán, J.; Jiménez-Xamán, C.; Álvarez, G.; Zavala-Guillén, I.; Hernández-Pérez, I.; Aguilar, J.O.
2016-01-01
Highlights: • Pseudo-transient thermal performance of a double pane window (DPW) was determined. • The DPW was analyzed each 5 s by a period from 8:00 to 18:00 h. • 57,600 computational runs were necessary and the additive correction multigrid was implemented. • Solar control coating (SCC) in a DPW reduces 1073.79 W/m 2 with respect to the DPW without SCC. • SCC is highly recommended in a DPW because it reduces a 53.88% of the amount of energy gained. - Abstract: The pseudo-transient thermal performance (each 5 s) of a double pane window without and with a solar control coating was determined numerically. The study considers warm climatic conditions (Mexico) and a period from 8:00 to 18:00 h. The effect of varying the indoor air temperature (15–30 °C); and the incident solar radiation and the outdoor air temperature as functions of time is analyzed. The simulations were done with a self-developed ForTran program and it was verified with results from the literature. To obtain the results, 57,600 computational runs were necessary. From the results, the double pane window with a solar control coating allows a smaller heat flux to enter into a room than the corresponding without a solar control coating. The solar control coating in double glass window reduces the amount of 1073.79 W h/m 2 with respect to the case without a solar control coating, which represents a reduction of 53.88% of the heat gain.
Virginia Solar Pathways Project Final Technical Report
Energy Technology Data Exchange (ETDEWEB)
Bond, Katharine; Cosby, Sarah
2018-03-28
This Report provides a technical review of the final results of a funding award to Virginia Electric and Power Company (Dominion Energy Virginia (DEV) or the Company) for a project under the U.S. Department of Energy’s Solar Energy Technologies Office. The three-year project was formally known as the Virginia Solar Pathways Project (VSPP or the Project). The purpose of the VSPP was to develop a collaborative utility-administered solar strategy (Solar Strategy) for DEV’s service territory in the Commonwealth that could serve as a replicable model for other states with similar policy environments. The U.S. Department of Energy (DOE) funding award enabled DEV to take a focused approach to developing the Solar Strategy for its Virginia service territory. The structure and funding from the DOE award also facilitated valuable input from a formal stakeholder team convened to serve as advisors (Advisory Team) to the VSPP and contribute their perspectives and expertise to both the analysis and strategy development aspects of the Project. The development of the Solar Strategy involved three main goals: • Establish a policy and program framework that would integrate existing solar programs with new options appropriate for the Commonwealth’s policy environment and broader economic development objectives; • Promote wider deployment of solar within a low retail electric rate environment; and • Serve as a sustainable, utility-administered solar model that could be replicated in other states with similar policy environments, including, but not limited to, the entire Southeast region. In support of the VSPP goals, the Project Team commissioned four studies to support the Solar Strategy development. Two studies, completed by Navigant Consulting, focused on the integration of solar into the electric grid. The first solar integration study focused on integration of solar into the distribution grid where the utility system directly connects to and serves end-use customers
Integrated control algorithms for plant environment in greenhouse
Zhang, Kanyu; Deng, Lujuan; Gong, Youmin; Wang, Shengxue
2003-09-01
In this paper a survey of plant environment control in artificial greenhouse was put forward for discussing the future development. Firstly, plant environment control started with the closed loop control of air temperature in greenhouse. With the emergence of higher property computer, the adaptive control algorithm and system identification were integrated into the control system. As adaptation control is more depending on observation of variables by sensors and yet many variables are unobservable or difficult to observe, especially for observation of crop growth status, so model-based control algorithm were developed. In order to evade modeling difficulty, one method is predigesting the models and the other method is utilizing fuzzy logic and neural network technology that realize the models by the black box and gray box theory. Studies on control method of plant environment in greenhouse by means of expert system (ES) and artificial intelligence (AI) have been initiated and developed. Nowadays, the research of greenhouse environment control focus on energy saving, optimal economic profit, enviornment protection and continualy develop.
Decoherence control in different environments
International Nuclear Information System (INIS)
Paavola, J.; Maniscalco, S.
2010-01-01
We investigate two techniques for controlling decoherence, focusing on the crucial role played by the environmental spectrum. We show how environments with different spectra lead to very different dynamical behaviors. Our study clearly proves that such differences must be taken into account when designing decoherence control schemes. The two techniques we consider are reservoir engineering and quantum Zeno control. We focus on a quantum harmonic oscillator initially prepared in a nonclassical state and derive analytically its non-Markovian dynamics in the presence of different bosonic thermal environments. On the one hand, we show how, by modifying the spectrum of the environment, it is possible to prolong or reduce the life of a Schroedinger cat state. On the other hand, we study the effect of nonselective energy measurements on the degradation of quantumness of initial Fock states. In this latter case, we see that the crossover between quantum Zeno and anti-Zeno effects, discussed by Maniscalco et al. [Phys. Rev. Lett. 97, 130402 (2006)], is highly sensitive to the details of the spectrum. In particular, for certain types of spectra, even very small variations of the system frequency may cause a measurement-induced acceleration of decoherence rather than its inhibition.
International Nuclear Information System (INIS)
Islam, S.; Huda, A.-U.
1999-01-01
The only really sustainable form of energy is solar energy. The densely populated tropical countries can do very well from this completely sustainable energy source without any novel technologies. Most of the commercial energy used worldwide is supplied by using non-renewable resources. Environmental damage - global warming, ozone hole, noise, chemical and radioactive waste - is due to high energy use. Environmental deterioration is a direct consequence of wealth generated and sustained by extremely cheap fossil fuel. The price of fossil fuel does not include the cost for the deterioration of the environment. We show in this paper that even a densely populated country like Bangladesh can attain a high standard of living by a proper utilization of solar energy. We suggest that poor tropical countries should mobilize their resources to develop solar technology. (author)
Energy Technology Data Exchange (ETDEWEB)
Islam, S.; Huda, A.-U. [University of Dhaka (Bangladesh). Physics Dept.
1999-06-01
The only really sustainable form of energy is solar energy. The densely populated tropical countries can do very well from this completely sustainable energy source without any novel technologies. Most of the commercial energy used worldwide is supplied by using non-renewable resources. Environmental damage - global warming, ozone hole, noise, chemical and radioactive waste - is due to high energy use. Environmental deterioration is a direct consequence of wealth generated and sustained by extremely cheap fossil fuel. The price of fossil fuel does not include the cost for the deterioration of the environment. We show in this paper that even a densely populated country like Bangladesh can attain a high standard of living by a proper utilization of solar energy. We suggest that poor tropical countries should mobilize their resources to develop solar technology. (author)
DOOCS environment for FPGA-based cavity control system and control algorithms development
International Nuclear Information System (INIS)
Pucyk, P.; Koprek, W.; Kaleta, P.; Szewinski, J.; Pozniak, K.T.; Czarski, T.; Romaniuk, R.S.
2005-01-01
The paper describes the concept and realization of the DOOCS control software for FPGAbased TESLA cavity controller and simulator (SIMCON). It bases on universal software components, created for laboratory purposes and used in MATLAB based control environment. These modules have been recently adapted to the DOOCS environment to ensure a unified software to hardware communication model. The presented solution can be also used as a general platform for control algorithms development. The proposed interfaces between MATLAB and DOOCS modules allow to check the developed algorithm in the operation environment before implementation in the FPGA. As the examples two systems have been presented. (orig.)
An operating environment for control systems on transputer networks
Tillema, H.G.; Schoute, Albert L.; Wijbrans, K.C.J.; Wijbrans, K.C.J.
1991-01-01
The article describes an operating environment for control systems. The environment contains the basic layers of a distributed operating system. The design of this operating environment is based on the requirements demanded by controllers which can be found in complex control systems. Due to the
Efficient Lightweight AC-AC Power Control for Solar UAV, Phase I
National Aeronautics and Space Administration — A highly efficient and lightweight dual bridge matrix power controller development is proposed that will provide high performance to a solar powered high altitude...
Characterization of multicrystalline solar cells
International Nuclear Information System (INIS)
Malik, A.Q.; Chong Chew Hah; Chan Siang Khwang; Tan Kha Sheng; Lim Chee Ming
2006-01-01
The evaluation and assessment of the performance of photovoltaic (PV) cells in terms of measurable parameters requires the measurement of the current as a function of voltage, temperature, intensity, wind speed and spectrum. Most noticeable of all these parameters in the PV conversion efficiency η, defined as the maximum electrical power P max produced by the PV cell divided by the incident photon power P in which is measured with respect to standard test conditions (Sc). These conditions refer to the spectrum (AM 1.5), solar radiation intensity (1000 Wm -2 ), cell temperature (25 ± 2 degree C) and wind speed (2 mph). Tests under STC are carried out in the laboratory at a controlled environment. There have been several studies that analyze uncertainties in the laboratory measurement of solar cell efficiencies using different solar simulators and their transference to operational situations. Our preliminary results demonstrate that the short circuit current (I SC ) of the solar cell decreases when irradiance is less than 1000 Wm -2 irrespective of the working temperature of the cell
Characterisation of multicrystalline solar cells
Directory of Open Access Journals (Sweden)
A.Q. Malik
2017-10-01
Full Text Available The evaluation and assessment of the performance of photovoltaic (PV cells in terms of measurable parameters requires the measurement of the current as a function of voltage, temperature, intensity, wind speed and spectrum. Mo st noticeable of all these parameters is the PV conversion efficiency η, defined as the maximum electrical power Pmax produced by the PV cell divided by the incident photon power P in which is measured with respect to standard test conditions (STC. These conditions refer to the spectrum (AM 1.5, solar radiation intensity (1000 Wm-2, cell temperature (25 ±2oC and wind speed (2 mph. Tests under STC are carried out in the laboratory at a controlled environment. There have been several studies that analyze uncertainties in the laboratory measurement of solar cell efficiencies using different solar simulators and their transference to operational situations. Our preliminary results demonstratethat the short circuit current (ISC of the solar cell decreases when irradiance is less than 1000 Wm-2 irrespective of the working temperature of the cell.
Implementation of FPGA-Based Charge Control for a Self-Sufficient Solar Tracking Power Supply System
Directory of Open Access Journals (Sweden)
Jui-Ho Chen
2016-02-01
Full Text Available This study used a field-programmable gate array (FPGA with a Xilinx Spartan-3 FPGA to implement Reflex charge control in a dual-axis solar tracking system with maximum power point tracking (MPPT. The chaos embedded particle swarm optimization method was used to search for the optimum gain constants of the PI controller and the Reflex charging frequency. This scheme not only increases the output power of solar panels but also has a significant effect on switching loss and oscillation of solar charging. The experiment results showed that the proposed method can also significantly improve temperature rise, and that charging efficiency is also better than it is in a traditional charge mode. The results also showed that charging power was enough for solar tracking and the requirements of the charging system. The most significant contribution of this paper is that the scheme can be applied to any active solar tracking and charging system.
Optimal control and performance test of solar-assisted cooling system
Huang, B.J.
2010-10-01
The solar-assisted cooling system (SACH) was developed in the present study. The ejector cooling system (ECS) is driven by solar heat and connected in parallel with an inverter-type air conditioner (A/C). The cooling load can be supplied by the ECS when solar energy is available and the input power of the A/C can be reduced. In variable weather, the ECS will probably operate at off-design condition of ejector and the cooling capability of the ECS can be lost completely. In order to make the ejector operate at critical or non-critical double-choking condition to obtain a better performance, an electronic expansion valve was installed in the suction line of the ejector to regulate the opening of the expansion valve to control the evaporator temperature. This will make the SACH always produce cooling effect even at lower solar radiation periods while the ejector performs at off-design conditions. The energy saving of A/C is experimentally shown 50-70% due to the cooling performance of ECS. The long-term performance test results show that the daily energy saving is around 30-70% as compared to the energy consumption of A/C alone (without solar-driven ECS). The total energy saving of A/C is 52% over the entire test period. © 2010 Elsevier Ltd. All rights reserved.
Control oriented concentrating solar power (CSP) plant model and its applications
Luo, Qi
Solar receivers in concentrating solar thermal power plants (CSP) undergo over 10,000 start-ups and shutdowns, and over 25,000 rapid rate of change in temperature on receivers due to cloud transients resulting in performance degradation and material fatigue in their expected lifetime of over 30 years. The research proposes to develop a three-level controller that uses multi-input-multi-output (MIMO) control technology to minimize the effect of these disturbances, improve plant performance, and extend plant life. The controller can be readily installed on any vendor supplied state-of-the-art control hardware. We propose a three-level controller architecture using multi-input-multi-output (MIMO) control for CSP plants that can be implemented on existing plants to improve performance, reliability, and extend the life of the plant. This architecture optimizes the performance on multiple time scalesreactive level (regulation to temperature set points), tactical level (adaptation of temperature set points), and strategic level (trading off fatigue life due to thermal cycling and current production). This controller unique to CSP plants operating at temperatures greater than 550 °C, will make CSPs competitive with conventional power plants and contribute significantly towards the Sunshot goal of 0.06/kWh(e), while responding with agility to both market dynamics and changes in solar irradiance such as due to passing clouds. Moreover, our development of control software with performance guarantees will avoid early stage failures and permit smooth grid integration of the CSP power plants. The proposed controller can be implemented with existing control hardware infrastructure with little or no additional equipment. In the thesis, we demonstrate a dynamics model of CSP, of which different components are modelled with different time scales. We also show a real time control strategy of CSP control oriented model in steady state. Furthermore, we shown different controllers
Parental Low Self-Control, Family Environments, and Juvenile Delinquency.
Meldrum, Ryan C; Connolly, George M; Flexon, Jamie; Guerette, Rob T
2016-10-01
Research consistently finds that low self-control is significantly correlated with delinquency. Only recently, however, have researchers started to examine associations between parental low self-control, family environments, and child antisocial behavior. Adding to this emerging area of research, the current study examines associations between parental low self-control, aspects of the family environment, and officially recoded juvenile delinquency among a sample (N = 101) of juveniles processed through a juvenile justice assessment facility located in the Southeastern United States. Furthermore, it considers whether aspects of family environments, particularly family cohesion, family conflict, and parental efficacy, mediate the influence of parental low self-control on delinquency. The results of a series of analyses indicate that parental low self-control is correlated with various aspects of family environments and juvenile delinquency, and that the association between parental low self-control and juvenile delinquency is mediated by family environments. Supplementary analyses also suggest that the association between parental low self-control and the family environment may be reciprocal. © The Author(s) 2015.
Solar Sail Propulsion Technology at NASA
Johnson, Charles Les
2007-01-01
NASA's In-Space Propulsion Technology Program developed the first generation of solar sail propulsion systems sufficient to accomplish inner solar system science and exploration missions. These first generation solar sails, when operational, will range in size from 40 meters to well over 100 meters in diameter and have an area density of less than 13 grams per square meter. A rigorous, multi-year technology development effort culminated in 2005 with the testing of two different 20-m solar sail systems under thermal vacuum conditions. This effort provided a number of significant insights into the optimal design and expected performance of solar sails as well as an understanding of the methods and costs of building and using them. In addition, solar sail orbital analysis tools for mission design were developed and tested. Laboratory simulations of the effects of long-term space radiation exposure were also conducted on two candidate solar sail materials. Detailed radiation and charging environments were defined for mission trajectories outside the protection of the earth's magnetosphere, in the solar wind environment. These were used in other analytical tools to prove the adequacy of sail design features for accommodating the harsh space environment. The presentation will describe the status of solar sail propulsion within NASA, near-term solar sail mission applications, and near-term plans for further development.
Fuzzy Approximate Model for Distributed Thermal Solar Collectors Control
Elmetennani, Shahrazed
2014-07-01
This paper deals with the problem of controlling concentrated solar collectors where the objective consists of making the outlet temperature of the collector tracking a desired reference. The performance of the novel approximate model based on fuzzy theory, which has been introduced by the authors in [1], is evaluated comparing to other methods in the literature. The proposed approximation is a low order state representation derived from the physical distributed model. It reproduces the temperature transfer dynamics through the collectors accurately and allows the simplification of the control design. Simulation results show interesting performance of the proposed controller.
How solar energy and electrochemical technologies may help developing countries and the environment
International Nuclear Information System (INIS)
Marini, S.; Strada, C.; Villa, M.; Berrettoni, M.; Zerlia, T.
2014-01-01
Highlights: • The failure of large scale solar/hydrogen projects in developing countries is analyzed. • Controlling the pH of Oceans with a solar chloralkali process is found too costly. • A zero-emission chloralkali plant in Sahara may compete with polluting EU plants. • A new process of syngas + Cl 2 production from CO 2 + HCl may have “negative emissions”. - Abstract: The policies of curbing CO 2 emissions have worked poorly on a global scale and an economically sound proposal of bringing electric power to Europe from an Algerian solar hub has just been dismissed. With reference to the Algerian – European relationships, we analyze the broad context where an environmental policy benefitting both developing and developed countries can be put in place. We then discuss the connection between anthropogenic CO 2 emissions and acidification of Oceans along with a geo-engineering proposal aimed at solving these pressing problems with large-scale solar-powered chloralkali plants. While the cost of sequestering a ton of CO 2 with dedicated chloralkali plants is unacceptably high, it is economically and environmentally sound to replace an existing European Cl 2 plant (consuming fossils) with a solar-powered plant in Algeria. If the Algerian plant uses a new, more efficient chloralkali process, it will be competitive with existing European plants even at the current low market value of the carbon emission credits. We finally explore the possibility of coupling Cl 2 production with CO 2 reuse and syngas production through a novel electrochemical process
Model predictive control for a smart solar tank based on weather and consumption forecasts
DEFF Research Database (Denmark)
Halvgaard, Rasmus; Bacher, Peder; Perers, Bengt
2012-01-01
In this work the heat dynamics of a storage tank were modelled on the basis of data and maximum likelihood methods. The resulting grey-box model was used for Economic Model Predictive Control (MPC) of the energy in the tank. The control objective was to balance the energy from a solar collector...... and the heat consumption in a residential house. The storage tank provides heat in periods where there is low solar radiation and stores heat when there is surplus solar heat. The forecasts of consumption patterns were based on data obtained from meters in a group of single-family houses in Denmark. The tank...... can also be heated by electric heating elements if necessary, but the electricity costs of operating these heating elements should be minimized. Consequently, the heating elements should be used in periods with cheap electricity. It is proposed to integrate a price-sensitive control to enable...
Kim, D.S.
2007-01-01
As the world concerns more and more on global climate changes and depleting energy resources, solar cooling technology receives increasing interests from the public as an environment-friendly and sustainable alternative. However, making a competitive solar cooling machine for the market still
Singular formalism and admissible control of spacecraft with rotating flexible solar array
Directory of Open Access Journals (Sweden)
Lu Dongning
2014-02-01
Full Text Available This paper is concerned with the attitude control of a three-axis-stabilized spacecraft which consists of a central rigid body and a flexible sun-tracking solar array driven by a solar array drive assembly. Based on the linearization of the dynamics of the spacecraft and the modal identities about the flexible and rigid coupling matrices, the spacecraft attitude dynamics is reduced to a formally singular system with periodically varying parameters, which is quite different from a spacecraft with fixed appendages. In the framework of the singular control theory, the regularity and impulse-freeness of the singular system is analyzed and then admissible attitude controllers are designed by Lyapunov’s method. To improve the robustness against system uncertainties, an H∞ optimal control is designed by optimizing the H∞ norm of the system transfer function matrix. Comparative numerical experiments are performed to verify the theoretical results.
Directory of Open Access Journals (Sweden)
N. J. T. Edberg
2009-12-01
Full Text Available We report on new simultaneous in-situ observations at Mars from Rosetta and Mars Express (MEX on how the Martian plasma environment is affected by high pressure solar wind. A significant sharp increase in solar wind density, magnetic field strength and turbulence followed by a gradual increase in solar wind velocity is observed during ~24 h in the combined data set from both spacecraft after Rosetta's closest approach to Mars on 25 February 2007. The bow shock and magnetic pileup boundary are coincidently observed by MEX to become asymmetric in their shapes. The fortunate orbit of MEX at this time allows a study of the inbound boundary crossings on one side of the planet and the outbound crossings on almost the opposite side, both very close to the terminator plane. The solar wind and interplanetary magnetic field (IMF downstream of Mars are monitored through simultaneous measurements provided by Rosetta. Possible explanations for the asymmetries are discussed, such as crustal magnetic fields and IMF direction. In the same interval, during the high solar wind pressure pulse, MEX observations show an increased amount of escaping planetary ions from the polar region of Mars. We link the high pressure solar wind with the observed simultaneous ion outflow and discuss how the pressure pulse could also be associated with the observed boundary shape asymmetry.
Design and implementation of adaptive cruise control system for the TU/e solar powered electric car
Papaliouras, I.
2016-01-01
The technical report presents the design and implementation of Adaptive Cruise Control. (ACC) system for the “Stella Lux” solar powered electric car, which was built by Solar Team Eindhoven and won the World Solar Challenge in Australia in 2015. Initially, an over-view of the context of the project
Solar thermal power: the seamless solar link to the conventional power world
International Nuclear Information System (INIS)
Geyer, Michael; Quaschning, Volker
2000-01-01
This article focuses on solar thermal power generation and describes two solar thermal power concepts, namely, the parabolic trough or solar farm, and the solar central receiver or power tower. Details are given of grid-connected parabolic trough power plants in California and recent developments in collector design and absorber tubes, and the operation of power tower plants with different heat transfer media. Market issues are discussed, and solar thermal power projects under development, and application for support for solar thermal power projects under the Global Environment Facility's Operational Programme by Egypt, India, Iran, Mexico and Morocco are reported
Comparison of two temperature control techniques in a forced water heater solar system
Hernández, E.; E Guzmán, R.; Santos, A.; Cordoba, E.
2017-12-01
a study on the performance of a forced solar heating system in which a comparative analysis of two control strategies, including the classic on-off control and PID control is presented. From the experimental results it was found that the two control strategies show a similar behaviour in the solar heating system forced an approximate settling time of 60 min and over-elongation 2°C for the two control strategies. Furthermore, the maximum temperature in the storage tank was 46°C and the maximum efficiency of flat plate collector was 76.7% given that this efficiency is the ratio of the energy of the radiation on the collector and the energy used to heat water. The efficiency obtained is a fact well accepted because the business efficiencies of flat plate collectors are approximately 70%.
A methodology for sunlight urban planning: a computer-based solar and sky vault obstruction analysis
Energy Technology Data Exchange (ETDEWEB)
Pereira, Fernando Oscar Ruttkay; Silva, Carlos Alejandro Nome [Federal Univ. of Santa Catarina (UFSC), Dept. of Architecture and Urbanism, Florianopolis, SC (Brazil); Turkienikz, Benamy [Federal Univ. of Rio Grande do Sul (UFRGS), Faculty of Architecture, Porto Alegre, RS (Brazil)
2001-07-01
The main purpose of the present study is to describe a planning methodology to improve the quality of the built environment based on the rational control of solar radiation and the view of the sky vault. The main criterion used to control the access and obstruction of solar radiation was the concept of desirability and undesirability of solar radiation. A case study for implementing the proposed methodology is developed. Although needing further developments to find its way into regulations and practical applications, the methodology has shown a strong potential to deal with an aspect that otherwise would be almost impossible. (Author)
Croley, D. R.; Garrett, H. B.; Murphy, G. B.; Garrard,T. L.
1995-01-01
The three large solar particle events, beginning on October 19, 1989 and lasting approximately six days, were characterized by high fluences of solar protons and heavy ions at 1 AU. During these events, an abnormally large number of upsets (243) were observed in the random access memory of the attitude control system (ACS) control processing electronics (CPE) on-board the geosynchronous TDRS-1 (Telemetry and Data Relay Satellite). The RAM unit affected was composed of eight Fairchild 93L422 memory chips. The Galileo spacecraft, launched on October 18, 1989 (one day prior to the solar particle events) observed the fluxes of heavy ions experienced by TDRS-1. Two solid-state detector telescopes on-board Galileo, designed to measure heavy ion species and energy, were turned on during time periods within each of the three separate events. The heavy ion data have been modeled and the time history of the events reconstructed to estimate heavy ion fluences. These fluences were converted to effective LET spectra after transport through the estimated shielding distribution around the TDRS-1 ACS system. The number of single event upsets (SEU) expected was calculated by integrating the measured cross section for the Fairchild 93L422 memory chip with average effective LET spectrum. The expected number of heavy ion induced SEU's calculated was 176. GOES-7 proton data, observed during the solar particle events, were used to estimate the number of proton-induced SEU's by integrating the proton fluence spectrum incident on the memory chips, with the two-parameter Bendel cross section for proton SEU'S. The proton fluence spectrum at the device level was gotten by transporting the protons through the estimated shielding distribution. The number of calculated proton-induced SEU's was 72, yielding a total of 248 predicted SEU'S, very dose to the 243 observed SEU'S. These calculations uniquely demonstrate the roles that solar heavy ions and protons played in the production of SEU
Solar Powered Remediation and pH Control
2017-04-13
zone. The PRT system was completely powered via an off-the-grid solar power system . The system consisted of four 85 watt photovoltaic solar panels...polarity of the proton reduction system can be periodically alternated (i.e., the anode becomes a cathode) to increase the size of the treatment area, to...PRT System The PRT system was completely powered via an off-the-grid solar power system . The system consisted of four 85 watt photovoltaic solar
Simulation model of ANN based maximum power point tracking controller for solar PV system
Energy Technology Data Exchange (ETDEWEB)
Rai, Anil K.; Singh, Bhupal [Department of Electrical and Electronics Engineering, Ajay Kumar Garg Engineering College, Ghaziabad 201009 (India); Kaushika, N.D.; Agarwal, Niti [School of Research and Development, Bharati Vidyapeeth College of Engineering, A-4 Paschim Vihar, New Delhi 110063 (India)
2011-02-15
In this paper the simulation model of an artificial neural network (ANN) based maximum power point tracking controller has been developed. The controller consists of an ANN tracker and the optimal control unit. The ANN tracker estimates the voltages and currents corresponding to a maximum power delivered by solar PV (photovoltaic) array for variable cell temperature and solar radiation. The cell temperature is considered as a function of ambient air temperature, wind speed and solar radiation. The tracker is trained employing a set of 124 patterns using the back propagation algorithm. The mean square error of tracker output and target values is set to be of the order of 10{sup -5} and the successful convergent of learning process takes 1281 epochs. The accuracy of the ANN tracker has been validated by employing different test data sets. The control unit uses the estimates of the ANN tracker to adjust the duty cycle of the chopper to optimum value needed for maximum power transfer to the specified load. (author)
Energy Technology Data Exchange (ETDEWEB)
Caldwell, M.M.; Flint, S.D. [Utah State Univ., Logan, UT (United States)
1994-12-31
This essay will consider both physical and photobiological aspects of controlled environment lighting in the spectral region beginning in the blue and taken to the normal limit of the solar spectrum in the ultraviolet. The primary emphasis is directed to questions of plant response to sunlight. Measurement and computations used in radiation dosimetry in this part of the spectrum are also briefly treated. Because of interest in the ozone depletion problem, there has been some activity in plant UV-B research and there are several recent reviews available. Some aspects of growth chamber lighting as it relates to UV-B research were covered earlier. Apart from work related to the blue/UV-A receptor, less attention has been given to UV-A responses.
Chetty, S.; Field, L. A.
2013-12-01
The Arctic ocean's continuing decrease of summer-time ice is related to rapidly diminishing multi-year ice due to the effects of climate change. Ice911 Research aims to develop environmentally respectful materials that when deployed will increase the albedo, enhancing the formation and/preservation of multi-year ice. Small scale deployments using various materials have been done in Canada, California's Sierra Nevada Mountains and a pond in Minnesota to test the albedo performance and environmental characteristics of these materials. SWIMS is a sophisticated autonomous sensor system being developed to measure the albedo, weather, water temperature and other environmental parameters. The system (SWIMS) employs low cost, high accuracy/precision sensors, high resolution cameras, and an extreme environment command and data handling computer system using satellite and terrestrial wireless communication. The entire system is solar powered with redundant battery backup on a floating buoy platform engineered for low temperature (-40C) and high wind conditions. The system also incorporates tilt sensors, sonar based ice thickness sensors and a weather station. To keep the costs low, each SWIMS unit measures incoming and reflected radiation from the four quadrants around the buoy. This allows data from four sets of sensors, cameras, weather station, water temperature probe to be collected and transmitted by a single on-board solar powered computer. This presentation covers the technical, logistical and cost challenges in designing, developing and deploying these stations in remote, extreme environments. Image captured by camera #3 of setting sun on the SWIMS station One of the images captured by SWIMS Camera #4
Solar control on irradiated Ta2O2 thin films
International Nuclear Information System (INIS)
Baydogan, N. D.; Zayim, E. Oe.
2007-01-01
coefficient is related to the colour centres, which are both present as intrinsic defects in structure and created induced defects by irradiation. The optical absorption bands were investigated depending on the gamma and beta irradiation. The changes of solar properties on irradiated Ta 2 O 5 films are associated with the formation of defect centers and radiolytic electrons or holes. Under irradiation, the defects centers are formed as a result of charge trapping by radiolytic electrons or holes. It can be said that the control of solar energy is possible while the shading coefficient decreases in the irradiation condition
Energy Technology Data Exchange (ETDEWEB)
Saravia, Maricela; Morillon Galvez, David [Instituto de Ingenieria, UNAM, Mexico, D. F. (Mexico)
1999-07-01
A bioclimatic study of El Salvador is presented, with the purpose of using window eaves as elements of passive solar control and to determine the optimal angles of orientation, in order to diminish the thermal gains by direct solar radiation and to manage to get close to the comfort conditions. The former with the intention of integrating measures that help to obtain energy efficiency and comfortable buildings, for the conditions of warm humid climate, characteristic of a Central American country like El Salvador. Besides offering a document of consultation among the professionals dedicated to the design and as base of bioclimatic considerations that must have the construction regulations. As a conclusion the optimal angles of eaves for each orientation are presented and a quantitative estimation of the savings that would imply not to consume electrical energy in cooling systems using these elements as a protection to the direct solar radiation. [Spanish] Se presenta un estudio del bioclima de El Salvador, con el fin de utilizar aleros de ventana como elementos de control solar pasivo y determinar los angulos optimos por orientacion, para disminuir las ganancias termicas por radiacion solar directa y lograr acercar a las condiciones de confort. Lo anterior con el objeto de integrar medidas que coadyuven a lograr edificios energeticamente eficientes y confortables, para las condiciones de clima calido humedo, caracteristico de un pais centroamericano como El Salvador. Ademas de brindar un documento de consulta entre los profesionales dedicados al dise y como base de consideraciones bioclimaticas que debe tener el reglamento de construcciones. Como conclusion se presentan los angulos optimos de alero por cada orientacion y una estimacion cuantitativa del ahorro que implicaria el no consumir energia electrica en sistemas de enfriamiento utilizando estos elementos como una proteccion a la radiacion solar directa.
Institute of Scientific and Technical Information of China (English)
Hua ZHU; Zhang-lu XU; Zi-juan CAO
2011-01-01
The charging characteristics of the valve-regulated lead acid (VRLA) battery driven by solar energy were experimentally studied through the pressure-control method in this paper. The aims of the research were to increase charging efficiency to make the most of solar energy and to improve charging quality to prolong life of battery. The charging process of a 12 V 12 A.h VRLA battery has been tested under the mode of a stand-alone photovoltaic (PV) system. Results show that the pressure-control method can effectively control PV charging of the VRLA battery and make the best of PV cells through the maximum power point tracking (MPPT). The damage of VRLA battery by excess oxygen accumulation can be avoided through the inner pressure control of VRLA battery. Parameters such as solar radiation intensity, charging power, inner pressure of the battery, and charging current and voltage during the charging process were measured and analyzed.
Electrodeposition of organic-inorganic tri-halide perovskites solar cell
Charles, U. A.; Ibrahim, M. A.; Teridi, M. A. M.
2018-02-01
Perovskite (CH3NH3PbI3) semiconductor materials are promising high-performance light energy absorber for solar cell application. However, the power conversion efficiency of perovskite solar cell is severely affected by the surface quality of the deposited thin film. Spin coating is a low-cost and widely used deposition technique for perovskite solar cell. Notably, film deposited by spin coating evolves surface hydroxide and defeats from uncontrolled precipitation and inter-diffusion reaction. Alternatively, vapor deposition (VD) method produces uniform thin film but requires precise control of complex thermodynamic parameters which makes the technique unsuitable for large scale production. Most deposition techniques for perovskite require tedious surface optimization to improve the surface quality of deposits. Optimization of perovskite surface is necessary to significantly improve device structure and electrical output. In this review, electrodeposition of perovskite solar cell is demonstrated as a scalable and reproducible technique to fabricate uniform and smooth thin film surface that circumvents the need for high vacuum environment. Electrodeposition is achieved at low temperatures, supports precise control and optimization of deposits for efficient charge transfer.
Experimental study of a combined system of solar Kang and solar air collector
International Nuclear Information System (INIS)
Wei, Wei; Ji, Jie; Chow, Tin-Tai; He, Wei; Chen, Haifei; Guo, Chao; Yu, Hancheng
2015-01-01
Highlights: • A combined system of solar Kang and solar air collector is proposed. • An experimental study on the combined system is made. • The mean air temperature reaches 18.5 °C and maintains above 18 °C for 13 h. • The corresponding mean indoor air temperature of the reference room is 8.9 °C. • The Kang surface temperature reaches 27 °C and maintains above 18 °C for 23 h. - Abstract: Chinese Kang is widely used as heated bed and for heat recovery of cooking stove in Northern China. However there are main drawbacks of indoor and outdoor air pollutant generation and heavy demands on solid fuel handling. A novel combined Kang system, which integrates solar Kang and solar air collector, is here proposed. Experiments were conducted to examine the alternative operating modes: (i) only solar air collector in service, (ii) only solar Kang in service, and (iii) both solar Kang and solar air collector in service. The results show that these three modes behave differently and have distinct effects on room thermal environment in winter. When this pollution-free system operates under the third combined mode, the room temperature increases significantly and the vertical temperature gradient reduces. The Kang surface temperature increases and its uniformity is improved. It is also found that the room air temperature is closely related to the Kang surface temperature. Furthermore, most of the time the thermal environment meets the occupant need. This paper reports the experimental work and investigates into the effects on indoor thermal environment as in rural residences in Northern China
Solar cooling in the hardware-in-the-loop test; Solare Kuehlung im Hardware-in-the-Loop-Test
Energy Technology Data Exchange (ETDEWEB)
Lohmann, Sandra; Radosavljevic, Rada; Goebel, Johannes; Gottschald, Jonas; Adam, Mario [Fachhochschule Duesseldorf (Germany). Erneuerbare Energien und Energieeffizienz E2
2012-07-01
The first part of the BMBF-funded research project 'Solar cooling in the hardware-in-the-loop test' (SoCool HIL) deals with the simulation of a solar refrigeration system using the simulation environment Matlab / Simulink with the toolboxes Stateflow and Carnot. Dynamic annual simulations and DoE supported parameter variations were used to select meaningful system configurations, control strategies and dimensioning of components. The second part of this project deals with hardware-in-the-loop tests using the 17.5 kW absorption chiller of the company Yazaki Europe Limited (Hertfordshire, United Kingdom). For this, the chiller is operated on a test bench in order to emulate the behavior of other system components (solar circuit with heat storage, recooling, buildings and cooling distribution / transfer). The chiller is controlled by a simulation of the system using MATLAB / Simulink / Carnot. Based on the knowledge on the real dynamic performance of the chiller the simulation model of the chiller can then be validated. Further tests are used to optimize the control of the chiller to the current cooling load. In addition, some changes in system configurations (for example cold backup) are tested with the real machine. The results of these tests and the findings on the dynamic performance of the chiller are presented.
