Impacts of reserve methodology on production cost in high-penetration renewable scenarios

Energy Technology Data Exchange (ETDEWEB)

Brinkman, G.; Lew, D.; Hummon, M.; Ibanez, E.; Ela, E.; Hodge, B.M. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2012-07-01

Prior to wind and solar penetration, electric power systems were designed to handle variability in system load, uncertainty in load forecasts, and contingency events. Frequency regulations reserve typically handles high frequency (less than 5-minute time scale) variability. Contingency reserves supply energy in the case of the loss of a generator or transmission line. Wind and solar photovoltaic generation and variability to electric power system generation that must be balanced by the system operator. New ancillary service products may be necessary to minimize the cost of integrating these variable renewable generators. For example, California ISO is studying incorporating a flexible ramping product to ensure sufficient ramping capability. A flexibility reserve product could help ensure that sufficient capacity is online to handle unexpected variability in wind and solar generation. (orig.)

Managing high penetration of renewable energy in MV grid by electric vehicle storage

DEFF Research Database (Denmark)

Kordheili, Reza Ahmadi; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

2015-01-01

This paper proposes an intelligent algorithm for dealing with high penetration of renewable energy sources (RESs) in the medium voltage by intelligently managing electric vehicles (EVs), as one of the grid flexible loads. The MV grid used in this work is a CIGRE benchmark grid. Different...... residential and industrial loads are considered in this grid. The connection of medium voltage wind turbines to the grid is investigated. The solar panels in this study are residential panels. Also, EVs are located among the buses with residential demand. The study is done for different winter and summer...... scenarios, considering typical load profiles in Denmark. Different scenarios have been studied with different penetration level of RESs in the grid. The results show the capability of the proposed algorithm to reduce voltage deviations among the grid buses, as well as to increase the RES penetration...

Sensitivity of portuguese electricity market prices to solar PV penetration : an analysis of 2016 prices

OpenAIRE

Cordeiro De Sousa, João

2017-01-01

The reduction in price of solar PV technology led, in the recent years, multiple investors to apply for installing new solar PV power plants in Portugal which would operate without subsidies or feed-in-tari s. In 2016 it was reported the approval of construction of such power plants and given the low variable cost of this technology it is expected that their penetration would reduce the electricity market prices. Hence, before doing the economic assessment of potential new sola...

Impact of onsite solar generation on system load demand forecast

International Nuclear Information System (INIS)

Kaur, Amanpreet; Pedro, Hugo T.C.; Coimbra, Carlos F.M.

2013-01-01

Highlights: • We showed the impact onsite solar generation on system demand load forecast. • Forecast performance degrades by 9% and 3% for 1 h and 15 min forecast horizons. • Error distribution for onsite case is best characterized as t-distribution. • Relation between error, solar penetration and solar variability is characterized. - Abstract: Net energy metering tariffs have encouraged the growth of solar PV in the distribution grid. The additional variability associated with weather-dependent renewable energy creates new challenges for power system operators that must maintain and operate ancillary services to balance the grid. To deal with these issues power operators mostly rely on demand load forecasts. Electric load forecast has been used in power industry for a long time and there are several well established load forecasting models. But the performance of these models for future scenario of high renewable energy penetration is unclear. In this work, the impact of onsite solar power generation on the demand load forecast is analyzed for a community that meets between 10% and 15% of its annual power demand and 3–54% of its daily power demand from a solar power plant. Short-Term Load Forecasts (STLF) using persistence, machine learning and regression-based forecasting models are presented for two cases: (1) high solar penetration and (2) no penetration. Results show that for 1-h and 15-min forecasts the accuracy of the models drops by 9% and 3% with high solar penetration. Statistical analysis of the forecast errors demonstrate that the error distribution is best characterized as a t-distribution for the high penetration scenario. Analysis of the error distribution as a function of daily solar penetration for different levels of variability revealed that the solar power variability drives the forecast error magnitude whereas increasing penetration level has a much smaller contribution. This work concludes that the demand forecast error distribution

Index-Based Assessment of Voltage Rise and Reverse Power Flow Phenomena in a Distribution Feeder Under High PV Penetration

DEFF Research Database (Denmark)

Hasheminamin, Maryam; Agelidis, Vassilios G.; Salehi, Vahid

2015-01-01

-based methodology for assessing the impact of high solar PV generation, considering the reverse power flow and voltage rise phenomena. Indices are defined that link these two phenomena and their impact on the voltage profile across the feeder. This assessment relies on detailed modeling of the network and the solar......The proliferation of photovoltaic (PV) generation in low- and medium-voltage distribution networks is expected to continue. Qualified studies can quantify adverse impacts of high PV penetration on distribution networks and assist utilities in decision making. This paper proposes an index...

Solar energetic particles in the Earth magnetosphere: kinematic modeling of the 'non-shock' penetration

International Nuclear Information System (INIS)

Pavlov, N N

2013-01-01

Penetration of solar energetic particles into the Earth's magnetosphere is quantitatively studied with a simple kinematic model. The goal is to assess, for the first time, how does effectiveness of the penetration depend on such geometry factors as: distance of the magneto-pause (MP) from the Earth; shape of MP; angle at which solar energetic particle crosses MP; location of the crossing point; type of the particle motion in the magnetosphere. To get off excessive details, the model deliberately operates with just equatorial section of the static dipolar magnetic field confined with asymmetric boundary – MP. Several rather obvious facts are illustrated: finite orbits of longitudinal drift reside only inside the circle of the Störmer-unit-length radius; deepest penetration of a particle occurs if the particle crosses MP at the point closest to the Earth and with velocity-vector oriented along the particle's longitudinal drift inside MP (westward for protons); etc. The model's software allows the inquirer to vary geometry of MP, the type, energy and direction of flight of the energetic particle(s), the location(s), aperture and orientation(s) of a virtual sensor, then to run the model and obtain the reference particle distributions either global (for entire magnetosphere) or for specified locations, all along the time, energy and flux-orientation axes. Static and animated plots can be easily produced. The model provides a toolkit allowing one to evaluate and illustrate the process of particle penetration into the magnetosphere under various conditions in space. It may be used for the configuring of the satellite particle sensors; its results may be compared with the observations for to assess how strongly the real magnetosphere differs from its simplified form; it may be used in education.

Development of high-performance concrete having high resistance to chloride penetration

International Nuclear Information System (INIS)

Oh, Byung Hwan; Cha, Soo Won; Jang, Bong Seok; Jang, Seung Yup

2002-01-01

The resistance to chloride penetration is one of the simplest measures to determine the durability of concrete, e.g. resistance to freezing and thawing, corrosion of steel in concrete and other chemical attacks. Thus, high-performance concrete may be defined as the concrete having high resistance to chloride penetration as well as high strength. The purpose of this paper is to investigate the resistance to chloride penetration of different types of concrete and to develop high-performance concrete that has very high resistance to chloride penetration, and thus, can guarantee high durability. A large number of concrete specimens have been tested by the rapid chloride permeability test method as designated in AASHTO T 277 and ASTM C 1202. The major test variables include water-to-binder ratios, type of cement, type and amount of mineral admixtures (silica fume, fly ash and blast-furnace slag), maximum size of aggregates and air-entrainment. Test results show that concrete containing optimal amount of silica fume shows very high resistance to chloride penetration, and high-performance concrete developed in this study can be efficiently employed to enhance the durability of concrete structures in severe environments such as nuclear power plants, water-retaining structures and other offshore structures

Opportunities for high wind energy penetration

DEFF Research Database (Denmark)

Tande, J.O.; Hansen, J.C.

1997-01-01

Wind power is today a mature technology, which at windy locations, is economically competitive to conventional power generation technologies. This and growing global environmental concerns have led governments to encourage and plan for wind energy development, a typical aim being 10% of electricity...... consumption. The successful operation of the three major power systems of Cape Verde, with a total wind energy penetration of about 15% since December 1994, demonstrates that power systems can be operated with high penetration of wind energy by adding simple control and monitoring systems only. Thorough...... analyses conclude that expanding to even above 15% wind energy penetration in the Cape Verde power systems is economical. Worldwide, numerous locations with favorable wind conditions and power systems similar to the Capeverdean provide good opportunities for installing wind farms and achieving high wind...

Renewable Electricity Futures Study. Volume 1: Exploration of High-Penetration Renewable Electricity Futures

Energy Technology Data Exchange (ETDEWEB)

Mai, T.; Wiser, R.; Sandor, D.; Brinkman, G.; Heath, G.; Denholm, P.; Hostick, D.J.; Darghouth, N.; Schlosser, A.; Strzepek, K.

2012-06-01

The Renewable Electricity Futures (RE Futures) Study investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. The analysis focused on the sufficiency of the geographically diverse U.S. renewable resources to meet electricity demand over future decades, the hourly operational characteristics of the U.S. grid with high levels of variable wind and solar generation, and the potential implications of deploying high levels of renewables in the future. RE Futures focused on technical aspects of high penetration of renewable electricity; it did not focus on how to achieve such a future through policy or other measures. Given the inherent uncertainties involved with analyzing alternative long-term energy futures as well as the multiple pathways that might be taken to achieve higher levels of renewable electricity supply, RE Futures explored a range of scenarios to investigate and compare the impacts of renewable electricity penetration levels (30%-90%), future technology performance improvements, potential constraints to renewable electricity development, and future electricity demand growth assumptions. RE Futures was led by the National Renewable Energy Laboratory (NREL) and the Massachusetts Institute of Technology (MIT).

Renewable Electricity Futures Study. Volume 1. Exploration of High-Penetration Renewable Electricity Futures

Energy Technology Data Exchange (ETDEWEB)

Hand, M. M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Baldwin, S. [U.S. Dept. of Energy, Washington, DC (United States); DeMeo, E. [Renewable Energy Consulting, Chicago, IL (United States); Reilly, J. M. [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Mai, T. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Arent, D. [Joint Inst. for Strategic Energy Analysis, Boulder, CO (United States); Porro, G. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Meshek, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sandor, D. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2012-06-15

The Renewable Electricity Futures (RE Futures) Study investigated the challenges and impacts of achieving very high renewable electricity generation levels in the contiguous United States by 2050. The analysis focused on the sufficiency of the geographically diverse U.S. renewable resources to meet electricity demand over future decades, the hourly operational characteristics of the U.S. grid with high levels of variable wind and solar generation, and the potential implications of deploying high levels of renewables in the future. RE Futures focused on technical aspects of high penetration of renewable electricity; it did not focus on how to achieve such a future through policy or other measures. Given the inherent uncertainties involved with analyzing alternative long-term energy futures as well as the multiple pathways that might be taken to achieve higher levels of renewable electricity supply, RE Futures explored a range of scenarios to investigate and compare the impacts of renewable electricity penetration levels (30%–90%), future technology performance improvements, potential constraints to renewable electricity development, and future electricity demand growth assumptions. RE Futures was led by the National Renewable Energy Laboratory (NREL) and the Massachusetts Institute of Technology (MIT). Learn more at the RE Futures website. http://www.nrel.gov/analysis/re_futures/

Real-Time Penetrating Particle Analyzer (PAN)

Science.gov (United States)

Wu, X.; Ambrosi, G.; Bertucci, B.

2018-02-01

The PAN can measure penetrating particles with great precision to study energetic particles, solar activities, and the origin and propagation of cosmic rays. The real-time monitoring of penetrating particles is crucial for deep space human travel.

Energy Storage Requirements for Achieving 50% Solar Photovoltaic Energy Penetration in California

Energy Technology Data Exchange (ETDEWEB)

Denholm, Paul; Margolis, Robert

2016-08-01

We estimate the storage required to enable PV penetration up to 50% in California (with renewable penetration over 66%), and we quantify the complex relationships among storage, PV penetration, grid flexibility, and PV costs due to increased curtailment. We find that the storage needed depends strongly on the amount of other flexibility resources deployed. With very low-cost PV (three cents per kilowatt-hour) and a highly flexible electric power system, about 19 gigawatts of energy storage could enable 50% PV penetration with a marginal net PV levelized cost of energy (LCOE) comparable to the variable costs of future combined-cycle gas generators under carbon constraints. This system requires extensive use of flexible generation, transmission, demand response, and electrifying one quarter of the vehicle fleet in California with largely optimized charging. A less flexible system, or more expensive PV would require significantly greater amounts of storage. The amount of storage needed to support very large amounts of PV might fit within a least-cost framework driven by declining storage costs and reduced storage-duration needs due to high PV penetration.

The Western Wind and Solar Integration Study Phase 2

Energy Technology Data Exchange (ETDEWEB)

Lew, Debra [National Renewable Energy Lab. (NREL), Golden, CO (United States); Brinkman, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ibanez, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Florita, A. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Heaney, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hodge, B. -M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hummon, M. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Stark, G. [National Renewable Energy Lab. (NREL), Golden, CO (United States); King, J. [RePPAE; Lefton, S. A. [Intertek-APTECH, Houston, TX (United States); Kumar, N. [Intertek-APTECH, Houston, TX (United States); Agan, D. [Intertek-APTECH, Houston, TX (United States); Jordan, G. [GE Energy, Fairfield, CT (United States); Venkataraman, S. [GE Energy, Fairfield, CT (United States)

2013-09-01

The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding wind and solar affects the operation of the other power plants and adding high penetrations can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 of the Western Wind and Solar Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of wind and solar on the fossil-fueled fleet. This built on Phase 1, one of the largest wind and solar integration studies ever conducted, which examined operational impacts of high wind and solar penetrations in the West(GE Energy 2010).

The Western Wind and Solar Integration Study Phase 2

Energy Technology Data Exchange (ETDEWEB)

Lew, D.; Brinkman, G.; Ibanez, E.; Hodge, B. M.; Hummon, M.; Florita, A.; Heaney, M.

2013-09-01

The electric grid is a highly complex, interconnected machine, and changing one part of the grid can have consequences elsewhere. Adding wind and solar affects the operation of the other power plants and adding high penetrations can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 of the Western Wind and Solar Integration Study (WWSIS-2) evaluated these costs and emissions and simulated grid operations for a year to investigate the detailed impact of wind and solar on the fossil-fueled fleet. This built on Phase 1, one of the largest wind and solar integration studies ever conducted, which examined operational impacts of high wind and solar penetrations in the West.

Solar Power Sources

DEFF Research Database (Denmark)

Kim, Katherine A.; Mentesidi, Konstantina; Yang, Yongheng

2017-01-01

a significant change. Beyond this energy transition, the still declining cost of the solar technology has become an important driving force for more solar-powered systems. However, high penetration of solar-powered systems also brings technical challenges to the entire energy systems. In order to fully address......Solar power is highly abundant, relatively reliable, and not limited to a geographic region, making it one of the most important renewable energy sources. Catering for a clean and green energy system, solar energy will be an active player in the future mixed power grid that is also undergoing...... those issues, the technological properties of solar power should be investigated. Thus, the basics of solar power technology will be introduced and discussed in this chapter....

Review of Power System Stability with High Wind Power Penetration

DEFF Research Database (Denmark)

Hu, Rui; Hu, Weihao; Chen, Zhe

2015-01-01

analyzing methods and stability improvement approaches. With increasing wind power penetration, system balancing and the reduced inertia may cause a big threaten for stable operation of power systems. To mitigate or eliminate the wind impacts for high wind penetration systems, although the practical......This paper presents an overview of researches on power system stability with high wind power penetration including analyzing methods and improvement approaches. Power system stability issues can be classified diversely according to different considerations. Each classified issue has special...... and reliable choices currently are the strong outside connections or sufficient reserve capacity constructions, many novel theories and approaches are invented to investigate the stability issues, looking forward to an extra-high penetration or totally renewable resource based power systems. These analyzing...

Southern California Edison High Penetration Photovoltaic Project - Year 1

Energy Technology Data Exchange (ETDEWEB)

Mather, B.; Kroposki, B.; Neal, R.; Katiraei, F.; Yazdani, A.; Aguero, J. R.; Hoff, T. E.; Norris, B. L.; Parkins, A.; Seguin, R.; Schauder, C.

2011-06-01

This report discusses research efforts from the first year of a project analyzing the impacts of high penetration levels of photovoltaic (PV) resources interconnected onto Southern California Edison's (SCE's) distribution system. SCE will be interconnecting a total of 500 MW of commercial scale PV within their service territory by 2015. This Year 1 report describes the need for investigating high-penetration PV scenarios on the SCE distribution system; discusses the necessary PV system modeling and distribution system simulation advances; describes the available distribution circuit data for the two distribution circuits identified in the study; and discusses the additional inverter functionality that could be implemented in order to specifically mitigate some of the undesirable distribution system impacts caused by high-penetration PV installations.

High-Penetration Photovoltaic Planning Methodologies

Energy Technology Data Exchange (ETDEWEB)

Gao, David Wenzhong [Alternative Power Innovations, LLC, Broomfield, CO (United States); Muljadi, Eduard [National Renewable Energy Lab. (NREL), Golden, CO (United States); Tian, Tian [National Renewable Energy Lab. (NREL), Golden, CO (United States); Miller, Mackay [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-02-24

The main objective of this report is to provide an overview of select U.S. utility methodologies for performing high-penetration photovoltaic (HPPV) system planning and impact studies. This report covers the Federal Energy Regulatory Commission's orders related to photovoltaic (PV) power system interconnection, particularly the interconnection processes for the Large Generation Interconnection Procedures and Small Generation Interconnection Procedures. In addition, it includes U.S. state interconnection standards and procedures. The procedures used by these regulatory bodies consider the impacts of HPPV power plants on the networks. Technical interconnection requirements for HPPV voltage regulation include aspects of power monitoring, grounding, synchronization, connection to the overall distribution system, back-feeds, disconnecting means, abnormal operating conditions, and power quality. This report provides a summary of mitigation strategies to minimize the impact of HPPV. Recommendations and revisions to the standards may take place as the penetration level of renewables on the grid increases and new technologies develop in future years.

Assessing high wind energy penetration

DEFF Research Database (Denmark)

Tande, J.O.

1995-01-01

In order to convincingly promote installing wind power capacity as a substantial part of the energy supply system, a set of careful analyses must be undertaken. This paper applies a case study concentrated on assessing the cost/benefit of high wind energy penetration. The case study considers...... expanding the grid connected wind power capacity in Praia, the capital of Cape Verde. The currently installed 1 MW of wind power is estimated to supply close to 10% of the electric energy consumption in 1996. Increasing the wind energy penetration to a higher level is considered viable as the project...... with the existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h....

The Contribution of Solar Power Funding for Online Content ...

African Journals Online (AJOL)

The Contribution of Solar Power Funding for Online Content Accessibility and Sustainability of Blended Learning in Rural Africa: The Tanzania Perspective. ... Despite these appealing features, penetration of solar electricity in remote and rural areas in Tanzania is limited by high initial cost of building a stand-alone solar ...

Stochastic Short-term High-resolution Prediction of Solar Irradiance and Photovoltaic Power Output

Energy Technology Data Exchange (ETDEWEB)

Melin, Alexander M. [ORNL; Olama, Mohammed M. [ORNL; Dong, Jin [ORNL; Djouadi, Seddik M. [ORNL; Zhang, Yichen [University of Tennessee, Knoxville (UTK), Department of Electrical Engineering and Computer Science

2017-09-01

The increased penetration of solar photovoltaic (PV) energy sources into electric grids has increased the need for accurate modeling and prediction of solar irradiance and power production. Existing modeling and prediction techniques focus on long-term low-resolution prediction over minutes to years. This paper examines the stochastic modeling and short-term high-resolution prediction of solar irradiance and PV power output. We propose a stochastic state-space model to characterize the behaviors of solar irradiance and PV power output. This prediction model is suitable for the development of optimal power controllers for PV sources. A filter-based expectation-maximization and Kalman filtering mechanism is employed to estimate the parameters and states in the state-space model. The mechanism results in a finite dimensional filter which only uses the first and second order statistics. The structure of the scheme contributes to a direct prediction of the solar irradiance and PV power output without any linearization process or simplifying assumptions of the signal’s model. This enables the system to accurately predict small as well as large fluctuations of the solar signals. The mechanism is recursive allowing the solar irradiance and PV power to be predicted online from measurements. The mechanism is tested using solar irradiance and PV power measurement data collected locally in our lab.

Expanding photovoltaic penetration with residential distributed generation from hybrid solar photovoltaic and combined heat and power systems

International Nuclear Information System (INIS)

Pearce, J.M.

2009-01-01

The recent development of small scale combined heat and power (CHP) systems has provided the opportunity for in-house power backup of residential-scale photovoltaic (PV) arrays. This paper investigates the potential of deploying a distributed network of PV + CHP hybrid systems in order to increase the PV penetration level in the U.S. The temporal distribution of solar flux, electrical and heating requirements for representative U.S. single family residences were analyzed and the results clearly show that hybridizing CHP with PV can enable additional PV deployment above what is possible with a conventional centralized electric generation system. The technical evolution of such PV + CHP hybrid systems was developed from the present (near market) technology through four generations, which enable high utilization rates of both PV-generated electricity and CHP-generated heat. A method to determine the maximum percent of PV-generated electricity on the grid without energy storage was derived and applied to an example area. The results show that a PV + CHP hybrid system not only has the potential to radically reduce energy waste in the status quo electrical and heating systems, but it also enables the share of solar PV to be expanded by about a factor of five. (author)

Wind and Solar Curtailment: International Experience and Practices

DEFF Research Database (Denmark)

Lew, Debra; Bird, Lori; Milligan, Michael

2013-01-01

High penetrations of wind and solar generation on power systems are resulting in increasing curtailment. Wind and solar integration studies predict increased curtailment as penetration levels grow. This paper examines experiences with curtailment on bulk power systems internationally. It discusses...... how much curtailment is occurring, how it is occurring, why it is occurring, and what is being done to reduce curtailment. This summary is produced as part of the International Energy Agency Wind Task 25 on Design and Operation of Power Systems with Large Amounts of Wind Power....

Convective penetration in a young sun

Science.gov (United States)

Pratt, Jane; Baraffe, Isabelle; Goffrey, Tom; MUSIC developers group

2018-01-01

To interpret the high-quality data produced from recent space-missions it is necessary to study convection under realistic stellar conditions. We describe the multi-dimensional, time implicit, fully compressible, hydrodynamic, implicit large eddy simulation code MUSIC. We use MUSIC to study convection during an early stage in the evolution of our sun where the convection zone covers approximately half of the solar radius. This model of the young sun possesses a realistic stratification in density, temperature, and luminosity. We approach convection in a stellar context using extreme value theory and derive a new model for convective penetration, targeted for one-dimensional stellar evolution calculations. This model provides a scenario that can explain the observed lithium abundance in the sun and in solar-like stars at a range of ages.

Grid of the Future: Quantification of Benefits from Flexible Energy Resources in Scenarios With Extra-High Penetration of Renewable Energy

Energy Technology Data Exchange (ETDEWEB)

Bebic, Jovan [General Electric International, Inc., Schenectady, NY (United States). Energy Consulting; Hinkle, Gene [General Electric International, Inc., Schenectady, NY (United States). Energy Consulting; Matic, Slobodan [General Electric International, Inc., Schenectady, NY (United States). Energy Consulting; Schmitt, William [General Electric International, Inc., Schenectady, NY (United States). Energy Consulting

2015-01-15

The main objective of this study is to quantify the entitlement for system benefits attainable by pervasive application of flexible energy resources in scenarios with extra-high penetration of renewable energy. The quantified benefits include savings in thermal energy and reduction of CO₂ emissions. Both are primarily a result of displacement of conventional thermal generation by renewable energy production, but there are secondary improvements that arise from lowering operating reserves, removing transmission constraints, and by partially removing energy-delivery losses due to energy production by distributed solar. The flexible energy resources in the context of this study include energy storage and adjustable loads. The flexibility of both was constrained to a time horizon of one day. In case of energy storage this means that the state of charge is restored to the starting value at the end of each day, while for load this means that the daily energy consumed is maintained constant. The extra-high penetration of renewable energy in the context of this study means the level of penetration resulting in significant number of hours where instantaneous power output from renewable resources added to the power output from baseload nuclear fleet surpasses the instantaneous power consumption by the load.

The environmental and public health benefits of achieving high penetrations of solar energy in the United States

International Nuclear Information System (INIS)

Wiser, Ryan; Millstein, Dev; Mai, Trieu; Macknick, Jordan; Carpenter, Alberta; Cohen, Stuart; Cole, Wesley; Frew, Bethany; Heath, Garvin

2016-01-01

We estimate the environmental and public health benefits that may be realized if solar energy cost reductions continue until solar power is competitive across the U.S. without subsidies. Specifically, we model, from 2015 to 2050, solar power–induced reductions to greenhouse gas (GHG) emissions, air pollutant emissions, and water usage. To find the incremental benefits of new solar deployment, we compare the difference between two scenarios, one where solar costs have fallen such that solar supplies 14% of the nation's electricity by 2030 and 27% by 2050, and a baseline scenario in which no solar is added after 2014. We monetize benefits, where credible methods exist to do so. We find that under these scenarios, solar power reduces GHG and air pollutants by ∼10%, from 2015 to 2050, providing a discounted present value of $56–$789 billion (central value of ∼$250 billion, equivalent to ∼2 ¢/kWh-solar) in climate benefits and $77–$298 billion (central value of $167 billion, or ∼1.4 ¢/kWh-solar) in air quality and public health benefits. The ranges reflect uncertainty within the literature about the marginal impact of emissions of GHG and air pollutants. Solar power is also found to reduce water withdrawals and consumption by 4% and 9%, respectively, including in many drought-prone states. - Highlights: • With feasible cost reductions, solar power can provide major environmental benefits. • U.S. electric-sector modeling indicates climate benefits worth ∼2 ¢/kWh-solar. • Further modeling indicates air quality public health benefits worth 1.4 ¢/kWh-solar. • Solar could reduce power-sector water withdrawals and consumption by 4% and 9%.

Solar radiation and its penetration in a tropical estuary

Digital Repository Service at National Institute of Oceanography (India)

Qasim, S.Z.; Bhattathiri, P.M.A.; Abidi, S.A.H.

The Cochin Backwater which is an estuarine area on the west coast of India receives maximum solar radiation from December to March and minimum from June to September. During the monsoon months the estuary becomes highly turbid as a result...

Study on Penetration Characteristics of Tungsten Cylindrical Penetrator

Energy Technology Data Exchange (ETDEWEB)

Jo, Jong Hyun; Lee, Young Shin; Kim, Jae Hoon [Chungnam Nat' l Univ., Daejeon (Korea, Republic of); Bae, Yong Woon [Agency for Defense Development, Daejeon (Korea, Republic of)

2013-09-15

The design of missile require extremely small warheads that must be highly efficient and lethal. The penetration characteristics of each penetrator and the total number of penetrators on the warhead are obvious key factors that influence warhead lethality. The design of the penetrator shape and size are directly related to the space and weight of the warhead. The design of the penetrator L/D was directly related to the space and weight of the warhead. L and D are the length and the diameter of the projectile, respectively. The AUTODYN-3a code was used to study the effect of penetrator penetration. The objective of numerical analysis was to determine the penetration characteristics of penetrator produced by hypervelocity impacts under different initial conditions such as initial velocity, obliquity angle and L/D of penetrator. The residual velocity and residual mass were decreased with increasing initial impact velocity under L/D{<=}4.

Design and proof of concept of an innovative very high temperature ceramic solar absorber

Science.gov (United States)

Leray, Cédric; Ferriere, Alain; Toutant, Adrien; Olalde, Gabriel; Peroy, Jean-Yves; Chéreau, Patrick; Ferrato, Marc

2017-06-01

Hybrid solar gas-turbine (HSGT) is an attractive technology to foster market penetration of CSP. HSGT offers some major advantages like for example high solar-to-electric conversion efficiency, reduced water requirement and low capital cost. A very high temperature solar receiver is needed when elevated solar share is claimed. A few research works, as reported by Karni et al. [8] and by Buck et al. [1], have been dedicated to solar receiver technologies able to deliver pressurized air at temperature above 750°C. The present work focuses on research aiming at developing an efficient and reliable solar absorber able to provide pressurized air at temperature up to 1000°C and more. A surface absorber technology is selected and a modular design of receiver is proposed in which each absorber module is made of BOOSTEC® SiC ceramic (silicon carbide) as bulk material with straight air channels inside. Early stage experimental works done at CNRS/PROMES on lab-scale absorbers showed that the thermo-mechanical behavior of this material is a critical issue, resulting in elevated probability of failure under severe conditions like large temperature gradient or steep variation of solar flux density in situations of cloud covering. This paper reports on recent progress made at CNRS/PROMES to address this critical issue. The design of the absorber has been revised and optimized according to thermo-mechanical numerical simulations, and an experimental proof of concept has been done on a pilot-scale absorber module at Themis solar tower facility.

On the Path to SunShot. Emerging Issues and Challenges in Integrating High Levels of Solar into the Electrical Generation and Transmission System

Energy Technology Data Exchange (ETDEWEB)

Denholm, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Clark, Kara [National Renewable Energy Lab. (NREL), Golden, CO (United States); O' Connell, Matt [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-05-01

This report examines how the bulk power system may need to evolve to accommodate the increased photovoltaic (PV) penetration resulting from achievement of the U.S. Department of Energy's SunShot cost targets. The variable and uncertain nature of PV-generated electricity presents grid-integration challenges. For example, the changing net load associated with high midday PV generation and low electricity demand can create 'overgeneration' that requires curtailment of PV output and reduces PV's value and cost-competitiveness. Accommodating the changes in net load resulting from increased variable generation requires enhancements to a power system's 'flexibility,' or ability to balance supply and demand over multiple time scales through options including changes in system operation, flexible generation, reserves from solar, demand response, energy storage, and enhanced transmission and regional coordination. For utility-scale PV with a baseline SunShot levelized cost of electricity (LCOE) of 6 cents/kWh, increasing the annual energy demand met by solar energy from 10% to 20% would increase the marginal LCOE of PV from 6 cents/kWh to almost 11 cents/kWh in a California grid system with limited flexibility. However, increasing system flexibility could minimize solar curtailment and keep PV cost-competitive at penetrations at least as high as 25%. In the longer term, energy storage technologies--such as concentrating solar power with thermal energy storage--could facilitate the cost-effective integration of even higher PV penetration. Efficient deployment of the grid-flexibility options needed to maintain solar's value will require various innovations, from the development of communication, control, and energy storage technologies to the implementation of new market rules and operating procedures.

On the Path to SunShot - Emerging Issues and Challenges in Integrating High Levels of Solar into the Electrical Generation and Transmission System

Energy Technology Data Exchange (ETDEWEB)

Denholm, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Clark, Kara [National Renewable Energy Lab. (NREL), Golden, CO (United States); O' Connell, Matt [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-05-01

Increasing the use of grid-flexibility options (improved grid management, demand response, and energy storage) could enable 25% or higher penetration of PV at low costs (see Denholm et al. 2016). Considering the large-scale integration of solar into electric-power systems complicates the calculation of the value of solar. In fact a comprehensive examination reveals that the value of solar technologies—or any other power-system technology or operating strategy—can only be understood in the context of the generation system as a whole. This is well illustrated by analysis of curtailment at high PV penetrations within the bulk power and transmission systems. As the deployment of PV increases, it is possible that during some sunny midday periods due to limited flexibility of conventional generators, system operators would need to reduce (curtail) PV output in order to maintain the crucial balance between electric supply and demand. As a result, PV’s value and cost competitiveness would degrade. For example, for utility-scale PV with a baseline SunShot LCOE of 6¢/kWh, increasing the annual energy demand met by solar energy from 10% to 20% would increase the marginal LCOE of PV from 6¢/kWh to almost 11¢/kWh in a California grid system with limited flexibility. However, this loss of value could be stemmed by increasing system flexibility via enhanced control of variable-generation resources, added energy storage, and the ability to motivate more electricity consumers to shift consumption to lower-demand periods. The combination of these measures would minimize solar curtailment and keep PV cost-competitive at penetrations at least as high as 25%. Efficient deployment of the grid-flexibility options needed to maintain solar’s value will require various innovations, from the development of communication, control, and energy storage technologies to the implementation of new market rules and operating procedures.