Liu, Quanhua
2014-01-01
Energy and environmental issues are among the most important problems of public concern. Wind and solar energy may be one of the alternative solutions to overcome energy shortage and to reduce greenhouse gaseous emission. Using electric cars in cities can significantly improve the air quality there. Through our analyses and modeling on the basis of the National Centers for Environment Prediction data we confirm that the amount of usable solar and wind energy far exceeds the world's total energy demand, considering the feasibility of the technology being used. Storing the surplus solar and wind energy and then releasing this surplus on demand is an important approach to maintaining uninterrupted solar- and wind-generated electricity. This approach requires us to be aware of the available solar and wind energy in advance in order to manage their storage. Solar and wind energy depends on weather conditions and we know weather forecasting. This implies that solar and wind energy is predictable. In this article, we demonstrate how solar and wind energy can be forecasted. We provide a web tool that can be used by all to arrive at solar and wind energy amount at any location in the world. The tool is available at http://www.renewableenergyst.org. The website also provides additional information on renewable energy, which is useful to a wide range of audiences, including students, educators, and the general public.
Directory of Open Access Journals (Sweden)
Layachi ZAGHBA
2017-12-01
Full Text Available In this study, is to investigate the effect of real climatic conditions on the performance parameters of a 9 kWp grid connected photovoltaic plant during one-year using typical days installed in the desert environment in south of Algeria (Ghardaia site. The PV plant contain the following components: solar PV array, with a DC/DC boost converter, neural MPPT, that allow maximal power conversion into the grid, have been included. These methods can extract maximum power from each of the independent PV arrays connected to DC link voltage level, a DC/AC inverter and a PI current control system. The PV array is divides in two parallel PV technology types; the first includes 100 PV modules mono-crystalline silicon (mc-Si arranged in 20 parallel groups of 5 modules in series, and the second of composed of 24 amorphous modules (Inventux X series, arranged in 6 parallel groups of 4 modules in series. The proposed system tested using MATLAB/SIMULINK platform in which a maximum power tracked under constant and real varying solar irradiance. The study concluded that output power and energy from two PV technology types (mc-Si and Amorphous-Si increases linearly with increase of solar irradiance.
Effects of the solar-terrestrial environment on satellite operations
International Nuclear Information System (INIS)
Baker, D.N.
1984-01-01
Hot plasma and energetic particle populations in space are known to produce spacecraft operational anomalies. In the inner part of the earth's magnetosphere, these effects are primarily due to durably trapped radiation belt particles, and the integrated doses can be calculated quite accurately for any given orbit. In the outer magnetosphere many spacecraft operational problems appear to be due to intense, transient phenomena. It is shown that three types of naturally-occurring, and highly variable, hostile particle radiation environments are encountered at, or near, the geostationary orbit: (1) high-energy protons due to solar flares; (2) very high energy electrons (2-10 MeV) of unknown origin; and (3) energetic ions and electrons produced by magnetospheric substorms. Present particle sensor systems provide energetic particle detection and assessment capabilities during these kinds of high-energy radiation events. Numerous operational anomalies and subsystem problems have occurred during each type of event period and the association of such upsets is demonstrated in this paper. Methods of prediction of magnetospheric disturbances are discussed, and overall recommendations are made for dealing with this continuing problem
Embracing Open Software Development in Solar Physics
Hughitt, V. K.; Ireland, J.; Christe, S.; Mueller, D.
2012-12-01
We discuss two ongoing software projects in solar physics that have adopted best practices of the open source software community. The first, the Helioviewer Project, is a powerful data visualization tool which includes online and Java interfaces inspired by Google Maps (tm). This effort allows users to find solar features and events of interest, and download the corresponding data. Having found data of interest, the user now has to analyze it. The dominant solar data analysis platform is an open-source library called SolarSoft (SSW). Although SSW itself is open-source, the programming language used is IDL, a proprietary language with licensing costs that are prohibative for many institutions and individuals. SSW is composed of a collection of related scripts written by missions and individuals for solar data processing and analysis, without any consistent data structures or common interfaces. Further, at the time when SSW was initially developed, many of the best software development processes of today (mirrored and distributed version control, unit testing, continuous integration, etc.) were not standard, and have not since been adopted. The challenges inherent in developing SolarSoft led to a second software project known as SunPy. SunPy is an open-source Python-based library which seeks to create a unified solar data analysis environment including a number of core datatypes such as Maps, Lightcurves, and Spectra which have consistent interfaces and behaviors. By taking advantage of the large and sophisticated body of scientific software already available in Python (e.g. SciPy, NumPy, Matplotlib), and by adopting many of the best practices refined in open-source software development, SunPy has been able to develop at a very rapid pace while still ensuring a high level of reliability. The Helioviewer Project and SunPy represent two pioneering technologies in solar physics - simple yet flexible data visualization and a powerful, new data analysis environment. We
Supramolecular Approaches to Nanoscale Morphological Control in Organic Solar Cells
Directory of Open Access Journals (Sweden)
Alexander M. Haruk
2015-06-01
Full Text Available Having recently surpassed 10% efficiency, solar cells based on organic molecules are poised to become a viable low-cost clean energy source with the added advantages of mechanical flexibility and light weight. The best-performing organic solar cells rely on a nanostructured active layer morphology consisting of a complex organization of electron donating and electron accepting molecules. Although much progress has been made in designing new donor and acceptor molecules, rational control over active layer morphology remains a central challenge. Long-term device stability is another important consideration that needs to be addressed. This review highlights supramolecular strategies for generating highly stable nanostructured organic photovoltaic active materials by design.
Solar-Powered, Liquid-Desiccant Air Conditioner for Low-Electricity Humidity Control
2012-11-01
reading Current transformer Regen and conditioner Continental Controls CTS-0750-30 1 % of reading Pyranometer Horizontal Campbell...indoor comfort conditions. A pyranometer was used to quantify the efficiency of the solar collector array. Two measurements of electric energy were
Sabry, Hanan; Sherif, Ahmed; Gadelhak, Mahmoud; Aly, Mohamed
2014-01-01
Solar screens are typically used to control solar access into building spaces. They proved their usefulness in improving the daylighting and energy performance of buildings in the hot arid desert environments which are endowed with abundance
Optimal control of a solar greenhouse
Ooteghem, van R.J.C.; Stigter, J.D.; Willigenburg, van L.G.; Straten, van G.
2003-01-01
A solar greenhouse has been designed that maximizes solar energy use and minimizes fossil energy consumption. It is based on a conventional greenhouse extended with a heat pump, a heat exchanger, an aquifer and ventilation with heat recovery. The aim is to minimize fossil energy consumption, while
Education in astronomy and solar-terrestrial relations in science research environment
Stoeva, Penka; Stoev, Alexey
2009 -more than 5000 people were happy to observe the Sun, Moon, Venus and other celestial objects; "The Galileoscope"; "Galilean Nights" -encourages everybody to go out to the streets and observe the cosmos; "Dark Skies Awareness" -Measuring of the light pollution level above the region of Stara Zagora; "Astronomy and World Heritage" -archaeoastronomical research of megalithic mon-uments and sanctuaries -examples of ancient observatories for observations of solar extreme rises, sets and meridional culminations; history of the first modern astronomical observatory in Bulgaria; "Galileo Teacher Training Program" -Teaching the teachers. At the beginning of every school year teacher-training course is conducted on astronomy and astrophysics. This year they will actively use telescopes to observe the sky with students; "Universe Awareness" -a lot of games and observations, modeling, exhibitions and parties are organized. "From Earth to the Universe" Exhibitions of astronomical photographs from space and ground based telescopes. Astronomy Olympiads -scientific teaching is improved when the students engaged in doing real science on real data. Fifteen years we participate in the International Astronomy Olympiad and our students win medals. Observarion of solar eclipses is an example of educa-tion in science research environment. We were happy to observe the longest for the last 2000 years total solar eclipse on July 22, 2009, in TianHuangPing, China, at 900m above the sea level. Immediately after the end of this unique phenomenon, images of the eclipsed Sun were sent in Bulgaria. Cooperations -we have good international and national cooperations with a lot of Institutes, Universities, organizations and mass media -radio, TV, magazines, news-papers Information and press conferences about the events have been regularly made available for journalists. With the experience we gained from the IHY and IYA initiatives, being a host of a SID Monitor, we focus on the new International
Solar radiation control using nematic curvilinear aligned phase (NCAP) liquid crystal technology
vanKonynenburg, Peter; Marsland, Stephen; McCoy, James
1987-11-01
A new, advanced liquid crystal technology has made economical, large area, electrically-controlled windows a commercial reality. The new technology, Nematic Curvilinear Aligned Phase (NCAP), is based on a polymeric material containing small droplets of nematic liquid crystal which is coated and laminated between transparent electrodes and fabricated into large area field effect devices. NCAP windows feature variable solar transmission and reflection through a voltage-controlled scattering mechanism. Laminated window constructions provide the excellent transmission and visibility of glass in the powered condition. In the unpowered condition, the windows are highly translucent, and provide 1) blocked vision for privacy, security, and obscuration of information, and 2) glare control and solar shading. The stability is excellent during accelerated aging tests. Degradation mechanisms which can limit performance and lifetime are discussed. Maximum long term stability is achieved by product designs that incorporate the appropriate window materials to provide environmental protection.
Off-season cultivation of capsicums in a solar greenhouse
Energy Technology Data Exchange (ETDEWEB)
Ghosal, M.K.; Tiwari, G.N. [Indian Inst. of Technology, New Delhi (India). Centre for Energy Studies
2001-10-01
The use of solar energy for growing capsicums in pots and in the ground has been studied both under a controlled environment in a solar greenhouse (IIT model) and in an open field during August 2000 to March 2001. Cooling arrangements (natural, forced convection, shading, evaporative cooling) and heating methods (ground air collector, movable insulation during the night) have been employed during the pre-winter and winter periods respectively to maintain the protected environment in the greenhouse. The effects of a north brick wall and the use of movable insulation during the night in the winter months to reduce heat loss from the greenhouse have been incorporated to study the efficacy of the greenhouse. The average height, weight and yield per plant of the greenhouse crop were higher than those of the open field. (author)
International lighting in controlled environments workshop: Proceedings
Energy Technology Data Exchange (ETDEWEB)
NONE
1994-12-31
Lighting is a central and critical aspect of control in environmental research for plant research and is gaining recognition as a significant factor to control carefully for animal and human research. Thus this workshop was convened to reevaluate the technology that is available today and to work toward developing guidelines for the most effective use of lighting in controlled environments with emphasis on lighting for plants but also to initiate interest in the development of improved guidelines for human and animal research. There are a number of established guidelines for lighting in human and animal environments. Development of new lighting guidelines is necessary for three reasons: (1) recent scientific discoveries show that in addition to supporting the sensation of vision, light has profound nonvisual biological and behavioral effects in both animals and humans; (2) federal regulations (EPACT 1992) are requiring all indoor environments to become more energy efficient with a specific emphasis on energy conservation in lighting; (3) lighting engineers and manufacturers have developed a wealth of new light sources and lighting products that can be applied in animal and human environments. The workshop was aimed at bringing together plant scientists and physical scientists to interact in the discussions. It involved participation of biological scientists involved in studying mechanisms of light reactions and those involved in utilizing lighting for production of plants and maintenance of animals in controlled environments. It included participation of physical scientists from universities and government involved in research as well as those from industry involved in producing lamps and in construction of controlled growth facilities. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.
CLOSED LOOP CONTROL OF EMBEDDED Z-SOURCE INVERTER WITH FUZZY CONTROLLER FOR SOLAR PV APPLICATIONS
Midde Mahesh*, K. Leleedhar Rao
2017-01-01
This paper proposes the use of Embedded Z –source inverter system with fuzzy controller for Solar Photo Voltaic (PV) applications with adjustable speed drives. Closed loop operation FUZZY control strategies of EZSI system are proposed. EZSI produces the same voltage gain as Z-source inverter (ZSI) but due to the DC sources embedded within the X- shaped impedance network, it has the added advantage of inherent source filtering capability and also reduced capacitor sizing. This can be achiev...
SolarProTeam - Final report; Solar production technology melts architects
Energy Technology Data Exchange (ETDEWEB)
2010-07-01
To this date, no module manufacturing line has been able to produce special designed multiple function modules or Custom Design Solution (hereafter CDS) modules at costs that are anywhere near the costs of standard modules. The goal of this R and D project was to provide the basis for eliminating the multiplication of costs for specialised modules. The purpose of the SolarProTeam R and D project is to form the foundation of special production equipment and production lay-out in order to realise a cost-effective CDS module production line. The main results derive from research and development of: (1) A number of new module designs corresponding to the special demands of end-users. For instance, black shiny modules with high efficiency; long large black modules with in-built thermal absorbers; flexible high voltage lightweight modules for ground water pumping; large area curved colorful modules with for architecturally advanced buildings; a solar tree for power supply placed along roads and in public places. Module designs are reported. (2) A new general concept 'Q-keys' based on a master plan and specially designed modules integrating both very large and medium sized individual solar plants in the environment of the end-user. I.e., in addition to integration with regard to architectural and environment demands, integration with respect to technical demands are met, such as storage, desalination plants, cooling, mini-grids, the general grid, etc. The Q-keys concept emphasizes the financial issue in that the solar plants are competitive with coal generated electricity and stand-alone diesel generation of electricity. (3) Fully automated production equipment and a semi-automatic module production line, which can mass produce advanced multifunctional and/or architecturally integrated modules at a cost effective price. The equipment and production line were inspired by the functional and technological demands of different types of costumer designed modules. Due
Evaluation of thermal control coatings for use on solar dynamic radiators in low earth orbit
Dever, Joyce A.; Rodriguez, Elvin; Slemp, Wayne S.; Stoyack, Joseph E.
1991-01-01
Thermal control coatings with high thermal emittance and low solar absorptance are needed for Space Station Freedom (SSF) solar dynamic power module radiator (SDR) surfaces for efficient heat rejection. Additionally, these coatings must be durable to low earth orbital (LEO) environmental effects of atomic oxygen, ultraviolet radiation and deep thermal cycles which occur as a result of start-up and shut-down of the solar dynamic power system. Eleven candidate coatings were characterized for their solar absorptance and emittance before and after exposure to ultraviolet (UV) radiation (200 to 400 nm), vacuum UV (VUV) radiation (100 to 200 nm) and atomic oxygen. Results indicated that the most durable and best performing coatings were white paint thermal control coatings Z-93, zinc oxide pigment in potassium silicate binder, and YB-71, zinc orthotitanate pigment in potassium silicate binder. Optical micrographs of these materials exposed to the individual environmental effects of atomic oxygen and vacuum thermal cycling showed that no surface cracking occurred.
Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.
2015-09-08
A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.
Photovoltaic solar concentrator
Nielson, Gregory N.; Gupta, Vipin P.; Okandan, Murat; Watts, Michael R.
2016-03-15
A photovoltaic solar concentrator is disclosed with one or more transverse-junction solar cells (also termed point contact solar cells) and a lens located above each solar cell to concentrate sunlight onto the solar cell to generate electricity. Piezoelectric actuators tilt or translate each lens to track the sun using a feedback-control circuit which senses the electricity generated by one or more of the solar cells. The piezoelectric actuators can be coupled through a displacement-multiplier linkage to provide an increased range of movement of each lens. Each lens in the solar concentrator can be supported on a frame (also termed a tilt plate) having three legs, with the movement of the legs being controlled by the piezoelectric actuators.
FUZZY LOGIC CONTROLLER IMPLEMENTATION FOR PHOTOVOLTAIC STATION
Directory of Open Access Journals (Sweden)
Imad Zein
2014-01-01
Full Text Available Solar panels have a nonlinear voltage-current characteristic, with a distinct maximum power point (MPP, which depends on the environmental factors, such as temperature and irradiation. In order to continuously harvest maximum power from the solar panels, they have to operate at their MPP despite the inevitable changes in the environment. This is why the controllers of all solar power electronic converters employ some method for maximum power point tracking (MPPT . Over the past years many MPPT techniques have been published and based on that the main paper’s objective is to analyze one of the most promising MPPT control algorithms: fuzzy logic controller.
Dynamic Modeling, Control, and Analysis of a Solar Water Pumping System for Libya
Directory of Open Access Journals (Sweden)
Muamer M. Shebani
2017-01-01
Full Text Available In recent years, one of the suitable solar photovoltaic (PV applications is a water pumping system. The simplest solar PV pumping system consists of PV array, DC-DC converter, DC motor, and water pump. In this paper, water pumping system sizing for Libya is evaluated based on a daily demand using HOMER software, and dynamic modeling of a solar PV water pumping system using a Permanent Magnet DC (PMDC motor is presented in Matlab/Simulink environment. The system performance with maximum power point tracking (MPPT based on Fractional Open Circuit Voltage (FOCV is evaluated with and without a battery storage system. In some applications, a rated voltage is needed to connect a PMDC motor to a PV array through a DC-DC converter and in other applications the input voltage can vary. The evaluation of the system is based on the performance during a change in solar irradiation. Using Matlab/Simulink, simulation results are assessed to see the efficiency of the system when it is operating at a specific speed or at the MPPT. The results show that an improvement in the system efficiency can be achieved when the PMDC motor is running at a specific speed rather than at the peak PV power point.
Sherif, A.
2012-09-01
In hot arid desert environments, the solar radiation passing through windows increases the cooling loads and the energy consumption of buildings. Shading of windows can reduce these loads. Unlike the woven solar screens, wooden solar screens have a thickness that provides selective shading properties. Perforated wooden solar screens were traditionally used for windows shading. Developing modern types of these shading systems can lead to significant energy savings. The paper addresses the influence of changing the perforation percentage and depth of these screens on the annual energy loads, hence defining the optimum depth/perforation configurations for various window orientations. Series of experiments were performed using the EnergyPlus simulation software for a typical residential building in the Kharga Oasis, located in the Egyptian desert. A range of perforation percentages and depths were tested. Conclusions prove that external fixed deep perforated solar screens could effectively achieve energy savings up to 30% of the total energy consumption in the West and South orientations. Optimum range of depths and perforation percentages were recommended. These are: 80-90% perforation rate and 1:1 depth/opening width ratio. These lighter and deeper solar screen configurations were found to be more efficient in energy consumption in comparison with the traditional ones. © 2012 Elsevier B.V. All rights reserved.
Organic Based Solar Cells with Morphology Control
DEFF Research Database (Denmark)
Andersen, Thomas Rieks
The field of organic solar cells has in the last years gone through an impressive development with efficiencies reported up to 12 %. For organic solar cells to take the leap from primarily being a laboratory scale technology to being utilized as renewable energy source, several issues need...... Microscopy and as solar cells in a blend with PCBM. It was concluded that these particles did not show a potential large enough for continuous work due to a high material loss and low efficiency when applied in solar cells. The second method to achieve was preparation of pre-arranged morphology organic...... nanoparticles consisting of a blend of donor and acceptor in an aqueous dispersion, thereby addressing two of the issues remaining in the field of organic solar cells. This approach was used on six different polymers, which all had the ability to prepare aqueous nanoparticle inks. The morphology...
Camtracker: a new camera controlled high precision solar tracker system for FTIR-spectrometers
Directory of Open Access Journals (Sweden)
M. Gisi
2011-01-01
Full Text Available A new system to very precisely couple radiation of a moving source into a Fourier Transform Infrared (FTIR Spectrometer is presented. The Camtracker consists of a homemade altazimuthal solar tracker, a digital camera and a homemade program to process the camera data and to control the motion of the tracker. The key idea is to evaluate the image of the radiation source on the entrance field stop of the spectrometer. We prove that the system reaches tracking accuracies of about 10 arc s for a ground-based solar absorption FTIR spectrometer, which is significantly better than current solar trackers. Moreover, due to the incorporation of a camera, the new system allows to document residual pointing errors and to point onto the solar disk center even in case of variable intensity distributions across the source due to cirrus or haze.
Pahud, D. M.; Niembro, T.
2014-12-01
The SHINE workshop is an annual meeting of solar and heliospheric scientists which, in addition to aiming to improve understanding of solar disturbances and their propagation to, and effect, on the Earth (shinecon.org), is dedicated to actively supporting students. This dedication is substantiated in part through the National Science Foundation (NSF) providing funding for student attendance to the workshop, which enables student participation. Another example of SHINE's commitment to its student members is the incorporation of a Student Day prior to the workshop since 2003, entirely organized and run by two student representatives. While there are variations in format from year to year, Student Day consists of tutorials and research talks exclusively by student volunteers to an audience of only students. The day is intended to provide a low-stress environment for students to learn about the various topics addressed during the workshop, to ask questions freely, and to engage in scientific discussion with other students which hopefully is a catalyst for collaboration. As a result of positive experiences, over the past decade student attendance and participation in the workshop have increased. At the SHINE 2014 workshop, nearly a third of attendees were students. SHINE student visibility has increased over the years, with student posters being advertised at breakfast, inclusion of a student day summary by the student representatives during a plenary session, and continued support from the steering committee. Students are also promoting a broader impact of SHINE sciences via increased social media presence. From a student representative's perspective, SHINE has built and fostered a healthy student community and encourages students to engage in shaping the future of the field.
Fuzzy Universal Model Approximator for Distributed Solar Collector Field Control
Elmetennani, Shahrazed
2014-07-01
This paper deals with the control of concentrating parabolic solar collectors by forcing the outlet oil temperature to track a set reference. A fuzzy universal approximate model is introduced in order to accurately reproduce the behavior of the system dynamics. The proposed model is a low order state space representation derived from the partial differential equation describing the oil temperature evolution using fuzzy transform theory. The resulting set of ordinary differential equations simplifies the system analysis and the control law design and is suitable for real time control implementation. Simulation results show good performance of the proposed model.
Intelligent solar-powered automobile-ventilation system
International Nuclear Information System (INIS)
Huang, K. David; Tzeng, S.-C.; Ma Weiping; Wu Mingfung
2005-01-01
This study adopts airflow management technology to improve the local temperature distributions in an automobile to counteract the greenhouse effect. The automobile's temperature can be reduced to almost the outside temperature before the driver or passenger gets into the vehicle. When the engine is idling, the greenhouse-control system can be activated to remove the hot air from the car. An appropriate negative pressure is maintained to prevent stuffiness and save energy. The greenhouse-control system requires electrical power when the engine is idle, and a battery cannot supply sufficient power. An auxiliary solar-power supply can save energy and reduce the greenhouse effect of sunlight, while creating a comfortable traveling environment. It ensures that the engine is not overburdened and increases its service life, conserving energy, protecting the environment and improving comfort
Solar shading how to integrate solar shading in sustainable buildings
Dolmans, Dick; Dutoo, Gonzague; Hall, Anders; Seppänen, Olli
2010-01-01
Solar Shading Guidebook gives a solid background on the physics of solar radiation and its behaviour in window with solar shading systems. Major focus of the Guidebook is on the effect of solar shading in the use of energy for cooling, heating and lighting. The book gives also practical guidance for selection, installation and operation of solar shading as well as future trends in integration of HVAC-systems with solar control.
Thermotropic and Thermochromic Polymer Based Materials for Adaptive Solar Control
Directory of Open Access Journals (Sweden)
Olaf Mühling
2010-12-01
Full Text Available The aim of this review is to present the actual status of development in adaptive solar control by use of thermotropic and organic thermochromic materials. Such materials are suitable for application in smart windows. In detail polymer blends, hydrogels, resins, and thermoplastic films with a reversible temperature-dependent switching behavior are described. A comparative evaluation of the concepts for these energy efficient materials is given as well. Furthermore, the change of strategy from ordinary shadow systems to intrinsic solar energy reflection materials based on phase transition components and a first remark about their realization is reported. Own current results concerning extruded films and high thermally stable casting resins with thermotropic properties make a significant contribution to this field.
Directory of Open Access Journals (Sweden)
Alberto Muscio
2018-02-01
Full Text Available Overheating of buildings and urban areas is a more and more severe issue in view of global warming combined with increasing urbanization. The thermal behavior of urban surfaces in the hot seasons is the result of a complex balance of construction and environmental parameters such as insulation level, thermal mass, shielding, and solar reflective capability on one side, and ambient conditions on the other side. Regulations makers and the construction industry have favored the use of parameters that allow the forecasting of the interaction between different material properties without the need for complex analyses. Among these, the solar reflectance index (SRI takes into account solar reflectance and thermal emittance to predict the thermal behavior of a surface subjected to solar radiation through a physically rigorous mathematical procedure that considers assigned air and sky temperatures, peak solar irradiance, and wind velocity. The correlation of SRI with the heat released to the urban environment is analyzed in this paper, as well as the sensitivity of its calculation procedure to variation of the input parameters, as possibly induced by the measurement methods used or by the material ageing.
Millstein, D.; Zhai, P.; Menon, S.
2011-12-01
used to investigate the effects of the various solar generation scenarios given emissions projections that account for changing regulatory environment, economic and population growth, and technological change. The results will help to quantify the potential air quality benefits of promotion of solar electricity generation in regions containing high penetration of coal-fired power generation. Note current national solar incentives that are based only on solar generation capacity. Further investigation of changes to regional climate due to emission reductions of aerosols and relevant precursors will provide insight into the environmental effects that may occur if solar power generation becomes widespread.
Fault Detection and Correction for the Solar Dynamics Observatory Attitude Control System
Starin, Scott R.; Vess, Melissa F.; Kenney, Thomas M.; Maldonado, Manuel D.; Morgenstern, Wendy M.
2007-01-01
The Solar Dynamics Observatory is an Explorer-class mission that will launch in early 2009. The spacecraft will operate in a geosynchronous orbit, sending data 24 hours a day to a devoted ground station in White Sands, New Mexico. It will carry a suite of instruments designed to observe the Sun in multiple wavelengths at unprecedented resolution. The Atmospheric Imaging Assembly includes four telescopes with focal plane CCDs that can image the full solar disk in four different visible wavelengths. The Extreme-ultraviolet Variability Experiment will collect time-correlated data on the activity of the Sun's corona. The Helioseismic and Magnetic Imager will enable study of pressure waves moving through the body of the Sun. The attitude control system on Solar Dynamics Observatory is responsible for four main phases of activity. The physical safety of the spacecraft after separation must be guaranteed. Fine attitude determination and control must be sufficient for instrument calibration maneuvers. The mission science mode requires 2-arcsecond control according to error signals provided by guide telescopes on the Atmospheric Imaging Assembly, one of the three instruments to be carried. Lastly, accurate execution of linear and angular momentum changes to the spacecraft must be provided for momentum management and orbit maintenance. In thsp aper, single-fault tolerant fault detection and correction of the Solar Dynamics Observatory attitude control system is described. The attitude control hardware suite for the mission is catalogued, with special attention to redundancy at the hardware level. Four reaction wheels are used where any three are satisfactory. Four pairs of redundant thrusters are employed for orbit change maneuvers and momentum management. Three two-axis gyroscopes provide full redundancy for rate sensing. A digital Sun sensor and two autonomous star trackers provide two-out-of-three redundancy for fine attitude determination. The use of software to maximize
Robot motion control in mobile environment
Institute of Scientific and Technical Information of China (English)
Iliya V Miroshnik; HUANG Xian-lin(黄显林); HE Jie(贺杰)
2003-01-01
With the problem of robot motion control in dynamic environment represented by mobile obstacles,working pieces and external mechanisms considered, a relevant control actions design procedure has been pro-posed to provide coordination of robot motions with respect to the moving external objects so that an extension ofrobot spatial motion techniques and active robotic strategies based on approaches of nonlinear control theory canbe achieved.
Early, Derrick A.; Haile, William B.; Turczyn, Mark T.; Griffin, Thomas J. (Technical Monitor)
2001-01-01
NASA Goddard Space Flight Center and the European Space Agency (ESA) conducted a disturbance verification test on a flight Solar Array 3 (SA3) for the Hubble Space Telescope using the ESA Large Space Simulator (LSS) in Noordwijk, the Netherlands. The LSS cyclically illuminated the SA3 to simulate orbital temperature changes in a vacuum environment. Data acquisition systems measured signals from force transducers and accelerometers resulting from thermally induced vibrations of the SAI The LSS with its seismic mass boundary provided an excellent background environment for this test. This paper discusses the analysis performed on the measured transient SA3 responses and provides a summary of the results.
Features of the low-power charge controller of lead-acid current sources charged by solar batteries
International Nuclear Information System (INIS)
Tukfatullin, O.F.; Yuldoshev, I.A.; Solieva, N.A.
2008-01-01
Influence of different factors on exploitations characteristics of solar photoelectric plant is investigated by field-performance data. A construction of charge controller of the lead-acid accumulator battery charging by means of solar battery is analyzed taking into account these factors. (authors)
Direct battery-driven solar LED lighting using constant-power control
Huang, Bin-Juine
2012-11-01
A direct battery-driven LED lighting technique using constant-power control is proposed in the present study. A system dynamics model of LED luminaire was derived and used in the design of the feedback constant-power control system. The test result has shown that the power of 18. W and 100. W LED luminaires can be controlled accurately with error at 2-5%. A solar LED street lighting system using constant-power and dimming control was designed and built for field test in a remote area. The long-term performance was satisfactory and no any failure since the installation. Since no high-power capacitor is used in the present constant-power control circuit, a longer lifetime is expected. © 2012 Elsevier Ltd.
Morphological Control of the Photoactive Layer in Bulk Heterojunction Organic Solar Cells
Su, Yisong
2011-07-23
For its inherent advantages, such as lightweight, low cost, flexibility, and opportunity to cover large surface areas, organic solar cells have attracted more and more attention in both academia and industry. However, the efficiency of organic solar cell is still much lower than silicon solar cells, but steadily rising as it now stands above 8%. The architecture of bulk heterojunction solar cells can improve the performance of organic solar cell a lot, but these improvements are highly dependent on the morphology of photoactive layer. Therefore, by controlling the morphology of photoactive layer, most commonly composed of a P3HT donor polymer and PCBM small molecule, the performance of organic solar cells could be optimized. The use of solvent additives in the solution formulation is particularly interesting, because it is a low cost method of controlling the phase separation of the photoactive layer and possibly removing the need for subsequent thermal and solvent vapor annealing. However, the role of the solvent additive remains not well understood and much debate remains on the mechanisms by which it impacts phase separation. In the first part of this thesis, we investigate the role of the solvent additive on the individual components (solvent, donor and acceptor) of the solution and the photoactive layer both in the bulk solution, during solution-processing and in the post-processing solid state of the film. In the second part of this thesis, we investigate the role of the additive on the blended solution state and resulting thin film phase separation. Finally, we propose a new method of controlling phase separation based on the insight into the role of the solvent additive. In the first part, we used an additive [octandiethiol (OT)] in the solvent to help the aggregation of P3HT in the solution. From the UV-vis experiments, the crystallinity of P3HT in the solutions increased while it decreased in thin films with steady increase of additive concentration. This
Sagan, Carl; Thompson, W. Reid; Chyba, Christopher F.; Khare, B. N.
1991-01-01
A review and partial summary of projects within several areas of research generally involving the origin, distribution, chemistry, and spectral/dielectric properties of volatiles and organic materials in the outer solar system and early terrestrial environments are presented. The major topics covered include: (1) impact delivery of volatiles and organic compounds to the early terrestrial planets; (2) optical constants measurements; (3) spectral classification, chemical processes, and distribution of materials; and (4) radar properties of ice, hydrocarbons, and organic heteropolymers.
Effect of soil solarization using plastic mulch in controlling root-knot ...
African Journals Online (AJOL)
A field experiment was conducted from February to May, 2004 and 2005 planting seasons at the Vegetable Evaluation and Research Station Farm located at Anse Boileau, Seychelles to evaluate the effect of soil solarization using plastic mulch in controlling root-knot nematode infestation and yield of lettuce.
Control of wheeled mobile robot in restricted environment
Ali, Mohammed A. H.; En, Chang Yong
2018-03-01
This paper presents a simulation and practical control system for wheeled mobile robot in restricted environment. A wheeled mobile robot with 3 wheels is fabricated and controlled by proportional derivative active force control (PD-AFC) to move in a pre-planned restricted environment to maintain the tracking errors at zero level. A control system with two loops, outer by PD controller and inner loop by Active Force Control, are designed to control the wheeled mobile robot. Fuzzy logic controller is implemented in the Active force Control to estimate the inertia matrix that will be used to calculate the actual torque applied on the wheeled mobile robot. The mobile robot is tested in two different trajectories, namely are circular and straight path. The actual path and desired path are compared.
Solar cell junction temperature measurement of PV module
Huang, B.J.
2011-02-01
The present study develops a simple non-destructive method to measure the solar cell junction temperature of PV module. The PV module was put in the environmental chamber with precise temperature control to keep the solar PV module as well as the cell junction in thermal equilibrium with the chamber. The open-circuit voltage of PV module Voc is then measured using a short pulse of solar irradiation provided by a solar simulator. Repeating the measurements at different environment temperature (40-80°C) and solar irradiation S (200-1000W/m2), the correlation between the open-circuit voltage Voc, the junction temperature Tj, and solar irradiation S is derived.The fundamental correlation of the PV module is utilized for on-site monitoring of solar cell junction temperature using the measured Voc and S at a short time instant with open circuit. The junction temperature Tj is then determined using the measured S and Voc through the fundamental correlation. The outdoor test results show that the junction temperature measured using the present method, Tjo, is more accurate. The maximum error using the average surface temperature Tave as the junction temperature is 4.8 °C underestimation; while the maximum error using the present method is 1.3 °C underestimation. © 2010 Elsevier Ltd.
International Nuclear Information System (INIS)
2006-01-01
Solar energy is the fastest growing energy source in the world. Government involvement is critical in the deployment of solar energy. This forum focused on the application of solar energy in government facilities. The forum was divided into 3 sessions: (1) solar technologies and markets; (2) government initiatives that support solar energy; and (3) the use of solar energy on government facilities in Canada. The current state of solar technologies and products in Canada was reviewed. Solar thermal markets were discussed with reference to passive solar energy and photovoltaic applications. On-site solar generation for federal facilities was discussed, and various federal initiatives were reviewed. Issues concerning Ontario's standard offer contract program were discussed. Government users and buyers of solar products spoke of their experiences in using solar energy and the challenges that were faced. The role that solar energy can play in reducing government costs was discussed, as well as the impact of solar energy on the environment. Opportunities and barriers to the use of solar energy in Canada were explored. The conference featured 14 presentations, of which 2 have been catalogued separately for inclusion in this database. refs., tabs., figs
The Solar-Terrestrial Environment
Hargreaves, John Keith
1995-05-01
The book begins with three introductory chapters that provide some basic physics and explain the principles of physical investigation. The principal material contained in the main part of the book covers the neutral and ionized upper atmosphere, the magnetosphere, and structures, dynamics, disturbances, and irregularities. The concluding chapter deals with technological applications. The account is introductory, at a level suitable for readers with a basic background in engineering or physics. The intent is to present basic concepts, and for that reason, the mathematical treatment is not complex. SI units are given throughout, with helpful notes on cgs units where these are likely to be encountered in the research literature. This book is suitable for advanced undergraduate and graduate students who are taking introductory courses on upper atmospheric, ionospheric, or magnetospheric physics. This is a successor to The Upper Atmosphere and Solar-Terrestrial Relations, published in 1979.
Solar Illumination Control of the Polar Wind
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.
Istvan Etesi, Laszlo; Tolbert, K.; Schwartz, R.; Zarro, D.; Dennis, B.; Csillaghy, A.