Storage Application in Smart Grid with High PV and EV Penetration

DEFF Research Database (Denmark)

Hashemi Toghroljerdi, Seyedmostafa; Yang, Guangya; Østergaard, Jacob

2013-01-01

grids with residential PVs and Electric Vehicles (EVs). The effect of EV home charging on EESS capacity in high PV penetration is also addressed. The results indicate that increasing the EV penetration in the network can decrease the EESS capacity need. This decrease is highest in situations with low PV...

Optimal Operation and Dispatch of Voltage Regulation Devices Considering High Penetrations of Distributed Photovoltaic Generation

Energy Technology Data Exchange (ETDEWEB)

Mather, Barry A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Hodge, Brian S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cho, Gyu-Jung [Sungkyunkwan University; Oh, Yun-Sik [Sungkyunkwan University; Kim, Min-Sung [Sungkyunkwan University; Kim, Ji-Soo [Sungkyunkwan University; Kim, Chul-Hwan [Sungkyunkwan University

2017-06-29

Voltage regulation devices have been traditionally installed and utilized to support distribution voltages. Installations of distributed energy resources (DERs) in distribution systems are rapidly increasing, and many of these generation resources have variable and uncertain power output. These generators can significantly change the voltage profile for a feeder; therefore, in the distribution system planning stage of the optimal operation and dispatch of voltage regulation devices, possible high penetrations of DERs should be considered. In this paper, we model the IEEE 34-bus test feeder, including all essential equipment. An optimization method is adopted to determine the optimal siting and operation of the voltage regulation devices in the presence of distributed solar power generation. Finally, we verify the optimal configuration of the entire system through the optimization and simulation results.

Reconciling Consumer and Utility Objectives in the Residential Solar PV Market

Science.gov (United States)

Arnold, Michael R.

Today's energy market is facing large-scale changes that will affect all market players. Near the top of that list is the rapid deployment of residential solar photovoltaic (PV) systems. Yet that growing trend will be influenced multiple competing interests between various stakeholders, namely the utility, consumers and technology provides. This study provides a series of analyses---utility-side, consumer-side, and combined analyses---to understand and evaluate the effect of increases in residential solar PV market penetration. Three urban regions have been selected as study locations---Chicago, Phoenix, Seattle---with simulated load data and solar insolation data at each locality. Various time-of-use pricing schedules are investigated, and the effect of net metering is evaluated to determine the optimal capacity of solar PV and battery storage in a typical residential home. The net residential load profile is scaled to assess system-wide technical and economic figures of merit for the utility with an emphasis on intraday load profiles, ramp rates and electricity sales with increasing solar PV penetration. The combined analysis evaluates the least-cost solar PV system for the consumer and models the associated system-wide effects on the electric grid. Utility revenue was found to drop by 1.2% for every percent PV penetration increase, net metering on a monthly or annual basis improved the cost-effectiveness of solar PV but not battery storage, the removal of net metering policy and usage of an improved the cost-effectiveness of battery storage and increases in solar PV penetration reduced the system load factor. As expected, Phoenix had the most favorable economic scenario for residential solar PV, primarily due to high solar insolation. The study location---solar insolation and load profile---was also found to affect the time of year at which the largest net negative system load was realized.

Highly penetrative liposome nanomedicine generated by a biomimetic strategy for enhanced cancer chemotherapy.

Science.gov (United States)

Jia, Yali; Sheng, Zonghai; Hu, Dehong; Yan, Fei; Zhu, Mingting; Gao, Guanhui; Wang, Pan; Liu, Xin; Wang, Xiaobing; Zheng, Hairong

2018-04-25

Liposome nanomedicine has been successfully applied for cancer chemotherapy in patients. However, in general, the therapeutic efficacy is confined by its limited accumulation and penetration in solid tumors. Here, we established a biomimetic strategy for the preparation of highly penetrative liposome nanomedicine for enhanced chemotherapeutic efficacy. By applying this unique type of nanomedicine, membrane proteins on the cancer cells are used as highly penetrative targeting ligands. Biomimetic liposomes are highly stable, exhibiting a superior in vitro homologous targeting ability, and a 2.25-fold deeper penetration in 3D tumor spheroids when compared to conventional liposome nanomedicine. The fluorescence/photoacoustic dual-modal imaging approach demonstrated enhanced tumor accumulation and improved tumor penetration of the biomimetic liposome in C6 glioma tumor-bearing nude mice. Following the intravenous administration of biomimetic liposome nanomedicine, the tumor inhibition rate reached up to 93.3%, which was significantly higher when compared to that of conventional liposome nanomedicine (69.3%). Moreover, histopathological analyses demonstrated that biomimetic liposome nanomedicine has limited side effects. Therefore, these results suggested that a cancer cell membrane-based biomimetic strategy may provide a breakthrough approach for enhancing drug penetration and improving treatment efficacy, holding a great promise for further clinical studies.

Distinct Pattern of Solar Modulation of Galactic Cosmic Rays above a High Geomagnetic Cutoff Rigidity

Science.gov (United States)

Mangeard, Pierre-Simon; Clem, John; Evenson, Paul; Pyle, Roger; Mitthumsiri, Warit; Ruffolo, David; Sáiz, Alejandro; Nutaro, Tanin

2018-05-01

Solar modulation refers to Galactic cosmic-ray variations with the ∼11 yr sunspot cycle and ∼22 yr solar magnetic cycle and is relevant to the space radiation environment and effects on Earth’s atmosphere. Its complicated dependence on solar and heliospheric conditions is only roughly understood and has been empirically modeled in terms of a single modulation parameter. Most analyses of solar modulation use neutron monitor (NM) data from locations with relatively low geomagnetic cutoff rigidity, i.e., the threshold for cosmic rays to penetrate Earth’s magnetic field. The Princess Sirindhorn Neutron Monitor at Doi Inthanon, Thailand, has the world’s highest cutoff rigidity (≈17 GV) where observations span a complete solar modulation cycle (since late 2007). The pattern of solar modulation at Doi Inthanon during 2011–2014 was qualitatively very different from that at a low geomagnetic cutoff and is not well described by the same modulation parameter. At other times, NM count rates from Doi Inthanon and McMurdo, Antarctica (cutoff ∼1 GV), were linearly correlated and confirm the observation from latitude surveys in the previous solar cycle that the slope of the correlation changes with solar magnetic polarity. Low solar magnetic tilt angles (magnetic field, which is consistent with an increase in diffusion at high rigidity short-circuiting the effects of drifts and the heliospheric current sheet.

Influence of jet thrust on penetrator penetration when studying the structure of space object blanket

Directory of Open Access Journals (Sweden)

N. A. Fedorova

2014-01-01

Full Text Available The article presents the calculation-and-theory-based research results to examine the possibility for using the jet thrust impulse to increase a penetration depth of high-velocity penetrator modules. Such devices can be used for studies of Earth surface layer composition, and in the nearest future for other Solar system bodies too. Research equipment (sensors and different instruments is housed inside a metal body of the penetrator with a sharpened nose that decreases drag force in soil. It was assumed, that this penetrator is additionally equipped with the pulse jet engine, which is fired at a certain stage of penetrator motion into target.The penetrator is considered as a rigid body of variable mass, which is subjected to drag force and reactive force applied at the moment the engine fires. A drag force was represented with a binomial empirical law, and penetrator nose part was considered to be conical. The jet thrust force was supposed to be constant during its application time. It was in accordance with assumption that mass flow and flow rate of solid propellant combustion products were constant. The amount of propellant in the penetrator was characterized by Tsiolkovsky number Z, which specifies the ratio between the fuel mass and the penetrator structure mass with no fuel.The system of equations to describe the penetrator dynamics was given in dimensionless form using the values aligned with penetration of an equivalent inert penetrator as the time and penetration depth scales. Penetration dynamics of penetrator represented in this form allowed to eliminate the influence of penetrator initial mass and its cross-section diameter on the solution results. The lack of such dependency is convenient for comparing the calculation results since they hold for penetrators of various initial masses and cross-sections.To calculate the penetration a lunar regolith was taken as a soil material. Calculations were carried out for initial velocities of

Fault Analysis and Detection in Microgrids with High PV Penetration

Energy Technology Data Exchange (ETDEWEB)

El Khatib, Mohamed [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hernandez Alvidrez, Javier [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ellis, Abraham [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2017-05-01

In this report we focus on analyzing current-controlled PV inverters behaviour under faults in order to develop fault detection schemes for microgrids with high PV penetration. Inverter model suitable for steady state fault studies is presented and the impact of PV inverters on two protection elements is analyzed. The studied protection elements are superimposed quantities based directional element and negative sequence directional element. Additionally, several non-overcurrent fault detection schemes are discussed in this report for microgrids with high PV penetration. A detailed time-domain simulation study is presented to assess the performance of the presented fault detection schemes under different microgrid modes of operation.

Penetration of UV-visible solar radiation in the global oceans: Insights from ocean color remote sensing

Science.gov (United States)

Lee, Zhongping; Hu, Chuanmin; Shang, Shaoling; Du, Keping; Lewis, Marlon; Arnone, Robert; Brewin, Robert

2013-09-01

Penetration of solar radiation in the ocean is determined by the attenuation coefficient (Kd(λ)). Following radiative transfer theory, Kd is a function of angular distribution of incident light and water's absorption and backscattering coefficients. Because these optical products are now generated routinely from satellite measurements, it is logical to evolve the empirical Kd to a semianalytical Kd that is not only spectrally flexible, but also the sun-angle effect is accounted for explicitly. Here, the semianalytical model developed in Lee et al. (2005b) is revised to account for the shift of phase function between molecular and particulate scattering from the short to long wavelengths. Further, using field data collected independently from oligotrophic ocean to coastal waters covering >99% of the Kd range for the global oceans, the semianalytically derived Kd was evaluated and found to agree with measured data within ˜7-26%. The updated processing system was applied to MODIS measurements to reveal the penetration of UVA-visible radiation in the global oceans, where an empirical procedure to correct Raman effect was also included. The results indicated that the penetration of the blue-green radiation for most oceanic waters is ˜30-40% deeper than the commonly used euphotic zone depth; and confirmed that at a depth of 50-70 m there is still ˜10% of the surface UVA radiation (at 360 nm) in most oligotrophic waters. The results suggest a necessity to modify or expand the light attenuation product from satellite ocean-color measurements in order to be more applicable for studies of ocean physics and biogeochemistry.

A Novel Penetration System for in situ Astrobiological Studies

Directory of Open Access Journals (Sweden)

Yang Gao

2005-12-01

Full Text Available Due to ultraviolet flux in the surface layers of most solar bodies, future astrobiological research is increasingly seeking to conduct subsurface penetration and drilling to detect chemical signature for extant or extinct life. To address this issue, we present a micro-penetrator concept (mass < 10 kg that is suited for extraterrestrial planetary deployment and in situ investigation of chemical and physical properties. The instrumentation in this concept is a bio-inspired drill to access material beneath sterile surface layer for biomarker detection. The proposed drill represents a novel concept of two-valve-reciprocating motion, inspired by the working mechanism of wood wasp ovipositors. It is lightweight (0.5 kg, driven at low power (3 W, and able to drill deep (1-2 m. Tests have shown that the reciprocating drill is feasible and has potential of improving drill efficiency without using any external force. The overall penetration system provides a small, light and energy efficient solution to in situ astrobiological studies, which is crucial for space engineering. Such a micro-penetrator can be used for exploration of terrestrial-type planets or other small bodies of the solar system with the minimum of modifications.

A Novel Penetration System for in situ Astrobiological Studies

Directory of Open Access Journals (Sweden)

Yang Gao

2008-11-01

Full Text Available Due to ultraviolet flux in the surface layers of most solar bodies, future astrobiological research is increasingly seeking to conduct subsurface penetration and drilling to detect chemical signature for extant or extinct life. To address this issue, we present a micro-penetrator concept (mass < 10 kg that is suited for extraterrestrial planetary deployment and in situ investigation of chemical and physical properties. The instrumentation in this concept is a bio-inspired drill to access material beneath sterile surface layer for biomarker detection. The proposed drill represents a novel concept of two-valve-reciprocating motion, inspired by the working mechanism of wood wasp ovipositors. It is lightweight (0.5 kg, driven at low power (3 W, and able to drill deep (1-2 m. Tests have shown that the reciprocating drill is feasible and has potential of improving drill efficiency without using any external force. The overall penetration system provides a small, light and energy efficient solution to in situ astrobiological studies, which is crucial for space engineering. Such a micro-penetrator can be used for exploration of terrestrial-type planets or other small bodies of the solar system with the minimum of modifications.

A solar reserve methodology for renewable energy integration studies based on sub-hourly variability analysis

Energy Technology Data Exchange (ETDEWEB)

Ibanez, Eduardo; Brinkman, Gregory; Hummon, Marissa [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lew, Debra

2012-07-01

Increasing penetration of wind and solar energy are raising concerns among electric system operators because of the variability and uncertainty associated with the power sources. Previous work focused on the quantification of reserves for systems with wind power. This paper presents a new methodology that allows the determination of necessary reserves for high penetrations of photovoltaic power and compares it to the wind-based methodology. The solar reserve methodology was applied to Phase 2 of the Western Wind and Solar Integration Study. A summary of the results is included. (orig.)

Approach to interior design for passive direct gain solar homes

Energy Technology Data Exchange (ETDEWEB)

Kachadorian, C.C.

1980-01-01

In response to requests from buyers and builders of direct gain passive solar homes interior design criteria either specific to, or emphasized by, passive solar buildings are investigated. Problems of high sunlight penetration, secondary illumination, material selection, sound control and psychology are approached. Material deterioration, fading, glare, noise, and a sense of spacial confinement can be minimized, contributing to the appeal and saleability of passive solar homes.

Hawaii Solar Integration Study: Solar Modeling Developments and Study Results; Preprint

Energy Technology Data Exchange (ETDEWEB)

Orwig, K.; Corbus, D.; Piwko, R.; Schuerger, M.; Matsuura, M.; Roose, L.

2012-12-01

The Hawaii Solar Integration Study (HSIS) is a follow-up to the Oahu Wind Integration and Transmission Study completed in 2010. HSIS focuses on the impacts of higher penetrations of solar energy on the electrical grid and on other generation. HSIS goes beyond the island of Oahu and investigates Maui as well. The study examines reserve strategies, impacts on thermal unit commitment and dispatch, utilization of energy storage, renewable energy curtailment, and other aspects of grid reliability and operation. For the study, high-frequency (2-second) solar power profiles were generated using a new combined Numerical Weather Prediction model/ stochastic-kinematic cloud model approach, which represents the 'sharp-edge' effects of clouds passing over solar facilities. As part of the validation process, the solar data was evaluated using a variety of analysis techniques including wavelets, power spectral densities, ramp distributions, extreme values, and cross correlations. This paper provides an overview of the study objectives, results of the solar profile validation, and study results.

Western Wind and Solar Integration Study: Phase 2 (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Lew, D.; Brinkman, G.; Ibanez, E.; Lefton, S.; Kumar, N.; Venkataraman, S.; Jordan, G.

2013-09-01

This presentation summarizes the scope and results of the Western Wind and Solar Integration Study Phase 2, which examined operational impacts of high penetrations of variable renewable generation in the West.