2010-05-01
In our project "Extending the Virtual Solar Observatory (VSO)” we have combined some of the features available in Solar Software (SSW) to produce an integrated environment for data analysis, supporting the complete workflow from data location, retrieval, preparation, and analysis to creating publication-quality figures. Our goal is an integrated analysis experience in IDL, easy-to-use but flexible enough to allow more sophisticated procedures such as multi-instrument analysis. To that end, we have made the transition from a locally oriented setting where all the analysis is done on the user's computer, to an extended analysis environment where IDL has access to services available on the Internet. We have implemented a form of Cloud Computing that uses the VSO search and a new data retrieval and pre-processing server (PrepServer) that provides remote execution of instrument-specific data preparation. We have incorporated the interfaces to the VSO search and the PrepServer into an IDL widget (SHOW_SYNOP) that provides user-friendly searching and downloading of raw solar data and optionally sends search results for pre-processing to the PrepServer prior to downloading the data. The raw and pre-processed data can be displayed with our plotting suite, PLOTMAN, which can handle different data types (light curves, images, and spectra) and perform basic data operations such as zooming, image overlays, solar rotation, etc. PLOTMAN is highly configurable and suited for visual data analysis and for creating publishable figures. PLOTMAN and SHOW_SYNOP work hand-in-hand for a convenient working environment. Our environment supports a growing number of solar instruments that currently includes RHESSI, SOHO/EIT, TRACE, SECCHI/EUVI, HINODE/XRT, and HINODE/EIS.
Neural network-based control of an intelligent solar Stirling pump
International Nuclear Information System (INIS)
Tavakolpour-Saleh, A.R.; Jokar, H.
2016-01-01
In this paper, an ANN (artificial neural network) control system is applied to a novel solar-powered active LTD (low temperature differential) Stirling pump. First, a mathematical description of the proposed Stirling pump is presented. Then, optimum operating frequencies of the converter corresponding to different operating conditions (i.e. different sink and source temperatures and water heads) are investigated using the proposed mathematical framework. It is found that the proposed complex mathematical scheme has a very slow convergence and thus, is not appropriate for real-time implementation of the model-based controller. Consequently, a NN (neural network) model with a lower complexity is proposed to learn the simulation data obtained from the mathematical model. The designed neural network controller is thus applied to a digital processor to effectively tune the converter frequency so that a maximum output power is acquired. Finally, the performance of the proposed mechatronic system is evaluated experimentally. The experimental results clearly demonstrate the feasibility of pumping water at low temperature difference under variable operating conditions using the proposed intelligent Stirling converter. - Highlights: • A novel intelligent solar-powered active LTD Stirling pump was introduced. • A neural network controller was used to tune the converter speed. • The intelligent converter was able to adapt itself to different operating conditions. • It was possible to excite the water column with its resonance mode. • Experimental results showed the effectiveness of the proposed converter.
Eperon, Giles E.
2013-09-09
Organometal trihalide perovskite based solar cells have exhibited the highest efficiencies to-date when incorporated into mesostructured composites. However, thin solid films of a perovskite absorber should be capable of operating at the highest efficiency in a simple planar heterojunction configuration. Here, it is shown that film morphology is a critical issue in planar heterojunction CH3NH3PbI3-xCl x solar cells. The morphology is carefully controlled by varying processing conditions, and it is demonstrated that the highest photocurrents are attainable only with the highest perovskite surface coverages. With optimized solution based film formation, power conversion efficiencies of up to 11.4% are achieved, the first report of efficiencies above 10% in fully thin-film solution processed perovskite solar cells with no mesoporous layer. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Internal control in an EDI environment.
Bae, Dal Hyeoung
1991-01-01
Approved for public release; distribution in unlimited. Electronic Data Interchange(EDI) is the electronic transmission of standard business documents in machine-readable format between parent companies and respective trading partners. As the use of EDI has grown, there have been the associated risks due to an uncontrolled environment. Accordingly, the necessity for effective internal controls in an EDI environment is on the rise. This thesis evaluates and analyzes the feasi...
A development environment for the SSC control system
International Nuclear Information System (INIS)
Murray, Doug; Martinsen, Garth; Wang, Judy
1994-01-01
The SSC is developing a design environment for control system development within the context of EPICS. The environment is aimed at developers of applications using the EPICS Input/Output Controller (IOC). The unique aspect of this effort is our emphasis on providing a simple and intuitive development environment compared with tools currently available. Our most important goal in this effort has been to hide the complexity of EPICS IOC development from the developers. This paper describes two tools which are under development; The Function Block Editor (FBE) and the State Machine Editor (SME). The FBE provides a visual editing environment for graphically describing control processes as a set of related functional blocks. The configuration of functional blocks is then translated into IOC records and executed. SME allows the user to visually construct a sequence using a notation we are modeling after Grafcet [1]. State machines are translated into EPICS State Notation Language programs and executed. Future extensions will be described. ((orig.))
Residential Solar Design Review: A Manual on Community Architectural Controls and Solar Energy Use.
Jaffe, Martin; Erley, Duncan
Presented are architectural design issues associated with solar energy use, and procedures for design review committees to consider in examining residential solar installation in light of existing aesthetic goals for their communities. Recommended design review criteria include the type of solar system being used and the ways in which the system…
Strong Solar Control of Infrared Aurora on Jupiter: Correlation Since the Last Solar Maximum
Kostiuk, T.; Livengood, T. A.; Hewagama, T.
2009-01-01
Polar aurorae in Jupiter's atmosphere radiate throughout the electromagnetic spectrum from X ray through mid-infrared (mid-IR, 5 - 20 micron wavelength). Voyager IRIS data and ground-based spectroscopic measurements of Jupiter's northern mid-IR aurora, acquired since 1982, reveal a correlation between auroral brightness and solar activity that has not been observed in Jovian aurora at other wavelengths. Over nearly three solar cycles, Jupiter auroral ethane emission brightness and solar 10.7 cm radio flux and sunspot number are positively correlated with high confidence. Ethane line emission intensity varies over tenfold between low and high solar activity periods. Detailed measurements have been made using the GSFC HIPWAC spectrometer at the NASA IRTF since the last solar maximum, following the mid-IR emission through the declining phase toward solar minimum. An even more convincing correlation with solar activity is evident in these data. Current analyses of these results will be described, including planned measurements on polar ethane line emission scheduled through the rise of the next solar maximum beginning in 2009, with a steep gradient to a maximum in 2012. This work is relevant to the Juno mission and to the development of the Europa Jupiter System Mission. Results of observations at the Infrared Telescope Facility (IRTF) operated by the University of Hawaii under Cooperative Agreement no. NCC5-538 with the National Aeronautics and Space Administration, Science Mission Directorate, Planetary Astronomy Program. This work was supported by the NASA Planetary Astronomy Program.
Progress in luminescent solar concentrator research: solar energy for the built environment
Verbunt, P.P.C.; Debije, M.G.
2011-01-01
This paper presents a concise review of recent research on the luminescent solar concentrator (LSC). The topics covered will include studies of novel luminophores and attempts to limit the losses in the devices, both surface and internal. These efforts include application of organic and
Development of an Electrostatically Clean Solar Array Panel
Stern, Theodore G.; Krumweide, Duane; Gaddy, Edward; Katz, Ira
2000-01-01
The results of design, analysis, and qualification of an Electrostatically Clean Solar Array (ECSA) panel are described. The objective of the ECSA design is to provide an electrostatic environment that does not interfere with sensitive instruments on scientific spacecraft. The ECSA design uses large, ITO-coated coverglasses that cover multiple solar cells, an aperture grid that covers the intercell areas, stress-relieved interconnects for connecting the aperture grid to the coverglasses, and edge clips to provides an electromagnetically shielded enclosure for the solar array active circuitry. Qualification coupons were fabricated and tested for photovoltaic response, conductivity, and survivability to launch acoustic and thermal cycling environments simulating LEO and GEO missions. The benefits of reducing solar panel interaction with the space environment are also discussed.
Dual Axis Controller for Extreme Environments, Phase II
National Aeronautics and Space Administration — The Dual Axis Controller for Extreme Environments (DACEE) addresses a critical need of NASA's future exploration plans to investigate extreme environments within our...
DEFF Research Database (Denmark)
Iversen, Anne; Nielsen, Toke Rammer; Svendsen, Svend
2008-01-01
A study was conducted in a test room equipped with an external reflecting solar shading system, energy efficient luminaires and a work station. The shading system reduces the illuminance level in the front of the room on days with clear sky and increases the illuminance in the back of the room...
International Nuclear Information System (INIS)
Croley, D.R.; Garrett, H.B.; Murphy, G.B.; Garrard, T.L.
1995-01-01
The three large solar particle events, beginning on October 19, 1989 and lasting approximately six days, were characterized by high fluences of solar protons and heavy ions at 1 AU. During these events, an abnormally large number of upsets (243) were observed in the random access memory of the attitude control system (ACS) control processing electronics (CPE) on-board the geosynchronous TDRS-1 (Telemetry and Data Relay Satellite). The RAM unit affected was composed of eight Fairchild 93L422 memory chips. The Galileo spacecraft, launched on October 18, 1989 (one day prior to the solar particle events) observed the fluxes of heavy ions experienced by TDRS-1. Two solid-state detector telescopes on-board Galileo, designed to measure heavy ion species and energy, were turned on during time periods within each of the three separate events. The heavy ion data have been modeled and the time history of the events reconstructed to estimate heavy ion fluences. These fluences were converted to effective LET spectra after transport through the estimated shielding distribution around the TDRS-1 ACS system. The number of single event upsets (SEU) expected was calculated by integrating the measured cross section for the Fairchild 93L422 memory chip with average effective LET spectrum. The expected number of heavy ion induced SEU's calculated was 176. GOES-7 proton data, observed during the solar particle events, were used to estimate the number of proton-induced SEU's by integrating the proton fluence spectrum incident on the memory chips, with the two-parameter Bendel cross section for proton SEU's. The proton fluence spectrum at the device level was gotten by transporting the protons through the estimated shielding distribution. The number of calculated proton-induced SEU's was 72, yielding a total of 248 predicted SEU's, very close to the 243 observed SEU's
Effects of Solar Activity and Space Environment in 2003 Oct.
Directory of Open Access Journals (Sweden)
Kyung-Seok Cho
2004-12-01
Full Text Available In this paper, we present a good example of extreme solar and geomagnetic activities from October to November, 2003. These activities are characterized by very large sunspot groups, X-class solar flares, strong particle events, and huge geomagnetic storms. We discuss ground-based and space-based data in terms of space weather scales. Especially, we present several solar and geomagnetic disturbance data produced in Korea : sunspots, geo-magnetograms, aurora, Ionogram, and Total Electron Content (TEC map by GPS data. Finally, we introduce some examples of the satellite orbit and communication effects caused by these activities; e.g., the disturbances of the KOMPSAT-1 operational orbit and HF communication.
International Nuclear Information System (INIS)
Abou Ghraibe, W.
1995-01-01
Solar energy could be used in pest control, in soil sterilization technology. The technique consists of covering humid soils by plastic films steadily fixed to the soil. Timing must be in summer during 4-8 weeks, where soil temperature increases to degrees high enough to control pests or to produce biological and chemical changes. The technique could be applied on many pests soil, mainly fungi, bacteria, nematods, weeds and pest insects. The technique could be used in greenhouses as well as in plastic film covers or in orchards where plastic films present double benefits: soil sterilization and production of black mulch. Mechanism of soil solarization is explained. Results show that soil solarization can be used in pest control after fruit crops cultivation and could be a method for an integrated pest control. 9 refs
Temperature Control Diagnostics for Sample Environments
International Nuclear Information System (INIS)
Santodonato, Louis J.; Walker, Lakeisha M.H.; Church, Andrew J.; Redmon, Christopher Mckenzie
2010-01-01
In a scientific laboratory setting, standard equipment such as cryocoolers are often used as part of a custom sample environment system designed to regulate temperature over a wide range. The end user may be more concerned with precise sample temperature control than with base temperature. But cryogenic systems tend to be specified mainly in terms of cooling capacity and base temperature. Technical staff at scientific user facilities (and perhaps elsewhere) often wonder how to best specify and evaluate temperature control capabilities. Here we describe test methods and give results obtained at a user facility that operates a large sample environment inventory. Although this inventory includes a wide variety of temperature, pressure, and magnetic field devices, the present work focuses on cryocooler-based systems.
International Nuclear Information System (INIS)
Scheer, H.
2001-07-01
In the decade since the 'Earth Summit' in Rio de Janeiro, the response of the world's governments and authorities to the threats to the global environment has been to enforce the reduction of energy consumption and harmful emissions - solutions primarily based around conventional energy resources and conventional thinking. The question is, though, whether this strategy is radical enough to address the key challenges now facing the environment, and whether it can be effective in avoiding catastrophe on a global scale. For Herman Scheer, the answer is a definite no. In this fully updated edition of A Solar Manifesto, he once more attacks the lack of political will to find answers outside a conventional frame of reference. Climate change, pollution, deforestation, destruction of the ozone layer, poverty and the population explosion are all problems created or exacerbated by the use of conventional energy. Seven years after the first edition of this book, answers are now more urgently required than ever, as current policies serve merely to alleviate the escalating symptoms rather than attempting a cure for what could become a terminal affliction. Herman Scheer shows that this crisis may yet be reversed - but it can only be made to happen through a fundamental change in political and economic strategies, paving the way towards a global solar energy economy sustained by new social principles. A Solar Manifesto champions the replacement of fossil and nuclear fuels with solar energy, as a real solution to the threat to the environment and associated social consequences. Scheer constructs a radical yet innovative political and economic model and argues the case with passion and conviction for the global solar economy as the route to a sustainable environment. Thought-provoking and profoundly challenging, this book will be an inspiration to anyone concerned with energy and the global environment. (author)
International Nuclear Information System (INIS)
Letz, T.
2006-01-01
This article gives details of Plan Soleil established in 2000 by the French Agency for Environment and Energy Management and its identification of solar hot water systems and combined domestic solar hot water and space heating as promising sectors for development. The setting up of a support scheme for investment by Plan Soleil is discussed along with subsidies and grants, manufacturers and importers, the guarantee of solar results, and the quality of plants, components, and installers. The costs of thermal solar equipment, and results of the French assessment programme are considered. The need for quality standards is stressed
Directory of Open Access Journals (Sweden)
Gilles Desthieux
2018-03-01
Full Text Available The paper presents the core methodology for assessing solar radiation and energy production on building rooftops and vertical facades (still rarely considered of the inner-city. This integrated tool is based on the use of LiDAR, 2D and 3D cadastral data. Together with solar radiation and astronomical models, it calculates the global irradiance for a set of points located on roofs, ground, and facades. Although the tool takes simultaneously roofs, ground, and facades, different methods of shadow casting are applied. Shadow casting on rooftops is based on image processing techniques. On the other hand, the assessment on facade involves first to create and interpolate points along the facades and then to implement a point-by-point shadow casting routine. The paper is structured in five parts: (i state of the art on the use of 3D GIS and automated processes in assessing solar radiation in the built environment, (ii overview on the methodological framework used in the paper, (iii detailed presentation of the method proposed for solar modeling and shadow casting, in particular by introducing an innovative approach for modeling the sky view factor (SVF, (iv demonstration of the solar model introduced in this paper through applications in Geneva’s building roofs (solar cadaster and facades, (v validation of the solar model in some Geneva’s spots, focusing especially on two distinct comparisons: solar model versus fisheye catchments on partially inclined surfaces (roof component; solar model versus photovoltaic simulation tool PVSyst on vertical surfaces (facades. Concerning the roof component, validation results emphasize global sensitivity related to the density of light sources on the sky vault to model the SVF. The low dense sky model with 145 light sources gives satisfying results, especially when processing solar cadasters in large urban areas, thus allowing to save computation time. In the case of building facades, introducing weighting factor
Edwards, D. L.; Hubbs, W. S.; Wertz, G. E.; Alstatt, R.; Munafo, Paul (Technical Monitor)
2001-01-01
The usage of solar sails as a propellantless propulsion system has been proposed for many years. The technical challenges associated with solar sails are fabrication of ultralightweight films, deploying the sails and controlling the spacecraft. Integral to all these challenges is the mechanical property integrity of the sail while exposed to the harsh environment of space. This paper describes testing and characterization of a candidate solar sail material, Aluminized Mylar. This material was exposed to a simulated Geosynchronous Transfer Orbit (GTO) and evaluated by measuring thermooptical and mechanical property changes. Testing procedures and results are presented.
NASA Solar Sail Propulsion Technology Development
Johnson, Les; Montgomery, Edward E.; Young, Roy; Adams, Charles
2007-01-01
NASA's In-Space Propulsion Technology Program has developed the first generation of solar sail propulsion systems sufficient to accomplish inner solar system science and exploration missions. These first generation solar sails, when operational, will range in size from 40 meters to well over 100 meters in diameter and have an areal density of less than 13 grams per square meter. A rigorous, multi-year technology development effort culminated in 2005 with the testing of two different 20-m solar sail systems under thermal vacuum conditions. The first system, developed by ATK Space Systems of Goleta, California, uses rigid booms to deploy and stabilize the sail. In the second approach, L'Garde, Inc. of Tustin, California uses inflatable booms that rigidize in the coldness of space to accomplish sail deployment. This effort provided a number of significant insights into the optimal design and expected performance of solar sails as well as an understanding of the methods and costs of building and using them. In a separate effort, solar sail orbital analysis tools for mission design were developed and tested. Laboratory simulations of the effects of long-term space radiation exposure were also conducted on two candidate solar sail materials. Detailed radiation and charging environments were defined for mission trajectories outside the protection of the earth's magnetosphere, in the solar wind environment. These were used in other analytical tools to prove the adequacy of sail design features for accommodating the harsh space environment. Preceding and in conjunction with these technology efforts, NASA sponsored several mission application studies for solar sails. Potential missions include those that would be flown in the near term to study the sun and be used in space weather prediction to one that would use an evolved sail capability to support humanity's first mission into nearby interstellar space. This paper will describe the status of solar sail propulsion within
Freeland, S.; Hurlburt, N.
2005-12-01
The SolarSoft system (SSW) is a set of integrated software libraries, databases, and system utilities which provide a common programming and data analysis environment for solar physics. The system includes contributions from a large community base, representing the efforts of many NASA PI team MO&DA teams,spanning many years and multiple NASA and international orbital and ground based missions. The SSW general use libraries include Many hundreds of utilities which are instrument and mission independent. A large subset are also SOLAR independent, such as time conversions, digital detector cleanup, time series analysis, mathematics, image display, WWW server communications and the like. PI teams may draw on these general purpose libraries for analysis and application development while concentrating efforts on instrument specific calibration issues rather than reinvention of general use software. By the same token, PI teams are encouraged to contribute new applications or enhancements to existing utilities which may have more general interest. Recent areas of intense evolution include space weather applications, automated distributed data access and analysis, interfaces with the ongoing Virtual Solar Observatory efforts, and externalization of SolarSoft power through Web Services. We will discuss the current status of SSW web services and demonstrate how this facilitates accessing the underlying power of SolarSoft in more abstract terms. In this context, we will describe the use of SSW services within the Collaborative Sun Earth Connector environment.
Elmetennani, Shahrazed
2017-04-01
This dissertation addresses the flow control problem in hyperbolic heat transfer mechanisms. It raises in concentrated distributed solar collectors to enhance their production efficiency under the unpredictable variations of the solar energy and the external disturbances. These factors which are either locally measured (the solar irradiance) or inaccessible for measurement (the collectors’ cleanliness) affect the source term of the distributed model and represent a major difficulty for the control design. Moreover, the temperature in the collector can only be measured at the boundaries. In this dissertation, we propose new adaptive control approaches to provide the adequate level of heat while coping with the unpredictable varying disturbances. First, we design model based control strategies for a better efficiency, in terms of accuracy and response time, with a relatively reduced complexity. Second, we enhance the controllers with on-line adaptation laws to continuously update the efficient value of the external conditions. In this study, we approach the control problem using both, the infinite dimensional model (late lumping) and a finite dimensional approximate representation (early lumping). For the early lumping approach, we introduce a new reduced order bilinear approximate model for system analysis and control design. This approximate state representation is then used to derive a nonlinear state feedback resorting to Lyapunov stability theory. To compensate for the external disturbances and the approximation uncertainties, an adaptive controller is developed based on a phenomenological representation of the system dynamics. For the late lumping approach, we propose two PDE based controllers by stabilization of the reference tracking error distributed profile. The control laws are explicitly defined as functions of the available measurement. The first one is obtained using a direct approach for error stabilization while the second one is derived through a
Modeling and control for closed environment plant production systems
Fleisher, David H.; Ting, K. C.; Janes, H. W. (Principal Investigator)
2002-01-01
A computer program was developed to study multiple crop production and control in controlled environment plant production systems. The program simulates crop growth and development under nominal and off-nominal environments. Time-series crop models for wheat (Triticum aestivum), soybean (Glycine max), and white potato (Solanum tuberosum) are integrated with a model-based predictive controller. The controller evaluates and compensates for effects of environmental disturbances on crop production scheduling. The crop models consist of a set of nonlinear polynomial equations, six for each crop, developed using multivariate polynomial regression (MPR). Simulated data from DSSAT crop models, previously modified for crop production in controlled environments with hydroponics under elevated atmospheric carbon dioxide concentration, were used for the MPR fitting. The model-based predictive controller adjusts light intensity, air temperature, and carbon dioxide concentration set points in response to environmental perturbations. Control signals are determined from minimization of a cost function, which is based on the weighted control effort and squared-error between the system response and desired reference signal.
Solar Sail Attitude Control System for the NASA Near Earth Asteroid Scout Mission
Orphee, Juan; Diedrich, Ben; Stiltner, Brandon; Becker, Chris; Heaton, Andrew
2017-01-01
An Attitude Control System (ACS) has been developed for the NASA Near Earth Asteroid (NEA) Scout mission. The NEA Scout spacecraft is a 6U cubesat with an eighty-six square meter solar sail for primary propulsion that will launch as a secondary payload on the Space Launch System (SLS) Exploration Mission 1 (EM-1) and rendezvous with a target asteroid after a two year journey, and will conduct science imagery. The spacecraft ACS consists of three major actuating subsystems: a Reaction Wheel (RW) control system, a Reaction Control System (RCS), and an Active Mass Translator (AMT) system. The reaction wheels allow fine pointing and higher rates with low mass actuators to meet the science, communication, and trajectory guidance requirements. The Momentum Management System (MMS) keeps the speed of the wheels within their operating margins using a combination of solar torque and the RCS. The AMT is used to adjust the sign and magnitude of the solar torque to manage pitch and yaw momentum. The RCS is used for initial de-tumble, performing a Trajectory Correction Maneuver (TCM), and performing momentum management about the roll axis. The NEA Scout ACS is able to meet all mission requirements including attitude hold, slews, pointing for optical navigation and pointing for science with margin and including flexible body effects. Here we discuss the challenges and solutions of meeting NEA Scout mission requirements for the ACS design, and present a novel implementation of managing the spacecraft Center of Mass (CM) to trim the solar sail disturbance torque. The ACS we have developed has an applicability to a range of potential missions and does so in a much smaller volume than is traditional for deep space missions beyond Earth.
Directory of Open Access Journals (Sweden)
Qijia Yao
2017-07-01
Full Text Available The optimal control of multibody spacecraft during the stretching process of solar arrays is investigated, and a hybrid optimization strategy based on Gauss pseudospectral method (GPM and direct shooting method (DSM is presented. First, the elastic deformation of flexible solar arrays was described approximately by the assumed mode method, and a dynamic model was established by the second Lagrangian equation. Then, the nonholonomic motion planning problem is transformed into a nonlinear programming problem by using GPM. By giving fewer LG points, initial values of the state variables and control variables were obtained. A serial optimization framework was adopted to obtain the approximate optimal solution from a feasible solution. Finally, the control variables were discretized at LG points, and the precise optimal control inputs were obtained by DSM. The optimal trajectory of the system can be obtained through numerical integration. Through numerical simulation, the stretching process of solar arrays is stable with no detours, and the control inputs match the various constraints of actual conditions. The results indicate that the method is effective with good robustness. Keywords: Motion planning, Multibody spacecraft, Optimal control, Gauss pseudospectral method, Direct shooting method
A Compatible Control Algorithm for Greenhouse Environment Control Based on MOCC Strategy
Directory of Open Access Journals (Sweden)
Bingkun Zhu
2011-03-01
Full Text Available Conventional methods used for solving greenhouse environment multi-objective conflict control problems lay excessive emphasis on control performance and have inadequate consideration for both energy consumption and special requirements for plant growth. The resulting solution will cause higher energy cost. However, during the long period of work and practice, we find that it may be more reasonable to adopt interval or region control objectives instead of point control objectives. In this paper, we propose a modified compatible control algorithm, and employ Multi-Objective Compatible Control (MOCC strategy and an extant greenhouse model to achieve greenhouse climate control based on feedback control architecture. A series of simulation experiments through various comparative studies are presented to validate the feasibility of the proposed algorithm. The results are encouraging and suggest the energy-saving application to real-world engineering problems in greenhouse production. It may be valuable and helpful to formulate environmental control strategies, and to achieve high control precision and low energy cost for real-world engineering application in greenhouse production. Moreover, the proposed approach has also potential to be useful for other practical control optimization problems with the features like the greenhouse environment control system.
A compatible control algorithm for greenhouse environment control based on MOCC strategy.
Hu, Haigen; Xu, Lihong; Zhu, Bingkun; Wei, Ruihua
2011-01-01
Conventional methods used for solving greenhouse environment multi-objective conflict control problems lay excessive emphasis on control performance and have inadequate consideration for both energy consumption and special requirements for plant growth. The resulting solution will cause higher energy cost. However, during the long period of work and practice, we find that it may be more reasonable to adopt interval or region control objectives instead of point control objectives. In this paper, we propose a modified compatible control algorithm, and employ Multi-Objective Compatible Control (MOCC) strategy and an extant greenhouse model to achieve greenhouse climate control based on feedback control architecture. A series of simulation experiments through various comparative studies are presented to validate the feasibility of the proposed algorithm. The results are encouraging and suggest the energy-saving application to real-world engineering problems in greenhouse production. It may be valuable and helpful to formulate environmental control strategies, and to achieve high control precision and low energy cost for real-world engineering application in greenhouse production. Moreover, the proposed approach has also potential to be useful for other practical control optimization problems with the features like the greenhouse environment control system.
The World Solar Summit Process. The solar electricity highway for peace and environment
International Nuclear Information System (INIS)
Berkovski, B.
1996-01-01
Due to the growth of the world, energy demand will continue to increase. The question of providing additional energy is discussed by the World Solar Summit Process (WSSP). The actions, plans, recommendations and possible prospects of WSSP are discussed. (R.P.)
Directory of Open Access Journals (Sweden)
Giovanna Avedian-González
2018-02-01
Full Text Available The present work provides a series of theoretical improvements of a control strategy in order to optimize the time of use of solar air-conditioning by an ejector distributed in multiple solar collectors of vacuum tubes for the residential sector, which will allow us to reduce carbon-dioxide emissions, costs and electrical energy consumption. In a solar ejector cooling system, the instability of the solar source of energy causes an operational conflict between the solar thermal system and ejector cooling cycle. A fuzzy control structure for the supervisory ejector cycle and multi-collector control system is developed: the first control is applied to control the mass flow of the generator and the evaporator for different cooling capacities (3, 3.5, 4, 4.5 and 5 kW and set a temperature reference according to the operating conditions; the second is applied to keep a constant temperature power source that feeds the low-grade ejector cooling cycle using R134aas refrigerant. For the present work, the temperature of the generator oscillates between 65 °C and 90 °C, a condenser temperature of 30 °C and an evaporator temperature of 10 °C. For the purpose of optimization, there are different levels of performance for time of use: the Mode 0 (economic gives a performance of 17.55 h, Mode 5 (maximum cooling power 14.86 h and variable mode (variable mode of capacities 16.25 h, on average. Simulations are done in MATLAB-Simulink applying fuzzy logic for a mathematical model of the thermal balance. They are compared with two different types of solar radiation: real radiation and disturbed radiation.
Solar energy and global heat balance of a city
Energy Technology Data Exchange (ETDEWEB)
Roulet, Claude-Alain [Ecole Polytechnique Federale, Lab. d' Energie Solaire et de Physique du Batiment, Lausanne (Switzerland)
2001-07-01
The global energy balance of a city involves numerous energy flows and is rather complex. It includes, among others, the absorbed solar radiation and the energy fuels on one hand, and the heat loss to the environment --- by radiation, convection and evaporation --- on the other hand. This balance generally results in a temperature in the town that is slightly higher than in the surrounding country. Using solar energy saves imported fuels on one hand, but increases the absorption of solar radiation on the other hand. Simple, steady state models are used to assess the change of heat released to the environment when replacing the use of classical fuels by solar powered plants, on both the global and city scale. The conclusion is that, in most cases, this will reduce the heat released to the environment. The exception is cooling, for which a good solar alternative does not exist today. (Author)
Ultra-Portable Solar-Powered 3D Printers for Onsite Manufacturing of Medical Resources.
Wong, Julielynn Y
2015-09-01
The first space-based fused deposition modeling (FDM) 3D printer is powered by solar photovoltaics. This study seeks to demonstrate the feasibility of using solar energy to power a FDM 3D printer to manufacture medical resources at the Mars Desert Research Station and to design an ultra-portable solar-powered 3D printer for off-grid environments. Six solar panels in a 3×2 configuration, a voltage regulator/capacitor improvised from a power adapter, and two 12V batteries in series were connected to power a FDM 3D printer. Three designs were printed onsite and evaluated by experts post analogue mission. A solar-powered 3D printer composed of off-the-shelf components was designed to be transported in airline carry-on luggage. During the analogue mission, the solar-powered printer could only be operated for solar-powered 3D printer was designed that could print an estimated 16 dental tools or 8 mallet finger splints or 7 scalpel handles on one fully charged 12V 150Wh battery with a 110V AC converter. It is feasible to use solar energy to power a 3D printer to manufacture functional and personalized medical resources at a Mars analogue research station. Based on these findings, a solar-powered suitcase 3D printing system containing solar panels, 12V battery with charge controller and AC inverter, and back-up solar charge controller and inverter was designed for transport to and use in off-grid communities.
Game-based training environment for nuclear plant control room
International Nuclear Information System (INIS)
Hung Tamin; Sun Tienlung; Yang Chihwei; Yang Lichen; Cheng Tsungchieh; Wang Jyhgang
2011-01-01
Nuclear power plant's safety is very important problem. In this very conscientious environment if operator has a little mistake, they may threaten with many people influence their safety. Therefore, operating training of control room is very important. However, the operator training is in limited space and time. Each operator must go to simulative control room do some training. If we can let each trainee having more time to do training and does not go to simulative control room. It may have some advantages for trainee. Moreover, in the traditional training ways, each operator may through the video, teaching manual or through the experienced instructor to learn the knowledge. This training way may let operator feel bored and stressful. So, in this paper aims, we hope utilizing virtual reality technology developing a game-based virtual training environment of control room. Finally, we will use presence questionnaire evaluating realism and feasibility of our virtual training environment. Expecting this initial concept of game-based virtual training environment can attract trainees having more learning motivation to do training in off-hour. (author)
The SolarPACES strategy for the solar thermal breakthrough
Energy Technology Data Exchange (ETDEWEB)
Burch, G.D. [U.S. Department of Energy, Washington, DC (United States)
1997-12-31
Our national solar thermal research programs and our combined efforts conducted through IEA/SolarPACES have brought about many breakthroughs in the development of solar thermal technology. We have components and systems that are much more efficient, much more reliable, and can be built much more cost-efficiently than just a few years ago. As our technology development proceeds, we undoubtedly will continue to make significant progress, breakthroughs in fact, in all these areas - progress that will bring us even closer to economic parity with more conventional forms of energy. And while this progress is absolutely necessary, the question is whether it will be enough to allow solar thermal to break into the mainstream of global energy supply. Our new IEA/SolarPACES strategy, crafted and approved over the course of the past year, has recognized the changes we must face and given us license to begin to make those changes. We must begin addressing financial hurdles, work to create a more favorable regulatory and tax environment, support development of international partnerships, and expand the visibility and excitement of solar thermal technology to achieve the final breakthroughs we need to allow solar thermal energy to live up to its vast potential. (orig./AKF)
Solar Probe: Humanity's First Visit to a Star
Hassler, D. M.; Solar Probe Science; Technology Definition Team
Solar Probe will experience first hand the processes and conditions in the solar atmosphere that ultimately impact our planet and shape the harsh solar system environment It will be humanity s first visit to a star and will explore a previously inaccessible region of the inner heliosphere The 2003 Space Science Enterprise Strategy called for study of a Solar Probe to fly through the solar atmosphere to answer fundamental questions that can be answered in no other way The mission received highest priority in the National Academy of Sciences decadal research strategy in solar and space physics in 2002 Significant advances have been made in the areas of solar and solar wind science instrument technology mission resources and the mission environment since the previous Solar Probe Science Definition Team reports of 1989 1995 and 1999 The 2004-05 Solar Probe Science and Technology Definition Team STDT recently completed a detailed study of the Solar Probe Mission based on an earliest launch date of October 2014 The report and its Executive Summary were published by NASA in September 2005 and can be found at the website http solarprobe gsfc nasa gov This talk provides an overview of the Solar Probe mission and a summary of the efforts of the STDT
Employee quality, monitoring environment and internal control
Chunli Liu; Bin Lin; Wei Shu
2017-01-01
We investigate the effect of internal control employees (ICEs) on internal control quality. Using special survey data from Chinese listed firms, we find that ICE quality has a significant positive influence on internal control quality. We examine the effect of monitoring on this result and find that the effect is more pronounced for firms with strict monitoring environments, especially when the firms implement the Chinese internal control regulation system (CSOX), have higher institutional ow...
EOSCOR: a light weight, microprocessor controlled solar neutron detector
International Nuclear Information System (INIS)
Koga, R.; Albats, P.; Frye, G.M. Jr.; Schindler, S.M.; Denehy, B.V.; Hopper, V.D.; Mace, O.B.
1979-01-01
A light weight high energy neutron detector with vertical detection efficiency of 0.005 at 40 MeV and 1.4 m 2 sensitive area has been developed for long duration super-pressure balloon flight observations of solar neutrons and gamma rays. It consists of two sets of four plastic scintillator hodoscopes separated by a 1 m time-of-flight path to observe n-p, C(n,p), and C(n,d) interactions. The neutron interactions are separated from gamma ray events through TOF measurements. For a large flare, the signal from solar neutrons is expected to be an order of magnitude greater than that of the atmospheric background. The microprocessor controls the data acquisition, accumulation of histograms, and the encoding of data for the telemetry systems. A test flight of the detector was made with a zero-pressure balloon. The expected many-week duration of a super-pressure balloon flight would significantly increase the probability of observing 20-150 MeV neutrons from a medium or large flare. (Auth.)
A photodiode based on PbS nanocrystallites for FYTRONIX solar panel automatic tracking controller
Wageh, S.; Farooq, W. A.; Tataroğlu, A.; Dere, A.; Al-Sehemi, Abdullah G.; Al-Ghamdi, Ahmed A.; Yakuphanoglu, F.
2017-12-01
The structural, optical and photoelectrical properties of the fabricated Al/PbS/p-Si/Al photodiode based on PbS nanocrystallites were investigated. The PbS nanocrystallites were characterized by X-ray diffraction (XRD), UV-VIS-NIR, Infrared and Raman spectroscopy. The XRD diffraction peaks show that the prepared PbS nanostructure is in high crystalline state. Various electrical parameters of the prepared photodiode were analyzed from the electrical characteristics based on I-V and C-V-G. The photodiode has a high rectification ratio of 5.85×104 at dark and ±4 V. Moreover, The photocurrent results indicate a strong photovoltaic behavior. The frequency dependence of capacitance and conductance characteristics was attributed to depletion region behavior of the photodiode. The diode was used to control solar panel power automatic tracking controller in dual axis. The fabricated photodiode works as a photosensor to control Solar tracking systems.
International Nuclear Information System (INIS)
Lentz, A.; Winter, R.
1993-07-01
Many aspects with regard to the practical use of solar energy are discussed. This guide is aimed at informing local and regional administrators, committee members of housing corporations and public utilities and public relations officers on the possibilities to use solar energy. In chapter one an overview is given of the use of solar energy in the housing sector, the recreational sector, agricultural sector, industry, trade and other sectors. In the chapters two, three and four attention is paid to passive solar energy, active thermal solar energy and photovoltaic energy respectively. In the chapters five and six aspects concerning the implementation of solar energy systems in practice are discussed. First an outline of the parties involved in implementing solar energy is given: the municipality, the energy utility, the province, local authorities, advisors, housing constructors and the occupants of the buildings. Then attention is paid to the consequences of implementing solar energy for the building inspection and regulations, the finances, energy savings and the environment. In chapter seven an overview is given of the subsidy regulations of the European Community, the Dutch national and local governments. Chapter contains addresses of solar thermal systems, photovoltaic systems and other institutes operating in the field of solar energy, as well as the titles of a number of brochures and courses. 51 figs., 7 tabs., 86 refs
DEFF Research Database (Denmark)
Liu, Gang; Lee, Seunggeun; Lee, Alice W
2018-01-01
test with case-control data. Our simulation studies suggest that the EB approach uses the gene-environment independence assumption in a data-adaptive way and provides power gain compared to the standard logistic regression analysis and better control of Type I error when compared to the analysis......There have been recent proposals advocating the use of additive gene-environment interaction instead of the widely used multiplicative scale, as a more relevant public health measure. Using gene-environment independence enhances the power for testing multiplicative interaction in case......-control studies. However, under departure from this assumption, substantial bias in the estimates and inflated Type I error in the corresponding tests can occur. This paper extends the empirical Bayes (EB) approach previously developed for multiplicative interaction that trades off between bias and efficiency...
Ecological and economical aspects of solar energy use
Directory of Open Access Journals (Sweden)
Sobczyk Wiktoria
2017-01-01
Full Text Available The natural environment is devastated by the industry and by households, which use fuels such as coal, oil and natural gas for heating water and buildings as well as for generating electricity. One of the ways to limit the degradation of the environment and the usage of natural resources is to use unconventional and renewable resources and to implement energy-saving technologies in construction, industry and households. A dynamic development of systems based on renewable energy sources such as biomass, water, wind, heat from inside the Earth and sunbeams has recently occurred in the whole world. This thesis is related to the purest and the least onerous for environment source of energy which is undoubtedly the energy that comes directly from the solar radiation. In this article the solar energy application is presented, taking into account its impact on the environment and financial costs of developing solar techniques. The installation of alternative energy sources are entitled to grants and credits, which reduces the investment costs. Ecological effects, although immeasurable, are significant and definitely testify in favor of the solar system.
DEFF Research Database (Denmark)
Radziwon, Michal Jędrzej; Goszczak, Arkadiusz Jaroslaw; Fernandes Cauduro, André Luis
-type domains in the active organic layer. The molecular packing in these is of same importance, as it strongly affects the carrier transport in the cells. In this work, we present the study of alpha-sexithiophene (α 6T) temperature dependent growth for standard, on gold anodes, and inverted, on electron...... accepting C60 layers, solar cell configurations. Furthermore, a comparative study of the correlation between the α-6T morphology and device performance parameters for standard and inverted solar cell configurations is presented. The morphology of the α 6T layer is controlled by means of the substrate...
Solar Water-Heater Design Package
1982-01-01
Information on a solar domestic-hot water heater is contained in 146 page design package. System consists of solar collector, storage tanks, automatic control circuitry and auxiliary heater. Data-acquisition equipment at sites monitors day-by-day performance. Includes performance specifications, schematics, solar-collector drawings and drawings of control parts.
CONTROL OF INDOOR ENVIRONMENTS VIA THE REGULATION OF BUILDING ENVELOPES
Directory of Open Access Journals (Sweden)
Mitja Košir
2011-01-01
Full Text Available The design of comfortable, healthy and stimulating indoor environments in buildings has a direct impact on the users and on energy consumption, as well as on the wider soci-economic environment of society.The indoor environment of buildings is defined with the formulation of the building envelope, which functions as an interface between the internal and external environments and its users. A properly designed, flexible and adequately controlled building envelope is a starting point in the formulation of a high-quality indoor environment. The systematic treatment of the indoor environment and building envelope from a user’s point of view represents an engineering approach that enables the holistic treatment of buildings, as well as integrated components and systems. The presented division of indoor environment in terms of visual, thermal, olfactory, acoustic and ergonomic sub-environments enables the classification and selection of crucial factors influencing design. This selection and classification can be implemented in the design, as well as in control applications of the building envelope. The implementation of the approach described is demonstrated with an example of an automated control system for the internal environment of an office in the building of the Faculty of Civil and Geodetic Engineering.
Variable solar control using thermotropic core/shell particles
Energy Technology Data Exchange (ETDEWEB)
Muehling, Olaf; Seeboth, Arno; Ruhmann, Ralf; Potechius, Elvira; Vetter, Renate [Fraunhofer Institute for Applied Polymer Research (IAP), Department of Chromogenic Polymers, Volmerstr. 7B, 12489 Berlin (Germany); Haeusler, Tobias [Brandenburg University of Technology (BTU Cottbus), Chair of Applied Physics/Thermophysics, Konrad-Zuse-Str. 1, 03046 Cottbus (Germany)
2009-09-15
Subject of our recent investigations is the utilization of a reversible thermotropic material for a self-regulating sun protection glazing that controls the solar energy input in order to avoid overheating. Based on the well-established UV curing technology for laminated glass a superior thermotropic material with tunable switching characteristics and of low material costs was developed. The polymer layer contains core/shell particles homogeneously dispersed in a UV-cured resin. The particle core in turn consists of an n-alkane mixture that is responsible for the temperature-induced clear/opaque switching. To obtain particles of well-defined size and with a narrow size distribution, the miniemulsion polymerization technique was used. The visible and solar optical properties (normal-normal, normal-hemispherical, and normal-diffuse transmittance) in the off (clear) and in the on state (opaque) were determined by UV/Vis/NIR spectroscopy. Samples containing particles of high median diameter (>800 nm) primarily scatter in the forward direction. However, with smaller particles (300-600 nm) a higher backscattering (reflection) efficiency was achieved. The largest difference in the normal-hemispherical transmittance could be found with a particle amount of 6% and a median scattering domain diameter of {proportional_to}380 nm. (author)
Ennaoui, A.; Tributsch, H.
1984-12-01
The abundant, naturally occurring natural compound pyrite (FeS2) can be used as a semiconducting material for photoelectrochemical and photovoltaic solar cells. Unlike most of the intensively studied photoactive materials, pyrite solar cell production would never be limited by the availability of the elements or by their compatibility with the environment. An energy gap of 0.95 eV has been determined for pyrite, and it is noted that the theoretical efficiency limit for solar energy conversion in this material is of the order of 15-20 percent.
Radiation and Internal Charging Environments for Thin Dielectrics in Interplanetary Space
Minow, Joseph I.; Parker, Linda Neergaard; Altstatt, Richard L.
2004-01-01
Spacecraft designs using solar sails for propulsion or thin membranes to shade instruments from the sun to achieve cryogenic operating temperatures are being considered for a number of missions in the next decades. A common feature of these designs are thin dielectric materials that will be exposed to the solar wind, solar energetic particle events, and the distant magnetotail plasma environments encountered by spacecraft in orbit about the Earth-Sun L2 point. This paper will discuss the relevant radiation and internal charging environments developed to support spacecraft design for both total dose radiation effects as well as dose rate dependent phenomenon, such as internal charging in the solar wind and distant magnetotail environments. We will describe the development of radiation and internal charging environment models based on nearly a complete solar cycle of Ulysses solar wind plasma measurements over a complete range of heliocentric latitudes and the early years of the Geotail mission where distant magnetotail plasma environments were sampled beyond X(sub GSE) = -100 Re to nearly L2 (X(sub GSE) -236 Re). Example applications of the environment models are shown to demonstrate the radiation and internal charging environments of thin materials exposed to the interplanetary space plasma environments.
Performance of a solar chimney by varying design parameters
CSIR Research Space (South Africa)
Kumirai, T
2015-08-01
Full Text Available the design of solar chimneys to ensure optimal performance. The purpose of this chapter is to discuss the performance of an example solar chimney by varying the design parameters and examining their effects on the interior ventilation performance... chimney by varying design parameters Tichaona Kumirai, Researcher, Built Environment CSIR Jan-Hendrik Grobler, DPSS CSIR Dr D.C.U. Conradie, Senior researcher, Built Environment CSIR 1 Introduction Trombe walls and solar chimneys are not widely...
Statistical and observational research of solar flare for total spectra and geometrical features
Nishimoto, S.; Watanabe, K.; Imada, S.; Kawate, T.; Lee, K. S.
2017-12-01
Impulsive energy release phenomena such as solar flares, sometimes affect to the solar-terrestrial environment. Usually, we use soft X-ray flux (GOES class) as the index of flare scale. However, the magnitude of effect to the solar-terrestrial environment is not proportional to that scale. To identify the relationship between solar flare phenomena and influence to the solar-terrestrial environment, we need to understand the full spectrum of solar flares. There is the solar flare irradiance model named the Flare Irradiance Spectral Model (FISM) (Chamberlin et al., 2006, 2007, 2008). The FISM can estimate solar flare spectra with high wavelength resolution. However, this model can not express the time evolution of emitted plasma during the solar flare, and has low accuracy on short wavelength that strongly effects and/or controls the total flare spectra. For the purpose of obtaining the time evolution of total solar flare spectra, we are performing statistical analysis of the electromagnetic data of solar flares. In this study, we select solar flare events larger than M-class from the Hinode flare catalogue (Watanabe et al., 2012). First, we focus on the EUV emission observed by the SDO/EVE. We examined the intensities and time evolutions of five EUV lines of 55 flare events. As a result, we found positive correlation between the "soft X-ray flux" and the "EUV peak flux" for all EVU lines. Moreover, we found that hot lines peaked earlier than cool lines of the EUV light curves. We also examined the hard X-ray data obtained by RHESSI. When we analyzed 163 events, we found good correlation between the "hard X-ray intensity" and the "soft X-ray flux". Because it seems that the geometrical features of solar flares effect to those time evolutions, we also looked into flare ribbons observed by SDO/AIA. We examined 21 flare events, and found positive correlation between the "GOES duration" and the "ribbon length". We also found positive correlation between the "ribbon
System dynamic model and charging control of lead-acid battery for stand-alone solar PV system
Huang, B.J.
2010-05-01
The lead-acid battery which is widely used in stand-alone solar system is easily damaged by a poor charging control which causes overcharging. The battery charging control is thus usually designed to stop charging after the overcharge point. This will reduce the storage energy capacity and reduce the service time in electricity supply. The design of charging control system however requires a good understanding of the system dynamic behaviour of the battery first. In the present study, a first-order system dynamics model of lead-acid battery at different operating points near the overcharge voltage was derived experimentally, from which a charging control system based on PI algorithm was developed using PWM charging technique. The feedback control system for battery charging after the overcharge point (14 V) was designed to compromise between the set-point response and the disturbance rejection. The experimental results show that the control system can suppress the battery voltage overshoot within 0.1 V when the solar irradiation is suddenly changed from 337 to 843 W/m2. A long-term outdoor test for a solar LED lighting system shows that the battery voltage never exceeded 14.1 V for the set point 14 V and the control system can prevent the battery from overcharging. The test result also indicates that the control system is able to increase the charged energy by 78%, as compared to the case that the charging stops after the overcharge point (14 V). © 2010 Elsevier Ltd. All rights reserved.
Morphology control and device optimization for efficient organic solar cells
Gevaerts, Veronique
2013-01-01
Renewable energy is paramount for a sustainable global future. Solar cells convert solar light directly into electricity and are therefore of great interest in meeting the world’s energy demand. Currently crystalline silicon solar cells dominate the market. Solution processed organic solar cells can
Solar boilers 1995. Five years solar boiler campaign
International Nuclear Information System (INIS)
Houtsma, R.; Van de Water, A.; Van Zee, E.
1995-01-01
An overview is given of the activities and the results of Marketing Communication Strategy for Solar Water Heaters in the Netherlands, carried out within the framework of the 1990-1994 National Research Program Thermal Solar Energy (NOZ-th) of the Netherlands Agency for Energy and the Environment (NOVEM). Subsequently attention is paid to the sales, the manufacturers and their products, public information activities and reactions from the consumers, the marketing activities of energy distribution companies, the role of installers, local governments and the building construction industry, and market developments. 24 figs., 21 ills., 5 tabs., 18 refs., 2 appendices
Testing of gallium arsenide solar cells on the CRRES vehicle
International Nuclear Information System (INIS)
Trumble, T.M.
1985-01-01
A flight experiment was designed to determine the optimum design for gallium arsenide (GaAs) solar cell panels in a radiation environment. Elements of the experiment design include, different coverglass material and thicknesses, welded and soldered interconnects, different solar cell efficiencies, different solar cell types, and measurement of annealing properties. This experiment is scheduled to fly on the Combined Release and Radiation Effects Satellite (CRRES). This satellite will simultaneously measure the radiation environment and provide engineering data on solar cell degradation that can be directly related to radiation damage
Solar power generation system. Solar denryoku hassei sochi
Energy Technology Data Exchange (ETDEWEB)
Ohaku, T [Toshiba Corp., Kawasaki (Japan)
1990-12-21
In a conventional solar power generation system having shunt elements for controlling generated power and supplying the controlled power to a load, it is difficult to carry out a stable power control, because the shunt characteristics of an analogue shunt element driving circuit vary widely as compared with a digital shunt element driving circuit, as the temperature varies. According to the present invention, in a solar power generation system having a plurality of solar cells divided into two of the first and second cell groups and a first and a second shunt element driving means provided for the first and second cell groups, the first shunt element driving means is composed of a combination of a resisance and level shift diode arranged, and the second shunt element driving means is composed of a combination of a transistor and level shift diode arranged. A stable current control of the shunt elements can be therefore realized, because the control voltage range of the first and second shunt element driving means is changed so as to be expanded, as the temperature varies, so that their overlapped voltage range is kept constant. 7 figs.
Energy Technology Data Exchange (ETDEWEB)
Gutierrez Castro, Lucia Monica; Quinto Diez, Pedro [Escuela Superior de Ingenieria Mecanica y Electrica, Instituto Politecnico Nacional, Mexico, D.F. (Mexico)]. E-mail: moni-80-lgc@hotmail.com; pqd510@hotmail.com; Tovar Galvez, Luis Raul [Centro Interdisciplinario de Investigaciones de Estudios sobre Medio Ambiente y Desarrollo, Instituto Politecnico Nacional, Mexico, D.F. (Mexico)]. E-mail: ltovarg@ipn.mx
2010-11-15
In this paper a Solar System of Heating Water (SSHW) to provide energy to a biodigester which produces biogas located in the Interdisciplinary Center of Investigation of Studies About Environment and Development (CIIEMAD) is assessed. This evaluation is made by means of the f Method considerating the extraterrestrial radiation, the earth radiation in the zone and the necessary energy to maintain at 55 degrees Celsius the mixture inside the biodigester. The data were introduced in the SOLAR program to calculate both the harnessing area m{sup 2} and the storage capacity in L/m{sup 2}. To guarantee the good performance of the SSHW, a control and monitoring system for the temperature of the mix inside the biodigester is proposed. It also controls the input and output temperature to the solar collectors, as well as the cost analysis which shows the savings of fuel of the SSHW with a conventional system to heating water. [Spanish] En este articulo se evalua un sistema solar de calentamiento de agua (SSCA) para proveer energia a un biodigestor que forma parte del sistema de generacion de biogas (SGB) ubicado en el Centro Interdisciplinario de Investigaciones de Estudios sobre Medio Ambiente y Desarrollo (CIIEMAD). Dicha evaluacion se realiza por medio del Metodo f de diseno que considera datos de radiacion terrestre, radiacion extraterrestre sobre la zona y la energia necesaria para mantener la temperatura de la mezcla dentro del biodigestor a 55 grados centigrados. Los datos fueron introducidos en el programa SOLAR para el calculo del area de captacion en m{sup 2} y la capacidad de almacenamiento en L/m{sup 2}. Para garantizar el buen funcionamiento del SSCA se propone un sistema de control y monitoreo de la temperatura de la mezcla dentro del biodigestor. Tambien se controla la temperatura de entrada y salida a los colectores solares, asi como el analisis de costos que muestra el ahorro de combustible del SSCA con un sistema convencional de calentamiento de agua.
Homeostasis control of building environment using sensor agent robot
Nagahama, Eri; Mita, Akira
2012-04-01
A human centered system for building is demanded to meet variety of needs due to the diversification and maturation of society. Smart buildings and smart houses have been studied to satisfy this demand. However, it is difficult for such systems to respond flexibly to unexpected events and needs that are caused by aging and complicate emotion changes. With this regards, we suggest "Biofied Buildings". The goal for this research is to realize buildings that are safer, more comfortable and more energy-efficient by embedding adaptive functions of life into buildings. In this paper, we propose a new control system for building environments, focused on physiological adaptation, particularly homeostasis, endocrine system and immune system. Residents are used as living sensors and controllers in the control loop. A sensor agent robot is used to acquire resident's discomfort feeling, and to output hormone-like signals to activate devices to control the environments. The proposed system could control many devices without establishing complicated scenarios. Results obtained from some simulations and the demonstration experiments using an LED lighting system showed that the proposed system were able to achieve robust and stable control of environments without complicated scenarios.
Energy Technology Data Exchange (ETDEWEB)
Kuhn, T.E. [Fraunhofer Institute for Solar Energy Systems ISE, Freiburg (Germany)
2006-06-15
The author has developed two new sun-shading systems together with two different companies. These systems are compared with state of the art products on the basis of the new general evaluation method for facades with venetian blinds or other solar control systems that has been presented in detail in [T.E. Kuhn, Solar control: a general evaluation method for facades with venetian blinds or other solar control systems to be used 'stand-alone' or within building simulation programs, Energy Buildings, in press]. The main advantage is that the method can take into account realistic user behaviour (different utilisation modes). Without the new methodology, it would not have been possible to recognise the weaknesses of products which are currently on the market. This recognition was the basis for the design of the two new products: 1. The new stainless steel blind s-enn(Registered Trademark) selectively shields certain regions of the sky. This leads to a transparent appearance while direct insolation of the room and the associated glare is prevented in most cases. 2. The special shape of the 'Genius slats' of a new venetian blind ensures good sun-shading properties which are relatively independent of the actual setting of the slats over broad ranges, which ensures robust performance despite so-called 'faulty operation'. In other words: The performance of the new venetian blind is relatively insensitive to different utilisation modes. (author)
Development of Inorganic Solar Cells by Nanotechnology
Institute of Scientific and Technical Information of China (English)
Yafei Zhang; Huijuan Geng; Zhihua Zhou; Jiang Wu; Zhiming Wang; Yaozhong Zhang; Zhongli Li; Liying Zhang; Zhi Yang; Huey Liang Hwang
2012-01-01
Inorganic solar cells, as durable photovoltaic devices for harvesting electric energy from sun light,have received tremendous attention due to the fear of exhausting the earth’s energy resources and damaging the living environment due to greenhouse gases. Some recent developments in nanotechnology have opened up new avenues for more relevant inorganic solar cells produced by new photovoltaic conversion concepts and effective solar energy harvesting nanostructures. In this review, the multiple exciton generation effect solar cells, hot carrier solar cells, one dimensional material constructed asymmetrical schottky barrier arrays, noble nanoparticle induced plasmonic enhancement, and light trapping nanostructured semiconductor solar cells are highlighted.
Coordinated weather balloon solar radiation measurements during a solar eclipse.
Harrison, R G; Marlton, G J; Williams, P D; Nicoll, K A
2016-09-28
Solar eclipses provide a rapidly changing solar radiation environment. These changes can be studied using simple photodiode sensors, if the radiation reaching the sensors is unaffected by cloud. Transporting the sensors aloft using standard meteorological instrument packages modified to carry extra sensors, provides one promising but hitherto unexploited possibility for making solar eclipse radiation measurements. For the 20 March 2015 solar eclipse, a coordinated campaign of balloon-carried solar radiation measurements was undertaken from Reading (51.44°N, 0.94°W), Lerwick (60.15°N, 1.13°W) and Reykjavik (64.13°N, 21.90°W), straddling the path of the eclipse. The balloons reached sufficient altitude at the eclipse time for eclipse-induced variations in solar radiation and solar limb darkening to be measured above cloud. Because the sensor platforms were free to swing, techniques have been evaluated to correct the measurements for their changing orientation. In the swing-averaged technique, the mean value across a set of swings was used to approximate the radiation falling on a horizontal surface; in the swing-maximum technique, the direct beam was estimated by assuming that the maximum solar radiation during a swing occurs when the photodiode sensing surface becomes normal to the direction of the solar beam. Both approaches, essentially independent, give values that agree with theoretical expectations for the eclipse-induced radiation changes.This article is part of the themed issue 'Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse'. © 2016 The Authors.
Homeostasis lighting control based on relationship between lighting environment and human behavior
Ueda, Risa; Mita, Akira
2015-03-01
Although each person has own preferences, living spaces which can respond to various preferences and needs have not become reality. Focusing on the lighting environments which influence on the impression of living spaces, this research aims to offer comfortable lighting environments for each resident by a flexible control. This research examines the relationship between lighting environments and human behaviors considering colored lights. In accord with the relationship, this research proposes an illuminance-color control system which flexibly changes spatial environments responding to human conditions. Firstly, the psychological evaluation was conducted in order to build human models for various environments. As a result, preferred lighting environments for each examinee were determined for particular behaviors. Moreover, satisfaction levels of lighting environments were calculated by using seven types of impression of the environments as parameters. The results were summarized as human models. Secondly, this research proposed "Homeostasis Lighting Control System", which employs the human models. Homeostasis lighting control system embodies the algorithm of homeostasis, which is one of the functions of the physiological adaptation. Human discomfort feelings are obtained automatically by the sensor agent robot. The system can offer comfortable lighting environments without controlling environments by residents autonomously based on the information from the robot. This research takes into accounts both illuminance and color. The robot communicates with the server which contains human models, then the system corresponds to individuals. Combining these three systems, the proposed system can effectively control the lighting environment. At last, the feasibility of the proposed system was verified by simulation experiments.
Solar system for soil drainage
International Nuclear Information System (INIS)
Kocic, Z.R.; Stojanovic, J.B.; Antic, M.A.; Pavlovic, T.M.
1999-01-01
The paper reviews solar system for drainage of the cultivable agricultural surfaces which can be situated near the rivers in plains. These are usually very fertile surfaces which cannot be cultivated die to constant presence of the water. Using such solar systems should increase the percentage of cultivable surfaces. These systems can also be installed on the cultivable agricultural surfaces, where the water surfaces or so called still waters appear, which make impossible the application of agritechnical measures on these surfaces, significantly decreasing crops and creating conditions for the growth of pond plants and animals. Increasing the percentage of cultivable agricultural surfaces would increase national agricultural income. At the same time, increasing the percentage of cultivable agricultural surfaces decreases the surfaces of unhealthy bog, swamp and marshland soils, where many insect breed. They are the cause for soil spraying from the air, which causes the pollution of environment. Solar systems do not pollute the environment because they use solar energy as the purest source of energy. Their usage has special significance in the places where there is no electricity distribution network
International Nuclear Information System (INIS)
Fathabadi, Hassan
2016-01-01
Highlights: • Novel high accurate sensorless dual-axis solar tracker. • It has the advantages of both sensor based and sensorless solar trackers. • It does not have the disadvantages of sensor based and sensorless solar trackers. • Tracking error of only 0.11° that is less than the tracking errors of others. • An increase of 28.8–43.6% depending on the seasons in the energy efficiency. - Abstract: In this study, a novel high accurate sensorless dual-axis solar tracker controlled by the maximum power point tracking unit available in almost all photovoltaic systems is proposed. The maximum power point tracking controller continuously calculates the maximum output power of the photovoltaic module/panel/array, and uses the altitude and azimuth angles deviations to track the sun direction where the greatest value of the maximum output power is extracted. Unlike all other sensorless solar trackers, the proposed solar tracking system is a closed loop system which means it uses the actual direction of the sun at any time to track the sun direction, and this is the contribution of this work. The proposed solar tracker has the advantages of both sensor based and sensorless dual-axis solar trackers, but it does not have their disadvantages. Other sensorless solar trackers all are open loop, i.e., they use offline estimated data about the sun path in the sky obtained from solar map equations, so low exactness, cloudy sky, and requiring new data for new location are their problems. A photovoltaic system has been built, and it is experimentally verified that the proposed solar tracking system tracks the sun direction with the tracking error of 0.11° which is less than the tracking errors of other both sensor based and sensorless solar trackers. An increase of 28.8–43.6% depending on the seasons in the energy efficiency is the main advantage of utilizing the proposed solar tracking system.
Implementation of a control system test environment in UNIX
International Nuclear Information System (INIS)
Brittain, C.R.; Otaduy, P.J.; Rovere, L.A.
1990-01-01
This paper discusses how UNIX features such as shared memory, remote procedure calls, and signalling have been used to implement a distributed computational environment ideal for the development and testing of digital control systems. The resulting environment -based on features commonly available in commercial workstations- is flexible, allows process simulation and controller development to proceed in parallel, and provides for testing and validation in a realistic environment. In addition, the use of shared memory to exchange data allows other tasks such as user interfaces and recorders to be added without affecting the process simulation or controllers. A library of functions is presented which provides a simple interface to using the features described. These functions can be used in either C or FORTRAN programs and have been tested on a network of Sun workstations and an ENCORE parallel computer. 6 refs., 2 figs
Microwave energy transmission system for solar power station
Energy Technology Data Exchange (ETDEWEB)
Matsumoto, Hiroshi
1988-05-05
This paper deals with a microwave wireless energy transmission system which will be required for a solar power station under investigation, particularly, it describes its foundation and future investigation. It is supposed that for realization of microwave wireless transmission techniques, it is most important to investigate the effect of strong microwave beams on a plasma environment, establish control techniques for microwave beams in which a retro-directive system is combined with a computer control system, and develop a semiconductor transmission module. Institute of Space and Astronautical Science (Japan) made an experiment on the effect of microwaves on ionospheric plasma by using an observatory rocket. The institute has planned to make an experiment on a microwave energy transmission system which is to be mounted to a small-scale space flyer unit in order to examine the control of microwave beams and 10 KW power transmission, in addition to investigation on the interaction of microwave energy beams with a plasma environment. (4 figs, 3 tabs, 20 refs)
Comprehensive Planning for Passive Solar Architectural Retrofit
1980-05-01
technical information, and the natural environ- ment. Since the Air Force Energy plan stresses Passive Solar (Architecture) before using Active Solar...retrofitted by-1990, and the Air Force Energy Plan stresses Passive Solar Applications. Bdcause of this requirement, you must consider the following retrofit...OF THI SUN AT NOON ON O CUMIN 21 EXAWMKU[ AT 3M. AN I S - W Figure 12-4 12-3 Skylight- use a reflector ,with horizontal skylights to ,iincrease solar
ICARUS Mission, Next Step of Coronal Exploration after Solar Orbiter and Solar Probe Plus
Krasnoselskikh, V.; Tsurutani, B.; Velli, M.; Maksimovic, M.; Balikhin, M. A.; Dudok de Wit, T.; Kretzschmar, M.
2017-12-01
The primary scientific goal of ICARUS, a mother-daughter satellite mission, will be to determine how the magnetic field and plasma dynamics in the outer solar atmosphere give rise to the corona, the solar wind and the heliosphere. Reaching this goal will be a Rosetta-stone step, with results broadly applicable in the fields of space plasma and astrophysics. Within ESA's Cosmic Vision roadmap, these goals address Theme 2: How does the solar system work ?" Investigating basic processes occurring from the Sun to the edge of the Solar System". ICARUS will not only advance our understanding of the plasma environment around the Sun, but also of the numerous magnetically active stars with hot plasma coronae. ICARUS I will perform the firstever direct in situ measurements of electromagnetic fields, particle acceleration, wave activity, energy distribution and flows directly in the regions where the solar wind emerges from the coronal plasma. ICARUS I will have a perihelion at 1 Solar radius from its surface, it will cross the region where the major energy deposition occurs. The polar orbit of ICARUS I will enable crossing the regions where both the fast and slow wind are generated. It will probe local characteristics of the plasma and provide unique information about the processes involved in the creation of the solar wind. ICARUS II will observe this region using remote-sensing instruments, providing simultaneous information about regions crossed by ICARUS I and the solar atmosphere below as observed by solar telescopes. It will provide bridges for understanding the magnetic links between heliosphere and solar atmosphere. Such information is crucial to understanding of the physics and electrodynamics of the solar atmosphere. ICARUS II will also play an important relay role, enabling the radio-link with ICARUS I. It will receive, collect and store information transmitted from ICARUS I during its closest approach to the Sun. It will perform preliminary data processing and
Swanson, T. D.; Ollendorf, S.
1979-01-01
This paper addresses the potential for enhanced solar system performance through sophisticated control of the collector loop flow rate. Computer simulations utilizing the TRNSYS solar energy program were performed to study the relative effect on system performance of eight specific control algorithms. Six of these control algorithms are of the proportional type: two are concave exponentials, two are simple linear functions, and two are convex exponentials. These six functions are typical of what might be expected from future, more advanced, controllers. The other two algorithms are of the on/off type and are thus typical of existing control devices. Results of extensive computer simulations utilizing actual weather data indicate that proportional control does not significantly improve system performance. However, it is shown that thermal stratification in the liquid storage tank may significantly improve performance.
Tropospheric weather influenced by solar wind through atmospheric vertical coupling downward control
Prikryl, Paul; Bruntz, Robert; Tsukijihara, Takumi; Iwao, Koki; Muldrew, Donald B.; Rušin, Vojto; Rybanský, Milan; Turňa, Maroš; Šťastný, Pavel
2018-06-01
Occurrence of severe weather in the context of solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system is investigated. It is observed that significant snowfall, wind and heavy rain, particularly if caused by low pressure systems in winter, tend to follow arrivals of high-speed solar wind. Previously published statistical evidence that explosive extratropical cyclones in the northern hemisphere tend to occur within a few days after arrivals of high-speed solar wind streams from coronal holes (Prikryl et al., 2009, 2016) is corroborated for the southern hemisphere. Cases of severe weather events are examined in the context of the magnetosphere-ionosphere-atmosphere (MIA) coupling. Physical mechanism to explain these observations is proposed. The leading edge of high-speed solar wind streams is a locus of large-amplitude magneto-hydrodynamic waves that modulate Joule heating and/or Lorentz forcing of the high-latitude lower thermosphere generating medium-scale atmospheric gravity waves that propagate upward and downward through the atmosphere. Simulations of gravity wave propagation in a model atmosphere using the Transfer Function Model (Mayr et al., 1990) reveal that propagating waves originating in the lower thermosphere can excite a spectrum of gravity waves in the lower atmosphere. In spite of significantly reduced amplitudes but subject to amplification upon reflection in the upper troposphere, these gravity waves can provide a lift of unstable air to release instabilities in the troposphere and initiate convection to form cloud/precipitation bands. It is primarily the energy provided by release of latent heat that leads to intensification of storms. These results indicate that vertical coupling in the atmosphere exerts downward control from solar wind to the lower atmospheric levels influencing tropospheric weather development.
High Temperature InGaN-based Solar Cells
National Aeronautics and Space Administration — An efficient generation of solar power in a space environment is an enduring challenging for all NASA missions. The current available solar cells, however, suffer...
International Nuclear Information System (INIS)
Hilali, Mohamed M; Banerjee, Sanjay; Sreenivasan, S V; Yang Shuqiang; Miller, Mike; Xu, Frank
2012-01-01
In this paper, we have explored manufacturable approaches to sub-wavelength controlled three-dimensional (3D) nano-patterns with the goal of significantly enhancing the photocurrent in amorphous silicon solar cells. Here we demonstrate efficiency enhancement of about 50% over typical flat a-Si thin-film solar cells, and report an enhancement of 20% in optical absorption over Asahi textured glass by fabricating sub-wavelength nano-patterned a-Si on glass substrates. External quantum efficiency showed superior results for the 3D nano-patterned thin-film solar cells due to enhancement of broadband optical absorption. The results further indicate that this enhanced light trapping is achieved with minimal parasitic absorption losses in the deposited transparent conductive oxide for the nano-patterned substrate thin-film amorphous silicon solar cell configuration. Optical simulations are in good agreement with experimental results, and also show a significant enhancement in optical absorption, quantum efficiency and photocurrent. (paper)
Mobile robot navigation in unknown static environments using ANFIS controller
Directory of Open Access Journals (Sweden)
Anish Pandey
2016-09-01
Full Text Available Navigation and obstacle avoidance are the most important task for any mobile robots. This article presents the Adaptive Neuro-Fuzzy Inference System (ANFIS controller for mobile robot navigation and obstacle avoidance in the unknown static environments. The different sensors such as ultrasonic range finder sensor and sharp infrared range sensor are used to detect the forward obstacles in the environments. The inputs of the ANFIS controller are obstacle distances obtained from the sensors, and the controller output is a robot steering angle. The primary objective of the present work is to use ANFIS controller to guide the mobile robot in the given environments. Computer simulations are conducted through MATLAB software and implemented in real time by using C/C++ language running Arduino microcontroller based mobile robot. Moreover, the successful experimental results on the actual mobile robot demonstrate the effectiveness and efficiency of the proposed controller.
A Compatible Control Algorithm for Greenhouse Environment Control Based on MOCC Strategy
Hu, Haigen; Xu, Lihong; Zhu, Bingkun; Wei, Ruihua
2011-01-01
Conventional methods used for solving greenhouse environment multi-objective conflict control problems lay excessive emphasis on control performance and have inadequate consideration for both energy consumption and special requirements for plant growth. The resulting solution will cause higher energy cost. However, during the long period of work and practice, we find that it may be more reasonable to adopt interval or region control objectives instead of point control objectives. In this pape...
Nanoparticles and nanoimaging for organic solar cells
DEFF Research Database (Denmark)
Pedersen, Emil Bøje Lind
Solar energy is one of the few energy sources with the potential to power humanity in a future scenario where fossil fuels are not attractive due to their effect on the global climate or fossil fuels have been depleted all together. Organic photovoltaics is a promising technology for solar...... is devoted to studying organic photovolatics on the micro to nanometer scale, in particular photoactive Landfester particles. The ultimate goal is to increase the performance of Landfester particle layers so they can become a viable alternative to photoactive layers cast from organic solvent. Transition...... to a water based ink would provide a production environment without toxic fumes from organic solvents and the nanoparticle structure would provide additional morphological control. The first part of the dissertation maps photodegradation in active layers cast from organic solvents. Reduction in degradation...
Solar energy; Product information. Zonne-energie; Produktinformatie
Energy Technology Data Exchange (ETDEWEB)
Kruisheer, N
1992-03-20
In five brief articles product information is given on solar energy applications with special attention to the Netherlands. After an introduction on solar energy availability in the Netherlands the developments in solar boiler techniques are dealt with. Solar water heaters have advantages for the environment, and government subsidies stimulate different uses of such water heaters. Also the developments of solar cells show good prospects, not only for developing countries, but also for the industrialized countries. In brief the developments in solar energy storage and the connection of solar equipment to the grid are discussed. Finally attention is paid to the applications of passive solar energy in the housing construction, the use of transparent thermal insulation and the developments of translucent materials. 18 figs., 18 ills.