A High Rated Solar Water Distillation Unit for Solar Homes

Directory of Open Access Journals (Sweden)

Abhishek Saxena

2016-01-01

Full Text Available India is presently focusing on complete utilization of solar energy and saving fossil fuels, which are limited. Various solar energy systems like solar cookers, solar water heaters, solar lanterns, solar PV lights, and solar lamps are continuously availing by the people of India at a low cost and on good subsidies. Apart from this, India is a solar energy promising country with a good number of solar homes (carrying solar energy systems in its various locations. The present paper focuses on a unique combination of solar dish cooker (SDC and solar water heater (SWH to produce distilled water with a high distillate and a high daily productivity. The procedure has been discussed on the basis of experimental testing to produce distilled water by combining an evacuated type SWH and a SDC. Experimentation has been carried out in MIT, Moradabad (longitude, 28.83°N, and latitude, 78.78°E by developing the same experimental setup on behalf of solar homes. The daily productivity of distilled water was found around 3.66 litres per day in full sunshine hours for an approximated pH value of 7.7 and a ppm value of 21. The payback period (PBP has been estimated around 1.16 years of the present system.

Thermo-chemical Ice Penetrator for Icy Moons

Science.gov (United States)

Arenberg, J. W.; Lee, G.; Harpole, G.; Zamel, J.; Sen, B.; Ross, F.; Retherford, K. D.

2016-12-01

The ability to place sensors or to take samples below the ice surface enables a wide variety of potential scientific investigations. Penetrating an ice cap can be accomplished via a mechanical drill, laser drill, kinetic impactor, or heated penetrator. This poster reports on the development of technology for the latter most option, namely a self-heated probe driven by an exothermic chemical reaction: a Thermo-chemical ice penetrator (TChIP). Our penetrator design employs a eutectic mix of alkali metals that produce an exothermic reaction upon contact with an icy surface. This reaction increases once the ice starts melting, so no external power is required. This technology is inspired by a classified Cold-War era program developed at Northrop Grumman for the US Navy. Terrestrial demonstration of this technology took place in the Arctic; however, this device cannot be considered high TRL for application at the icy moons of the solar system due to the environmental differences between Earth's Arctic and the icy moons. These differences demand a TChIP design specific to these cold, low mass, airless worlds. It is expected that this model of TChIP performance will be complex, incorporating all of the forces on the penetrator, gravity, the thermo-chemistry at the interface between penetrator and ice, and multi-phase heat and mass transport, and hydrodynamics. Our initial efforts are aimed at the development of a validated set of tools and simulations to predict the performance of the penetrator for both the environment found on these icy moons and for a terrestrial environment. The purpose of the inclusion of the terrestrial environment is to aid in model validation. Once developed and validated, our models will allow us to design penetrators for a specific scientific application on a specific body. This poster discusses the range of scientific investigations that are enabled by TChIP. We also introduce the development plan to advance TChIP to the point where it can be

Akon - A Penetrator for Europa

Science.gov (United States)

Jones, Geraint

2016-04-01

Jupiter's moon Europa is one of the most intriguing objects in our Solar System. This 2000km-wide body has a geologically young solid water ice crust that is believed to cover a global ocean of liquid water. The presence of this ocean, together with a source of heating through tidal forces, make Europa a conceivable location for extraterrestrial life. The science case for exploring all aspects of this icy world is compelling. NASA has selected the Europa Mission (formerly Europa Clipper) to study Europa in detail in the 2020s through multiple flybys, and ESA's JUICE mission will perform two flybys of the body in the 2030s. The US agency has extended to the European Space Agency an invitation to provide a contribution to their mission. European scientists interested in Europa science and exploration are currently organizing themselves, in the framework of a coordinated Europa M5 Inititative to study concurrently the main options for this ESA contribution, from a simple addition of individual instruments to the NASA spacecraft, to a lander to investigate Europa's surface in situ. A high speed lander - a penetrator - is by far the most promising technology to achieve this latter option within the anticipated mass constraints, and studies of such a hard lander, many funded by ESA, are now at an advanced level. An international team to formally propose an Europa penetrator to ESA in response to the anticipated ESA M5 call is growing. The working title of this proposal is Akon (Άκων), named after the highly accurate javelin gifted to Europa by Zeus in ancient Greek mythology. We present plans for the Akon penetrator, which would impact Europa's surface at several hundred metres per second, and travel up to several metres into the moon's subsurface. To achieve this, the penetrator would be delivered to the surface by a dedicated descent module, to be destroyed on impact following release of the penetrator above the surface. It is planned that the instruments to be

Are high penetrations of commercial cogeneration good for society?

Science.gov (United States)

Keen, Jeremy F.; Apt, Jay

2016-12-01

Low natural gas prices, market reports and evidence from New York State suggest that the number of commercial combined heat and power (CHP) installations in the United States will increase by 2%-9% annually over the next decade. We investigate how increasing commercial CHP penetrations may affect net emissions, the distribution network, and total system energy costs. We constructed an integrated planning and operations model that maximizes owner profit through sizing and operation of CHP on a realistic distribution feeder in New York. We find that a greater penetration of CHP reduces both total system energy costs and network congestion. Commercial buildings often have low and inconsistent heat loads, which can cause low fuel utilization efficiencies, low CHP rates-of-return and diminishing avoided emissions as CHP penetration increases. In the northeast, without policy intervention, a 5% penetration of small commercially owned CHP would increase CO2 emissions by 2% relative to the bulk power grid. Low emission CHP installations can be encouraged with incentives that promote CHP operation only during times of high heat loads. Time-varying rates, such as time-of-day and seasonal rates, are one option and were shown to reduce customer emissions without reducing profits. In contrast, natural gas rate discounts, a common incentive for industrial CHP in some states, can encourage CHP operation during low heat loads and thus increase emissions.

[Congenital valvular heart disease with high familial penetrance].

Science.gov (United States)

Dattilo, Giuseppe; Lamari, Annalisa; Tulino, Viviana; Scarano, Michele; De Luca, Eleonora; Mutone, Daniela; Busacca, Paolo

2012-12-01

Bicuspid valve aortic (BVA) is one of the most common congenital malformations. Only 20% of patients preserves a normal valve function throughout life. There are sporadic and familial forms, the latter to autosomal dominant. We present a case of familiarity of BVA high penetrance. Patient with aortic stenosis by BVA, is the father of two children with BVA.

High Penetrated Wind Farm Impacts on the Electricity Price

DEFF Research Database (Denmark)

Haji Bashi, Mazaher; Yousefi, G. R.; Bak, Claus Leth

2016-01-01

of the high penetrated wind farm integration into electricity markets. Then, stochastic programming approach is employed to compare the volume of trades for a typical wind farm in a high and low wind penetrated market. Although increasing price spikes and volatility was reported in the literature......Energy trading policies, intermittency of wind farm output power, low marginal cost of the production, are the key factors that cause the wind farms to be effective on the electricity price. In this paper, the Danish electricity market is studied as a part of Nord Pool. Considering the completely...... fossil fuel free overview in Danish energy policies, and the currently great share of wind power (more than 100% for some hours) in supplying the load, it is an interesting benchmark for the future electricity markets. Negative prices, price spikes, and price volatility are considered as the main effects...

The Market Value and Cost of Solar Photovoltaic Electricity Production

OpenAIRE

Borenstein, Severin

2008-01-01

The high cost of power from solar photovoltaic (PV) panels has been a major deterrent to the technology’s market penetration. Proponents have argued, however, that typical analyses overlook many of the benefits of solar PV. Some of those benefits are in the realm of environmental and security externalities, but others occur within the electricity markets. In this paper, I attempt to do a more complete market valuation of solar PV. I incorporate the fact that power from solar PV panels is gene...

Optimizing the U.S. Electric System with a High Penetration of Renewables

Science.gov (United States)

Corcoran, B. A.; Jacobson, M. Z.

2013-12-01

As renewable energy generators are increasingly being installed throughout the U.S., there is growing interest in interconnecting diverse renewable generators (primarily wind and solar) across large geographic areas through an enhanced transmission system. This reduces variability in the aggregate power output, increases system reliability, and allows for the development of the best overall group of renewable technologies and sites to meet the load. Studies are therefore needed to determine the most efficient and economical plan to achieve large area interconnections in a future electric system with a high penetration of renewables. This research quantifies the effects of aggregating electric load together with diverse renewable generation throughout the ten Federal Energy Regulatory Commission (FERC) regions in the contiguous U.S. A deterministic linear program has been built in AMPL (A Mathematical Programming Language) to solve for the least-cost organizational structure and system (generators, transmission, and storage) for a highly renewable electric grid. The analysis will 1) examine a highly renewable 2006 electric system, including various sensitivity cases and additional system components such as additional load from electric vehicles, and 2) create a 'roadmap' from the existing 2006 system to a highly renewable system in 2030, accounting for projected price and demand changes and generator retirements based on age and environmental regulations. Ideally, results from this study will offer insight for a federal renewable energy policy (such as a renewable portfolio standard) and how to best organize U.S. regions for transmission planning.

Alternatives in solar energy

Science.gov (United States)

Schueler, D. G.

1978-01-01

Although solar energy has the potential of providing a significant source of clean and renewable energy for a variety of applications, it is expected to penetrate the nation's energy economy very slowly. The alternative solar energy technologies which employ direct collection and conversion of solar radiation as briefly described.

Solar Flares and the High Energy Solar Spectroscopic Imager (HESSI)

Science.gov (United States)

Holman, Gordon D.; Fisher, Richard R. (Technical Monitor)

2001-01-01

Solar flares are the biggest explosions in the solar system. They are important both for understanding explosive events in the Universe and for their impact on human technology and communications. The satellite-based HESSI is designed to study the explosive release of energy and the acceleration of electrons, protons, and other charged particles to high energies in solar flares. HESSI produces "color" movies of the Sun in high-energy X rays and gamma rays radiated by these energetic particles. HESSI's X-ray and gamma-ray images of flares are obtained using techniques similar to those used in radio interferometry. Ground-based radio observations of the Sun provide an important complement to the HESSI observations of solar flares. I will describe the HESSI Project and the high-energy aspects of solar flares, and how these relate to radio astronomy techniques and observations.

Electricity demand profile with high penetration of heat pumps in Nordic area

DEFF Research Database (Denmark)

Liu, Zhaoxi; Wu, Qiuwei; Nielsen, Arne Hejde

2013-01-01

This paper presents the heat pump (HP) demand profile with high HP penetration in the Nordic area in order to achieve the carbon neutrality power system. The calculation method in the European Standard EN14825 was used to estimate the HP electricity demand profile. The study results show...... there will be high power demand from HPs and the selection of supplemental heating for heat pumps has a big impact on the peak electrical power load of heating. The study in this paper gives an estimate of the scale of the electricity demand with high penetration of heat pumps in the Nordic area....

Dinamics of penetration of solar cosmic rays in Earth magnetosphere according to the ''Interkosmos-19'' satellite data

International Nuclear Information System (INIS)

Glukhov, G.A.; Daudov, Z.Kh.; Kratenko, Yu.P.; Mineev, Yu.V.; Spir'kova, E.S.; Shavrin, P.I.; Moskovskij Gosudarstvennyj Univ.

1982-01-01

Investigations of solar electron fluxes with 0.3-2 MeV energies and proton fluxes with energies >= 0.5 MeV penetrating into the Earth magnetosphere are performed. The experiments are carried out using the differential electron spectrometer on the base of semiconductor detectors installed at the ''Interkosmos-19'' satellite. Some examples of intensity profile of electron fluxes with energies not less than 40 and 100 keV and also protons with energies not less than 0.5 MeV and 2.0 MeV are given. The material was accumulated during the magnetic storm on 10-11.03, 1979. The results obtained point out to the electron pulsation in different regions of magnetosphere

Assessing high wind energy penetration

International Nuclear Information System (INIS)

Tande, J.O.

1995-01-01

In order to convincingly promote installing wind power capacity as a substantial part of the energy supply system, a set of careful analyses must be undertaken. This paper applies a case study concentrated on assessing the cost/benefit of high wind energy penetration. The case study considers expanding the grid connected wind power capacity in Praia, the capital of Cape Verde. The currently installed 1 MW of wind power is estimated to supply close to 10% of the electric energy consumption in 1996. Increasing the wind energy penetration to a higher level is considered viable as the project settings are close to ideal, including a very capable national utility company, Electra, a conventional power supply system based on imported heavy fuel and gas oil, and favourable wind conditions with an estimated annual average of 9.3 m/s at the hub height of the wind turbines. With the applied case study assumptions, simulations with WINSYS over the lifetime of the assessed wind power investment show that investments up to 4.2 MW are economically viable. The economic optimum is found at 2.4 MW reaching an internal rate of return of almost 8% p.a. This 2.4 MW of wind power would, together with the existing wind power, supply over 30% of the electric consumption in 1996. Applying the recommended practices for estimating the cost of wind energy, the life-cycle cost of this 2.4 MW investment is estimated at a 7% discount rate and a 20 year lifetime to 0.26 DKK/kW h. (Author)

Solar Deployment System (SolarDS) Model: Documentation and Sample Results

Energy Technology Data Exchange (ETDEWEB)

Denholm, P.; Drury, E.; Margolis, R.

2009-09-01

The Solar Deployment System (SolarDS) model is a bottom-up, market penetration model that simulates the potential adoption of photovoltaics (PV) on residential and commercial rooftops in the continental United States through 2030. NREL developed SolarDS to examine the market competitiveness of PV based on regional solar resources, capital costs, electricity prices, utility rate structures, and federal and local incentives. The model uses the projected financial performance of PV systems to simulate PV adoption for building types and regions then aggregates adoption to state and national levels. The main components of SolarDS include a PV performance simulator, a PV annual revenue calculator, a PV financial performance calculator, a PV market share calculator, and a regional aggregator. The model simulates a variety of installed PV capacity for a range of user-specified input parameters. PV market penetration levels from 15 to 193 GW by 2030 were simulated in preliminary model runs. SolarDS results are primarily driven by three model assumptions: (1) future PV cost reductions, (2) the maximum PV market share assumed for systems with given financial performance, and (3) PV financing parameters and policy-driven assumptions, such as the possible future cost of carbon emissions.

Lower price for solar boilers must improve market penetration

International Nuclear Information System (INIS)

Koevoet, J.B.J.

1999-01-01

The Dutch government aims at 1.7 PJ thermal energy for the year 2007 to be supplied by solar water heaters. For that target the number of installed solar boilers must increase seven times the number of installed solar boilers in 1998. This can be stimulated by a considerable reduction of the market price for such boilers

Western Wind and Solar Integration Study Phase 3 – Frequency Response and Transient Stability

Energy Technology Data Exchange (ETDEWEB)

Miller, N. W. [GE Energy Management, Schenectady, NY (United States); Shao, M. [GE Energy Management, Schenectady, NY (United States); Pajic, S. [GE Energy Management, Schenectady, NY (United States); D' Aquila, R. [GE Energy Management, Schenectady, NY (United States)

2014-12-01

Power system operators and utilities worldwide have concerns about the impact of high-penetration wind and solar generation on electric grid reliability (EirGrid 2011b, Hydro-Quebec 2006, ERCOT 2010). The stability of North American grids under these conditions is a particular concern and possible impediment to reaching future renewable energy goals. Phase 3 of the Western Wind and Solar Integration Study (WWSIS-3) considers a 33% wind and solar annual energy penetration level that results in substantial changes to the characteristics of the bulk power system, including different power flow patterns, different commitment and dispatch of existing synchronous generation, and different dynamic behavior of wind and solar generation. WWSIS-3 evaluates two specific aspects of fundamental frequency system stability: frequency response and transient stability.

Solar energy grid integration systems : final report of the Florida Solar Energy Center Team.