Energy Technology Data Exchange (ETDEWEB)
Caneppele, Fernando de Lima [Universidade Estadual Paulista (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Curso de Pos-Graduacao em Energia na Agricultura], E-mail: fernando@itapeva.unesp.br; Seraphim, Odivaldo Jose [Universidade Estadual Paulista (FCA/UNESP), Botucatu, SP (Brazil). Fac. de Ciencias Agronomicas. Dept. de Engenharia Rural], E-mail: seraphim@fca.unesp.br
2010-07-01
This paper presents the application and use of a methodology based on fuzzy theory and simulates its use in intelligent control of a hybrid system for generating electricity, using solar energy, photovoltaic and wind. When using a fuzzy control system, it reached the point of maximum generation of energy, thus shifting all energy generated from the alternative sources-solar photovoltaic and wind, cargo and / or batteries when its use not immediately. The model uses three variables used for entry, which are: wind speed, solar radiation and loading the bank of batteries. For output variable has to choose which of the batteries of the battery bank is charged. For the simulations of this work is used MATLAB software. In this environment mathematical computational are analyzed and simulated all mathematical modeling, rules and other variables in the system described fuzzy. This model can be used in a system of control of hybrid systems for generating energy, providing the best use of energy sources, sun and wind, so we can extract the maximum energy possible these alternative sources without any prejudice to the environment. (author)
Energy Technology Data Exchange (ETDEWEB)
Behringer, Rolf; Goetz, Michael
2008-07-01
Even in the Western and Central European climate, solar cookers can enable environment-friendly cooking and baking on about 100 to 150 days of the year. Some foods taste better when cooked more carefully, and vitamins and nutrients will be better preserved than in conventionally cooked food. After a short historical outline, the authors present some commercial solar cookers suited for our climate. This is followed by a detailed guide on how to construct a simple wooden solar cooker box from commercially available materials. Examples of solar cooking initiatives illustrate the many applications of solar cookers and parabolic trough cookers. The text is supplemented by practical hints and recipes.
Verdoni, A. P.; Denker, C.; Varsik, J. R.; Shumko, S.; Nenow, J.; Coulter, R.
2007-09-01
The New Solar Telescope (NST) is a 1.6-meter off-axis Gregory-type telescope with an equatorial mount and an open optical support structure. To mitigate the temperature fluctuations along the exposed optical path, the effects of local/dome-related seeing have to be minimized. To accomplish this, NST will be housed in a 5/8-sphere fiberglass dome that is outfitted with 14 active vents evenly spaced around its perimeter. The 14 vents house louvers that open and close independently of one another to regulate and direct the passage of air through the dome. In January 2006, 16 thermal probes were installed throughout the dome and the temperature distribution was measured. The measurements confirmed the existence of a strong thermal gradient on the order of 5° Celsius inside the dome. In December 2006, a second set of temperature measurements were made using different louver configurations. In this study, we present the results of these measurements along with their integration into the thermal control system (ThCS) and the overall telescope control system (TCS).
Receding Horizon Optimal Control of a Solar Greenhouse
Ooteghem, van R.J.C.; Willigenburg, van L.G.; Straten, van G.
2005-01-01
A solar greenhouse has been designed that maximizes solar energy use and minimizes fossil energy consumption. It is based on a conventional Venlo greenhouse extended with a heat pump, a heat exchanger, an aquifer and ventilation with heat recovery. The goal is to minimize fossil energy consumption,
Effect of HIV/AIDS on the control environment.
Coetzee, Philna
2006-07-01
The management of organizations is responsible for risk management and control systems. HIV/AIDS could be a great threat in the achievement of strategic business objectives, implicating a great concern for management. Management needs to understand this possible risk. This study aims to identify the effect that HIV/AIDS could have on the different elements of the control environment. The archival research method was used. It was established that no formal research was conducted to date on the effect of HIV/AIDS on the control environment as a whole. Various studies have included the effect of HIV/AIDS on certain factors of the control environment. These studies will be discussed briefly to identify relevant findings. The study indicated that the disease could affect various aspects of the control environment, namely: competency of the workforce (e.g. productivity, quality of work, absenteeism, loss of skills and knowledge, training and recruitment, etc.); organizational structure (e.g. increase use of technology labour, disruption of processes, level of employees affected by the disease); human resource (HR) policies and practices (e.g. legislation applicable, prevention and awareness programmes, compensation and benefits). Research limitation: HIV/AIDS is a relatively new potential risk to organizations. Knowledge of the disease is limited. HIV/AIDS is also a very sensitive issue as people fear the disease and do not like to discuss its existence. Government determined that it should be a non-notifiable disease and the disease is currently greatly stigmatized. The databases of companies investigated by other research studies were not developed to gather all the relevant information. Management should be aware that HIV/AIDS poses a possible risk to organizations. Data on the effect of HIV/AIDS should be gathered and used in the decision-making process on how to manage this risk. To be able to fulfil this duty, management first has to determine: whether HIV/AIDS is
Study of a 30-M Boom For Solar Sail-Craft: Model Extendibility and Control Strategy
Keel, Leehyun
2005-01-01
extendibility question of the analytical models. In operation, rapid temperature changes can be induced in solar sails as they transition from day to night and vice versa. This generates time dependent thermally induced forces, which may in turn create oscillation in structural members such as booms. Such oscillations have an adverse effect on system operations, precise pointing of instruments and antennas and can lead to self excited vibrations of increasing amplitude. The latter phenomenon is known as thermal flutter and can lead to the catastrophic failure of structural systems. To remedy this problem, an active vibration suppression system has been developed. It was shown that piezoelectric actuators used in conjunction with a Proportional Feedback Control (PFC) law (or Velocity Feedback Control (VFC) law) can induce moments that can suppress structural vibrations and prevent flutter instability in spacecraft booms. In this study, we will investigate control strategies using piezoelectric transducers in active, passive, and/or hybrid control configurations. Advantages and disadvantages of each configuration will be studied and experiments to determine their capabilities and limitations will be planned. In particular, special attention will be given to the hybrid control, also known as energy recycling, configuration due to its unique characteristics.
Designing of new structure PID controller of boost converter for solar photovoltaic stability
Shabrina, Hanifati Nur; Setiawan, Eko Adhi; Sabirin, Chip Rinaldi
2017-03-01
Nowadays, the utilization of renewable energy as the source on distributed generation system is increasing. It aims to reduce reliance and power losses from utility grid and improve power stability in near loads. One example of renewable energy technology that have been highly proven on the market is solar photovoltaic (PV). This technology converts photon from sunlight into electricity. However, the fluctuation of solar radiation that often occurs become the main problem for this system. Due to this condition, the power conversion is needed to convert the change frequently in photovoltaic panel into a stable voltage to the system. Developing control of boost converter has important role to keep ability of system stabilization. A conventional PID (Proportional, Integral, Derivative) control is mostly used to achieve this goal. In this research, a design of new structure PID controller of boost converter is offered to better optimize system stability comparing to the conventional PID. Parameters obtained from this PID structure have been successfully yield a stable boost converter output at 200 V with 10% overshoot, 1.5 seconds of settling time, and 1.5% of steady-state error.
Heliosheath Space Environment Interactions with Icy Bodies in the Outermost Solar System
Cooper, John F.; Hill, Matthew E.; Richardson, John D.; Sturner, Steven J.
2006-01-01
The Voyager 1 and 2 spacecraft are exploring the space environment of the outermost solar system at the same time that earth-based astronomy continues to discover new icy bodies, one larger than Pluto, in the transitional region outward from the Classical Kuiper Belt to the Inner Oort Cloud. Some of the Scattered Disk Objects in this region periodically pass through the heliosheath, entered by Voyager 1 in Dec. 2004 and later expected to be reached by Voyager 2, and out even beyond the heliopause into the Very Local Interstellar Medium. The less energetic heliosheath ions, important for implantation and sputtering processes, are abundant near and beyond the termination shock inner boundary, but the source region of the more penetrating anomalous cosmic ray component has not yet been found. Advantageous for modeling of icy body interactions, the measured heliosheath flux spectra are relatively more stable within this new regime of isotropic compressional magnetic turbulence than in the upstream heliospheric environment. The deepest interactions and resultant radiation-induced chemistry arise from the inwardly diffusing component of the galactic cosmic ray ions with significant intensity modulation also arising in the heliosheath beyond Voyager 1. Surface gardening by high-velocity impacts of smaller bodies (e.g., fragments of previous KBO collisions) and dust is a further space weathering process setting the time scales for long term exposure of different regolith layers to the ion irradiation. Sputtering and ionization of impact ejecta grains may provide a substantial feedback of pickup ions for multiple cycles of heliosheath acceleration and icy body interaction. Thus the space weathering interactions are potentially of interest not only for effects on sensible surface composition of the icy bodies but also for evolution of the heliosheath plasma energetic ion, and neutral emission environment.
The Preservation of "Non-Biological" Environments in the Solar System
Hargrove, Eugene
Nature preservation will be a central element of the exploration of the Solar System, whether this emphasis is initially planned for or not. Exploration of extraterrestrial environments will generate images and scientific information that will excite the imagination of the general public throughout the world and be supportive of more funding for exploration. However, damage to the environments visited, once made public, will likely generate a backlash against exploration programs that could inhibit exploration or even bring it completely to an end. The exploration in the nineteenth century of the western United States, with landscapes aesthetically very different from those found in Europe but very similar to those existing on the Moon and on Mars, provides an excellent indication of what will happen in off-planet exploration. Nearly every place painted by a major artist or photographed by a photographer on a geological survey during that time period is today a national park or national monument. If extraterrestrial environments are not protected, the major space societies that are currently enthusiastically supportive of space agencies around the world could become political opponents, much as the Sierra Club evolved into a serious and effective critic of the U.S. Forest Service and National Park Service in the United States. At a minimum, space agencies must be protective of the historical landing sites on the Moon, avoid strip mining on the Moon that may draw criticism, and protect major features on Mars from damage, such as the Cydonian Face on Mars, Valles Marineris, the grand canyon of Mars, and Olympus Mons, a mountain three times as tall as Mount Everest. A good first step might be to establish a world-heritage-style site to protect the visible side of the Moon. Although extraterrestrial sites may initially be labeled "non-biological," caution must be taken to be protective of possible extraterrestrial life, active or dormant, even in the most unlikely
Directory of Open Access Journals (Sweden)
Hideki Takebayashi
2018-01-01
Full Text Available The outdoor open space is used for various purposes, e.g., to walk, rest, talk, meet, study, exercise, play, perform, eat, and drink. Therefore, it is desirable to provide various thermal environments according to users’ needs and their actual conditions. In this study, the radiation environment was evaluated, focusing on ground cover materials and solar radiation shading, through the examination on the redevelopment buildings in front of Central Osaka Station. The spatial distribution of solar radiation shading was calculated using ArcGIS and building shape data. Surface temperatures on the ground and wall are calculated based on the surface heat budget equation. MRT (Mean Radiant Temperature of the human body is calculated assuming that the human body is a sphere. The most dominant factor for the radiant environment is solar radiation shielding and the next is the improvement of surface cover. It is difficult to make SET* (Standard new Effective Temperature comfortable in the afternoon by both solar radiation shielding and improved surface cover because the air temperature is too high on a typical summer day (August. However, particularly in Rooftop Gardens and Green Garden, because the areas of shade grass and water are large, there are several places where people do not feel uncomfortable.
The efficacy of control environment as fraud deterrence in local government
Directory of Open Access Journals (Sweden)
Nuswantara Dian Anita
2017-12-01
Full Text Available In a globalised scenario, the topic of an enormous increase of malfeasance in the local governments, posing catastrophic threats which come from vicious bureaucratic apparatus, becomes a global phenomenon. This current study uses case study material on the risk management control system specially the control environment in Indonesia local governments to extend existing theory by developing a contingency theory for the public sector. Within local government, contingency theory has emerged as a lens for exploring the links between public sector initiatives to improve risk mitigation and the structure of the control system. The case illustrates that the discretion of control environment - the encouragement of a local government’s control environment - is considered as a springboard for fraud deterrence and might be the loopholes in the government control systems.
Optical solar energy adaptations and radiative temperature control of green leaves and tree barks
Energy Technology Data Exchange (ETDEWEB)
Henrion, Wolfgang; Tributsch, Helmut [Department of Si-Photovoltaik and Solare Energetik, Hahn-Meitner-Institut Berlin, 14109 Berlin (Germany)
2009-01-15
Trees have adapted to keep leaves and barks cool in sunshine and can serve as interesting bionic model systems for radiative cooling. Silicon solar cells, on the other hand, loose up to one third of their energy efficiency due to heating in intensive sunshine. It is shown that green leaves minimize absorption of useful radiation and allow efficient infrared thermal emission. Since elevated temperatures are detrimental for tensile water flow in the Xylem tissue below barks, the optical properties of barks should also have evolved so as to avoid excessive heating. This was tested by performing optical studies with tree bark samples from representative trees. It was found that tree barks have optimized their reflection of incoming sunlight between 0.7 and 2 {mu}m. This is approximately the optical window in which solar light is transmitted and reflected by green vegetation. Simultaneously, the tree bark is highly absorbing and thus radiation emitting between 6 and 10 {mu}m. These two properties, mainly provided by tannins, create optimal conditions for radiative temperature control. In addition, tannins seem to have adopted a function as mediators for excitation energy towards photo-antioxidative activity for control of radiation damage. The results obtained are used to discuss challenges for future solar cell optimization. (author)
DEFF Research Database (Denmark)
Toftum, Jørn
2010-01-01
of control, as perceived by occupants, seemed more important for the prevalence of adverse symptoms and building-related symptoms than the ventilation mode per se. This result indicates that even though the development and application of new indoor environment sensors and HVAC control systems may allow...... for fully automated IEQ control, such systems should not compromise occupants' perception of having some degree of control of their indoor environment....... a discrepancy in the degree of perceived control. The database was composed of 1272 responses obtained in 24 buildings of which 15 had mechanical ventilation (997 responses) and 9 had natural ventilation (275 responses). The number of occupant-reported control opportunities was higher in buildings with natural...
Overview of the LHD central control room data monitoring environment
International Nuclear Information System (INIS)
Emoto, M.; Yoshinuma, M.; Yoshida, M.; Nakanishi, H.; Iwata, C.; Ohsuna, M.; Nonomura, M.; Imazu, S.; Yokota, M.; Aoyagi, M.; Ogawa, H.; Ida, K.; Watanabe, K.; Kaneko, O.
2016-01-01
Highlights: • In this paper, the data monitoring environments in the LHD central control room, for example, summary data graph and video monitoring tools are introduced. Also, the environments for the remote participants are introduced. - Abstract: During the Large Helical Device (LHD) experiments, many scientists and technical staff are working in the central control room to operate the experiment. They must manage the diagnostics and controlling devices referring to the results of the last plasma shot. Also, the experiment coordinator must decide the conditions for the subsequent experiments using the results. Furthermore, many scientists are participating in the experiment from remote sites. Therefore, it is important to share the information in the control room quickly, such as the results of the last plasma discharge, with the remote user as well as with the staff in the room. In this paper, the data monitoring environment in the LHD central control room is introduced.
Overview of the LHD central control room data monitoring environment
Energy Technology Data Exchange (ETDEWEB)
Emoto, M., E-mail: emoto.masahiko@nifs.ac.jp; Yoshinuma, M.; Yoshida, M.; Nakanishi, H.; Iwata, C.; Ohsuna, M.; Nonomura, M.; Imazu, S.; Yokota, M.; Aoyagi, M.; Ogawa, H.; Ida, K.; Watanabe, K.; Kaneko, O.
2016-11-15
Highlights: • In this paper, the data monitoring environments in the LHD central control room, for example, summary data graph and video monitoring tools are introduced. Also, the environments for the remote participants are introduced. - Abstract: During the Large Helical Device (LHD) experiments, many scientists and technical staff are working in the central control room to operate the experiment. They must manage the diagnostics and controlling devices referring to the results of the last plasma shot. Also, the experiment coordinator must decide the conditions for the subsequent experiments using the results. Furthermore, many scientists are participating in the experiment from remote sites. Therefore, it is important to share the information in the control room quickly, such as the results of the last plasma discharge, with the remote user as well as with the staff in the room. In this paper, the data monitoring environment in the LHD central control room is introduced.
Design of a solar-assisted drying system using the double-pass solar collector
International Nuclear Information System (INIS)
Sopian, K.; Daud, W.R.; Supranto; Othman, M.Y.; Yatim, B.
2000-01-01
A solar-assisted drying system that uses the double-pass solar collector with porous media in the second channel has been designed and constructed at the Solar Energy Research Park, Universiti Kebangsaan Malaysia. The drying system has a total of six double-pass solar collectors. Each collector has a length of 240 cm and a width of 120 cm. The upper channel depth is 3.5 cm and the lower channel depth is 10.5 cm. The lower channel is filled up with steel wool as the porous media. The solar collectors are arranged as 2 banks of 3 collectors each in series. Internal manifold are used to connect the collectors. An auxiliary heater source is installed to supply heat under unfavourable solar radiation conditions. An on/off controller is used to control the startup and shutdown of the auxiliary heater. An outlet temperature of 80-90 0 C can be achieved at a solar radiation range of 800-900 W/m 3 , ambient temperature of 29 degree C and flow rate of O.20 kg/s. (Author)
Optimization of humidifying procedure in controlled environment for ...
African Journals Online (AJOL)
This study investigated mushroom cultivation in controlled indoor environment. For this, the environmental factors including humidity and temperature were controlled by humidifier and ventilation. Four ventilations were installed on tops to bring the air from inside to outside and four small ventilations were installed on side ...
An Economic Analysis of Solar Water & Space Heating.
Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.
Solar system designs for 13 cities were optimized so as to minimize the life cycle cost over the assumed 20-year lifetime of the solar energy systems. A number of major assumptions were made regarding the solar system, type and use of building, financial considerations, and economic environment used in the design optimization. Seven optimum…
Nicholson, Wayne L.; Schuerger, Andrew C.; Setlow, Peter
2005-01-01
The environment in space and on planets such as Mars can be lethal to microorganisms because of the high vacuum and high solar radiation flux, in particular UV radiation, in such environments. Spores of various Bacillus species are among the organisms most resistant to the lethal effects of high vacuum and UV radiation, and as a consequence are of major concern for planetary contamination via unmanned spacecraft or even natural processes. This review focuses on the spores of various Bacillus species: (i) their mechanisms of UV resistance; (ii) their survival in unmanned spacecraft, space flight and simulated space flight and Martian conditions; (iii) the UV flux in space and on Mars; (iv) factors affecting spore survival in such high UV flux environments.
International Nuclear Information System (INIS)
Nicholson, Wayne L.; Schuerger, Andrew C.; Setlow, Peter
2005-01-01
The environment in space and on planets such as Mars can be lethal to microorganisms because of the high vacuum and high solar radiation flux, in particular UV radiation, in such environments. Spores of various Bacillus species are among the organisms most resistant to the lethal effects of high vacuum and UV radiation, and as a consequence are of major concern for planetary contamination via unmanned spacecraft or even natural processes. This review focuses on the spores of various Bacillus species: (i) their mechanisms of UV resistance; (ii) their survival in unmanned spacecraft, space flight and simulated space flight and Martian conditions; (iii) the UV flux in space and on Mars; (iv) factors affecting spore survival in such high UV flux environments
Energy Technology Data Exchange (ETDEWEB)
Nicholson, Wayne L. [Department of Microbiology and Cell Science, University of Florida, Mail Code UF-1, Building M6-1025/SLSL, Kennedy Space Center, FL 32899 (United States)]. E-mail: WLN@ufl.edu; Schuerger, Andrew C. [Department of Plant Pathology, University of Florida, Mail Code UF-1, Space Life Sciences Laboratory, Kennedy Space Center, FL 32899 (United States)]. E-mail: acschuerger@ifas.ufl.edu; Setlow, Peter [Department of Molecular, Microbial and Structural Biology, University of Connecticut Health Center, 263 Farmington Avenue, Farmington, CT 06030 (United States)]. E-mail: setlow@nso2.uchc.edu
2005-04-01
The environment in space and on planets such as Mars can be lethal to microorganisms because of the high vacuum and high solar radiation flux, in particular UV radiation, in such environments. Spores of various Bacillus species are among the organisms most resistant to the lethal effects of high vacuum and UV radiation, and as a consequence are of major concern for planetary contamination via unmanned spacecraft or even natural processes. This review focuses on the spores of various Bacillus species: (i) their mechanisms of UV resistance; (ii) their survival in unmanned spacecraft, space flight and simulated space flight and Martian conditions; (iii) the UV flux in space and on Mars; (iv) factors affecting spore survival in such high UV flux environments.
Solar heating of the produced water of petroleum; Aquecimento solar da agua produzida de petroleo
Energy Technology Data Exchange (ETDEWEB)
Santos, Rogerio Pitanga; Chiavone-Filho, Osvaldo; Bezerra, Magna A. Santos; Melo, Josette Lourdes Sousa de; Oliveira, Jackson Araujo de; Ramos, Rafael E. Moura [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Schuhli, Juliana Bregenski; Andrade, Vivian Tavares de [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)
2008-07-01
In this work, experimental data of solar heating for common water and saline solution were measured. The solar heater is formed by a flat-plane collector and a thermal reservoir ('boiler'). The objective is to quantify the variation of fluids' temperature, and correlate it to environment variables, especially solar irradiation. Thereby, it is possible to estimate the solar heating of produced water of petroleum. The solar heater is part of a system of treatment of produced water, and its function is to pre-heat the fluid that enters into the solar distiller, increasing the productivity of distilled water. A saline solution that represents produced water was used in the experiments, using sodium chloride (1000 ppm). The experimental data demonstrates that the solar heater is capable to heat the fluid to temperatures close to 70 deg C, reaching temperatures close to 50 deg C even during cloudy days with low solar radiation. Furthermore, the solar collector energy system provides a higher rate of heating and trough of the thermal reservoir the temperature can remain longer. These are important aspects to the integration with solar distillation. (author)
Solar heating of the produced water of petroleum; Aquecimento solar da agua produzida de petroleo
Energy Technology Data Exchange (ETDEWEB)
Santos, Rogerio Pitanga; Chiavone-Filho, Osvaldo; Bezerra, Magna A. Santos; Melo, Josette Lourdes Sousa de; Oliveira, Jackson Araujo de; Ramos, Rafael E. Moura [Universidade Federal do Rio Grande do Norte (UFRN), Natal, RN (Brazil); Schuhli, Juliana Bregenski; Andrade, Vivian Tavares de [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas (CENPES)
2008-07-01
In this work, experimental data of solar heating for common water and saline solution were measured. The solar heater is formed by a flat-plane collector and a thermal reservoir ('boiler'). The objective is to quantify the variation of fluids' temperature, and correlate it to environment variables, especially solar irradiation. Thereby, it is possible to estimate the solar heating of produced water of petroleum. The solar heater is part of a system of treatment of produced water, and its function is to pre-heat the fluid that enters into the solar distiller, increasing the productivity of distilled water. A saline solution that represents produced water was used in the experiments, using sodium chloride (1000 ppm). The experimental data demonstrates that the solar heater is capable to heat the fluid to temperatures close to 70 deg C, reaching temperatures close to 50 deg C even during cloudy days with low solar radiation. Furthermore, the solar collector energy system provides a higher rate of heating and trough of the thermal reservoir the temperature can remain longer. These are important aspects to the integration with solar distillation. (author)
DEFF Research Database (Denmark)
Kazanci, Ongun Berk; Olesen, Bjarne W.
2015-01-01
indoor environment. For the energy consumption of the HVAC system, air-to-brine heat pump, mixing station and controller of the radiant floor, and the air handling unit were considered. The measurements were analyzed based on the achieved indoor environment category (according to EN 15251...... the floor cooling system) and increasing the ventilation rate provided a better thermal indoor environment but with increased energy consumption. The thermal indoor environment and energy performance of the house can be improved with decreased glazing area, increased thermal mass, installation of solar...
Employee quality, monitoring environment and internal control
Directory of Open Access Journals (Sweden)
Chunli Liu
2017-03-01
Full Text Available We investigate the effect of internal control employees (ICEs on internal control quality. Using special survey data from Chinese listed firms, we find that ICE quality has a significant positive influence on internal control quality. We examine the effect of monitoring on this result and find that the effect is more pronounced for firms with strict monitoring environments, especially when the firms implement the Chinese internal control regulation system (CSOX, have higher institutional ownership or attach greater importance to internal control. Our findings suggest that ICEs play an important role in the design and implementation of internal control systems. Our study should be of interest to both top managers who wish to improve corporate internal control quality and regulators who wish to understand the mechanisms of internal control monitoring.
Attitude Control System Design for the Solar Dynamics Observatory
Starin, Scott R.; Bourkland, Kristin L.; Kuo-Chia, Liu; Mason, Paul A. C.; Vess, Melissa F.; Andrews, Stephen F.; Morgenstern, Wendy M.
2005-01-01
The Solar Dynamics Observatory mission, part of the Living With a Star program, will place a geosynchronous satellite in orbit to observe the Sun and relay data to a dedicated ground station at all times. SDO remains Sun- pointing throughout most of its mission for the instruments to take measurements of the Sun. The SDO attitude control system is a single-fault tolerant design. Its fully redundant attitude sensor complement includes 16 coarse Sun sensors, a digital Sun sensor, 3 two-axis inertial reference units, 2 star trackers, and 4 guide telescopes. Attitude actuation is performed using 4 reaction wheels and 8 thrusters, and a single main engine nominally provides velocity-change thrust. The attitude control software has five nominal control modes-3 wheel-based modes and 2 thruster-based modes. A wheel-based Safehold running in the attitude control electronics box improves the robustness of the system as a whole. All six modes are designed on the same basic proportional-integral-derivative attitude error structure, with more robust modes setting their integral gains to zero. The paper details the mode designs and their uses.
Modeling of Maximum Power Point Tracking Controller for Solar Power System
Directory of Open Access Journals (Sweden)
Aryuanto Soetedjo
2012-09-01
Full Text Available In this paper, a Maximum Power Point Tracking (MPPT controller for solar power system is modeled using MATLAB Simulink. The model consists of PV module, buck converter, and MPPT controller. The contribution of the work is in the modeling of buck converter that allowing the input voltage of the converter, i.e. output voltage of PV is changed by varying the duty cycle, so that the maximum power point could be tracked when the environmental changes. The simulation results show that the developed model performs well in tracking the maximum power point (MPP of the PV module using Perturb and Observe (P&O Algorithm.
Derancourt, C; Bourdon-Lanoy, E; Grob, J-J; Guillaume, J-C; Bernard, P; Bastuji-Garin, S
2007-01-01
Multiple solar lentigos commonly seen on the upper back and shoulders of adults are classically considered as a sign of photodamage, although epidemiological studies are scarce. To assess whether these lesions are clinical markers of past severe sunburn. A case-control study in two outpatient dermatology clinics in French university hospitals. Past episodes of moderate and severe sunburn were compared between 145 adult patients with multiple solar lentigos on the upper back and 145 matched controls. In multivariate analysis adjusted for potential confounders, recalled episodes of sunburn during childhood, adolescence and adulthood were independently associated with the presence of multiple solar lentigos (adjusted odds ratios, 95% confidence intervals: 2.3 (1.1-5.2) and 28.1 (10.4-75.6) for moderate and severe sunburn, respectively). Multiple solar lentigos on the upper back and shoulders of adults are potential clinical markers of past severe sunburn which may thus be used to identify a population at higher risk of developing cutaneous malignant melanoma.
Adarsh Kumar; ChandraShekhar Sharma; Dr. Rajesh Kumar; Avinashkumar haldkar
2016-01-01
:Charge controller is the most important part of a Solar Photovoltaic Home LightingSystem (SPVHLS) which controls the charging ofbattery from photovoltaic (PV) module and discharging of battery through load. This paper analyzes testresults of fourteen charge controllers (CC) available in Indiaaccording to the Ministry of New and RenewableEnergy (MNRE) specification. The different parameters of charge controllers to be tested arebattery high voltage disconnect (HVD), lo...
Suematsu, Y.
2015-12-01
The Solar-C is a Japan-led international solar mission planned to be launched in mid2020. It is designed to investigate the magnetic activities of the Sun, focusing on the study in heating and dynamical phenomena of the chromosphere and corona, and also to develop an algorithm for predicting short and long term solar evolution. Since it has been revealed that the different parts of the magnetized solar atmosphere are essentially coupled, the SOLAR-C should tackle the spatial scales and temperature regimes that need to be observed in order to achieve a comprehensive physical understanding of this coupling. The science of Solar-C will greatly advance our understanding of the Sun, of basic physical processes operating throughout the universe. To dramatically improve the situation, SOLAR-C will carry three dedicated instruments; the Solar UV-Vis-IR Telescope (SUVIT), the EUV Spectroscopic Telescope (EUVST) and the High Resolution Coronal Imager (HCI), to jointly observe the entire visible solar atmosphere with essentially the same high spatial resolution (0.1-0.3 arcsec), performing high resolution spectroscopic measurements over all atmospheric regions and spectro-polarimetric measurements from the photosphere through the upper chromosphere. In addition, Solar-C will contribute to our understanding on the influence of the Sun-Earth environments with synergetic wide-field observations from ground-based and other space missions. Some leading science objectives and the mission concept, including designs of the three instruments aboard SOLAR-C will be presented.
Fundamentals of Solar Heating. Correspondence Course.
Sheet Metal and Air Conditioning Contractors National Association, Vienna, VA.
This course is designed for the use of employees of the air conditioning industry, and offers supervised correspondence instruction about solar technology. The following aspects of applied solar technology are covered: solar heating and cooling, solar radiation, solar collectors, heat storage control devices and specialty items, sizing solar…
Directory of Open Access Journals (Sweden)
Kideok Kwon
2015-04-01
Full Text Available A number of research works has studied packet scheduling policies in energy scavenging wireless sensor networks, based on the predicted amount of harvested energy. Most of them aim to achieve energy neutrality, which means that an embedded system can operate perpetually while meeting application requirements. Unlike other renewable energy sources, solar energy has the feature of distinct periodicity in the amount of harvested energy over a day. Using this feature, this paper proposes a packet transmission control policy that can enhance the network performance while keeping sensor nodes alive. Furthermore, this paper suggests a novel solar energy prediction method that exploits the relation between cloudiness and solar radiation. The experimental results and analyses show that the proposed packet transmission policy outperforms others in terms of the deadline miss rate and data throughput. Furthermore, the proposed solar energy prediction method can predict more accurately than others by 6.92%.
Kwon, Kideok; Yang, Jihoon; Yoo, Younghwan
2015-04-24
A number of research works has studied packet scheduling policies in energy scavenging wireless sensor networks, based on the predicted amount of harvested energy. Most of them aim to achieve energy neutrality, which means that an embedded system can operate perpetually while meeting application requirements. Unlike other renewable energy sources, solar energy has the feature of distinct periodicity in the amount of harvested energy over a day. Using this feature, this paper proposes a packet transmission control policy that can enhance the network performance while keeping sensor nodes alive. Furthermore, this paper suggests a novel solar energy prediction method that exploits the relation between cloudiness and solar radiation. The experimental results and analyses show that the proposed packet transmission policy outperforms others in terms of the deadline miss rate and data throughput. Furthermore, the proposed solar energy prediction method can predict more accurately than others by 6.92%.
GENI: A graphical environment for model-based control
International Nuclear Information System (INIS)
Kleban, S.; Lee, M.; Zambre, Y.
1989-10-01
A new method to operate machine and beam simulation programs for accelerator control has been developed. Existing methods, although cumbersome, have been used in control systems for commissioning and operation of many machines. We developed GENI, a generalized graphical interface to these programs for model-based control. This ''object-oriented''-like environment is described and some typical applications are presented. 4 refs., 5 figs
Desarrollo de un horno solar para el secado de plantas y vegetales usando control difuso
Directory of Open Access Journals (Sweden)
Oscar G. Ibarra Manzano
2012-05-01
Full Text Available Recientemente, el aprovechamiento de la energía solar en el deshidratado de productos agrícolas se ha vuelto cada día más común debido a los altos rendimientos en los productos post-cosecha. La inversión en tecnologías propias para contribuir con los productores del sector agroalimentario es un factor importante para el desarrollo de las cadenas productivas de nuestro país. En este trabajo se presenta el desarrollo de un horno solar para el secado de plantas y vegetales utilizando control difuso. Este es un sistema térmicamente controlado que permite disminuir el tiempo de secado de varios días a unas horas. Se realizaron pruebas de secado usando flor de jamaica, en las cuales se pudo disminuir el tiempo de secado de cuatro días a aproximadamente 5 h. Se presentan tanto la parte de diseño conceptual, como resultados experimentales del mismo. Los resultados obtenidos permiten ver la viabilidad del diseño propuesto.Recently, the use of solar energy in the dehydration of agricultural products is becomingmore common as high yields in the post-harvest products. Investment in technologies forcontributing to the producers of food products is an important factor for the development ofthe productive chains of our country. This paper presents the development of a solar oven fordrying plants and vegetables using fuzzy control. This is a heat-controlled system that allowsdecreasing the drying time from several days to hours. Drying tests were conducted usingjamaica flower, which could decrease the drying time from four days to about 5 h. We presentboth the conceptual design of the experimental results. The results obtained allow us to seethe feasibility of the proposed design.
Output feedback control of heat transport mechanisms in parabolic distributed solar collectors
Elmetennani, Shahrazed
2016-08-05
This paper presents an output feedback control for distributed parabolic solar collectors. The controller aims at forcing the outlet temperature to track a desired reference in order to manage the produced heat despite the external disturbances. The proposed control strategy is derived using the distributed physical model of the system to avoid the loss of information due to model approximation schemes. The system dynamics are driven to follow reference dynamics defined by a transport equation with a constant velocity, which allows to control the transient behavior and the response time of the closed loop. The designed controller depends only on the accessible measured variables which makes it easy for real time implementation and useful for industrial plants. Simulation results show the efficiency of the reference tracking closed loop under different working conditions.
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
Development of Inorganic Solar Cells by Nano-technology
Institute of Scientific and Technical Information of China (English)
Yafei Zhang; HueyLiang Hwang; Huijuan Geng; Zhihua Zhou; Jiang Wu; Zhiming Wang; Yaozhong Zhang; Zhongli Li; Liying Zhang; Zhi Yang
2012-01-01
Inorganic solar cells, as durable photovoltaic devices for harvesting electric energy from sun light, have received tremendous attention due to the fear of exhausting the earth’s energy resources and damaging the living environment due to greenhouse gases. Some recent developments in nanotechnology have opened up new avenues for more relevant inorganic solar cells produced by new photovoltaic conversion concepts and effective solar energy harvesting nanostructures. In this review, the multiple exciton generation effect solar cells, hot carrier solar cells, one dimensional material constructed asymmetrical schottky barrier arrays, noble nanoparticle induced plasmonic enhancement, and light trapping nanostructured semiconductor solar cells are highlighted.
Predicted solar cell edge radiation effects
International Nuclear Information System (INIS)
Gates, M.T.
1993-01-01
The Advanced Solar Cell Orbital Test (ASCOT) will test six types of solar cells in a high energy proton environment. During the design of the experiment a question was raised about the effects of proton radiation incident on the edge of the solar cells and whether edge radiation shielding was required. Historical geosynchronous data indicated that edge radiation damage is not detectable over the normal end of life solar cell degradation; however because the ASCOT radiation environment has a much higher and more energetic fluence of protons, considerably more edge damage is expected. A computer analysis of the problem was made by modeling the expected radiation damage at the cell edge and using a network model of small interconnected solar cells to predict degradation in the cell's electrical output. The model indicated that the deepest penetration of edge radiation was at the top of the cell near the junction where the protons have access to the cell through the low density cell/cover adhesive layer. The network model indicated that the cells could tolerate high fluences at their edge as long as there was high electrical resistance between the edge radiated region and the contact system on top of the cell. The predicted edge radiation related loss was less than 2% of maximum power for GaAs/Ge solar cells. As a result, no edge radiation protection was used for ASCOT
Bilateral teleoperation control to improve transparency in stiff environment with time delay
Directory of Open Access Journals (Sweden)
M. Azadegan
2014-09-01
Full Text Available This paper proposes a new bilateral control scheme to ensure both transparency and robust stability under unknown constant time delay in stiff environment. Furthermore, this method guaranties suitable performance and robust stability when transition occurs between soft and stiff environments. This framework is composed of an adaptive sliding mode controller and an adaptive impedance controller, where online estimation of the environment impedance is performed, and then used as the desired impedance at the master side. Numerical simulations are provided to verify the theoretical results under different conditions, such as constant and time-varying delay, obstructed environment and transitioning between soft and stiff environment. Afterwards, comparison with a recent work is addressed.