Energy Technology Data Exchange (ETDEWEB)

Ropp, Michael (Northern Plains Power Technologies, Brookings, SD); Gonzalez, Sigifredo; Schaffer, Alan (Lakeland Electric Utilities, Lakeland, FL); Katz, Stanley (Satcon Technology Corporation, Boston, MA); Perkinson, Jim (Satcon Technology Corporation, Boston, MA); Bower, Ward Isaac; Prestero, Mark (Satcon Technology Corporation, Boston, MA); Casey, Leo (Satcon Technology Corporation, Boston, MA); Moaveni, Houtan (Florida Solar Energy Center of the University of Central Florida, Cocoa, FL); Click, David (Florida Solar Energy Center of the University of Central Florida, Cocoa, FL); Davis, Kristopher (Florida Solar Energy Center of the University of Central Florida, Cocoa, FL); Reedy, Robert (Florida Solar Energy Center of the University of Central Florida, Cocoa, FL); Kuszmaul, Scott S.; Sena-Henderson, Lisa; David, Carolyn; Akhil, Abbas Ali

2012-03-01

Initiated in 2008, the Solar Energy Grid Integration Systems (SEGIS) program is a partnership involving the U.S. DOE, Sandia National Laboratories, private sector companies, electric utilities, and universities. Projects supported under the program have focused on the complete-system development of solar technologies, with the dual goal of expanding utility-scale penetration and addressing new challenges of connecting large-scale solar installations in higher penetrations to the electric grid. The Florida Solar Energy Center (FSEC), its partners, and Sandia National Laboratories have successfully collaborated to complete the work under the third and final stage of the SEGIS initiative. The SEGIS program was a three-year, three-stage project that include conceptual design and market analysis in Stage 1, prototype development and testing in Stage 2, and moving toward commercialization in Stage 3. Under this program, the FSEC SEGIS team developed a comprehensive vision that has guided technology development that sets one methodology for merging photovoltaic (PV) and smart-grid technologies. The FSEC team's objective in the SEGIS project is to remove barriers to large-scale general integration of PV and to enhance the value proposition of photovoltaic energy by enabling PV to act as much as possible as if it were at the very least equivalent to a conventional utility power plant. It was immediately apparent that the advanced power electronics of these advanced inverters will go far beyond conventional power plants, making high penetrations of PV not just acceptable, but desirable. This report summarizes a three-year effort to develop, validate and commercialize Grid-Smart Inverters for wider photovoltaic utilization, particularly in the utility sector.

Penetration of Liquid Jets into a High-velocity Air Stream

Science.gov (United States)

Chelko, Louis J

1950-01-01

Data are presented showing the penetration characteristics of liquid jets directed approximately perpendicular to a high-velocity air stream for jet-nozzle-throat diameters from 0.0135 to 0.0625 inch, air stream densities from 0.0805 to 0.1365 pound per cubic foot, liquid jet velocities from 168.1 to 229.0 feet per second and a liquid jet density of approximately 62 pounds per cubic foot. The data were analyzed and a correlation was developed that permitted the determination of the penetration length of the liquid jet for any operation condition within the range of variables investigated.

Annual cycle of solar radiation in a deciduous forest

International Nuclear Information System (INIS)

Hutchison, B.A.; Matt, D.R.

1977-01-01

Periodic solar radiation measurements within and above an east Tennessee Liriodendron forest and continuous records of insolation from a nearby NOAA weather station were used to derive an approximation of the animal radiation regime within and above the deciduous forest. The interaction of changing solar elevations, insolation, and forest phenology are shown to control the radiation climate within the forest. Maximum radiation penetrates the forest in early spring as solar paths rise higher in the sky each day just prior to leaf expansion. After leaf expansion begins, average radiation received within the forest decreases rapidly despite continued increases in solar elevations and daily insolation. This forest attains full leaf in early June and from then until the advent of leaf abscission near the autumnal equinox, forest structure remains relatively static. Solar elevations and daily insolation decline following the summer solstice, however, and as a result, average radiation penetrating the forest slowly declines throughout the summer reaching an annual minimum in early autumn. With leaf fall, slightly increased amounts of radiation penetrate the forest but as within-forest solar paths continue to lengthen, radiation within the forest again declines. Minimum amounts of solar radiation penetrate the leafless forest around the winter solstice

Optimal Operation of Plug-In Electric Vehicles in Power Systems with High Wind Power Penetrations

DEFF Research Database (Denmark)

Hu, Weihao; Su, Chi; Chen, Zhe

2013-01-01

in the power systems with high wind power penetrations. In this paper, the integration of plug-in electric vehicles in the power systems with high wind power penetrations is proposed and discussed. Optimal operation strategies of PEV in the spot market are proposed in order to decrease the energy cost for PEV......The Danish power system has a large penetration of wind power. The wind fluctuation causes a high variation in the power generation, which must be balanced by other sources. The battery storage based Plug-In Electric Vehicles (PEV) may be a possible solution to balance the wind power variations...... owners. Furthermore, the application of battery storage based aggregated PEV is analyzed as a regulation services provider in the power system with high wind power penetrations. The western Danish power system where the total share of annual wind power production is more than 27% of the electrical energy...

IMP-8 observations of the spectra, composition, and variability of solar heavy ions at high energies relevant to manned space missions

International Nuclear Information System (INIS)

Tylka, Allan J.; Dietrich, William F.

1999-01-01

In more than 25 years of almost continuous observations, the University of Chicago's Cosmic Ray Telescope (CRT) on IMP-8 has amassed a unique database on high-energy solar heavy ions of potential relevance to manned spaceflight. In the very largest particle events, IMP-8/CRT has even observed solar Fe ions above the Galactic cosmic ray background up to ∼800 MeV/nucleon, an energy sufficiently high to penetrate nearly 25 g/cm 2 of shielding. IMP-8/CRT observations show that high-energy heavy-ion spectra are often surprisingly hard power laws, without the exponential roll-offs suggested by stochastic acceleration fits to lower energy measurements alone. Also, in many solar particle events the Fe/O ratio grows with increasing energy, contrary to the notion that ions with higher mass-to-charge ratios should be less abundant at higher energies. Previous studies of radiation hazards for manned spaceflight have often assumed heavy-ion composition and steeply-falling energy spectra inconsistent with these observations. Conclusions based on such studies should therefore be re-assessed. The significant event-to-event variability observed in the high-energy solar heavy ions also has important implications for strategies in building probabilistic models of solar particle radiation hazards

Evaluation of nodal reliability risk in a deregulated power system with photovoltaic power penetration

DEFF Research Database (Denmark)

Zhao, Qian; Wang, Peng; Goel, Lalit

2014-01-01

Owing to the intermittent characteristic of solar radiation, power system reliability may be affected with high photovoltaic (PV) power penetration. To reduce large variation of PV power, additional system balancing reserve would be needed. In deregulated power systems, deployment of reserves...... and customer reliability requirements are correlated with energy and reserve prices. Therefore a new method should be developed to evaluate the impacts of PV power on customer reliability and system reserve deployment in the new environment. In this study, a method based on the pseudo-sequential Monte Carlo...... simulation technique has been proposed to evaluate the reserve deployment and customers' nodal reliability with high PV power penetration. The proposed method can effectively model the chronological aspects and stochastic characteristics of PV power and system operation with high computation efficiency...

Neutral escape at Mars induced by the precipitation of high-energy protons and hydrogen atoms of the solar wind origin

Science.gov (United States)

Shematovich, Valery I.

2017-04-01

One of the first surprises of the NASA MAVEN mission was the observation by the SWIA instrument of a tenuous population of protons with solar wind energies travelling anti-sunward near periapsis, at altitudes of 150-250 km (Halekas et al., 2015). While the penetration of solar wind protons to low altitude is not completely unexpected given previous Mars Express results, this population maintains exactly the same velocity as the solar wind observed. From previous studies it was known that some fraction of the solar wind can interact with the extended corona of Mars. By charge exchange with the neutral particles in this corona, some fraction of the incoming solar wind protons can gain an electron and become an energetic neutral hydrogen atom. Once neutral, these particles penetrate through the Martian induced magnetosphere with ease, with free access to the collisional atmosphere/ionosphere. The origin, kinetics and transport of the suprathermal O atoms in the transition region (from thermosphere to exosphere) of the Martian upper atmosphere due to the precipitation of the high-energy protons and hydrogen atoms are discussed. Kinetic energy distribution functions of suprathermal and superthermal (ENA) oxygen atoms formed in the Martian upper atmosphere were calculated using the kinetic Monte Carlo model (Shematovich et al., 2011, Shematovich, 2013) of the high-energy proton and hydrogen atom precipitation into the atmosphere. These functions allowed us: (a) to estimate the non-thermal escape rates of neutral oxygen from the Martian upper atmosphere, and (b) to compare with available MAVEN measurements of oxygen corona. Induced by precipitation the escape of hot oxygen atoms may become dominant under conditions of extreme solar events - solar flares and coronal mass ejections, - as it was shown by recent observations of the NASA MAVEN spacecraft (Jakosky et al., 2015). This work is supported by the RFBR project and by the Basic Research Program of the Praesidium of

Pumped storage in systems with very high wind penetration

International Nuclear Information System (INIS)

Tuohy, A.; O'Malley, M.

2011-01-01

This paper examines the operation of the Irish power system with very high levels of wind energy, with and without pumped storage. A unit commitment model which accounts for the uncertainty in wind power is used. It is shown that as wind penetration increases, the optimal operation of storage depends on wind output as well as load. The main benefit from storage is shown to be a decrease in wind curtailment. The economics of the system are examined to find the level at which storage justifies its capital costs and inefficiencies. It is shown that the uncertainty of wind makes the option of storage more attractive. The size of the energy store has an impact on results. At lower levels of installed wind (up to approximately 50% of energy from wind in Ireland), the reduction in curtailment is insufficient to justify building storage. At greater levels of wind, storage reduces curtailment sufficiently to justify the additional capital costs. It can be seen that if storage replaces OCGTs in the plant mix instead of CCGTs, then the level at which it justifies itself is lower. Storage increases the level of carbon emissions at wind penetration below 60%. - Research highlights: → Examines operation of pumped storage unit in a system with levels of wind from 34%-68% of energy. → High capital cost of storage is not justified until system has high (approx. 45%) wind penetration. → Results are driven by the amount of wind curtailment avoided and plant mix of system. → Other flexible options (e.g. interconnection) offer many of the same benefits as storage.

Penetration of magnetosonic waves into the magnetosphere: influence of a transition layer

Directory of Open Access Journals (Sweden)

A. S. Leonovich

Full Text Available We have constructed a theory for the penetration of magnetosonic waves from the solar wind into the magnetosphere through a transition layer in a plane-stratified model for the medium. In this model the boundary layer is treated as a region, inside of which the parameters of the medium vary from values characteristic for the magnetosphere, to values typical of the solar wind. It is shown that if such a layer has sufficiently sharp boundaries, then magnetosonic eigen-oscillations can be excited inside of it. The boundaries of such a layer are partially permeable for magnetosonic waves. Therefore, if the eigen-oscillations are not sustained by an external source, they will be attenuated, because some of the energy is carried away by the oscillations that penetrate the solar wind and the magnetosphere. It is shown that about 40% of the energy flux of the waves incident on the transition layer in the magnetotail region penetrate to the magnetosphere’s interior. This energy flux suffices to sustain the stationary convection of magnetospheric plasma. The total energy input to the magnetosphere during a time interval of the order of the substorm growth phase time is comparable with the energetics of an average substorm.

Key words. Magnetospheric physics (MHD waves and instabilities; solar wind–magnetosphere interactions – Space plasma physics (kinetic and MHD theory

Penetration of magnetosonic waves into the magnetosphere: influence of a transition layer

Directory of Open Access Journals (Sweden)

A. S. Leonovich

2003-05-01

Full Text Available We have constructed a theory for the penetration of magnetosonic waves from the solar wind into the magnetosphere through a transition layer in a plane-stratified model for the medium. In this model the boundary layer is treated as a region, inside of which the parameters of the medium vary from values characteristic for the magnetosphere, to values typical of the solar wind. It is shown that if such a layer has sufficiently sharp boundaries, then magnetosonic eigen-oscillations can be excited inside of it. The boundaries of such a layer are partially permeable for magnetosonic waves. Therefore, if the eigen-oscillations are not sustained by an external source, they will be attenuated, because some of the energy is carried away by the oscillations that penetrate the solar wind and the magnetosphere. It is shown that about 40% of the energy flux of the waves incident on the transition layer in the magnetotail region penetrate to the magnetosphere’s interior. This energy flux suffices to sustain the stationary convection of magnetospheric plasma. The total energy input to the magnetosphere during a time interval of the order of the substorm growth phase time is comparable with the energetics of an average substorm.Key words. Magnetospheric physics (MHD waves and instabilities; solar wind–magnetosphere interactions – Space plasma physics (kinetic and MHD theory

Securitization of residential solar photovoltaic assets: Costs, risks and uncertainty

International Nuclear Information System (INIS)

Alafita, T.; Pearce, J.M.

2014-01-01

Limited access to low-cost financing is an impediment to high-velocity technological diffusion and high grid penetration of solar photovoltaic (PV) technology. Securitization of solar assets provides a potential solution to this problem. This paper assesses the viability of solar asset-backed securities (ABS) as a lower cost financing mechanism and identifies policies that could facilitate implementation of securitization. First, traditional solar financing is examined to provide a baseline for cost comparisons. Next, the securitization process is modeled. The model enables identification of several junctures at which risk and uncertainty influence costs. Next, parameter values are assigned and used to generate cost estimates. Results show that, under reasonable assumptions, securitization of solar power purchase agreements (PPA) can significantly reduce project financing costs, suggesting that securitization is a viable mechanism for improving the financing of PV projects. The clear impediment to the successful launch of a solar ABS is measuring and understanding the riskiness of underlying assets. This study identifies three classes of policy intervention that lower the cost of ABS by reducing risk or by improving the measurement of risk: (i) standardization of contracts and the contracting process, (ii) improved access to contract and equipment performance data, and (iii) geographic diversification. - Highlights: • Limited access to low-cost financing is hampering penetration of solar PV. • Solar asset-backed securities (ABS) provide a low cost financing mechanism. • Results for securitization of solar leases and power purchase agreements (PPA). • Securitization can significantly reduce project financing costs. • Identifies policy intervention that lower cost of ABS by reducing risk

Representation of Solar Capacity Value in the ReEDS Capacity Expansion Model

Energy Technology Data Exchange (ETDEWEB)

Sigrin, B. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sullivan, P. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Ibanez, E. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Margolis, R. [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2014-03-01

An important issue for electricity system operators is the estimation of renewables' capacity contributions to reliably meeting system demand, or their capacity value. While the capacity value of thermal generation can be estimated easily, assessment of wind and solar requires a more nuanced approach due to the resource variability. Reliability-based methods, particularly assessment of the Effective Load-Carrying Capacity, are considered to be the most robust and widely-accepted techniques for addressing this resource variability. This report compares estimates of solar PV capacity value by the Regional Energy Deployment System (ReEDS) capacity expansion model against two sources. The first comparison is against values published by utilities or other entities for known electrical systems at existing solar penetration levels. The second comparison is against a time-series ELCC simulation tool for high renewable penetration scenarios in the Western Interconnection. Results from the ReEDS model are found to compare well with both comparisons, despite being resolved at a super-hourly temporal resolution. Two results are relevant for other capacity-based models that use a super-hourly resolution to model solar capacity value. First, solar capacity value should not be parameterized as a static value, but must decay with increasing penetration. This is because -- for an afternoon-peaking system -- as solar penetration increases, the system's peak net load shifts to later in the day -- when solar output is lower. Second, long-term planning models should determine system adequacy requirements in each time period in order to approximate LOLP calculations. Within the ReEDS model we resolve these issues by using a capacity value estimate that varies by time-slice. Within each time period the net load and shadow price on ReEDS's planning reserve constraint signals the relative importance of additional firm capacity.

Distributed Solar Photovoltaic Power Production - Technology and Benefits

Energy Technology Data Exchange (ETDEWEB)

Matos, Al [PSE& G; Stuby, Rick [Petra Solar

2011-11-02

As part of its nationally recognized Solar 4 All program, PSE&G has partnered with Petra Solar to deploy the world’s first and largest pole attached solar project. The project, based on Petra Solar’s distributed Smart Solar solution, will create a 40 megawatt solar “virtual power plant.” In deployment as 200,000 individual grid-connected solar power producers on utility poles in PSE&G territory, Petra Solar SunWave® solutions leverage Smart Grid communications and high-tech panel-level inverters to implement a robust system with many technical benefits over traditional solar photovoltaic solutions. The program overview, deployment model, smart grid communications and enabling inverter technology and safety features will be presented, as well the future challenges of, and solutions for, solar power intermittency as photovoltaic penetration on the electric grid increases.

Hydrodynamic analysis and design of high-level radioactive waste disposal model penetrators

International Nuclear Information System (INIS)

Visintini, L.; Mazazzi, R.; Murray, C.N.

1991-01-01

The Commission of the European Communities is studying in the framework of the NEA/OECD Internationally Co-ordinational Seabed Programme the feasibility of using deep ocean sedimentary geological formations as a final disposal medium for vitrified high level waste and fuel elements. At present, two options are being considered for the embedment of such wastes in the sediment column, drilling and free fall penetrators. In the second case, the high level waste would be contained in specially designed drums which would be placed into torpedo-shaped projectiles. These penetrators would then be launched from a semi-submersible platform or ship and allowed to fall freely through the water column (≅ 5 km depth) and to bury themselves within the sediment column. The present article reports some work which has been carried out by the Joint Research Centre, Ispra Establishment on designing large model penetrators for tests at two sites in the North Atlantic

High-Penetration Photovoltaics Standards and Codes Workshop, Denver, Colorado, May 20, 2010: Workshop Proceedings

Energy Technology Data Exchange (ETDEWEB)

Coddington, M.; Kroposki, B.; Basso, T.; Lynn, K.; Herig, C.; Bower, W.

2010-09-01

Effectively interconnecting high-level penetration of photovoltaic (PV) systems requires careful technical attention to ensuring compatibility with electric power systems. Standards, codes, and implementation have been cited as major impediments to widespread use of PV within electric power systems. On May 20, 2010, in Denver, Colorado, the National Renewable Energy Laboratory, in conjunction with the U.S. Department of Energy (DOE) Office of Energy Efficiency and Renewable Energy (EERE), held a workshop to examine the key technical issues and barriers associated with high PV penetration levels with an emphasis on codes and standards. This workshop included building upon results of the High Penetration of Photovoltaic (PV) Systems into the Distribution Grid workshop held in Ontario California on February 24-25, 2009, and upon the stimulating presentations of the diverse stakeholder presentations.

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

DEFF Research Database (Denmark)

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

2016-01-01

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

Integrated Simulation Development and Decision Support Tool-Set for Utility Market and Distributed Solar Power Generation Electricore, Inc.

Energy Technology Data Exchange (ETDEWEB)

Daye, Tony [Green Power Labs (GPL), San Diego, CA (United States)

2013-09-30

This project will enable utilities to develop long-term strategic plans that integrate high levels of renewable energy generation, and to better plan power system operations under high renewable penetration. The program developed forecast data streams for decision support and effective integration of centralized and distributed solar power generation in utility operations. This toolset focused on real time simulation of distributed power generation within utility grids with the emphasis on potential applications in day ahead (market) and real time (reliability) utility operations. The project team developed and demonstrated methodologies for quantifying the impact of distributed solar generation on core utility operations, identified protocols for internal data communication requirements, and worked with utility personnel to adapt the new distributed generation (DG) forecasts seamlessly within existing Load and Generation procedures through a sophisticated DMS. This project supported the objectives of the SunShot Initiative and SUNRISE by enabling core utility operations to enhance their simulation capability to analyze and prepare for the impacts of high penetrations of solar on the power grid. The impact of high penetration solar PV on utility operations is not only limited to control centers, but across many core operations. Benefits of an enhanced DMS using state-of-the-art solar forecast data were demonstrated within this project and have had an immediate direct operational cost savings for Energy Marketing for Day Ahead generation commitments, Real Time Operations, Load Forecasting (at an aggregate system level for Day Ahead), Demand Response, Long term Planning (asset management), Distribution Operations, and core ancillary services as required for balancing and reliability. This provided power system operators with the necessary tools and processes to operate the grid in a reliable manner under high renewable penetration.

Penetrators for delivering Scientific equipment to minor bodies by flying-pass missions.

Science.gov (United States)

Bagrov, Alexander; Martynov, Maxim; Pichkhadze, Konstantin M.; Dolgopolov, Vladimir; Sysoev, Valentin

Many space missions are planned to have close encounters with Solar system minor bodies as a pass-fly. Short time of such close encounters were effectively used for photographing of these bodies, i.e. for distant investigations only because of large velocities of the encounter. We propose to use high-velocity penetrators to provide contact investigations of the minor bodies in situ. These devices were designed by Lavochkin Association for lunar missions. They were designed for long lived scientific equipment to be placed under surface up to depth 2...3 m. Penetrators could survive under 500 g shock, so the contact velocity was from 90 to 250 m/s, so each of them had booster engine to decelerate orbital velocity. As flying-pass velocity near minor body can be more then 10 km/s, penetrators would hit target at speed above 1 km/s and successfully bear 1500 g. To do so we propose to fulfill whole internal space inside penetrator with distilled water and froze it to temperature - 80°C or lower. At this temperature water ice is as hard as steel, so penetrator will plunge into target like armour-piercing shell. After landing protective ice will be evaporated (particularly due to heating from collision) and all sensitive mechanics will be set free.

Conditions for plasmoid penetration across abrupt magnetic barriers

International Nuclear Information System (INIS)

Brenning, Nils; Hurtig, Tomas; Raadu, Michael A.

2005-01-01

The penetration of plasma clouds, or plasmoids, across abrupt magnetic barriers (of the scale less than a few ion gyro radii, using the plasmoid directed velocity) is studied. The insight gained earlier, from detailed experimental and computer simulation investigations of a case study, is generalized into other parameter regimes. It is concluded for what parameters a plasmoid should be expected to penetrate the magnetic barrier through self-polarization, penetrate through magnetic expulsion, or be rejected from the barrier. The scaling parameters are n e , v 0 , B perpendicular , m i , T i , and the width w of the plasmoid. The scaling is based on a model for strongly driven, nonlinear magnetic field diffusion into a plasma which is a generalization of the earlier laboratory findings. The results are applied to experiments earlier reported in the literature, and also to the proposed application of impulsive penetration of plasmoids from the solar wind into the Earth's magnetosphere

Design of a high-power, high-brightness Nd:YAG solar laser.

Science.gov (United States)

Liang, Dawei; Almeida, Joana; Garcia, Dário

2014-03-20

A simple high-power, high-brightness Nd:YAG solar laser pumping approach is presented in this paper. The incoming solar radiation is both collected and concentrated by four Fresnel lenses and redirected toward a Nd:YAG laser head by four plane-folding mirrors. A fused-silica secondary concentrator is used to compress the highly concentrated solar radiation to a laser rod. Optimum pumping conditions and laser resonator parameters are found through ZEMAX and LASCAD numerical analysis. Solar laser power of 96 W is numerically calculated, corresponding to the collection efficiency of 24  W/m². A record-high solar laser beam brightness figure of merit of 9.6 W is numerically achieved.

The HESP (High Energy Solar Physics) project

Science.gov (United States)

Kai, K.

1986-01-01

A project for space observations of solar flares for the coming solar maximum phase is briefly described. The main objective is to make a comprehensive study of high energy phenomena of flares through simultaneous imagings in both hard and soft X-rays. The project will be performed with collaboration from US scientists. The HESP (High Energy Solar Physics) WG of ISAS (Institute of Space and Astronautical Sciences) has extensively discussed future aspects of space observations of high energy phenomena of solar flares based on successful results of the Hinotori mission, and proposed a comprehensive research program for the next solar maximum, called the HESP (SOLAR-A) project. The objective of the HESP project is to make a comprehensive study of both high energy phenomena of flares and quiet structures including pre-flare states, which have been left uncovered by SMM and Hinotori. For such a study simultaneous imagings with better resolutions in space and time in a wide range of energy will be extremely important.

Integrating Solar Power onto the Electric Grid - Bridging the Gap between Atmospheric Science, Engineering and Economics

Science.gov (United States)

Ghonima, M. S.; Yang, H.; Zhong, X.; Ozge, B.; Sahu, D. K.; Kim, C. K.; Babacan, O.; Hanna, R.; Kurtz, B.; Mejia, F. A.; Nguyen, A.; Urquhart, B.; Chow, C. W.; Mathiesen, P.; Bosch, J.; Wang, G.

2015-12-01

One of the main obstacles to high penetrations of solar power is the variable nature of solar power generation. To mitigate variability, grid operators have to schedule additional reliability resources, at considerable expense, to ensure that load requirements are met by generation. Thus despite the cost of solar PV decreasing, the cost of integrating solar power will increase as penetration of solar resources onto the electric grid increases. There are three principal tools currently available to mitigate variability impacts: (i) flexible generation, (ii) storage, either virtual (demand response) or physical devices and (iii) solar forecasting. Storage devices are a powerful tool capable of ensuring smooth power output from renewable resources. However, the high cost of storage is prohibitive and markets are still being designed to leverage their full potential and mitigate their limitation (e.g. empty storage). Solar forecasting provides valuable information on the daily net load profile and upcoming ramps (increasing or decreasing solar power output) thereby providing the grid advance warning to schedule ancillary generation more accurately, or curtail solar power output. In order to develop solar forecasting as a tool that can be utilized by the grid operators we identified two focus areas: (i) develop solar forecast technology and improve solar forecast accuracy and (ii) develop forecasts that can be incorporated within existing grid planning and operation infrastructure. The first issue required atmospheric science and engineering research, while the second required detailed knowledge of energy markets, and power engineering. Motivated by this background we will emphasize area (i) in this talk and provide an overview of recent advancements in solar forecasting especially in two areas: (a) Numerical modeling tools for coastal stratocumulus to improve scheduling in the day-ahead California energy market. (b) Development of a sky imager to provide short term

Perovskite Solar Cells for High-Efficiency Tandems

Energy Technology Data Exchange (ETDEWEB)

McGehee, Michael [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Buonassisi, Tonio [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)

2017-09-30

organic cation evolution and moisture penetration to overcome the often-reported thermal and environmental instability of metal halide perovskites. Previous perovskite-containing tandems utilized molybdenum oxide (MoO_x) as a sputter buffer layer, but this has raised concerns over long-term stability, as the iodide in the perovskite can chemically react with MoO_x. Mixed-cation perovskite solar cells have consistently outperformed their single-cation counterparts. The first perovskite device to exceed 20% PCE was fabricated with a mixture of methylammonium (MA) and formamidinium (FA). Recent reports have shown promising results with the introduction of cesium mixtures, enabling high efficiencies with improved photo-, moisture, and thermal stability. The increased moisture and thermal stability are especially important as they broaden the parameter space for processing on top of the perovskite, enabling the deposition of metal oxide contacts through atomic layer deposition (ALD) or chemical vapor deposition (CVD) that may require elevated temperatures or water as a counter reagent. Both titanium dioxide (TiO₂) and tin oxide (SnO₂) have consistently proven to be effective electron-selective contacts for perovskite solar cells and both can be deposited via ALD at temperatures below 150 °C. We introduced a bilayer of SnO₂ and zinc tin oxide (ZTO) that can be deposited by either low-temperature ALD or pulsed-CVD as a window layer with minimal parasitic absorption, efficient electron extraction, and sufficient buffer properties to prevent the organic and perovskite layers from damage during the subsequent sputter deposition of a transparent ITO electrode. We explored pulsed-CVD as a modified ALD process with a continual, rather than purely step-wise, growth component in order to considerably reduce the process time of the SnO₂ deposition process and minimize potential perovskite degradation. These layers, when

High-resolution geophysical profiling using a stepped-frequency ground penetrating radar

Energy Technology Data Exchange (ETDEWEB)

Noon, D; Longstaff, D [The University of Queensland, (Australia)

1996-05-01

This paper describes the results of a ground penetrating radar (GPR) system which uses stepped-frequency waveforms to obtain high-resolution geophysical profiles. The main application for this system is the high-resolution mapping of thin coal seam structures, in order to assist surface mining operations in open-cut coal mines. The required depth of penetration is one meter which represents the maximum thickness of coal seams that are designated `thin`. A resolution of five centimeters is required to resolve the minimum thickness of coal (or shale partings) which can be economically recovered in an open-cut coal mine. For this application, a stepped-frequency GPR system has been developed, because of its ultrawide bandwidth (1 to 2 GHz) and high external loop sensitivity (155 dB). The field test results of the stepped-frequency GPR system on a concrete pavement and at two Australian open-cut coal mines are also presented. 7 refs., 5 figs.

Reconsidering solar grid parity

International Nuclear Information System (INIS)

Yang, C.-J.

2010-01-01

Grid parity-reducing the cost of solar energy to be competitive with conventional grid-supplied electricity-has long been hailed as the tipping point for solar dominance in the energy mix. Such expectations are likely to be overly optimistic. A realistic examination of grid parity suggests that the cost-effectiveness of distributed photovoltaic (PV) systems may be further away than many are hoping for. Furthermore, cost-effectiveness may not guarantee commercial competitiveness. Solar hot water technology is currently far more cost-effective than photovoltaic technology and has already reached grid parity in many places. Nevertheless, the market penetration of solar water heaters remains limited for reasons including unfamiliarity with the technologies and high upfront costs. These same barriers will likely hinder the adoption of distributed solar photovoltaic systems as well. The rapid growth in PV deployment in recent years is largely policy-driven and such rapid growth would not be sustainable unless governments continue to expand financial incentives and policy mandates, as well as address regulatory and market barriers.

Extended-Term Dynamic Simulations with High Penetrations of Photovoltaic Generation.

Energy Technology Data Exchange (ETDEWEB)

Concepcion, Ricky James [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Elliott, Ryan Thomas [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Donnelly, Matt [Montana Tech., Butte, MT (United States); Sanchez-Gasca, Juan [GE Energy, Schenectady, NY (United States)

2016-01-01

The uncontrolled intermittent availability of renewable energy sources makes integration of such devices into today's grid a challenge. Thus, it is imperative that dynamic simulation tools used to analyze power system performance are able to support systems with high amounts of photovoltaic (PV) generation. Additionally, simulation durations expanding beyond minutes into hours must be supported. This report aims to identify the path forward for dynamic simulation tools to accom- modate these needs by characterizing the properties of power systems (with high PV penetration), analyzing how these properties affect dynamic simulation software, and offering solutions for po- tential problems. We present a study of fixed time step, explicit numerical integration schemes that may be more suitable for these goals, based on identified requirements for simulating high PV penetration systems. We also present the alternative of variable time step integration. To help determine the characteristics of systems with high PV generation, we performed small signal sta- bility studies and time domain simulations of two representative systems. Along with feedback from stakeholders and vendors, we identify the current gaps in power system modeling including fast and slow dynamics and propose a new simulation framework to improve our ability to model and simulate longer-term dynamics.

Cutaneous Permeation and Penetration of Sunscreens: Formulation Strategies and In Vitro Methods

Directory of Open Access Journals (Sweden)

Silvia Tampucci

2017-12-01

Full Text Available Sunscreens are the most common products used for skin protection against the harmful effects of ultraviolet radiation. However, as frequent application is recommended, the use of large amount of sunscreens could reflect in possible systemic absorption and since these preparations are often applied on large skin areas, even low penetration rates can cause a significant amount of sunscreen to enter the body. An ideal sunscreen should have a high substantivity and should neither penetrate the viable epidermis, the dermis and the systemic circulation, nor in hair follicle. The research of methods to assess the degree of penetration of solar filters into the skin is nowadays even more important than in the past, due to the widespread use of nanomaterials and the new discoveries in cosmetic formulation technology. In the present paper, different in vitro studies, published in the last five years, have been reviewed, in order to focus the attention on the different methodological approaches employed to effectively assess the skin permeation and retention of sunscreens.

Application of Power Systems Economics to Wind and Solar Power Integration

OpenAIRE

Mills, Andrew David

2015-01-01

The focus of this dissertation is the economic implications of the technical challenges of integrating variable generation, namely wind and solar, into the electric power system. The research is organized around three topics: short-term variability of wind and solar generation, changes in the economic value of wind and solar with increasing penetration, and the effectiveness of different measures at mitigating changes in economic value with increasing penetration levels. Early studies of PV g...