Numerical analysis of orbital transfers to Mars using solar sails and attitude control
Pereira, M. C.; de Melo, C. F.; Meireles, L. G.
2017-10-01
Solar sails present a promising alternative method of propulsion for the coming phases of the space exploration. With the recent advances in materials engineering, the construction of lighter and more resistant materials capable of impelling spaceships with the use of solar radiation pressure has become increasingly viable technologically and economically. The studies, simulations and analysis of orbital transfers from Earth to Mars proposed in this work were implemented considering the use of a flat solar sail. Maneuvers considering the delivery of a sailcraft from a Low Earth Orbit to the border of the Earth’s sphere of influence and interplanetary trajectories to Mars were investigated. A set of simulations were implemented varying the attitude of the sail relative to the Sun. Results show that a sailcraft can carry out transfers with final velocity with respect to Mars smaller than the interplanetary Patched-conic approximation, although this requires a longer time of transfers, provided the attitude of the sailcraft relative to the Sun can be controlled in some points of the trajectories.
Discussion on environment control technology of escaping cavern to uranium mines
International Nuclear Information System (INIS)
Cao Yongkai
2012-01-01
As the important refuge of Uranium Mines, the environment of Escaping Cavern is important to the miner's life. In order to attain the standard of Environment Control, the paper gave the method of Environment Control to the fire danger, pervious, collapse; Gave the isolating prevention time; represented the scheme of compressed-air self-help system, high pressure oxygen system, emergency oxygen system; Introduced the air purge equipment to handle the CO, CO 2 , bacterium and other harmful gas. At the same time, gave the method to control the temperature with the phase-change materials and private prevention. (author)
Environmental sampling program for a solar evaporation pond for liquid radioactive wastes
International Nuclear Information System (INIS)
Romero, R.; Gunderson, T.C.; Talley, A.D.
1980-04-01
Los Alamos Scientific Laboratory (LASL) is evaluating solar evaporation as a method for disposal of liquid radioactive wastes. This report describes a sampling program designed to monitor possible escape of radioactivity to the environment from a solar evaporation pond prototype constructed at LASL. Background radioactivity levels at the pond site were determined from soil and vegetation analyses before construction. When the pond is operative, the sampling program will qualitatively and quantitatively detect the transport of radioactivity to the soil, air, and vegetation in the vicinity. Possible correlation of meteorological data with sampling results is being investigated and measures to control export of radioactivity by biological vectors are being assessed
Pham, Kim; Bialas, Thomas
2012-01-01
The DDS SDOGS Integration Manager (DSIM) provides translation between native control and status formats for systems within DDS and SDOGS, and the ASIST (Advanced Spacecraft Integration and System Test) control environment in the SDO MOC (Solar Dynamics Observatory Mission Operations Center). This system was created in response for a need to centralize remote monitor and control of SDO Ground Station equipments using ASIST control environment in SDO MOC, and to have configurable table definition for equipment. It provides translation of status and monitoring information from the native systems into ASIST-readable format to display on pages in the MOC. The manager is lightweight, user friendly, and efficient. It allows data trending, correlation, and storing. It allows using ASIST as common interface for remote monitor and control of heterogeneous equipments. It also provides failover capability to back up machines.
Energy Technology Data Exchange (ETDEWEB)
Hennig, Jakob [Technische Univ. Bergakademie Freiberg (Germany); Hafner, Armin [SINTEF Energy Research, Trondheim (Norway); Eikevik, Trygve M. [NTNU, Trondheim (Norway)
2012-07-01
The investigation of alternative, sustainable concepts for cold production is worthwhile in times of increasing energy demand for cooling and air conditioning applications. Energy sources such as solar radiation can help to reduce the burden on the environment and energy networks. Solar electricity from photovoltaic cells or solar power from solar collectors can be used in refrigerating equipment (such as cold vapor compression chiller, absorption chiller, adsorption chillers, open systems, thermo-mechanical systems or ejector-based systems) are fed in order to produce the desired coldness. In many cases, the temporal coincidence of radiation supply and cooling requirements makes the solar cooling to a promising concept, especially at sites with a high solar radiation, large cooling demand, high energy prices, or insufficient access to public power grids. A model-based investigation of different solar cooling systems with an equivalent cooling capacity was carried out. The results show that the performance potential strongly depends on the selected technology and the site of the system. A balanced daily energy balance can be achieved with an appropriately dimensioned solar power plant with cooling concept. Depending on the system and interpretation, primary energy savings or a primary energy overhead can be achieved within a year in comparison to a conventional system.
The Ionizing Radiation Environment on the Moon
Adams, J. H., Jr.; Bhattacharya, M.; Lin, Zi-Wei; Pendleton, G.
2006-01-01
The ionizing radiation environment on the moon that contributes to the radiation hazard for astronauts consists of galactic cosmic rays, solar energetic particles and albedo particles from the lunar surface. We will present calculations of the absorbed dose and the dose equivalent to various organs in this environment during quiet times and during large solar particle events. We will evaluate the contribution of solar particles other than protons and the contributions of the various forms of albedo. We will use the results to determine which particle fluxes must be known in order to estimate the radiation hazard.
Solar Probe Plus MAG Sensor Thermal Design for Low Heater Power and Extreme Thermal Environment
Choi, Michael K.
2015-01-01
The heater power available for the Solar Probe Plus FIELDS MAG sensor is less than half of the heritage value for other missions. Nominally the MAG sensors are in the spacecraft's umbra. In the worst hot case, approximately 200 spacecraft communication downlinks, up to 10 hours each, are required at 0.7 AU. These downlinks require the spacecraft to slew 45 deg. about the Y-axis, exposing the MAG sensors and boom to sunlight. This paper presents the thermal design to meet the MAG sensor thermal requirements in the extreme thermal environment and with low heater power. A thermal balance test on the MAG sensor engineering model has verified the thermal design and correlated the thermal model for flight temperature predictions.
Solar radiation absorbing material
Googin, John M.; Schmitt, Charles R.; Schreyer, James M.; Whitehead, Harlan D.
1977-01-01
Solar energy absorbing means in solar collectors are provided by a solar selective carbon surface. A solar selective carbon surface is a microporous carbon surface having pores within the range of 0.2 to 2 micrometers. Such a surface is provided in a microporous carbon article by controlling the pore size. A thermally conductive substrate is provided with a solar selective surface by adhering an array of carbon particles in a suitable binder to the substrate, a majority of said particles having diameters within the range of about 0.2-10 microns.
Control device for automatic orientation of a solar panel based on a microcontroller (PIC16f628a)
Rezoug, M. R.; Krama, A.
2016-07-01
This work proposes a control device for autonomous solar tracker based on one axis, It consists of two main parts; the control part which is based on "the PIC16f628a"; it has the role of controlling, measuring and plotting responses. The second part is a mechanical device, which has the role of making the solar panel follows the day-night change of the sun throughout the year. Both parties are established to improve energy generation of the photovoltaic panels. In this paper, we will explain the main operating principles of our system. Also, we will provide experimental results which demonstrate the good performance and the efficiency of this system. This innovation is different from what has been proposed in previous studies. The important points of this system are maximum output energy and minimum energy consumption of solar tracker, its cost is relatively low with simplicity in implementation. The average power increase produced by using the tracking system for a particular day, is over 30 % compared with the static panel.
CDPP supporting tools to Solar Orbiter and Parker Solar Probe data exploitation
Genot, V. N.; Cecconi, B.; Dufourg, N.; Gangloff, M.; André, N.; Bouchemit, M.; Jacquey, C.; Pitout, F.; Rouillard, A.; Nathanaël, J.; Lavraud, B.; Durand, J.; Tao, C.; Buchlin, E.; Witasse, O. G.
2017-12-01
In recent years the French Centre de Données de la Physique des Plasmas (CDPP) has extended its data analysis capability by designing a number of new tools. In the solar and heliospheric contexts, and in direct support to the forthcoming solar ESA and NASA missions in these fields, these tools comprise of the Propagation Tool which helps linking solar perturbations observed both in remote and in-situ data; this is achieved through direct connection to the companion solar database MEDOC and the CDPP AMDA database. More recently, in the frame of Europlanet 2020 RI, a 1D MHD solar wind propagation code (Tao et al., 2005) has been interfaced to provide real time solar wind monitors at cruising probes and planetary environments using ACE real time data as inputs (Heliopropa service). Finally, simulations, models and data may be combined and visualized in a 3D context with 3DView. This presentation will overview the various functionalities of these tools and provide examples, in particular a 'CME tracking' case recently published (Witasse et al., 2017). Europlanet 2020 RI has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 654208.
Environmental and solar energy techniques
International Nuclear Information System (INIS)
Zaidi, Z.I.
2003-01-01
Technologies for fossil fuel extraction, transportation, processing and their use have harmful impact on the environment which cause direct and indirect negative impact on human heath, animals, crops and structure etc. The end use of all the fossil fuels is combustion irrespective of the final purpose i.e. heating, electricity production and motive power for transportation. The main constituents of fossil fuels are carbon and hydrogen but some other ingredients, which are originally in the fuel e.g. sulfur or are added during refining e.g. lead, alcohol etc. Combustion of the fossil fuel produces various gases (CO/sub x/, SO/sub x/ NO/sub x/, CH,), soot, ash, droplets of tar and other organic compounds, which are all released into the atmosphere. High rate of population growth and industrialization in the developing countries are causing unsustainable use of forest resources and fossil fuels, hence, are serious hurdles in environmental improvement. The situation in Pakistan is even worse as it has very limited fossil fuels and 40% of its commercial energy requirement are to be imported every year. Renewable energy technologies on the other hand, can play a vital role in improving the environmental condition globally. Pakistan Council of Renewable Energy Technologies (PCRET) is working in the field of renewable energy technologies. The Council has developed solar modules and solar thermal devices including solar cookers, solar dryers, solar stills and solar water heaters. The paper describes these devices and contribution they can make towards the improvement of environment. (author)
A Distributed Control System Prototyping Environment to Support Control Room Modernization
Energy Technology Data Exchange (ETDEWEB)
Lew, Roger Thomas [Idaho National Lab. (INL), Idaho Falls, ID (United States); Boring, Ronald Laurids [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ulrich, Thomas Anthony [Idaho National Lab. (INL), Idaho Falls, ID (United States)
2014-12-01
Operators of critical processes, such as nuclear power production, must contend with highly complex systems, procedures, and regulations. Developing human-machine interfaces (HMIs) that better support operators is a high priority for ensuring the safe and reliable operation of critical processes. Human factors engineering (HFE) provides a rich and mature set of tools for evaluating the performance of HMIs, however the set of tools for developing and designing HMIs is still in its infancy. Here we propose a rapid prototyping approach for integrating proposed HMIs into their native environments before a design is finalized. This approach allows researchers and developers to test design ideas and eliminate design flaws prior to fully developing the new system. We illustrate this approach with four prototype designs developed using Microsoft’s Windows Presentation Foundation (WPF). One example is integrated into a microworld environment to test the functionality of the design and identify the optimal level of automation for a new system in a nuclear power plant. The other three examples are integrated into a full-scale, glasstop digital simulator of a nuclear power plant. One example demonstrates the capabilities of next generation control concepts; another aims to expand the current state of the art; lastly, an HMI prototype was developed as a test platform for a new control system currently in development at U.S. nuclear power plants. WPF possesses several characteristics that make it well suited to HMI design. It provides a tremendous amount of flexibility, agility, robustness, and extensibility. Distributed control system (DCS) specific environments tend to focus on the safety and reliability requirements for real-world interfaces and consequently have less emphasis on providing functionality to support novel interaction paradigms. Because of WPF’s large user-base, Microsoft can provide an extremely mature tool. Within process control applications,WPF is
International Nuclear Information System (INIS)
Selwynraj, A. Immanuel; Iniyan, S.; Suganthi, L.; Livshits, Maya; Polonsky, Guy; Kribus, Abraham
2016-01-01
Highlights: • Study on the influence of local climatic conditions on solar STIG cycle is presented. • The annual solar to electricity efficiency ranges between 11.2 and 17.1% and the solar fraction ranges 9.3–41.7%. • The range of annual specific CO_2 emission is 312–408 kg/MWh and incremental CO_2 avoidance is 4.2–104 kg/MWh. • The levelized tariff (LT) is 0.2–0.23 $/kWh, and the solar levelized tariff (SLT) ranges from 0.11 to 0.27 $/kWh. - Abstract: The solarized steam injection gas turbine (STIG) cycle uses both the fuel and solar heat simultaneously for power generation. The annual thermodynamic performances of the cycle for sites in India with local climatic conditions such as ambient temperature, relative humidity and availability of direct normal irradiance (DNI) to the solar concentrators under two modes of constant and variable power are presented in this paper. The results reveal that the solar to electricity efficiency of solar hybrid STIG plant with a simple parabolic trough collector (PTC) is similar to existing solar thermal technologies, and also higher solar share is obtained. The study also reveals that the annual CO_2 emission is similar to combined cycle plants and lower than gas turbine technologies. The incremental CO_2 avoidance is also computed due to solar participation. The annual values of exergetic solar fraction and exergetic efficiency at Indore are higher than Jaipur. Results of an improved economic assessment show that the levelized tariff (LT) of solar hybrid STIG plant is 0.2–0.23 $/kWh and the levelized tariff (solar only) or solar levelized tariff (SLT) of solar STIG plant ranges from 0.11 to 0.27 $/kWh for both constant and variable power scenarios.
MPPT Based on Fuzzy Logic Controller (FLC) for Photovoltaic (PV) System in Solar Car
Aji, Seno; Ajiatmo, Dwi; Robandi, Imam; Suryoatmojo, Heri
2013-01-01
This paper presents a control called Maximum Power Point Tracking (MPPT) for photovoltaic (PV) system in a solar car. The main purpose of this system is to extracts PV power maximally while keeping small losses using a simple design of converter. Working principle of MPPT based fuzzy logic controller (MPPT-FLC) is to get desirable values of reference current and voltage. MPPT-FLC compares them with the values of the PV's actual current and voltage to control duty cycle value. Then the duty cy...
An intelligent simulation environment for control system design
International Nuclear Information System (INIS)
Robinson, J.T.
1989-01-01
The Oak Ridge National Laboratory is currently assisting in the development of advanced control systems for the next generation of nuclear power plants. This paper presents a prototype interactive and intelligent simulation environment being developed to support this effort. The environment combines tools from the field of Artificial Intelligence; in particular object-oriented programming, a LISP programming environment, and a direct manipulation user interface; with traditional numerical methods for simulating combined continuous/discrete processes. The resulting environment is highly interactive and easy to use. Models may be created and modified quickly through a window oriented direct manipulation interface. Models may be modified at any time, even as the simulation is running, and the results observed immediately via real-time graphics. 8 refs., 3 figs
International Nuclear Information System (INIS)
Bhattacharya, J.; De, B.K.; Guha, A.
2014-01-01
In this paper, a comparative study between the solar X-ray flares and solar radio bursts in terms of their duration and energy has been done. This has been done by analyzing the data in a statistical way covering the descending phase of the 22nd and 23rd solar cycles. It has been observed that the most probable value of duration of both solar X-ray flares and solar radio bursts remain same for a particular cycle. There is a slight variation in the most probable value of duration in going from 22nd cycle to 23rd cycle in the case of both kinds of events. This small variation may be due to the variation of polar field. A low correlation has been observed between energy fluxes in solar X-ray flares and in solar radio bursts. This has been attributed to the non symmetric contribution of energy to the solar radio and X-ray band controlled by solar magnetic field
Energy Technology Data Exchange (ETDEWEB)
Perez V, Jesus B; Robles G, Saul; Villa M, Hector A; Cabanillas L, Rafael E [Universidad de Sonora, Hermosillo, Sonora (Mexico)
2000-07-01
In this work the development of an interactive software, visible over the World Wide Web, is presented to support the basic calculation required to control the solar gain inside buildings and houses. The site has two main parts: one part describes in a very required parameters to design devices for the control of the illumination inside the buildings, like overhangs and wingwalls for shading. The other part has the routines and procedures to calculate the sun position for any date and position over the earth, and the horizontal and vertical protection angles. The part to implement the calculations has been developed as a Java applet which can run on any platform and let the users, in an interactive way, to get the results. This software makes possible that any Internet user can run the application from his/her own computer without having to compile of use sophisticated procedures as it happens with traditional languages. With this web site it is intended to cover the necessity of having simple and reliable means for architects and civil engineers to support the use of solar energy and the saving of energy in bioclimatic design of buildings. [Spanish] En este trabajo se presenta el desarrollo de un sitio interactivo visible en el World Wide Web (WWW) que pretende servir de apoyo para los calculos basicos de control de asoleamiento en viviendas y edificios. El sitio esta conformado por dos partes principales: una parte cubre el aspecto informativo, donde en forma sencilla y clara, se explican los conceptos y parametros necesarios para disenar los dispositivos de control, alerones y parteluces. La otra parte contiene los procedimientos y las rutinas de calculo para la determinacion de la posicion solar para cualquier fecha del ano desde cualquier punto sobre la tierra, asi como los angulos de sombreado vertical y horizontal. Para la realizacion de los calculos se ha construido un applet de Java, el cual puede ejecutarse desde cualquier plataforma de computacion y
Design and analysis of a dead volume control for a solar Stirling engine with induction generator
International Nuclear Information System (INIS)
Beltrán-Chacon, Ricardo; Leal-Chavez, Daniel; Sauceda, D.; Pellegrini-Cervantes, Manuel; Borunda, Mónica
2015-01-01
In this work, a power generation system dish/Stirling with cavity receiver and an electrical induction generator was simulated. We propose a control system using a variable-dead-volume and analyze its influence on the mechanical performance. A system with a dead volume of 160 cm"3 was designed to control the power and speed of the engine considering annual insolation, mechanical properties of the heater and the limits of frequency and voltage for the systems interconnected to the electricity network. The designed system achieves net efficient solar conversion to electric of 23.38% at an irradiance of 975 W/m"2 and allows an annual increase of 18% of the useful electrical energy compared to a system without control. - Highlights: • Numerical simulation of a nitrogen charged solar Stirling engine for electric power generation. • Design and analysis of a dead volume control for performance increase and power modulation. • Effect of dead space on average working pressure and mass flow rate. • Comparison between dead volume and average pressure control methods. • Impact of Stirling engine control settings on annual generated electric power.
Real-time control environment for the RFX experiment
International Nuclear Information System (INIS)
Barana, O.; Cavinato, M.; Luchetta, A.; Manduchi, G.; Taliercio, C.
2005-01-01
A comprehensive set of control schemes can be presently implemented on RFX due to the enhanced load assembly and renewed power supply system. The schemes include: plasma equilibrium control and resistive wall mode stabilization, aiming at controlling actively the discharge when the passive action of the shell vanishes; the rotation of the localised helical deformation to minimize the enhanced plasma-wall interaction; the MHD mode control and the 'intelligent shell', aiming at achieving a better comprehension of the underlying physics. To the purpose, an integrated, distributed, digital system has been developed consisting of a set of computing nodes. Each node can act either as pre-processing or control station, the former acquiring raw data and computing intermediate control parameters, the latter executing control algorithms and driving the power amplifiers. An overview of the system architecture is presented in the paper with reference to the software real-time environment providing both basic functions, such as data read-out and real-time communication, and useful tools to program control algorithms, to perform simulations and to commission the system. To simulate the control schemes, the real-time environment is extended to include a so called 'simulation mode', in which the real-time nodes exchange their input/output signals with one station running a suitable model of the experiment, for instance the two dimensional FEM code MAXFEA in the case of the equilibrium control. In this way the control system can be tested offline and the time needed for the commissioning of algorithms reduced
System Identification and Resonant Control of Thermoacoustic Engines for Robust Solar Power
Directory of Open Access Journals (Sweden)
Boe-Shong Hong
2015-05-01
Full Text Available It was found that thermoacoustic solar-power generators with resonant control are more powerful than passive ones. To continue the work, this paper focuses on the synthesis of robustly resonant controllers that guarantee single-mode resonance not only in steady states, but also in transient states when modelling uncertainties happen and working temperature temporally varies. Here the control synthesis is based on the loop shifting and the frequency-domain identification in advance thereof. Frequency-domain identification is performed to modify the mathematical modelling and to identify the most powerful mode, so that the DSP-based feedback controller can online pitch the engine to the most powerful resonant-frequency robustly and accurately. Moreover, this paper develops two control tools, the higher-order van-der-Pol oscillator and the principle of Dynamical Equilibrium, to assist in system identification and feedback synthesis, respectively.
Drift-free solar sail formations in elliptical Sun-synchronous orbits
Parsay, Khashayar; Schaub, Hanspeter
2017-10-01
To study the spatial and temporal variations of plasma in the highly dynamic environment of the magnetosphere, multiple spacecraft must fly in a formation. The objective for this study is to investigate the feasibility of solar sail formation flying in the Earth-centered, Sun-synchronous orbit regime. The focus of this effort is to enable formation flying for a group of solar sails that maintain a nominally fixed Sun-pointing attitude during formation flight, solely for the purpose of precessing their orbit apse lines Sun-synchronously. A fixed-attitude solar sail formation is motivated by the difficulties in the simultaneous control of orbit and attitude in flying solar sails. First, the secular rates of the orbital elements resulting from the effects of solar radiation pressure (SRP) are determined using averaging theory for a Sun-pointing attitude sail. These averaged rates are used to analytically derive the first-order necessary conditions for a drift-free solar sail formation in Sun-synchronous orbits, assuming a fixed Sun-pointing orientation for each sail in formation. The validity of the first-order necessary conditions are illustrated by designing quasi-periodic relative motions. Next, nonlinear programming is applied to design truly drift-free two-craft solar sail formations. Lastly, analytic expressions are derived to determine the long-term dynamics and sensitivity of the formation with respect to constant attitude errors, uncertainty in orbital elements, and uncertainty in a sail's characteristic acceleration.
Solar influence on Earth's climate
DEFF Research Database (Denmark)
Marsh, N.; Svensmark, Henrik
2003-01-01
An increasing number of studies indicate that variations in solar activity have had a significant influence on Earth's climate. However, the mechanisms responsible for a solar influence are still not known. One possibility is that atmospheric transparency is influenced by changing cloud properties...... and thereby influence the radiative properties of clouds. If the GCR-Cloud link is confirmed variations in galactic cosmic ray flux, caused by changes in solar activity and the space environment, could influence Earth's radiation budget....... via cosmic ray ionisation (the latter being modulated by solar activity). Support for this idea is found from satellite observations of cloud cover. Such data have revealed a striking correlation between the intensity of galactic cosmic rays (GCR) and low liquid clouds (
International Nuclear Information System (INIS)
Choi, Kyu-Chae; Lee, Eun-Jin; Baek, Youn-Kyoung; Lim, Dong-Chan; Kang, Yong-Cheol; Kim, Yang-Do; Kim, Ki Hyun; Kim, Jae Pil; Kim, Young-Kuk
2015-01-01
Highlights: • Enhanced efficiency of solar cells using ZnO nanocrystals for charge transport. • Morphology of the charge transport layer is controlled. • Mixture of nanoparticles and nanorods are advantageous for cell efficiency. - ABSTRACT: The morphology of ZnO electron transport layers based on ZnO nanoparticles were modified with incorporation of ZnO nanorods via their co-deposition from mixed colloidal solution of nanoparticles and nanorods. In particular, the short circuit current density and the fill factor of the constructed photovoltaic device were simultaneously improved by applying mixture of ZnO nanoparticles and nanorods. As a result, a large improvement of power conversion efficiency up to 9% for the inverted organic solar cells having a blend of low band gap polymers and fullerene derivative as an active layer was demonstrated with the morphologically controlled ZnO electron transport layer.
Stable high efficiency two-dimensional perovskite solar cells via cesium doping
Zhang, Xu
2017-08-15
Two-dimensional (2D) organic-inorganic perovskites have recently emerged as one of the most important thin-film solar cell materials owing to their excellent environmental stability. The remaining major pitfall is their relatively poor photovoltaic performance in contrast to 3D perovskites. In this work we demonstrate cesium cation (Cs) doped 2D (BA)(MA)PbI perovskite solar cells giving a power conversion efficiency (PCE) as high as 13.7%, the highest among the reported 2D devices, with excellent humidity resistance. The enhanced efficiency from 12.3% (without Cs) to 13.7% (with 5% Cs) is attributed to perfectly controlled crystal orientation, an increased grain size of the 2D planes, superior surface quality, reduced trap-state density, enhanced charge-carrier mobility and charge-transfer kinetics. Surprisingly, it is found that the Cs doping yields superior stability for the 2D perovskite solar cells when subjected to a high humidity environment without encapsulation. The device doped using 5% Cs degrades only ca. 10% after 1400 hours of exposure in 30% relative humidity (RH), and exhibits significantly improved stability under heating and high moisture environments. Our results provide an important step toward air-stable and fully printable low dimensional perovskites as a next-generation renewable energy source.
Development of Solar Powered Irrigation System
International Nuclear Information System (INIS)
Abdelkerim, A I; Eusuf, M M R Sami; Salami, M J E; Aibinu, A; Eusuf, M A
2013-01-01
Development of a solar powered irrigation system has been discussed in this paper. This system would be SCADA-based and quite useful in areas where there is plenty of sunshine but insufficient water to carry out farming activities, such as rubber plantation, strawberry plantation, or any plantation, that requires frequent watering. The system is powered by solar system as a renewable energy which uses solar panel module to convert Sunlight into electricity. The development and implementation of an automated SCADA controlled system that uses PLC as a controller is significant to agricultural, oil and gas monitoring and control purpose purposes. In addition, the system is powered by an intelligent solar system in which solar panel targets the radiation from the Sun. Other than that, the solar system has reduced energy cost as well as pollution. The system is equipped with four input sensors; two soil moisture sensors, two level detection sensors. Soil moisture sensor measures the humidity of the soil, whereas the level detection sensors detect the level of water in the tank. The output sides consist of two solenoid valves, which are controlled respectively by two moistures sensors
Molded polymer solar water heater
Bourne, Richard C.; Lee, Brian E.
2004-11-09
A solar water heater has a rotationally-molded water box and a glazing subassembly disposed over the water box that enhances solar gain and provides an insulating air space between the outside environment and the water box. When used with a pressurized water system, an internal heat exchanger is integrally molded within the water box. Mounting and connection hardware is included to provide a rapid and secure method of installation.
Solar Probe Plus: Report of the Science and Technology Definition Team
2008-01-01
Solar Probe+ will be an extraordinary and historic mission, exploring what is arguably the last region of the solar system to be visited by a spacecraft, the Sun s outer atmosphere or corona as it extends out into space. Approaching as close as 9.5 RS* (8.5 RS above the Sun s surface), Solar Probe+ will repeatedly sample the near-Sun environment, revolutionizing our knowledge and understanding of coronal heating and of the origin and evolution of the solar wind and answering critical questions in heliophysics that have been ranked as top priorities for decades. Moreover, by making direct, in-situ measurements of the region where some of the most hazardous solar energetic particles are energized, Solar Probe+ will make a fundamental contribution to our ability to characterize and forecast the radiation environment in which future space explorers will work and live.
Advanced Solar Cells for Satellite Power Systems
Flood, Dennis J.; Weinberg, Irving
1994-01-01
The multiple natures of today's space missions with regard to operational lifetime, orbital environment, cost and size of spacecraft, to name just a few, present such a broad range of performance requirements to be met by the solar array that no single design can suffice to meet them all. The result is a demand for development of specialized solar cell types that help to optimize overall satellite performance within a specified cost range for any given space mission. Historically, space solar array performance has been optimized for a given mission by tailoring the features of silicon solar cells to account for the orbital environment and average operating conditions expected during the mission. It has become necessary to turn to entirely new photovoltaic materials and device designs to meet the requirements of future missions, both in the near and far term. This paper will outline some of the mission drivers and resulting performance requirements that must be met by advanced solar cells, and provide an overview of some of the advanced cell technologies under development to meet them. The discussion will include high efficiency, radiation hard single junction cells; monolithic and mechanically stacked multiple bandgap cells; and thin film cells.
Cesium lead iodide solar cells controlled by annealing temperature.
Kim, Yu Geun; Kim, Tae-Yoon; Oh, Jeong Hyeon; Choi, Kyoung Soon; Kim, Youn-Jea; Kim, Soo Young
2017-02-22
An inorganic lead halide perovskite film, CsPbI 3 , used as an absorber in perovskite solar cells (PSCs) was optimized by controlling the annealing temperature and the layer thickness. The CsPbI 3 layer was synthesized by one-step coating of CsI mixed with PbI 2 and a HI additive in N,N-dimethylformamide. The annealing temperature of the CsPbI 3 film was varied from 80 to 120 °C for different durations and the thickness was controlled by changing the spin-coating rpm. After annealing the CsPbI 3 layer at 100 °C under dark conditions for 10 min, a black phase of CsPbI 3 was formed and the band gap was 1.69 eV. Most of the yellow spots disappeared, the surface coverage was almost 100%, and the rms roughness was minimized to 3.03 nm after annealing at 100 °C. The power conversion efficiency (PCE) of the CsPbI 3 based PSC annealed at 100 °C was 4.88%. This high PCE value is attributed to the low yellow phase ratio, high surface coverage, low rms roughness, lower charge transport resistance, and lower charge accumulation. The loss ratio of the PCE of the CH 3 NH 3 PbI x Cl 3-x and CsPbI 3 based PSCs after keeping in air was 47 and 26%, respectively, indicating that the stability of the CsPbI 3 based PSC is better than that of the CH 3 NH 3 PbI x Cl 3-x based PSC. From these results, it is evident that CsPbI 3 is a potential candidate for solar cell applications.
Two-Axis Solar Heat Collection Tracker System for Solar Thermal Applications
Directory of Open Access Journals (Sweden)
Tsung-Chieh Cheng
2013-01-01
Full Text Available An experimental study was performed to investigate the effect of using a continuous operation two-axes tracking on the solar heat energy collected. This heat-collection sun tracking which LDR (light dependent resistor sensors installed on the Fersnel lens was used to control the tracking path of the sun with programming method of control with a closed loop system. The control hardware was connected to a computer through Zigbee wireless module and it also can monitor the whole tracking process information on a computer screen. An experimental study was performed to investigate the effect of using two-axes tracking on the solar heat energy collected. The results indicate that sun tracking systems are being increasingly employed to enhance the efficiency of heat collection by polar-axis tracking of the sun. Besides, the heating power was also measured by designed power measurement module at the different focal length of Fresnel lens, and the design of shadow mask of LDR sensors is an important factor for solar photothermal applications. Moreover, the results also indicated that the best time to obtain the largest solar irradiation power is during 11:00 –13:00 in Taiwan.
Solar Effects of Low-Earth Orbit objects in ORDEM 3.0
Vavrin, A. B.; Anz-Meador, P.; Kelley, R. L.
2014-01-01
Variances in atmospheric density are directly related to the variances in solar flux intensity between 11- year solar cycles. The Orbital Debris Engineering Model (ORDEM 3.0) uses a solar flux table as input for calculating orbital lifetime of intact and debris objects in Low-Earth Orbit. Long term projections in solar flux activity developed by the NASA Orbital Debris Program Office (ODPO) extend the National Oceanic and Atmospheric Administration Space Environment Center (NOAA/SEC) daily historical flux values with a 5-year projection. For purposes of programmatic scheduling, the Q2 2009 solar flux table was chosen for ORDEM 3.0. Current solar flux activity shows that the current solar cycle has entered a period of lower solar flux intensity than previously forecasted in 2009. This results in a deviation of the true orbital debris environment propagation in ORDEM 3.0. In this paper, we present updated orbital debris populations in LEO using the latest solar flux values. We discuss the effects on recent breakup events such as the FY-1C anti-satellite test and the Iridium 33 / Cosmos 2251 accidental collision. Justifications for chosen solar flux tables are discussed.
Abdallah, Amir
2017-09-22
We report on the performance of Silicon Heterojunction (SHJ) solar cell under high operating temperature and varying irradiance conditions typical to desert environment. In order to define the best solar cell configuration that resist high operating temperature conditions, two different intrinsic passivation layers were tested, namely, an intrinsic amorphous silicon a-SiO:H with CO/SiH ratio of 0.4 and a-SiOx:H with CO/SiH ratio of 0.8, and the obtained performance were compared with those of a standard SHJ cell configuration having a-Si:H passivation layer. Our results showed how the short circuit current density J, and fill factor FF temperature-dependency are impacted by the cell\\'s configuration. While the short circuit current density J for cells with a-SiO:H layers was found to improve as compared with that of standard a-Si:H layer, introducing the intrinsic amorphous silicon oxide (a-SiO:H) layer with CO/SiH ratio of 0.8 has resulted in a reduction of the FF at room temperature due to hindering the carrier transport by the band structure. Besides, this FF was found to improve as the temperature increases from 15 to 45°C, thus, a positive FF temperature coefficient.
Abdallah, Amir; Daif, Ounsi El; Aï ssa, Brahim; Kivambe, Maulid; Tabet, Nouar; Seif, Johannes; Haschke, Jan; Cattin, Jean; Boccard, Mathieu; De Wolf, Stefaan; Ballif, Christophe
2017-01-01
We report on the performance of Silicon Heterojunction (SHJ) solar cell under high operating temperature and varying irradiance conditions typical to desert environment. In order to define the best solar cell configuration that resist high operating temperature conditions, two different intrinsic passivation layers were tested, namely, an intrinsic amorphous silicon a-SiO:H with CO/SiH ratio of 0.4 and a-SiOx:H with CO/SiH ratio of 0.8, and the obtained performance were compared with those of a standard SHJ cell configuration having a-Si:H passivation layer. Our results showed how the short circuit current density J, and fill factor FF temperature-dependency are impacted by the cell's configuration. While the short circuit current density J for cells with a-SiO:H layers was found to improve as compared with that of standard a-Si:H layer, introducing the intrinsic amorphous silicon oxide (a-SiO:H) layer with CO/SiH ratio of 0.8 has resulted in a reduction of the FF at room temperature due to hindering the carrier transport by the band structure. Besides, this FF was found to improve as the temperature increases from 15 to 45°C, thus, a positive FF temperature coefficient.
Invariant Solar Sail Formations in Elliptical Sun-Synchronous Orbits
Parsay, Khashayar
Current and past missions that study the Earth's geomagnetic tail require multiple spacecraft to fly in formation about a highly eccentric Keplerian reference orbit that has its apogee inside a predefined science region of interest. Because the geomagnetic tail is directed along the Sun-Earth line and therefore rotates annually, inertially fixed Keplerian orbits are only aligned with the geomagnetic tail once per year. This limitation reduces the duration of the science phase to less than a few months annually. Solar sails are capable of creating non-Keplerian, Sun-synchronous orbits that rotate with the geomagnetic tail. A solar sail flying in a Sun-synchronous orbit will have a continuous presence in the geomagnetic tail throughout the entire year, which significantly improves the in situ observations of the magnetosphere. To achieve a Sun-synchronous orbit, a solar sail is required to maintain a Sun-pointing attitude, which leads to the artificial precession of the orbit apse line in a Sun-synchronous manner, leaving the orbit apogee inside the science region of interest throughout entire the year. To study the spatial and temporal variations of plasma in the highly dynamic environment of the magnetosphere, multiple spacecraft must fly in a formation. The objective for this dissertation is to investigate the feasibility of solar sail formation flying in the Earth-centered, Sun-synchronous orbit regime. The focus of this effort is to enable formation flying for a group of solar sails that maintain a nominally fixed Sun-pointing attitude during formation flight, solely for the purpose of precessing their orbit apse lines Sun-synchronously. A fixed-attitude solar sail formation is motivated by the difficulties in the simultaneous control of orbit and attitude in flying solar sails. First, the secular rates of the orbital elements resulting from the effects of solar radiation pressure (SRP) are determined using averaging theory for a Sun-pointing attitude sail
Optimal critic learning for robot control in time-varying environments.