Integrating solar PV (photovoltaics) in utility system operations: Analytical framework and Arizona case study

International Nuclear Information System (INIS)

Wu, Jing; Botterud, Audun; Mills, Andrew; Zhou, Zhi; Hodge, Bri-Mathias; Heaney, Mike

2015-01-01

A systematic framework is proposed to estimate the impact on operating costs due to uncertainty and variability in renewable resources. The framework quantifies the integration costs associated with sub-hourly variability and uncertainty as well as day-ahead forecasting errors in solar PV (photovoltaics) power. A case study illustrates how changes in system operations may affect these costs for a utility in the southwestern United States (Arizona Public Service Company). We conduct an extensive sensitivity analysis under different assumptions about balancing reserves, system flexibility, fuel prices, and forecasting errors. We find that high solar PV penetrations may lead to operational challenges, particularly during low-load and high solar periods. Increased system flexibility is essential for minimizing integration costs and maintaining reliability. In a set of sensitivity cases where such flexibility is provided, in part, by flexible operations of nuclear power plants, the estimated integration costs vary between $1.0 and $4.4/MWh-PV for a PV penetration level of 17%. The integration costs are primarily due to higher needs for hour-ahead balancing reserves to address the increased sub-hourly variability and uncertainty in the PV resource. - Highlights: • We propose an analytical framework to estimate grid integration costs for solar PV. • Increased operating costs from variability and uncertainty in solar PV are computed. • A case study of a utility in Arizona is conducted. • Grid integration costs are found in the $1.0–4.4/MWh range for a 17% PV penetration. • Increased system flexibility is essential for minimizing grid integration costs

High Radiation Resistance IMM Solar Cell

Science.gov (United States)

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.

Impact of Rooftop Solar PV on Residential Distribution Network

DEFF Research Database (Denmark)

Bhattarai, Bishnu Prasad; Bak-Jensen, Birgitte; Pillai, Jayakrishnan Radhakrishna

Increased environmental awareness in recent years has encouraged rapid growth of renewable energy sources especially solar PV and wind. Among them, small scale solar PV has been gaining more momentum especially at residential level. Even today moderate penetration of grid tied rooftop solar PV has...... become reality in many countries. In spite of various benefits, higher penetration of rooftop PVs might come up with number of detrimental effects, with power quality and overcurrent protection being the major ones. Therefore, it is reasonable to quantify both drawback and benefits of rooftop PV...

Technology for a Thermo-chemical Ice Penetrator for Icy Moons

Science.gov (United States)

Arenberg, Jonathan; Harpole, George; Zamel, James; Sen, Bashwar; Lee, Greg; Ross, Floyd; Retherford, Kurt D.

2016-10-01

The ability to place sensors or to take samples below the ice surface enables a wide variety of potential scientific investigations. Penetrating an ice cap can be accomplished via a mechanical drill, laser drill, kinetic impactor, or heated penetrator. This poster reports on the development of technology for the latter most option, namely a self-heated probe driven by an exothermic chemical reaction: a Thermo-chemical ice penetrator (TChIP). Our penetrator design employs a eutectic mix of alkali metals that produce an exothermic reaction upon contact with an icy surface. This reaction increases once the ice starts melting, so no external power is required. This technology is inspired by a classified Cold-War era program developed at Northrop Grumman for the US Navy. Terrestrial demonstration of this technology took place in the Arctic; however, this device cannot be considered high TRL for application at the icy moons of the solar system due to the environmental differences between Earth's Arctic and the icy moons. These differences demand a TChIP design specific to these cold, low mass, airless worlds. It is expected that this model of TChIP performance will be complex, incorporating all of the forces on the penetrator, gravity, the thermo-chemistry at the interface between penetrator and ice, and multi-phase heat and mass transport, and hydrodynamics. Our initial efforts are aimed at the development of a validated set of tools and simulations to predict the performance of the penetrator for both the environment found on these icy moons and for a terrestrial environment. The purpose of the inclusion of the terrestrial environment is to aid in model validation. Once developed and validated, our models will allow us to design penetrators for a specific scientific application on a specific body. This poster discusses the range of scientific investigations that are enabled by TChIP. We also introduce the development plan to advance TChIP to the point where it can be

Western Wind and Solar Integration Study Phase 3A: Low Levels of Synchronous Generation

Energy Technology Data Exchange (ETDEWEB)

Miller, Nicholas W. [GE Energy Management, Atlanta, GA (United States); Leonardi, Bruno [GE Energy Management, Atlanta, GA (United States); D' Aquila, Robert [GE Energy Management, Atlanta, GA (United States); Clark, Kara [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-11-17

The stability of the North American electric power grids under conditions of high penetrations of wind and solar is a significant concern and possible impediment to reaching renewable energy goals. The 33% wind and solar annual energy penetration considered in this study results in substantial changes to the characteristics of the bulk power system. This includes different power flow patterns, different commitment and dispatch of existing synchronous generation, and different dynamic behavior from wind and solar generation. The Western Wind and Solar Integration Study (WWSIS), sponsored by the U.S. Department of Energy, is one of the largest regional solar and wind integration studies to date. In multiple phases, it has explored different aspects of the question: Can we integrate large amounts of wind and solar energy into the electric power system of the West? The work reported here focused on the impact of low levels of synchronous generation on the transient stability performance in one part of the region in which wind generation has displaced synchronous thermal generation under highly stressed, weak system conditions. It is essentially an extension of WWSIS-3. Transient stability, the ability of the power system to maintain synchronism among all elements following disturbances, is a major constraint on operations in many grids, including the western U.S. and Texas systems. These constraints primarily concern the performance of the large-scale bulk power system. But grid-wide stability concerns with high penetrations of wind and solar are still not thoroughly understood. This work focuses on 'traditional' fundamental frequency stability issues, such as maintaining synchronism, frequency, and voltage. The objectives of this study are to better understand the implications of low levels of synchronous generation and a weak grid on overall system performance by: 1) Investigating the Western Interconnection under conditions of both high renewable

The Penetration of Solar Radiation Into Carbon Dioxide Ice

Science.gov (United States)

Chinnery, H. E.; Hagermann, A.; Kaufmann, E.; Lewis, S. R.

2018-04-01

Icy surfaces behave differently to rocky or regolith-covered surfaces in response to irradiation. A key factor is the ability of visible light to penetrate partially into the subsurface. This results in the solid-state greenhouse effect, as ices can be transparent or translucent to visible and shorter wavelengths, while opaque in the infrared. This can lead to significant differences in shallow subsurface temperature profiles when compared to rocky surfaces. Of particular significance for modeling the solid-state greenhouse effect is the e-folding scale, otherwise known as the absorption scale length, or penetration depth, of the ice. While there have been measurements for water ice and snow, pure and with mixtures, to date, there have been no such measurements published for carbon dioxide ice. After an extensive series of measurements we are able to constrain the e-folding scale of CO2 ice for the cumulative wavelength range 300 to 1,100 nm, which is a vital parameter in heat transfer models for the Martian surface, enabling us to better understand surface-atmosphere interactions at Mars' polar caps.

Western Wind and Solar Integration Study Phase 2 (Presentation)

Energy Technology Data Exchange (ETDEWEB)

Lew, D.; Brinkman, G.; Ibanez, E.; Kumar, N.; Lefton, S.; Jordan, G.; Venkataraman, S.; King, J.

2013-06-01

This presentation accompanies Phase 2 of the Western Wind and Solar Integration Study, a follow-on to Phase 1, which examined the operational impacts of high penetrations of variable renewable generation on the electric power system in the West and was one of the largest variable generation studies to date. High penetrations of variable generation can induce cycling of fossil-fueled generators. Cycling leads to wear-and-tear costs and changes in emissions. Phase 2 calculated these costs and emissions, and simulated grid operations for a year to investigate the detailed impact of variable generation on the fossil-fueled fleet. The presentation highlights the scope of the study and results.

Some problems of solar-terrestrial energy relations

International Nuclear Information System (INIS)

Kovalevskij, I.V.

1982-01-01

Energy aspects of relations of phenomena occurring on the Sun, in the interplanetary space, magnetosphere, ionosphere and on the Earth's surface are discussed. Particular attention is given to the energy radiated by the Sun (flares, coronal holes). The problems are considered of the energy transfer and transformation in high-velocity and flare flows of solar wind. Estimates are performed: of densities of various types of energy of the interplanetary space at the Earth's orbit level; energy fluxes incident on the magnetosphere; energy accumulated inside the magnetosphere; a series of energy parameters of magnetic storms. It is pointed out that nowadays one of the main problems of the magnetosphere physics is studying ways of the interplanatary space energy transfer into the magnetosphere. In this connection some problems are investigated: plasma penetration through the dayside magnetopause, solar wind plasma entry into the magnetotail, the electric field effect on transition region plasma penetration into the distant magnetotail

Chloride Penetration through Cracks in High-Performance Concrete and Surface Treatment System for Crack Healing

Directory of Open Access Journals (Sweden)

In-Seok Yoon

2012-01-01

Full Text Available For enhancing the service life of concrete structures, it is very important to minimize crack at surface. Even if these cracks are very small, the problem is to which extend these cracks may jeopardize the durability of these decks. It was proposed that crack depth corresponding with critical crack width from the surface is a crucial factor in view of durability design of concrete structures. It was necessary to deal with chloride penetration through microcracks characterized with the mixing features of concrete. This study is devoted to examine the effect of high strength concrete and reinforcement of steel fiber on chloride penetration through cracks. High strength concrete is regarded as an excellent barrier to resist chloride penetration. However, durability performance of cracked high strength concrete was reduced seriously up to that of ordinary cracked concrete. Steel fiber reinforcement is effective to reduce chloride penetration through cracks because steel fiber reinforcement can lead to reduce crack depth significantly. Meanwhile, surface treatment systems are put on the surface of the concrete in order to seal the concrete. The key-issue is to which extend a sealing is able to ensure that chloride-induced corrosion can be prevented. As a result, penetrant cannot cure cracks, however, coating and combined treatment can prevent chloride from flowing in concrete with maximum crack width of 0.06 mm and 0.08 mm, respectively.

Facing the challenges of distribution systems operation with high wind power penetration

DEFF Research Database (Denmark)

Das, Kaushik; Altin, Müfit; Hansen, Anca Daniela

2017-01-01

power flow in 60kV distribution networks through controlling the ability of wind power plants (WPPs) to generate or absorb reactive power. This paper aims to understand the characteristics of a distribution network with high penetration of distributed generation. A detailed analysis of the active...... and reactive power flows in a real distribution network under different wind and load conditions based on actual measurements is performed in order to understand the correlation between the consumption, wind power production, and the network losses. Conclusive remarks are presented, briefly expressing......This paper addresses the challenges associated with the operation of a distribution system with high penetration of wind power. The paper presents some preliminary investigations of an ongoing Danish research work, which has as main objective to reduce the network losses by optimizing the reactive...

High-pressure-induced water penetration into 3-isopropylmalate dehydrogenase

International Nuclear Information System (INIS)

Nagae, Takayuki; Kawamura, Takashi; Chavas, Leonard M. G.; Niwa, Ken; Hasegawa, Masashi; Kato, Chiaki; Watanabe, Nobuhisa

2012-01-01

Structures of 3-isopropylmalate dehydrogenase were determined at pressures ranging from 0.1 to 650 MPa. Comparison of these structures gives a detailed picture of the swelling of a cavity at the dimer interface and the generation of a new cleft on the molecular surface, which are accompanied by water penetration. Hydrostatic pressure induces structural changes in proteins, including denaturation, the mechanism of which has been attributed to water penetration into the protein interior. In this study, structures of 3-isopropylmalate dehydrogenase (IPMDH) from Shewanella oneidensis MR-1 were determined at about 2 Å resolution under pressures ranging from 0.1 to 650 MPa using a diamond anvil cell (DAC). Although most of the protein cavities are monotonically compressed as the pressure increases, the volume of one particular cavity at the dimer interface increases at pressures over 340 MPa. In parallel with this volume increase, water penetration into the cavity could be observed at pressures over 410 MPa. In addition, the generation of a new cleft on the molecular surface accompanied by water penetration could also be observed at pressures over 580 MPa. These water-penetration phenomena are considered to be initial steps in the pressure-denaturation process of IPMDH

A review of penetration mechanisms and dynamic properties of tungsten and depleted uranium penetrators

International Nuclear Information System (INIS)

Andrew, S.P.; Caligiuri, R.D.; Eiselstein, L.E.

1991-01-01

Kinetic energy penetrators must posses the best possible combination of hardness, stiffness, strength, and fracture toughness characteristics to be effective against modern armor systems. Over the last decade, depleted uranium (DU) and tungsten alloys have been the materials of choice for kinetic energy penetrators. Du and tungsten perform abut the same against semi-infinite targets, and DU outperforms tungsten penetrators in oblique, spaced array targets, but because of environmental and subsequent cost concerns, effort has focused on improving the performance of tungsten penetrators over the last few years. However, despite recent improvements in material properties, the penetration performance of tungsten still lags behind that of DU. One possible reason is the difference in deformation mechanisms at the leading edge of the penetrator during the penetration process-DU alloys tend to shear band and sharpen as they penetrate the target material, whereas tungsten penetrators tend to mushroom and blunt. As a first step to determine whether shear banding is truly the reason for superior DU performance, a review of the fabrication, high strain-rate properties, and penetration phenomena of penetrators manufactured from both tungsten and DU alloys. Specifically, the effects of composition, processing, and heat treatment on material properties and penetration mechanisms of these alloys are discussed

High-performance flat-panel solar thermoelectric generators with high thermal concentration

Science.gov (United States)

Kraemer, Daniel; Poudel, Bed; Feng, Hsien-Ping; Caylor, J. Christopher; Yu, Bo; Yan, Xiao; Ma, Yi; Wang, Xiaowei; Wang, Dezhi; Muto, Andrew; McEnaney, Kenneth; Chiesa, Matteo; Ren, Zhifeng; Chen, Gang

2011-07-01

The conversion of sunlight into electricity has been dominated by photovoltaic and solar thermal power generation. Photovoltaic cells are deployed widely, mostly as flat panels, whereas solar thermal electricity generation relying on optical concentrators and mechanical heat engines is only seen in large-scale power plants. Here we demonstrate a promising flat-panel solar thermal to electric power conversion technology based on the Seebeck effect and high thermal concentration, thus enabling wider applications. The developed solar thermoelectric generators (STEGs) achieved a peak efficiency of 4.6% under AM1.5G (1 kW m-2) conditions. The efficiency is 7-8 times higher than the previously reported best value for a flat-panel STEG, and is enabled by the use of high-performance nanostructured thermoelectric materials and spectrally-selective solar absorbers in an innovative design that exploits high thermal concentration in an evacuated environment. Our work opens up a promising new approach which has the potential to achieve cost-effective conversion of solar energy into electricity.

High-performance flat-panel solar thermoelectric generators with high thermal concentration.

Science.gov (United States)

Kraemer, Daniel; Poudel, Bed; Feng, Hsien-Ping; Caylor, J Christopher; Yu, Bo; Yan, Xiao; Ma, Yi; Wang, Xiaowei; Wang, Dezhi; Muto, Andrew; McEnaney, Kenneth; Chiesa, Matteo; Ren, Zhifeng; Chen, Gang

2011-05-01

The conversion of sunlight into electricity has been dominated by photovoltaic and solar thermal power generation. Photovoltaic cells are deployed widely, mostly as flat panels, whereas solar thermal electricity generation relying on optical concentrators and mechanical heat engines is only seen in large-scale power plants. Here we demonstrate a promising flat-panel solar thermal to electric power conversion technology based on the Seebeck effect and high thermal concentration, thus enabling wider applications. The developed solar thermoelectric generators (STEGs) achieved a peak efficiency of 4.6% under AM1.5G (1 kW m(-2)) conditions. The efficiency is 7-8 times higher than the previously reported best value for a flat-panel STEG, and is enabled by the use of high-performance nanostructured thermoelectric materials and spectrally-selective solar absorbers in an innovative design that exploits high thermal concentration in an evacuated environment. Our work opens up a promising new approach which has the potential to achieve cost-effective conversion of solar energy into electricity. © 2011 Macmillan Publishers Limited. All rights reserved

Renewable energy worldwide outlooks: solar energy

International Nuclear Information System (INIS)

Darnell, J.R.