Wang, Chen; Li, Yanan; Ge, Shuzhi Sam; Lee, Tong Heng
2015-10-01
In this paper, optimal critic learning is developed for robot control in a time-varying environment. The unknown environment is described as a linear system with time-varying parameters, and impedance control is employed for the interaction control. Desired impedance parameters are obtained in the sense of an optimal realization of the composite of trajectory tracking and force regulation. Q -function-based critic learning is developed to determine the optimal impedance parameters without the knowledge of the system dynamics. The simulation results are presented and compared with existing methods, and the efficacy of the proposed method is verified.
Solar Probe Cup: Laboratory Performance
Case, A. W.; Kasper, J. C.; Korreck, K. E.; Stevens, M. L.; Larson, D. E.; Wright, K. H., Jr.; Gallagher, D. L.; Whittlesey, P. L.
2017-12-01
The Solar Probe Cup (SPC) is a Faraday Cup instrument that will fly on the Paker Solar Probe (PSP) spacecraft, orbiting the Sun at as close as 9.86 solar radii. The SPC instrument is designed to measure the thermal solar wind plasma (protons, alphas, and electrons) that will be encountered throughout its close encounter with the Sun. Due to the solar wind flow being primarily radial, the SPC instrument is pointed directly at the Sun, resulting in an extreme thermal environment that must be tolerated throughout the primary data collection phase. Laboratory testing has been performed over the past 6 months to demonstrate the instrument's performance relative to its requirements, and to characterize the measurements over the expected thermal range. This presentation will demonstrate the performance of the instrument as measured in the lab, describe the operational configurations planned for flight, and discuss the data products that will be created.
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.
Directory of Open Access Journals (Sweden)
Mohsen Taherbaneh
2010-01-01
Full Text Available In applications with low-energy conversion efficiency, maximizing the output power improves the efficiency. The maximum output power of a solar panel depends on the environmental conditions and load profile. In this paper, a method based on simultaneous use of two fuzzy controllers is developed in order to maximize the generated output power of a solar panel in a photovoltaic system: fuzzy-based sun tracking and maximum power point tracking. The sun tracking is performed by changing the solar panel orientation in horizontal and vertical directions by two DC motors properly designed. A DC-DC converter is employed to track the solar panel maximum power point. In addition, the proposed system has the capability of the extraction of solar panel I-V curves. Experimental results present that the proposed fuzzy techniques result in increasing of power delivery from the solar panel, causing a reduction in size, weight, and cost of solar panels in photovoltaic systems.
Kojima, Hirohisa; Hiraiwa, Kana; Yoshimura, Yasuhiro
2018-02-01
This paper presents the results of line-of-sight (LOS) attitude control using control moment gyros under a micro-gravity environment generated by parabolic flight. The W-Z parameters are used to describe the spacecraft attitude. In order to stabilize the current LOS to the target LOS, backstepping-based feedback control is considered using the W-Z parameters. Numerical simulations and experiments under a micro-gravity environment are carried out, and their results are compared in order to validate the proposed control methods.
A comparative study between control strategies for a solar sailcraft in an Earth-Mars transfer
Mainenti-Lopes, I.; Souza, L. C. Gadelha; De Sousa, Fabiano. L.
2016-10-01
The goal of this work was a comparative study of solar sail trajectory optimization using different control strategies. Solar sailcraft is propulsion system with great interest in space engineering, since it uses solar radiation to propulsion. So there is no need for propellant to be used, thus it can remains active throughout the entire transfer maneuver. This type of propulsion system opens the possibility to reduce the cost of exploration missions in the solar system. In its simplest configuration, a Flat Solar Sail (FSS) consists of a large and thin structure generally composed by a film fixed to flexible rods. The performance of these vehicles depends largely on the sails attitude relative to the Sun. Using a FSS as propulsion, an Earth-Mars transfer optimization problem was tackled by the algorithms GEOreal1 and GEOreal2 (Generalized Extremal Optimization with real codification). Those algorithms are Evolutionary Algorithms (AE) based on the theory of Self-Organized Criticality. They were used to optimize the FSS attitude angle so it could reach Mars orbit in minimum time. It was considered that the FSS could perform up to ten attitude maneuvers during orbital transfer. Moreover, the time between maneuvers can be different. So, the algorithms had to optimize an objective function with 20 design variables. The results obtained in this work were compared with previously results that considered constant values of time between maneuvers.
Compatibility of Anfis controller and FPGA in solar power generation for a domestic oad
Directory of Open Access Journals (Sweden)
Arulprakash Andigounder
2016-06-01
Full Text Available Among other soft computing techniques, the Adaptive Neuro Fuzzy Inference System (Anfis gives a significant and advantageous result in solar power generation, especially in tracking the maximum power point. Due to the dynamic nature of solar irradiance and temperature, efficient energy conversion is not possible. However, advancements in the areas of artificial intelligence have made it possible to overcome the hurdles. The Maximum Power Point Tracking (MPPT technique adopting the advantages of Anfis has been proven to be more successful with a fast dynamic response and high accuracy. The complete system is modeled using Matlab/Simulink; the hardware results are validated with the benefits of Field Programmable Logic Array (FPGA instead of ordinary micro-controllers.
The Electrostatic Environments of Mars and the Moon
Calle, Carlos I.
2011-01-01
The electrical activity present in the environment near the surfaces of Mars and the moon has very different origins and presents a challenge to manned and robotic planetary exploration missions. Mars is covered with a layer of dust that has been redistributed throughout the entire planet by global dust storms. Dust, levitated by these storms as well as by the frequent dust devils, is expected to be electrostatically charged due to the multiple grain collisions in the dust-laden atmosphere. Dust covering the surface of the moon is expected to be electrostatically charged due to the solar wind, cosmic rays, and the solar radiation itself through the photoelectric effect. Electrostatically charged dust has a large tendency to adhere to surfaces. NASA's Mars exploration rovers have shown that atmospheric dust falling on solar panels can decrease their efficiency to the point of rendering the rover unusable. And as the Apollo missions to the moon showed, lunar dust adhesion can hinder manned and unmanned lunar exploration activities. Taking advantage of the electrical activity on both planetary system bodies, dust removal technologies are now being developed that use electrostatic and dielectrophoretic forces to produce controlled dust motion. This paper presents a short review of the theoretical and semiempirical models that have been developed for the lunar and Martian electrical environments.
The electrostatic environments of Mars and the Moon
International Nuclear Information System (INIS)
Calle, C I
2011-01-01
The electrical activity present in the environment near the surfaces of Mars and the moon has very different origins and presents a challenge to manned and robotic planetary exploration missions. Mars is covered with a layer of dust that has been redistributed throughout the entire planet by global dust storms. Dust, levitated by these storms as well as by the frequent dust devils, is expected to be electrostatically charged due to the multiple grain collisions in the dust-laden atmosphere. Dust covering the surface of the moon is expected to be electrostatically charged due to the solar wind, cosmic rays, and the solar radiation itself through the photoelectric effect. Electrostatically charged dust has a large tendency to adhere to surfaces. NASA's Mars exploration rovers have shown that atmospheric dust falling on solar panels can decrease their efficiency to the point of rendering the rover unusable. And as the Apollo missions to the moon showed, lunar dust adhesion can hinder manned and unmanned lunar exploration activities. Taking advantage of the electrical activity on both planetary system bodies, dust removal technologies are now being developed that use electrostatic and dielectrophoretic forces to produce controlled dust motion. This paper presents a short review of the theoretical and semiempirical models that have been developed for the lunar and Martian electrical environments.
Magnetic fields in the solar system planets, moons and solar wind interactions
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...
Optimum solar collector fluid flow rates
DEFF Research Database (Denmark)
Furbo, Simon; Shah, Louise Jivan
1996-01-01
Experiments showed that by means of a standard electronically controlled pump, type UPE 2000 from Grundfos it is possible to control the flow rate in a solar collector loop in such a way that the flow rate is strongly influenced by the temperature of the solar collector fluid passing the pump....... The flow rate is increasing for increasing temperature.The flow rate at the high temperature level is typically 70 % greater than the flow rate at the low temperature level.Further, the energy consumption for the electronically controlled pump in a solar heating system will be somewhat smaller than...... the energy consumption of a normal ciculation pump in the solar heating system.Calculations showed that the highest thermal performances for small SDHW systems based on mantle tanks with constant volume flow rates in the solar collector loops are achieved if the flow rate is situated in the interval from 0...
Integrated solar water-heater and solar water cooler performance during winter time
International Nuclear Information System (INIS)
Shaikh, N.U.; Siddiqui, M.A
2012-01-01
Solar powered water heater and water cooler is an important contribution for the reduction of fossil fuel consumptions and harmful emissions to the environment. This study aims to harness the available solar potential of Pakistan and provide an option fulfilling the domestic hot and cold water demands during winter and summer seasons respectively. The system was designed for the tap-water temperature of 65 degree C (149 degree F) and the chilled drinking-water temperature of 14 degree C (57 degree F) that are the recommended temperatures by World Health Organization (WHO). The solar water heater serves one of the facilities of the Department of Mechanical Engineering at NED University of Engineering and Technology whereas, the solar water cooler will provide drinking water to approximately 50 people including both faculty and students. A pair of single glazed flat plate solar collector was installed to convert solar radiations to heat. Hot water storage and supply system was carefully designed and fabricated to obtain the designed tap-water temperature. Vapour-absorption refrigeration system was designed to chill drinking water. Intensity of solar radiations falling on the solar collector, water temperatures at the inlet and outlet of the solar collectors and the tap water temperature were measured and analyzed at different hours of the day and at different days of the month. The results show that the installed solar collector system has potential to feed hot water of temperatures ranging from 65 degree C (149 degree F) to 70 Degree C (158 degree F), that is the required hot water temperature to operate a vapour absorption chilled water production system. (author)
Luminescent solar concentrator
Directory of Open Access Journals (Sweden)
Tugce Tosun
2015-07-01
Full Text Available Luminescent solar concentrator (LSC is a device that has luminescent molecules embedding or topping polymeric or glass waveguide to generate electricity from sunlight with a photovoltaic cell attachment. LSCs can be employed both in small and large scale projects, independent on the direction or angle of the surface with respect to the sun, promising more freedom for integration in urban environments compared to the traditional PV systems. The aim of the SEB&C PDEng project is to investigate the applicability of this innovative technology in the built environment and to bridge the gap of knowledge linking societal, design and technological aspects. The final goal is to exhibit potential application concepts of LSC developed by co-creative methods at SPARK campus which is a hub for open innovation in built environment. Necessity of a paradigm shift towards sustainable and smart cities came into being due to the significant increase in energy demand of the buildings. The challenge is to increase renewable sources in the energy mix while designing aesthetic environments. Thus, building integrated renewable energy technologies represent a great opportunity to help overcome this current challenge. Smart energy, energy efficiency and use of renewable sources are key aspects to be considered nowadays and many innovative technologies need further exploitation to be commercially viable, such as luminescent solar concentrator.
Investigations of solar combi systems
DEFF Research Database (Denmark)
Andersen, Elsa
2005-01-01
). However, it is still too early to draw conclusions on the design of solar combi systems. Among others, the following questions needs to be answered: Is an external domestic hot water preparation more desirable than an internal domestic hot water preparation? Is a stratification manifold always more......A large variety of solar combi systems are on the marked to day. The best performing systems are highly advanced energy systems with thermal stratification manifolds, an efficient boiler and only one control system, which controls both the boiler and the solar collector loop (Weiss et al., 2003...... desirable than a fixed inlet position? This paper presents experimental investigations of an advanced solar combi system with thermal stratification manifold inlets both in the solar collector loop and in the space heating system and with an external domestic hot water preparation. Theoretical...
The ancient heritage of water ice in the solar system.
Cleeves, L Ilsedore; Bergin, Edwin A; Alexander, Conel M O'D; Du, Fujun; Graninger, Dawn; Öberg, Karin I; Harries, Tim J
2014-09-26
Identifying the source of Earth's water is central to understanding the origins of life-fostering environments and to assessing the prevalence of such environments in space. Water throughout the solar system exhibits deuterium-to-hydrogen enrichments, a fossil relic of low-temperature, ion-derived chemistry within either (i) the parent molecular cloud or (ii) the solar nebula protoplanetary disk. Using a comprehensive treatment of disk ionization, we find that ion-driven deuterium pathways are inefficient, which curtails the disk's deuterated water formation and its viability as the sole source for the solar system's water. This finding implies that, if the solar system's formation was typical, abundant interstellar ices are available to all nascent planetary systems. Copyright © 2014, American Association for the Advancement of Science.
International Nuclear Information System (INIS)
Kilper, T.; Donker, M.N. van den; Carius, R.; Rech, B.; Braeuer, G.; Repmann, T.
2008-01-01
Silicon thin-film solar cells based on microcrystalline silicon (μc-Si:H) were prepared in a 30 x 30 cm 2 plasma-enhanced chemical vapor deposition reactor using 13.56 or 40.68 MHz plasma excitation frequency. Plasma emission was recorded by optical emission spectroscopy during μc-Si:H absorber layer deposition at deposition rates between 0.5 and 2.5 nm/s. The time course of SiH * and H β emission indicated strong drifts in the process conditions particularly at low total gas flows. By actively controlling the SiH 4 gas flow, the observed process drifts were successfully suppressed resulting in a more homogeneous i-layer crystallinity along the growth direction. In a deposition regime with efficient usage of the process gas, the μc-Si:H solar cell efficiency was enhanced from 7.9 % up to 8.8 % by applying process control
Norton, Brian
2013-01-01
Systems engineered by man to harness solar heat in a controlled manner now include a diverse range of technologies each serving distinctive needs in particular climate contexts. This text covers the breadth of solar energy technologies for the conversion of solar energy to provide heat, either as the directly-used output or as an intermediary to other uses such as power generation or cooling. It is a wholly updated, extended and revised version of “Solar Energy Thermal Technology†first published in 1992. The text draws on the own author’s research and that of numerous colleagues and
Solar system astrophysics planetary atmospheres and the outer solar system
Milone, Eugene F
2008-01-01
Solar System Astrophysics opens with coverage of the atmospheres, ionospheres and magnetospheres of the Earth, Venus and Mars and the magnetosphere of Mercury. The book then provides an introduction to meteorology and treating the physics and chemistry of these areas in considerable detail. What follows are the structure, composition, particle environments, satellites, and rings of Jupiter, Saturn, Uranus and Neptune, making abundant use of results from space probes. Solar System Astrophysics follows the history, orbits, structure, origin and demise of comets and the physics of meteors and provides a thorough treatment of meteorites, the asteroids and, in the outer solar system, the Kuiper Belt objects. The methods and results of extrasolar planet searches, the distinctions between stars, brown dwarfs, and planets, and the origins of planetary systems are examined. Historical introductions precede the development and discussion in most chapters. A series of challenges, useful as homework assignments or as foc...
Space Station solar water heater
Horan, D. C.; Somers, Richard E.; Haynes, R. D.
1990-01-01
The feasibility of directly converting solar energy for crew water heating on the Space Station Freedom (SSF) and other human-tended missions such as a geosynchronous space station, lunar base, or Mars spacecraft was investigated. Computer codes were developed to model the systems, and a proof-of-concept thermal vacuum test was conducted to evaluate system performance in an environment simulating the SSF. The results indicate that a solar water heater is feasible. It could provide up to 100 percent of the design heating load without a significant configuration change to the SSF or other missions. The solar heater system requires only 15 percent of the electricity that an all-electric system on the SSF would require. This allows a reduction in the solar array or a surplus of electricity for onboard experiments.
Hargreaves, J. K.
This textbook is a successor to "The upper atmosphere and solar-terrestrial relations" first published in 1979. It describes physical conditions in the upper atmosphere and magnetosphere of the Earth. This geospace environment begins 70 kilometres above the surface of the Earth and extends in near space to many times the Earth's radius. It is the region of near-Earth environment where the Space Shuttle flies, the aurora is generated, and the outer atmosphere meets particles streaming out of the sun. The account is introductory. The intent is to present basic concepts, and for that reason the mathematical treatment is not complex. There are three introductory chapters that give basic physics and explain the principles of physical investigation. The principal material contained in the main part of the book covers the neutral and ionized upper atmosphere, the magetosphere, and structures, dynamics, disturbances and irregularities. The concluding chapter deals with technological applications.
Pumps for medium sized solar systems
DEFF Research Database (Denmark)
Furbo, Simon
1996-01-01
The suitability of the electronically controlled circulation pump type UPE 2000 from Grundfos for large solar heating systems was elucidated.......The suitability of the electronically controlled circulation pump type UPE 2000 from Grundfos for large solar heating systems was elucidated....
Digital Speed Cascade Control, using Scilab / Xcos Environment
Directory of Open Access Journals (Sweden)
Petru Chioncel
2016-10-01
Full Text Available This paper presents an application of digital cascade control implemented in Scilab / Xcos environment, using a P type regulator for the position adjustment circuit, a PI controller for the speed circuit adjustment; the current respectively moments control circuits are rendered by elements of PT1 type. On this basis the program is done in Scilab and the related signal block diagram implemented in Xcos; through simulation, the step response of the system is analyzed for different sampling times.
Calculation of Digital Control Circuits using Scilab Environment
Directory of Open Access Journals (Sweden)
Petru Chioncel
2015-09-01
Full Text Available The paper presents the computing of digital control circuits using Scilab environment. It exemplifies the influence of the sampling time in case of a transfer system described by a PT3 element composed of one PT1 and one PT2 element. For a continuous control system, the transfer function in z is computed and replaced with a digital control system. The presented calculation, done in Scilab, highlights the test responses of the process evidencing the systems performances.
DEFF Research Database (Denmark)
Causone, Francesco; Corgnati, Stefano P.; Filippi, Marco
2010-01-01
The study of the influence of solar radiation on the built environment is a basic issue in building physics and currently it is extremely important because glazed envelopes are widely used in contemporary architecture. In the present study, the removal of solar heat gains by radiant cooling systems...... is investigated. Particular attention is given to the portion of solar radiation converted to cooling load, without taking part in thermal absorption phenomena due to the thermal mass of the room. This specific component of the cooling load is defined as the Direct Solar Load. A simplified procedure to correctly...... calculate the magnitude of the Direct Solar Load in cooling load calculations is proposed and it is implemented with the Heat Balance method and the Radiant Time Series method. The F ratio of the solar heat gains directly converted to cooling load, in the case of a low thermal mass radiant ceiling...
Investigation of Solar and Solar-Gas Thermal Energy Sources
Ivan Herec; Jan Zupa
2003-01-01
The article deals with the investigation of solar thermal sources of electrical and heat energy as well as the investigation of hybrid solar-gas thermal sources of electrical and heat energy (so called photothermal sources). Photothermal sources presented here utilize computer-controlled injection of the conversion fluid into special capillary porous substance that is adjusted to direct temperature treatment by the concentrated thermal radiation absorption.
Maljaars, E.; Felici, F.; Blanken, T.C.; Galperti, C.; Sauter, O.; de Baar, M.R.; Carpanese, F.; Goodman, T.P.; Kim, D.; Kim, S.H.; Kong, M.G.; Mavkov, B.; Merle, A.; Moret, J.M.; Nouailletas, R.; Scheffer, M.; Teplukhina, A.A.; Vu, N.M.T.
2017-01-01
The successful performance of a model predictive profile controller is demonstrated in simulations and experiments on the TCV tokamak, employing a profile controller test environment. Stable high-performance tokamak operation in hybrid and advanced plasma scenarios requires control over the safety
Maljaars, B.; Felici, F.; Blanken, T. C.; Galperti, C.; Sauter, O.; de Baar, M. R.; Carpanese, F.; Goodman, T. P.; Kim, D.; Kim, S. H.; Kong, M.; Mavkov, B.; Merle, A.; Moret, J.; Nouailletas, R.; Scheffer, M.; Teplukhina, A.; Vu, T.
2017-01-01
The successful performance of a model predictive profile controller is demonstrated in simulations and experiments on the TCV tokamak, employing a profile controller test environment. Stable high-performance tokamak operation in hybrid and advanced plasma scenarios requires control over the safety
International Nuclear Information System (INIS)
Fyfe, W.S.; Powell, M.A.
1991-01-01
At present about 90% of the world's energy consumption is met by the fossil carbon fuel used in the form of coal, oil and natural gas. This results into release of vast amounts of waste gas CO 2 into the atmosphere posing a threat to the global environment. Moreover this energy source is not sustainable (renewable) and its use amounts to spending Earth's capital resources. The options to this energy source are biomass energy, hydro power, solar energy, geothermal energy and nuclear energy. The potentials, limitations, geological impact and environmental dangers, if any, of these sources are discussed in brief. Energy conservation through energy efficient systems is also one more option. Problems and potential for change to sustainable energy systems with respect to India and Canada are examined. Finally it is pointed out that the ultimate solution to the world's energy problem lies in population control and population reduction. This will make possible for the world to have a sustainable energy system primarily based on solar energy. (M.G.B.). 15 refs
Solar Flares and Their Prediction
Adams, Mitzi L.
1999-01-01
Solar flares and coronal mass ejection's (CMES) can strongly affect the local environment at the Earth. A major challenge for solar physics is to understand the physical mechanisms responsible for the onset of solar flares. Flares, characterized by a sudden release of energy (approx. 10(exp 32) ergs for the largest events) within the solar atmosphere, result in the acceleration of electrons, protons, and heavier ions as well as the production of electromagnetic radiation from hard X-rays to km radio waves (wavelengths approx. = 10(exp -9) cm to 10(exp 6) cm). Observations suggest that solar flares and sunspots are strongly linked. For example, a study of data from 1956-1969, reveals that approx. 93 percent of major flares originate in active regions with spots. Furthermore, the global structure of the sunspot magnetic field can be correlated with flare activity. This talk will review what we know about flare causes and effects and will discuss techniques for quantifying parameters, which may lead to a prediction of solar flares.
Energy development and environment: What about solar energy in a long term perspective?
Dessus, Benjamin; Pharabod, Francois
After decades of strong growth, the next century might be that in which the world population is stabilized around 11 billion inhabitants. Next century's main concerns include the development hoped for the probable consequences of an increase of the greenhouse effect due to main induced emissions, and the risks posed by possible dissemination of nuclear energy to all the regions of the globe. In order to shed some light on these questions, we propose an energy scenario, based on an analysis of evolution of demographics, energy needs, renewable and fossil reserves, environmental issues, technological possibilities and regional imbalances. This scenario shows that solar energy could contribute significantly in the long term energy mix. We discuss the respective advantages and drawbacks of the different solar technologies: solar power satellites, ground solar power plants and decentralized applications, as they to the needs that must be satisfied.
A Solar System Perspective on Laboratory Astrophysics
Cruikshank, Dale P.
2002-01-01
Planetary science deals with a wide variety of natural materials in a wide variety of environments. These materials include metals, minerals, ices, gases, plasmas, and organic chemicals. In addition, the newly defined discipline of astrobiology introduces biological materials to planetary science. The environments range from the interiors of planets with megapascal pressures to planetary magnetospheres, encompassing planetary mantles, surfaces, atmospheres, and ionospheres. The interplanetary environment includes magnetic and electrical fields, plasma, and dust. In order to understand planetary processes over these vast ranges, the properties of materials must be known, and most of the necessary information comes from the laboratory. Observations of the bodies and materials in the Solar System are accomplished over the full range of the electromagnetic spectrum by remote sensing from Earth or spacecraft. Comets exemplify this; molecular and atomic identifications are made from the hard ultraviolet to radio wavelengths, while X-rays are emitted as comets interact with the solar wind. Gamma rays from the surfaces of the Moon and asteroids are diagnostic of the mineral and ice content of those bodies; eventually, gamma rays will also be observed by probes to comets. A number of planetary materials are available in the laboratory for extensive Study: rocks from the Moon, Mars, several asteroids, as well as dust from comets (and perhaps the Kuiper Belt) are closely studied at every level, including atomic (isotopic). Even pre-solar interstellar grains isolated from meteorites are scrutinized for composition and crystalline structure. Beyond the materials themselves, various agents and processes have altered them over the 4.6-Gy age of the Solar System. Solar radiation, solar wind particles, trapped magnetospheric particles, cosmic rays, and micrometeoroid impacts have produced chemical, physical, and morphological changes in the atmospheres and on the surfaces of all
Recalde Regalado, Néstor Xavier; Prieto Briceño, Fernando Javier
2014-01-01
In the project the difference by putting a solar panel on static mode compared with a solar panel in dynamic mode, the dynamic mode solar panel system works with a Fuzzy-PID controller is implemented in a microcontroller is shown, this control system is to position the solar panel in a good position to take advantage of solar radiation and thus, it is possible to store the energy collected by the solar panel in a battery. En el proyecto se demuestra la diferencia que existe al colocar un p...
Thoughts and suggestions on development of China solar industry
Energy Technology Data Exchange (ETDEWEB)
Huang, Ming [Chinese Renewable Energy Society (China)
2008-07-01
This paper discussed the seven extremenesses of solar thermal utilization industry, twelve problems faced by solar thermal utilization and four prejudices of public awareness on the use of solar thermal industry. At the same time, this paper also introduced the experience and lesson of foreign countries in renewable energy development, the gladness and worries about ''RENEWABLE ENERGY LAW'' and there appeals to improve the environment in the development of the solar energy industry. (orig.)
Framework for analysis of solar energy systems in the built environment from an exergy perspective
Torio, H.; Schmidt, D.
2010-01-01
Exergy analysis is a more powerful tool than mere energy analysis for showing the improvement potential of energy systems. Direct use of solar radiation instead of degrading other high quality energy resources found in nature is advantageous. Yet, due to physical inconsistencies present in the exergy analysis framework for assessing direct-solar systems commonly found in literature, high exergy losses arise in the conversion process of solar radiation in direct-solar systems. However, these l...
AN APPLICATION FOR ELECTRICAL PRODUCTION WITH SOLAR TOWER SYSTEM
Directory of Open Access Journals (Sweden)
Reşat SELBAŞ
2003-02-01
Full Text Available The requirement of electric energy rises with increasing of the population and faster improvement demands. Energy necessity generally is provided by using fossil based fuel sources. In order to supply energy requirements, today, using alternative sources became necessary because of the problems such as decreasing of available fossil fuel sources and environment pollution from this fuel. The solar energy which has a wide range of application potential is the most hopeful and unlimited energy source without environment pollution in electric energy production. In this paper, the electric production methods from solar energy are studied and the most suitable method for solar energy plant is tried to find out. The selected method, known as Solar Tower in literature is an electric production method. In this study, technical and cost analysis of an application using this method are carried out.
Magnetohydrodynamic process in solar activity
Directory of Open Access Journals (Sweden)
Jingxiu Wang
2014-01-01
Full Text Available Magnetohydrodynamics is one of the major disciplines in solar physics. Vigorous magnetohydrodynamic process is taking place in the solar convection zone and atmosphere. It controls the generating and structuring of the solar magnetic fields, causes the accumulation of magnetic non-potential energy in the solar atmosphere and triggers the explosive magnetic energy release, manifested as violent solar flares and coronal mass ejections. Nowadays detailed observations in solar astrophysics from space and on the ground urge a great need for the studies of magnetohydrodynamics and plasma physics to achieve better understanding of the mechanism or mechanisms of solar activity. On the other hand, the spectacular solar activity always serves as a great laboratory of magnetohydrodynamics. In this article, we reviewed a few key unresolved problems in solar activity studies and discussed the relevant issues in solar magnetohydrodynamics.
Development of Electrostatically Clean Solar Array Panels
Stern, Theodore G.
2000-01-01
Certain missions require Electrostatically Clean Solar Array (ECSA) panels to establish a favorable environment for the operation of sensitive scientific instruments. The objective of this program was to demonstrate the feasibility of an ECSA panel that minimizes panel surface potential below 100mV in LEO and GEO charged particle environments, prevents exposure of solar cell voltage and panel insulating surfaces to the ambient environment, and provides an equipotential, grounded structure surrounding the entire panel. An ECSA panel design was developed that uses a Front Side Aperture-Shield (FSA) that covers all inter-cell areas with a single graphite composite laminate, composite edge clips for connecting the FSA to the panel substrate, and built-in tabs that interconnect the FSA to conductive coated coverglasses using a conductive adhesive. Analysis indicated the ability of the design to meet the ECSA requirements. Qualification coupons and a 0.5m x 0.5m prototype panel were fabricated and tested for photovoltaic performance and electrical grounding before and after exposure to acoustic and thermal cycling environments. The results show the feasibility of achieving electrostatic cleanliness with a small penalty in mass, photovoltaic performance and cost, with a design is structurally robust and compatible with a wide range of current solar panel technologies.
International Nuclear Information System (INIS)
Bezat, Jean-Michel; Leplatre, Simon
2017-01-01
This article comments the massive development of solar energy in many countries due to a significant decrease of solar array cost, to massive investments and to environmental constraints. More than a half of production means installed in 2015 are solar ones. After 50 GW installed in 2015, 70 GW are expected for 2016. Price drop is notably due to the Chinese dominant position. If equipment is cheaper, it has also become more reliable with a longer lifetime. Emerging countries are leaders in terms of development of installations even though China, the USA and Japan still represent the majority of additional capacities in 2015. Technological advances in solar cell technology are evoked. The associated evolution of the World energy mix is also evoked as well as the threat related by recent positions of President Trump in favour of fossil energies. Chinese policy for the environment and for the development of solar energy is briefly presented
Integrated control of the South African border environment
CSIR Research Space (South Africa)
Taute, BJE
2007-03-01
Full Text Available flights enter our airspace. To control/coordinate the border environment effectively requires a vast range of information sources, reconnaissance and surveillance sensors, a communications infrastructure and a hub where information can be collected...
Status of the Instrument Control Unit for EPD on-board Solar Orbiter
Sánchez Prieto, Sebastián; Da Silva, Antonio; Rodriguez Polo, Oscar; Parra Espada, Pablo; Gutierrez Molina, Oscar; Fernandez Salgado, Javier
Solar Orbiter is the next heliospheric mission sponsored by ESA. The launch is planned for 2017 and it will be as close as 0.28 AU from the Sun. One of the instruments for Solar Orbiter is the Energetic Particle Detector (EPD) responsible for measuring energies from 2 keV to 200 MeV/n. EPD consists of four detectors, Electron Proton Telescope (EPT), High Energy Telescope (HET), SupraThermal Electrons, Ions, & Neutrals (STEIN), and Suprathermal Ion Spectrograph (SIS), plus the Instrument Control Unit called ICU. The Space Research Group of the University of Alcalá in Spain is the responsible for developing the ICU. In this work we present the development status of the ICU after the Critical Design Review. We also address the planned activities for the next year including the development of the Engineering and Qualification Model (EQM) and Flight Model (PM). Special focus is paid to the software and verification & validation activities.
Energy Technology Data Exchange (ETDEWEB)
Yebra, L.J.; Romero, M.; Martinez, D.; Valverde, A. [CIEMAT - Plataforma Solar de Almeria, Tabernas (Spain); Berenguel, M. [Almeria Univ. (Spain). Departamento de Lenguajes y Computacion
2004-07-01
This work overviews some of the main activities and research lines that are being carried out within the scope of the specific collaboration agreement between the Plataforma Solar de Almeria-CIEMAT (PSA-CIEMAT) and the Automatic Control, Electronics and Robotics research group of the Universidad de Almeria (TEP197) titled ''Development of control systems and tools for thermosolar plants'' and the projects financed by the MCYT DPI2001-2380-C02-02 and DPI2002-04375-C03. The research is directed by the need of improving the efficiency of the process through which the energy provided by the sun is totally or partially used as energy source, as far as diminishing the costs associated to the operation and maintenance of the installations that use this energy source. The final objective is to develop different automatic control systems and techniques aimed at improving the competitiveness of solar plants. The paper summarizes different objectives and automatic control approaches that are being implemented in different facilities at the PSA-CIEMAT: central receiver systems and solar furnace. For each one of these facilities, a systematic procedure is being followed, composed of several steps: (i) development of dynamic models using the newest modeling technologies (both for simulation and control purposes), (ii) development of fully automated data acquisition and control systems including software tools facilitating the analysis of data and the application of knowledge to the controlled plants and (iii) synthesis of advanced controllers using techniques successfully used in the process industry and development of new and optimized control algorithms for solar plants. These aspects are summarized in this work. (orig.)
An analysis of solar assisted ground source heat pumps in cold climates
International Nuclear Information System (INIS)
Emmi, Giuseppe; Zarrella, Angelo; De Carli, Michele; Galgaro, Antonio
2015-01-01
Highlights: • The work focuses on solar assisted ground source heat pump in cold climates. • Multi-year simulations of SAGSHP, are carried out in six cold locations. • GSHP and SAGSHP are compared. • The effect of total borehole length on the heat pump energy efficiency is studied. • A dedicated control strategy is used to manage both solar and ground loops. - Abstract: Exploiting renewable energy sources for air-conditioning has been extensively investigated over recent years, and many countries have been working to promote the use of renewable energy to decrease energy consumption and CO_2 emissions. Electrical heat pumps currently represent the most promising technology to reduce fossil fuel usage. While ground source heat pumps, which use free heat sources, have been taking significant steps forward and despite the fact that their energy performance is better than that of air source heat pumps, their development has been limited by their high initial investment cost. An alternative solution is one that uses solar thermal collectors coupled with a ground source heat pump in a so-called solar assisted ground source heat pump. A ground source heat pump system, used to heat environments located in a cold climate, was investigated in this study. The solar assisted ground source heat pump extracted heat from the ground by means of borehole heat exchangers and it injected excess solar thermal energy into the ground. Building load profiles are usually heating dominated in cold climates, but when common ground source heat pump systems are used only for heating, their performance decreases due to an unbalanced ground load. Solar thermal collectors can help to ensure that systems installed in cold zones perform more efficiently. Computer simulations using a Transient System Simulation (TRNSYS) tool were carried out in six cold locations in order to investigate solar assisted ground source heat pumps. The effect of the borehole length on the energy efficiency of
Energy Technology Data Exchange (ETDEWEB)
Gur, Ilan [Univ. of California, Berkeley, CA (United States)
2006-01-01
This dissertation presents the results of a research agenda aimed at improving integration and stability in nanocrystal-based solar cells through advances in active materials and device architectures. The introduction of 3-dimensional nanocrystals illustrates the potential for improving transport and percolation in hybrid solar cells and enables novel fabrication methods for optimizing integration in these systems. Fabricating cells by sequential deposition allows for solution-based assembly of hybrid composites with controlled and well-characterized dispersion and electrode contact. Hyperbranched nanocrystals emerge as a nearly ideal building block for hybrid cells, allowing the controlled morphologies targeted by templated approaches to be achieved in an easily fabricated solution-cast device. In addition to offering practical benefits to device processing, these approaches offer fundamental insight into the operation of hybrid solar cells, shedding light on key phenomena such as the roles of electrode-contact and percolation behavior in these cells. Finally, all-inorganic nanocrystal solar cells are presented as a wholly new cell concept, illustrating that donor-acceptor charge transfer and directed carrier diffusion can be utilized in a system with no organic components, and that nanocrystals may act as building blocks for efficient, stable, and low-cost thin-film solar cells.
Directory of Open Access Journals (Sweden)
W. Bettiol
1994-12-01
Full Text Available A solarização, durante dois meses, de um solo naturalmente infestado com Pythium, promoveu o controle do patógeno, de modo semelhante à aplicação de metalaxyl + mancozeb, na cultura de crisântemo. A incidência média de plantas mortas foi de 2,3% nas parcelas solarizadas; 1,0% no solo solarizado que recebeu metade da dose dos fungicidas; 9,0% com a aplicação da dose completa dos fungicidas (1 g de metalaxyl + 4,8 g de mancozeb/m² e 38,9%, na testemunha não tratada. A solarização também promoveu o controle de plantas daninhas, avaliado através do peso da matéria seca das plantas emergentes aos 21 dias após o transplante das mudas, semelhantemente ao herbicida oxidiazon.Two months solarization of a soil naturally infested with Pythium sp. promoted a level of control similar to what was obtained with the application of methalaxyl + mancozeb for the chrysanthemum crop. The average rate of dead plants was 9.0% with the application of fungicides (1 g of methalaxyl + 4.8 g of mancozeb/ m²; 2.3% in solarized plots; 1.0% in solarized plots which received half the dosages of the fungicides and 38.9% in control plots. Similar control of weeds was obtained in solarized plots and plots treated with the herbicide oxidiazon.
Market Barriers to Solar in Michigan
Energy Technology Data Exchange (ETDEWEB)
Miller, E.; Nobler, E.; Wolf, C.; Doris, E.
2012-08-01
The solar industry in the United States is at a turning point; the cost of PV hardware has declined substantially in recent years, placing new attention on reducing the balance of system (BOS) costs of solar that now contribute to a growing percentage of installation expenses. How states address these costs through the creation of a favorable policy and regulatory environment is proving to be a critical determinant of a thriving statewide solar market. This report addresses the permitting and tax issues that may stimulate the solar market growth in Michigan. By making PV installations easier to complete through reduced BOS costs, Michigan would become a more attractive location for manufacturers and installers. As PV module costs decline and BOS costs make up a greater share of the cost of solar, action taken today on these issues will prove beneficial in the long term, providing Michigan an opportunity to establish a leadership position in the solar industry.
Energy Technology Data Exchange (ETDEWEB)
Lee, Eleanor S.; Thanachareonkit, Anothai; Touzani, Samir; Dutton, Spencer; Shackelford, Jordan; Dickerhoff, Darryl; Selkowitz, Stephen
2016-09-01
The objective of this monitored field study was to identify near-term innovative façade technologies for solar control and daylighting with a goal of 20-40% energy use savings below Title 24 2013 in the 30-ft deep perimeter zone near vertical windows within cost and comfort constraints. The targeted market was new or existing commercial office buildings or buildings with similar patterns of use.
1980-01-01
Several features of the interactions of the Solar Power Satellite (SPS) with its space environment are examined theoretically. The voltages produced at various surfaces due to space plasmas and the plasma leakage currents through the kapton and sapphire solar cell blankets are calculated. At geosynchronous orbit, this parasitic power loss is only 0.7%, and is easily compensated by oversizing. At low Earth orbit, the power loss is potentially much larger (3%), and anomalous arcing is expected for the EOTV high voltage negative surfaces. Preliminary results of a three dimensional self consistent plasma and electric field computer program are presented, confirming the validity of the predictions made from the one dimensional models. Lastly, magnetic shielding of the satellite is considered to reduce the power drain and to protect the solar cells from energetic electron and plasma ion bombardment. It is concluded that minor modifications can allow the SPS to operate safely and efficiently in its space environment. Subsequent design changes will substantially alter the basic conclusions.
On protection of freedom's solar dynamic radiator from the orbital debris environment. Part 2
International Nuclear Information System (INIS)
Rhatigan, J.L.
1992-01-01
In this paper, recent progress to better understand the environmental threat of micrometeoroid and space debris to the solar dynamic radiator for the Space Station Freedom power system is reported. The objective was to define a design which would perform to survivability requirements over the expected lifetime of the radiator. A previous paper described the approach developed to assess on-orbit survivability of the solar dynamic radiator due to micrometeoroid and space debris impacts. Preliminary analyses were presented to quantify the solar dynamic radiator survivability. These included the type of particle and particle population expected to defeat the radiator bumpering. Results of preliminary hypervelocity impact (HVI) testing performed on radiator panel samples were also presented. This paper presents results of a more extensive test program undertaken to further define the response of the solar dynamic radiator to HVI. Tests were conducted on representative radiator panels (under ambient, nonoperating conditions) over a range of particle size, particle density, impact angle, and impact velocity. Target parameters were also varied. Data indicate that analytical penetration predictions are conservative (i.e., pessimistic) for the specific configuration of the solar dynamic radiator. Test results are used to define more rigorously the solar dynamic radiator reliability with respect to HVI. Test data, analyses, and survivability results are presented
Design of the support structure, drive pedestal, and controls for a solar concentrator
Energy Technology Data Exchange (ETDEWEB)
Goldberg, V.R.; Ford, J.L.; Anderson, A.E. (WG Associates, Dallas, TX (United States))
1991-08-01
The glass/metal McDonnell-Douglas dish is the state-of-the-art of parabolic dish concentrators. Because of the perceived high production cost of this concentrator, the Department of Energy's Solar Thermal Program is developing stretch-membrane technology for large (75 kWt) solar concentrators for integration with receivers and engines in 25 kWe dish-Stirling systems. The objective of this development effort is to reduce the cost of the concentrator while maintaining the high levels of performance characteristic of glass-metal dishes. Under contract to Sandia National Laboratories, Science Applications International Corporation, Solar Kinetics Inc. and WG Associates are developing a faceted stretched-membrane heliostat technology. This design will result in a low-risk, near-term concentrator for dish-Stirling systems. WG Associates has designed the support structure, drives and tracking controls for this dish. The structure is configured to support 12 stretched-membrane, 3.5-meter diameter facets in a shaped dish configuration. The dish design is sized to power a dish-Stirling system capable of producing 25 kW (electric). In the design of the structure, trade-off studies were conducted to determine the best'' facet arrangement, dish contour, dish focal length, tracking control and walk-off protection. As part of the design, in-depth analyses were performed to evaluate pointing accuracy, compliance with AISC steel design codes, and the economics of fabrication and installation. Detailed fabrication and installation drawings were produced, and initial production cost estimates for the dish were developed. These issues, and the final dish design, are presented in this report. 7 refs., 33 figs., 18 tabs.
A novel solar multifunctional PV/T/D system for green building roofs
International Nuclear Information System (INIS)
Feng, Chaoqing; Zheng, Hongfei; Wang, Rui; Yu, Xu; Su, Yuehong
2015-01-01
Highlights: • A novel transparent roof combines the solar PV/T/D system with green building design. • Novel photovoltaic-thermal roofing design can achieve excellent light control at noon. • The roof has no obvious influence on indoor light intensity in morning and afternoon. • Higher efficiency of solar energy utilization could be achieved with new roofing. - Abstract: A novel transparent roof which is made of solid CPC (Compound Parabolic Concentrator) PV/T/D (Photovoltaic/Thermal/Day lighting) system is presented. It combines the solar PV/T/D system with green building design. The PV/T/D system can achieve excellent light control at noon and adjust the thermal environment in the building, such that high efficiency utilization of solar energy could be achieved in modern architecture. This kind of roof can increase the visual comfort for building occupants; it can also avoid the building interior from overheating and dazzling at noon which is caused by direct sunlight through transparent roof. Optical simulation software is used to track the light path in different incidence angles. CFD (Computational Fluid Dynamics) simulation and steady state experiment have been taken to investigate the thermal characteristic of PV/T/D device. Finally, the PV/T/D experimental system was built; and the PV efficiency, light transmittance and air heating power of the system are tested under real sky conditions
Development of an Embedded Solar Tracker using Compact RIO
Energy Technology Data Exchange (ETDEWEB)
Oh, Seung Jin; Lee, Yoon Joon; Chun, Won Gee [Jeju National University, Jeju (Korea, Republic of)
2011-08-15
An embedded two-axis solar tracking system using LabVIEW to write the operation and control algorithms was developed for enhancing solar energy utilization. The system consists of a real-time processor, two motion- control modules, two step drives, two step motors, feedback devices, and other accessories needed for functional stability. The real-time processor allows the solar tracker to be used as a stand-alone, real-time system that can operate automatically without any external control. The system combines two different solar tracking methods: the optical method and the astronomical method. CdS sensors are employed to continuously generate feedback signals to the controller, ensuring high-precision solar tracking even under adverse conditions. CdS sensor is a resistor whose resistance decreases with increasing incident light intensity. A database of solar altitude, azimuth, and sunrise and sunset times is provided by this solar tracking system. Other solar trackers operating in an astronomical method may access and use this database over the Internet. Solar position and sunrise and sunset times in the database were compared with those of the Astronomical Applications Department of the U.S. Naval Observatory. The differences were found to be negligible.
Development of an Embedded Solar Tracker using Compact RIO
International Nuclear Information System (INIS)
Oh, Seung Jin; Lee, Yoon Joon; Chun, Won Gee
2011-01-01
An embedded two-axis solar tracking system using LabVIEW to write the operation and control algorithms was developed for enhancing solar energy utilization. The system consists of a real-time processor, two motion- control modules, two step drives, two step motors, feedback devices, and other accessories needed for functional stability. The real-time processor allows the solar tracker to be used as a stand-alone, real-time system that can operate automatically without any external control. The system combines two different solar tracking methods: the optical method and the astronomical method. CdS sensors are employed to continuously generate feedback signals to the controller, ensuring high-precision solar tracking even under adverse conditions. CdS sensor is a resistor whose resistance decreases with increasing incident light intensity. A database of solar altitude, azimuth, and sunrise and sunset times is provided by this solar tracking system. Other solar trackers operating in an astronomical method may access and use this database over the Internet. Solar position and sunrise and sunset times in the database were compared with those of the Astronomical Applications Department of the U.S. Naval Observatory. The differences were found to be negligible
DEFF Research Database (Denmark)
Demirok, Erhan; Gonzalez, Pablo Casado; Frederiksen, Kenn H. B.
2011-01-01
on sensitivity analysis. The sensitivity analysis shows that the same amount of reactive power becomes more effective for grid voltage support if the solar inverter is located at the end of a feeder. Based on this fundamental knowledge, a location-dependent power factor set value can be assigned to each inverter......voltage (LV) grids by means of solar inverters with reactive power control capability. This paper underlines weak points of standard reactive power strategies which are already imposed by certain grid codes, and then, the study introduces a new reactive power control method that is based......, and the grid voltage support can be achieved with less total reactive power consumption. In order to prevent unnecessary reactive power absorption from the grid during admissible voltage range or to increase reactive power contribution from the inverters that are closest to the transformer during grid...
Using Solar Radiation Pressure to Control L2 Orbits
Tene, Noam; Richon, Karen; Folta, David
1998-01-01
The main perturbations at the Sun-Earth Lagrange points L1 and L2 are from solar radiation pressure (SRP), the Moon and the planets. Traditional approaches to trajectory design for Lagrange-point orbits use maneuvers every few months to correct for these perturbations. The gravitational effects of the Moon and the planets are small and periodic. However, they cannot be neglected because small perturbations in the direction of the unstable eigenvector are enough to cause exponential growth within a few months. The main effect of a constant SRP is to shift the center of the orbit by a small distance. For spacecraft with large sun-shields like the Microwave Anisotropy Probe (MAP) and the Next Generation Space Telescope (NGST), the SRP effect is larger than all other perturbations and depends mostly on spacecraft attitude. Small variations in the spacecraft attitude are large enough to excite or control the exponential eigenvector. A closed-loop linear controller based on the SRP variations would eliminate one of the largest errors to the orbit and provide a continuous acceleration for use in controlling other disturbances. It is possible to design reference trajectories that account for the periodic lunar and planetary perturbations and still satisfy mission requirements. When such trajectories are used the acceleration required to control the unstable eigenvector is well within the capabilities of a continuous linear controller. Initial estimates show that by using attitude control it should be possible to minimize and even eliminate thruster maneuvers for station keeping.
Optimal Control of Solar Heating System
Huang, Bin-Juine; Ton, Wei-Zhe; Wu, Chen-Chun; Ko, Hua-Wei; Chang, Hsien-Shun; Yen, Rue-Her
2017-01-01
was used in the feedback design of MPPT. The field test results show that the pumping power is 89 W at Qs = 13.7 kW and IT = 892 W/m2. A very high electrical COP of the solar heating system (Qs/Wp = 153.8) is obtained.
da Fonseca, Ijar M.; Rade, Domingos A.; Goes, Luiz C. S.; de Paula Sales, Thiago
2017-10-01
The primary purpose of this paper is to provide insight into control-structure interaction for satellites comprising flexible appendages and internal moving components. The physical model considered herein aiming to attend such purpose is a rigid-flexible satellite consisting of a rigid platform containing two rotating flexible solar panels. The solar panels rotation is assumed to be in a sun-synchronous configuration mode. The panels contain surface-bonded piezoelectric patches that can be used either as sensors for the elastic displacements or as actuators to counteract the vibration motion. It is assumed that in the normal mode operation the satellite platform points towards the Earth while the solar arrays rotate so as to follow the Sun. The vehicle moves in a low Earth polar orbit. The technique used to obtain the mathematical model combines the Lagrangian formulation with the Finite Elements Method used to describe the dynamics of the solar panel. The gravity-gradient torque as well as the torque due to the interaction of the Earth magnetic field and the satellite internal residual magnetic moment is included as environmental perturbations. The actuators are three reaction wheels for attitude control and piezoelectric actuators to control the flexible motion of the solar arrays. Computer simulations are performed using the MATLAB® software package. The following on-orbit satellite operating configurations are object of analysis: i) Satellite pointing towards the Earth (Earth acquisition maneuver) by considering the initial conditions in the elastic displacement equal to zero, aiming the assessment of the flexible modes excitation by the referred maneuver; ii) the satellite pointing towards the Earth with the assumption of an initial condition different from zero for the flexible motion such that the attitude alterations are checked against the elastic motion disturbance; and iii) attitude acquisition accomplished by taking into account initial conditions
The PV LED Engine - a new generation of intelligent solar powered LED lighting
DEFF Research Database (Denmark)
Poulsen, Peter Behrensdorff; Thorsteinsson, Sune
parameters are ltered mathematical by the optical properties of the materials in front of the solar panel and assumptions about the soiling parameters. Lab measurements of solar cells/panels underdierent lighting conditions (spectrally and intensity) makes it possible to simulate performance of realsolar...... projectat design and simulation tool for small PV applications for the urban environment is developed. The tool is advanced in its calculations on the solar irradiation parameters being very dierent in the urban environment compared to roof top applications both spectrally and in intensity variations...... panels of different technologies in the addressed environment since detailed electrical characteristicsis known by the measurements. Optical parameters for the protection layer (in front of the solar panel)are put into a material library so the optimal choice can be made for a given application...
LQG and maximum entropy control design for the Hubble Space Telescope
Collins, Emmanuel G., Jr.; Richter, Stephen
Solar array vibrations are responsible for serious pointing control problems on the Hubble Space Telescope (HST). The original HST control law was not designed to attenuate these disturbances because they were not perceived to be a problem prior to launch. However, significant solar array vibrations do occur due to large changes in the thermal environment as the HST orbits the earth. Using classical techniques, Marshall Space Flight Center in conjunction with Lockheed Missiles and Space Company developed modified HST controllers that were able to suppress the influence of the vibrations of the solar arrays on the line-of-sight (LOS) performance. Substantial LOS improvement was observed when two of these controllers were implemented on orbit. This paper describes the development of modified HST controllers by using modern control techniques, particularly linear-quadratic-gaussian (LQG) design and Maximum Entropy robust control design, a generalization of LQG that incorporates robustness constraints with respect to modal errors. The fundamental issues are discussed candidly and controllers designed using these modern techniques are described.
System design and installation for RS600 programmable control system for solar heating and cooling
1978-01-01
Procedures for installing, operating, and maintaining a programmable control system which utilizes a F8 microprocessor to perform all timing, control, and calculation functions in order to customize system performance to meet individual requirements for solar heating, combined heating and cooling, and/or hot water systems are described. The manual discusses user configuration and options, displays, theory of operation, trouble-shooting procedures, and warranty and assistance. Wiring lists, parts lists, drawings, and diagrams are included.
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
Solar Water Heater Installation Package
1982-01-01
A 48-page report describes water-heating system, installation (covering collector orientation, mounting, plumbing and wiring), operating instructions and maintenance procedures. Commercial solar-powered water heater system consists of a solar collector, solar-heated-water tank, electrically heated water tank and controls. Analysis of possible hazards from pressure, electricity, toxicity, flammability, gas, hot water and steam are also included.
The virtual enhancements - solar proton event radiation (VESPER) model
Aminalragia-Giamini, Sigiava; Sandberg, Ingmar; Papadimitriou, Constantinos; Daglis, Ioannis A.; Jiggens, Piers
2018-02-01
A new probabilistic model introducing a novel paradigm for the modelling of the solar proton environment at 1 AU is presented. The virtual enhancements - solar proton event radiation model (VESPER) uses the European space agency's solar energetic particle environment modelling (SEPEM) Reference Dataset and produces virtual time-series of proton differential fluxes. In this regard it fundamentally diverges from the approach of existing SPE models that are based on probabilistic descriptions of SPE macroscopic characteristics such as peak flux and cumulative fluence. It is shown that VESPER reproduces well the dataset characteristics it uses, and further comparisons with existing models are made with respect to their results. The production of time-series as the main output of the model opens a straightforward way for the calculation of solar proton radiation effects in terms of time-series and the pairing with effects caused by trapped radiation and galactic cosmic rays.
Cates, Nichole C.
2009-12-09
We demonstrate that intercalation of fullerene derivatives between the side chains of conjugated polymers can be controlled by adjusting the fullerene size and compare the properties of intercalated and nonintercalated poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene (pBTTT):fullerene blends. The intercalated blends, which exhibit optimal solar-cell performance at 1:4 polymer:fullerene by weight, have better photoluminescence quenching and lower absorption than the nonintercalated blends, which optimize at 1:1. Understanding how intercalation affects performance will enable more effective design of polymer:fullerene solar cells. © 2009 American Chemical Society.
Cates, Nichole C.; Gysel, Roman; Beiley, Zach; Miller, Chad E.; Toney, Michael F.; Heeney, Martin; McCulloch, Iain; McGehee, Michael D.
2009-01-01
We demonstrate that intercalation of fullerene derivatives between the side chains of conjugated polymers can be controlled by adjusting the fullerene size and compare the properties of intercalated and nonintercalated poly(2,5-bis(3-hexadecylthiophen-2-yl)thieno[3,2-b]thiophene (pBTTT):fullerene blends. The intercalated blends, which exhibit optimal solar-cell performance at 1:4 polymer:fullerene by weight, have better photoluminescence quenching and lower absorption than the nonintercalated blends, which optimize at 1:1. Understanding how intercalation affects performance will enable more effective design of polymer:fullerene solar cells. © 2009 American Chemical Society.
International Nuclear Information System (INIS)
Berner, Joachim
2011-01-01
There are many different combinations of solar heating systems and heat pumps in the market; some of them differ considerably in terms of the design concept, control management and storage technology. One thing they all have in common is that solar heating comes first.
Energy Technology Data Exchange (ETDEWEB)
Puettmer, M. [Goetz GmbH, Metall- und Anlagenbau, Fellbach (Germany); Kranz, H.R. [Siemens AG, Karlsruhe (Germany)
1995-12-31
In chapter 11 of the anthology about building control the subject solar cooling is described. The following aspects are discussed: changed preconditions for thermal building concepts, building facades and energy supply - one unit. Can cold be economically generated by solar energy? (BWI) [Deutsch] Kapitel 11 des Sammelbandes ueber Building Control ist dem Thema der solaren Kuehlung gewidmet. In diesem Zusammenhang werden folgende Themenkreise angesprochen: Geaenderte Voraussetzungen fuer thermische Gebaeudekonzepte; Gebaeudefassade und Energieversorgung: eine Einheit; Kann Kaelte mit der Sonne wirtschaftlich erzeugt werden? (BWI)
Prikryl, Paul; Tsukijihara, Takumi; Iwao, Koki; Muldrew, Donald B.; Bruntz, Robert; Rušin, Vojto; Rybanský, Milan; Turňa, Maroš; Šťastný, Pavel; Pastirčák, Vladimír
2017-04-01
(Prikryl et al., Ann. Geophys., 27, 31-57, 2009). It is primarily the energy provided by release of latent heat that leads to intensification of storms. These results indicate that vertical coupling in the atmosphere exerts downward control from solar wind to the lower atmospheric levels influencing tropospheric weather development.
Results from the high efficiency solar panel experiment flown on CRRES
International Nuclear Information System (INIS)
Ray, K.P.; Mullen, E.G.; Trumble, T.M.
1993-01-01
This paper presents results from the High Efficiency Solar Panel Experiment (HESP) flown on the Combined Release and Radiation Effects Satellite (CRRES). The on-orbit solar cell degradation is correlated with the proton and electron environments. Comparisons between gallium arsenide germanium (GaAs/Ge) and silicon (Si) solar cells are presented, and results from three different annealing methods of like GaAs solar cells are compared
Energy Technology Data Exchange (ETDEWEB)
Halsey, Jeffery D. [Broward County, Fort Lauderdale, FL (United States)
2013-08-28
Broward County and its partners (the Go SOLAR Team), operating under a Department of Energy Rooftop Solar Challenge Agreement, designed, developed and implemented an online permitting system for rooftop solar PV systems. This is a single web based system with a single permit fee that will issue a permit, with a set of design plans preapproved by partner building officials, within one hour. The system is currently available at gosolar.broward.org for use within any of the partner Authorities Having [permitting] Jurisdiction (AHJ). Additionally, the Go SOLAR Team researched, developed and to the extent feasible, implemented three best management practices to make a fertile environment for the new online permit system. These included Net Metering and Interconnection Standards, Solar-Friendly Financing, and Planning and Zoning Ordinances. Finally, the team implemented a substantial outreach effort to advocate for the development of solar in Broward County, with an emphasis on Solar Rights, concluding with a Go SOLAR Fest day and a half conference with over 1,200 attendees and 50 exhibitors. The Go SOLAR project was completed on time, under DOE’s budgeted amount, and all project objectives were met or exceeded.
Family control, institutional environment and cash dividend policy: Evidence from China
Directory of Open Access Journals (Sweden)
Zhihua Wei
2011-06-01
Full Text Available Using a sample of 1486 Chinese A-share listed companies for the period 2004–2008, this study empirically tests the impact of family control, institutional environment and their interaction on the cash dividend policy of listed companies. Our results indicate that (1 family firms have a lower cash dividend payout ratio and propensity to pay dividends than non-family firms; (2 a favorable regional institutional environment has a significant positive impact on the cash dividend payout ratio and propensity to pay dividends of listed companies; and (3 the impact of the regional institutional environment on cash dividends is stronger in family firms than in non-family firms. Somewhat surprisingly, we find that controlling family shareholders in China may intensify Agency Problem I (the owner–manager conflict rather than Agency Problem II (the controlling shareholder–minority shareholder conflict, and thus have a significant negative impact on cash dividend policy. In contrast, a favorable regional institutional environment plays a positive corporate governance role in mitigating Agency Problem I and encouraging family firms to pay cash dividends.
Midmarket Solar Policies in the United States: A Guide for Midsized Solar Customers
Energy Technology Data Exchange (ETDEWEB)
Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Liu, Chang [National Renewable Energy Lab. (NREL), Golden, CO (United States); O' Shaughnessy, Eric [National Renewable Energy Lab. (NREL), Golden, CO (United States); Mathur, Shivani [National Renewable Energy Lab. (NREL), Golden, CO (United States); Holm, Alison [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, John [National Renewable Energy Lab. (NREL), Golden, CO (United States)
2016-09-01
use solar policies in a dynamic policy environment. The second part of this guide provides a complete, state-by-state inventory of midmarket solar policies for potential customers and developers to use as reference when making policy-based decisions. Although solar policies are dynamic, the profiles provide a framework for assessing policies to build the parameters that could be used to determine feasibility and structure of a solar PV system for midmarket customers and developers.
Directory of Open Access Journals (Sweden)
Amjad Ali
2015-01-01
Full Text Available A new simple moving voltage average (SMVA technique with fixed step direct control incremental conductance method is introduced to reduce solar photovoltaic voltage (VPV oscillation under nonuniform solar irradiation conditions. To evaluate and validate the performance of the proposed SMVA method in comparison with the conventional fixed step direct control incremental conductance method under extreme conditions, different scenarios were simulated. Simulation results show that in most cases SMVA gives better results with more stability as compared to traditional fixed step direct control INC with faster tracking system along with reduction in sustained oscillations and possesses fast steady state response and robustness. The steady state oscillations are almost eliminated because of extremely small dP/dV around maximum power (MP, which verify that the proposed method is suitable for standalone PV system under extreme weather conditions not only in terms of bus voltage stability but also in overall system efficiency.
International Nuclear Information System (INIS)
Sauer, H.H.; Stonehocker, G.H.
1977-04-01
The first part of the report provides background information on the occurrence of solar activity and the consequent sporadic production of electromagnetic and particle emissions from the sun. A summary is given of the current procedures for the forecasting of solar activity together with procedures used to verify these forecasts as currently available. A summary of current forecasting of radiation hazards as provided in support of the Concorde SST program is also given. The second part of the report describes a forecast message distribution system developed in conjunction with solar cosmic radiation forecasts and warnings of the Space Environment Laboratory of NOAA for the Federal Aviation Administration's (FAA) Office of Aviation Medicine. The study analyzes the currently available and future aeronautical telecommunication system facilities to determine an optimum system to distribute forecasts to the preflight planning centers in the international flight service stations for polar-flying subsonic and supersonic transport (SST) type aircraft. Also recommended for the system are timely and reliable distribution of warnings to individual in-flight aircraft in polar areas by the responsible air traffic control authority
High Radiation Resistance IMM Solar Cell
Pan, Noren
2015-01-01
Due to high launch costs, weight reduction is a key driver for the development of new solar cell technologies suitable for space applications. This project is developing a unique triple-junction inverted metamorphic multijunction (IMM) technology that enables the manufacture of very lightweight, low-cost InGaAsP-based multijunction solar cells. This IMM technology consists of indium (In) and phosphorous (P) solar cell active materials, which are designed to improve the radiation-resistant properties of the triple-junction solar cell while maintaining high efficiency. The intrinsic radiation hardness of InP materials makes them of great interest for building solar cells suitable for deployment in harsh radiation environments, such as medium Earth orbit and missions to the outer planets. NASA Glenn's recently developed epitaxial lift-off (ELO) process also will be applied to this new structure, which will enable the fabrication of the IMM structure without the substrate.
Solar air heaters and their applications
Selcuk, M. K.
1977-01-01
The solar air heater appears to be the most logical choice, as far as the ultimate application of heating air to maintain a comfortable environment is concerned. One disadvantage of solar air heaters is the need for handling larger volumes of air than liquids due to the low density of air as a working substance. Another disadvantage is the low thermal capacity of air. In cases where thermal storage is needed, water is superior to air. Design variations of solar air heaters are discussed along with the calculation of the efficiency of a flat plate solar air heater, the performance of various collector types, and the applications of solar air heaters. Attention is given to collectors with nonporous absorber plates, collectors with porous absorbers, the performance of flat plate collectors with finned absorbers, a wire mesh absorber, and an overlapped glass plate air heater.
Design consideration of solar powered cars
Energy Technology Data Exchange (ETDEWEB)
Koten, Hasan; Yilmaz, Mustafa; Zafer Gul, M. [Marmara University Mechanical Engineering Department (Turkey)], E-mail: hasan.koten@marmara.edu.tr
2011-07-01
With the coming shortage of fossil fuels and the rising concerns over the environment, it is important to develop new technologies that reduce both energy consumption and pollution at the same time. Using solar energy is a good solution which could meet the world's energy needs. The aim of this study is to present the design process in the production of a solar powered car. Designing a solar powered car is a difficult task as there are strict requirements in term of efficiency: the car must have low drag resistance, be light-weight, and have low rolling resistance. In addition this paper presents the use of the solar powered Stirling engine technology rather than a photovoltaic conversion system for vehicle propulsion. This study presented a design process in the construction of a solar powered car and is expected to provide a new topic of research in the transportation field.
Spatially Resolved Images and Solar Irradiance Variability R ...
Indian Academy of Sciences (India)
Abstract. The Sun is the primary source of energy that governs both the terrestrial climate and near-earth space environment. Variations in UV irradiances seen at earth are the sum of global (solar dynamo) to regional. (active region, plage, network, bright points and background) solar mag- netic activities that can be ...
Proceedings of the IASTED international conference on solar energy : SOE 2009
Energy Technology Data Exchange (ETDEWEB)
Hamza, M.H. [International Association of Science and Technology for Development, Calgary, AB (Canada)] (ed.)
2009-07-01
This solar energy conference was attended by international researchers and practitioners working with leading edge solar energy technology as well as related areas such as renewable energy and clean energy. The topics of discussion included nanotechnologies for solar energy; photovoltaic energy; solar fuel cells; solar-powered vehicles; solar thermal energy; thin film batteries; desalination systems; solar cooling; clean energy; renewable energy; biomass energy; sustainability; flexible solar cells; hybrid power generation; organic solar cells; remote sensing of solar radiation; solar thermal conversion; sustainable buildings; and thin film silicon solar cells. Some of the presentations discussed the application of solar energy in agriculture, environment, economics and home construction. The sessions were entitled: grid connection and energy conversion; photovoltaic and nanotechnology; solar energy and applications; and solar thermal energy. Seventeen of the 18 presentations have been catalogued separately for inclusion in this database.
Solar air-conditioning. Proceedings
Energy Technology Data Exchange (ETDEWEB)
NONE
2009-07-01
Within the 3rd International Conference on solar air-conditioning in Palermo (Italy) at 30th September to 2nd October, 2009 the following lectures were held: (1) Removal of non-technological barriers to solar cooling technology across Southern European islands (Stefano Rugginenti); (2) The added economic and environmental value of solar thermal systems in microgrids with combined heat and power (Chris Marney); (3) Australian solar cooling interest group (Paul Kohlenbach); (4) Designing of a technology roadmap for solar assisted air conditioning in Austria (Hilbert Focke); (5) Solar cooling in the new context of renewable policies at European level (Raffaele Piria); (6) Prototype of a solar driven steam jet ejector chiller (Clemens Pollerberg); (7) New integrated solar air conditioning system (Joan Carlos Bruno); (8) Primary energy optimised operation of solar driven desiccant evaporative cooling systems through innovative control strategies; (9) Green chiller association (Uli Jakob); (10) Climate Well {sup registered} (Olof Hallstrom); (11) Low capacity absorption chillers for solar cooling applications (Gregor Weidner); (12) Solar cooling in residential, small scale commercial and industrial applications with adsorption technology (Walter Mittelbach); (13) French solar heating and cooling development programme based on energy performance (Daniel Mugnier); (14) Mirrox fresnel process heat collectors for industrial applications and solar cooling (Christian Zahler); (15) Modelling and analyzing solar cooling systems in polysun (Seyen Hossein Rezaei); (16) Solar cooling application in Valle Susa Italy (Sufia Jung); (17) Virtual case study on small solar cooling systems within the SolarCombi+Project (Bjoern Nienborg); (18) Design of solar cooling plants under uncertainty (Fernando Dominguez-Munoz); (19) Fast pre-design of systems using solar thermally driven chillers (Hans-Martin Henning); (20) Design of a high fraction solar heating and cooling plant in southern
Solar-pumped lasers for space power transmission
Taussig, R.; Bruzzone, C.; Nelson, L.; Quimby, D.; Christiansen, W.
1979-01-01
Multi-Megawatt CW solar-pumped lasers appear to be technologically feasible for space power transmission in the 1990s time frame. A new concept for a solar-pumped laser is presented which utilizes an intermediate black body cavity to provide a uniform optical pumping environment for the lasant, either CO or CO2. Reradiation losses are minimized with resulting high efficiency operation. A 1 MW output laser may weigh as little as 8000 kg including solar collector, black body cavity, laser cavity and ducts, pumps, power systems and waste heat radiator. The efficiency of such a system will be on the order of 10 to 20%. Details of the new concept, laser design, comparison to competing solar-powered lasers and applications to a laser solar power satellite (SPS) concept are presented.
In-orbit attitude actuation using solar panels
Directory of Open Access Journals (Sweden)
Renuganth Varatharajoo
2008-06-01
Full Text Available A specific technique is developed to wield the internal disturbance torque caused by the solar panel actuation for spacecraft attitude control tasks. This work is the maiden work towards integrating the attitude control and the solar tracking tasks, forming a combined attitude and solar tracking system. The feasibility of this concept for spacecraft is proven and eventually the combined concept is validated. A technical proof is presented corresponding to the end-to-end system demonstration. The investigation starts with the determination of the solar tracking constraints. Then, the mathematical models describing the attitude and solar tracking are established, and eventually the onboard architecture is implemented. The numerical treatments using MatlabTM were performed to evaluate the developed onboard architecture. The simulation results are discussed especially from the attitude control standpoint. The integrated system complies very well with the reference mission requirements.
The Near-Earth Space Radiation Environment
Xapsos, Michael
2008-01-01
This viewgraph presentation reviews the effects of the Near-Earth space radiation environment on NASA missions. Included in this presentation is a review of The Earth s Trapped Radiation Environment, Solar Particle Events, Galactic Cosmic Rays and Comparison to Accelerator Facilities.
Solar energy demonstration zones in the Dalmatian region
Energy Technology Data Exchange (ETDEWEB)
Hrastnik, B. [Energy Institute, Zagreb (Croatia); Frankovic, B. [University of Rijeka (Croatia). Faculty of Engineering
2001-11-01
The energy consumption in the Dalmatian region was estimated for residential and public sector, tourism, commercial sector and industry. The national energy program for the use of solar energy, SUNEN, assessed solar energy potential in Croatia. Energy from fossil fuels and electricity consumption in the region, which is mostly used in households for preparing hot water and space heating, could be economically substituted by renewable energy. The situation is most promising for the islands of the Adriatic, where solar thermal collectors, PV modules and wind generators could substitute conventional energy sources in satisfying the present thermal and electric demand. The Dalmatian Islands, characterised by a small density of energy consumption, are proposed as unique candidates in Europe for renewable zones, which could demonstrate the full potential of the renewable energy option. As a practical demonstration, the island of Lastovo and the planned tourist village and yacht marina in the Bay of Jurjeva Luka are proposed as a first solar demonstration project on the islands. Technical, economic, legal and institutional barriers, as well as shortages of financing the project identification process produced hereto an adverse environment for solar applications in Croatia. This paper is an initiative for eliminating the barriers and intensify the solar energy use in Croatia providing the clean environment and activation of indigenous energy resources in the region. (author)
Three Sides Billboard Wind-Solar Hybrid System Design
Directory of Open Access Journals (Sweden)
Bai Xuefeng
2015-01-01
Full Text Available With the high development of world economy, the demand of energy is increasing all the time, As energy shortage and environment problem are increasing outstanding, Renewable energy has been attracting more and more attention. A kind of three sides billboard supply by wind-Solar hybrid system has been designed in this paper, the overall structure of the system, components, working principle and control strategy has been analyzed from the system perspective. The software and hardware of the system are debugged together and the result is acquired. System function is better and has achieved the expected results.
DEFF Research Database (Denmark)
Liu, Mingzhe; Wittchen, Kim Bjarne; Heiselberg, Per
2014-01-01
The research aims to develop a simplified calculation method for intelligent glazed facade under different control conditions (night shutter, solar shading and natural ventilation) to simulate the energy performance and indoor environment of an office room installed with the intelligent facade......, it is possible to calculate the whole year performance of a room or building with intelligent glazed façade, which makes it a less time consuming tool to investigate the performance of the intelligent façade under different control strategies in the design stage with acceptable accuracy. Results showed good....... The method took the angle dependence of the solar characteristic into account, including the simplified hourly building model developed according to EN 13790 to evaluate the influence of the controlled façade on both the indoor environment (indoor air temperature, solar transmittance through the façade...
Mathematical and computational modeling simulation of solar drying Systems
Mathematical modeling of solar drying systems has the primary aim of predicting the required drying time for a given commodity, dryer type, and environment. Both fundamental (Fickian diffusion) and semi-empirical drying models have been applied to the solar drying of a variety of agricultural commo...