1994-01-01

Solar energy yield is weak because it is very diffuse. The solar energy depends on the weather. The collectors need the beam radiation. Wavelength is important for some applications that include not only the visible spectrum but also infrared and ultraviolet radiation. The areas of the greatest future population growth are high on solar energy resources. We have different types of conversion systems where energy can be converted from solar to electric or thermal energy. Photovoltaic cells are made of silicone or gallium arsenide, this latter for the space use. For the solar energy applications there is a storage problem: electric batteries or superconducting magnets. Today, the highest use of solar energy is in the low temperature thermal category with over 90% of the world contribution from this energy. The penetration of solar energy will be higher in rural areas than in urban regions. But there are technical, institutional, economic constraints. In spite of that the use of solar energy would be increasing and will go on to increase thereafter. The decreasing costs over time are a real phenomenon and there is a broad public support for increased use of that energy. 15 figs

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

A review of penetration mechanisms and dynamic properties of tungsten and depleted uranium penetrators

International Nuclear Information System (INIS)

Andrew, S.P.; Caligiuri, R.D.; Eiselstein, L.E.

1991-01-01

Over the last decade, depleted uranium (DU) and tungsten alloys have been the materials of choice for kinetic energy penetrators. However, despite improvements in mechanical properties in recent years, the penetration performance of tungsten still lags behind that of DU. One possible reason is the difference in deformation mechanisms- DU alloys tend to shear band as they penetrate the target material, whereas tungsten penetrators tend to mushroom. As a first step to determining whether shear banding is truly the reason for superior DU performance, a review and summary of the available information was performed. This paper presents a state-of-the-art review of the formulation, high strain- rate properties, and penetration phenomena of penetrators manufactured from both tungsten and DU alloys. Specifically, the effects of composition, processing, and heat treatment on mechanical properties and penetration mechanisms of these alloys are discussed. Penetration data and models for penetration mechanisms (in particular shear banding) are also presented, as well as the applicability of these models and their salient features

On the Path to SunShot. The Environmental and Public Health Benefits of Achieving High Solar Penetrations in the United States

Energy Technology Data Exchange (ETDEWEB)

Wiser, Ryan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mai, Trieu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Millstein, Dev [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Carpenter, Alberta [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cohen, Stuart [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cole, Wesley [National Renewable Energy Lab. (NREL), Golden, CO (United States); Frew, Bethany [National Renewable Energy Lab. (NREL), Golden, CO (United States); Heath, Garvin [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-05-01

Compared with fossil fuel generators, photovoltaics (PV) and concentrating solar power (CSP) produce far lower lifecycle levels of greenhouse gas (GHG) emissions and harmful pollutants including fine particular matter (PM2.5), sulfur dioxide (SO₂), and nitrogen oxides (NO_x). In this report, we monetize the emission reductions from achieving the U.S. Department of Energy's SunShot deployment goals: 14% of U.S. electricity demand met by solar in 2030 and 27% in 2050. We estimate that achieving these goals could reduce cumulative power-sector GHG emissions by 10% between 2015 and 2050, resulting in savings of $238-$252 billion. This is equivalent to 2.0-2.2 cents per kilowatt-hour of solar installed (cents/kWh-solar). Similarly, realizing these levels of solar deployment could reduce cumulative power-sector emissions of PM2.5 by 8%, SO₂ by 9%, and NOx by 11% between 2015 and 2050. This could produce $167 billion in savings from lower future health and environmental damages, or 1.4 cents/kWh-solar--while also preventing 25,000-59,000 premature deaths. To put this in perspective, this estimated combined benefit of 3.5 cents/kWh-solar due to SunShot-level solar deployment is approximately equal to the additional levelized cost of electricity reduction needed to make unsubsidized utility-scale solar competitive with conventional generators today. In addition, the analysis shows that achieving the SunShot goals could save 4% of total power-sector water withdrawals and 9% of total power-sector water consumption over the 2015-2050 period--a particularly important consideration for arid states where substantial solar will be deployed. These results have potential implications for policy innovation and the economic competitiveness of solar and other generation technologies.

Multi-wavelength imaging of solar plasma. High-beta disruption model of solar flares

International Nuclear Information System (INIS)

Shibasaki, Kiyoto

2007-01-01

Solar atmosphere is filled with plasma and magnetic field. Activities in the atmosphere are due to plasma instabilities in the magnetic field. To understand the physical mechanisms of activities / instabilities, it is necessary to know the physical conditions of magnetized plasma, such as temperature, density, magnetic field, and their spatial structures and temporal developments. Multi-wavelength imaging is essential for this purpose. Imaging observations of the Sun at microwave, X-ray, EUV and optical ranges are routinely going on. Due to free exchange of original data among solar physics and related field communities, we can easily combine images covering wide range of spectrum. Even under such circumstances, we still do not understand the cause of activities in the solar atmosphere well. The current standard model of solar activities is based on magnetic reconnection: release of stored magnetic energy by reconnection is the cause of solar activities on the Sun such as solar flares. However, recent X-ray, EUV and microwave observations with high spatial and temporal resolution show that dense plasma is involved in activities from the beginning. Based on these observations, I propose a high-beta model of solar activities, which is very similar to high-beta disruptions in magnetically confined fusion experiments. (author)

Mesoporous multi-shelled ZnO microspheres for the scattering layer of dye sensitized solar cell with a high efficiency

Energy Technology Data Exchange (ETDEWEB)

Xia, Weiwei; Mei, Chao; Zeng, Xianghua, E-mail: xhzeng@yzu.edu.cn; Wu, Guoqing; Shen, Xiaoshuang [College of Physics Science and Technology and Institute of Optoelectronic Technology, Yangzhou University, Yangzhou 225002 (China); Chang, Shuai [Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081 (China)

2016-03-14

Both light scattering and dye adsorbing are important for the power conversion efficiency PCE performance of dye sensitized solar cell (DSSC). Nanostructured scattering layers with a large specific surface area are regarded as an efficient way to improve the PCE by increasing dye adsorbing, but excess adsorbed dye will hinder light scattering and light penetration. Thus, how to balance the dye adsorbing and light penetration is a key problem to improve the PCE performance. Here, multiple-shelled ZnO microspheres with a mesoporous surface are fabricated by a hydrothermal method and are used as scattering layers on the TiO{sub 2} photoanode of the DSSC in the presence of N719 dye and iodine–based electrolyte, and the results reveal that the DSSCs based on triple shelled ZnO microsphere with a mesoporous surface exhibit an enhanced PCE of 7.66%, which is 13.0% higher than those without the scattering layers (6.78%), indicating that multiple-shelled microspheres with a mesoporous surface can ensure enough light scattering between the shells, and a favorable concentration of the adsorbed dye can improve the light penetration. These results may provide a promising pathway to obtain the high efficient DSSCs.

High-flux solar concentration with imaging designs

Energy Technology Data Exchange (ETDEWEB)

Feuermann, D. [Ben-Gurion University of the Negev (Israel). Jacob Blaustein Institute for Desert Research; Gordon, J.M. [Ben-Gurion University of the Negev (Israel). Jacob Blaustein Institute for Desert Research; Ben-Gurion University of the Negev (Israel). Dept. of Mechanical Engineering; Ries, H. [Ries and Partners, Munich (Germany)

1999-02-01

Most large solar concentrators designed for high flux concentration at high collection efficiency are based on imaging primary mirrors and nonimaging secondary concentrators. In this paper, we offer an alternative purely imaging two-stage solar concentrator that can attain high flux concentration at high collection efficiency. Possible practical virtues include: (1) an inherent large gap between absorber and secondary mirror; (2) a restricted angular range on the absorber; and (3) an upward-facing receiver where collected energy can be extracted via the (shaded) apex of the parabola. We use efficiency-concentration plots to characterize the solar concentrators considered, and to evaluate the potential improvements with secondary concentrators. (author)

High-velocity Penetration of Concrete Targets with Three Types of Projectiles: Experiments and Analysis

Directory of Open Access Journals (Sweden)

Shuang Zhang

Full Text Available Abstract This study conducted high-velocity penetration experiments using conventional ogive-nose, double-ogive-nose, and grooved-tapered projectiles of approximately 2.5 kg and initial velocities between 1000 and 1360 m/s to penetrate or perforate concrete targets with unconfined compressive strengths of nominally 40MPa. The penetration performance data of these three types of projectiles with two different types of materials (i.e., AerMet100 and DT300 were obtained. The crater depth model considering both the projectile mass and the initial velocity was proposed based on the test results and a theoretical analysis. The penetration ability and the trajectory stability of these three projectile types were compared and analyzed accordingly. The results showed that, under these experimental conditions, the effects of these two different kinds of projectile materials on the penetration depth and mass erosion rate of projectile were not obvious. The existing models could not reflect the crater depths for projectiles of greater weights or higher velocities, whereas the new model established in this study was reliable. The double-ogive-nose has a certain effect of drag reduction. Thus, the double-ogive-nose projectile has a higher penetration ability than the conventional ogive-nose projectile. Meanwhile, the grooved-tapered projectile has a better trajectory stability, because the convex parts of tapered shank generated the restoring moment to stabilize the trajectory.

Eddy current testing with high penetration

International Nuclear Information System (INIS)

Becker, R.; Kroening, M.

1999-01-01

The low-frequency eddy current testing method is used when penetration into very deep layers is required. The achievable penetration depth is determined among other parameters by the lowest testing frequency that can be realised together with the eddy current sensor. When using inductive sensors, the measuring effect declines proportional to the lowering frequency (induction effect). Further reduction of testing frequency requires other types of sensors, as e.g. the GMR (Giant Magnetic Resistance), which achieves a constant measuring sensitivity down to the steady field. The multi-frequency eddy current testing method MFEC 3 of IZFP described here can be operated using three different scanning frequencies at a time. Two variants of eddy current probes are used in this case. Both have an inductive winding at their emitters, of the type of a measuring probe. The receiver end is either also an inductive winding, or a magnetic field-responsive resistance (GMR). (orig./CB) [de

Microgrid optimal scheduling considering impact of high penetration wind generation

Science.gov (United States)

Alanazi, Abdulaziz

The objective of this thesis is to study the impact of high penetration wind energy in economic and reliable operation of microgrids. Wind power is variable, i.e., constantly changing, and nondispatchable, i.e., cannot be controlled by the microgrid controller. Thus an accurate forecasting of wind power is an essential task in order to study its impacts in microgrid operation. Two commonly used forecasting methods including Autoregressive Integrated Moving Average (ARIMA) and Artificial Neural Network (ANN) have been used in this thesis to improve the wind power forecasting. The forecasting error is calculated using a Mean Absolute Percentage Error (MAPE) and is improved using the ANN. The wind forecast is further used in the microgrid optimal scheduling problem. The microgrid optimal scheduling is performed by developing a viable model for security-constrained unit commitment (SCUC) based on mixed-integer linear programing (MILP) method. The proposed SCUC is solved for various wind penetration levels and the relationship between the total cost and the wind power penetration is found. In order to reduce microgrid power transfer fluctuations, an additional constraint is proposed and added to the SCUC formulation. The new constraint would control the time-based fluctuations. The impact of the constraint on microgrid SCUC results is tested and validated with numerical analysis. Finally, the applicability of proposed models is demonstrated through numerical simulations.

A hybrid solar chemical looping combustion system with a high solar share

International Nuclear Information System (INIS)

Jafarian, Mehdi; Arjomandi, Maziar; Nathan, Graham J.

2014-01-01

Highlights: • A novel hybrid solar chemical looping combustion system is presented. • This hybrid CLC system integrates a CLC plant with a solar thermal energy plant. • The oxygen carrier particles are used for chemical and sensible thermal energy storage. • A solar cavity reactor is proposed for fuel reactor. • The calculations show a total solar share of around 60% can be achieved. - Abstract: A novel hybrid solar chemical looping combustion (Hy-Sol-CLC) is presented, in which the oxygen carrier particles in a CLC system are employed to provide thermal energy storage for concentrated solar thermal energy. This hybrid aims to take advantage of key features of a chemical looping combustion (CLC) system that are desirable for solar energy systems, notably their inherent chemical and sensible energy storage systems, the relatively low temperature of the “fuel” reactor (to which the concentrated solar thermal energy is added in a hybrid) relative to that of the final temperature of the product gas and the potential to operate the fuel reactor at a different pressure to the heated gas stream. By this approach, it is aimed to achieve high efficiency of the solar energy, infrastructure sharing, economic synergy, base load power generation and a high solar fraction of the total energy. In the proposed Hy-Sol-CLC system, a cavity solar receiver has been chosen for fuel reactor while for the storage of the oxygen carrier particles two reservoirs have been added to a conventional CLC. A heat exchanger is also proposed to provide independent control of the temperatures of the storage reservoirs from those of solar fuel and air reactors. The system is simulated using Aspen Plus software for the average diurnal profile of normal irradiance for Port Augusta, South Australia. The operating temperature of the fuel reactor, solar absorption efficiency, solar share, fraction of the solar thermal energy stored within the solar reactor, the fractions of sensible and

Improved high temperature solar absorbers for use in Concentrating Solar Power central receiver applications.

Energy Technology Data Exchange (ETDEWEB)

Stechel, Ellen Beth; Ambrosini, Andrea; Hall, Aaron Christopher; Lambert, Timothy L.; Staiger, Chad Lynn; Bencomo, Marlene

2010-09-01

Concentrating solar power (CSP) systems use solar absorbers to convert the heat from sunlight to electric power. Increased operating temperatures are necessary to lower the cost of solar-generated electricity by improving efficiencies and reducing thermal energy storage costs. Durable new materials are needed to cope with operating temperatures >600 C. The current coating technology (Pyromark High Temperature paint) has a solar absorptance in excess of 0.95 but a thermal emittance greater than 0.8, which results in large thermal losses at high temperatures. In addition, because solar receivers operate in air, these coatings have long term stability issues that add to the operating costs of CSP facilities. Ideal absorbers must have high solar absorptance (>0.95) and low thermal emittance (<0.05) in the IR region, be stable in air, and be low-cost and readily manufacturable. We propose to utilize solution-based synthesis techniques to prepare intrinsic absorbers for use in central receiver applications.

High-speed solar wind streams and polar mesosphere winter echoes at Troll, Antarctica

Directory of Open Access Journals (Sweden)

S. Kirkwood

2015-06-01

Full Text Available A small, 54 MHz wind-profiler radar, MARA, was operated at Troll, Antarctica (72° S, 2.5° E, continuously from November 2011 to January 2014, covering two complete Antarctic winters. Despite very low power, MARA observed echoes from heights of 55–80 km (polar mesosphere winter echoes, PMWE on 60% of all winter days (from March to October. This contrasts with previous reports from radars at high northern latitudes, where PWME have been reported only by very high power radars or during rare periods of unusually high electron density at PMWE heights, such as during solar proton events. Analysis shows that PWME at Troll were not related to solar proton events but were often closely related to the arrival of high-speed solar wind streams (HSS at the Earth, with PWME appearing at heights as low as 56 km and persisting for up to 15 days following HSS arrival. This demonstrates that HSS effects penetrate directly to below 60 km height in the polar atmosphere. Using local observations of cosmic-noise absorption (CNA, a theoretical ionization/ion-chemistry model and a statistical model of precipitating energetic electrons associated with HSS, the electron density conditions during the HSS events are estimated. We find that PMWE detectability cannot be explained by these variations in electron density and molecular-ion chemistry alone. PWME become detectable at different thresholds depending on solar illumination and height. In darkness, PWME are detected only when the modelled electron density is above a threshold of about 1000 cm−3, and only above 75 km height, where negative ions are few. In daylight, the electron density threshold falls by at least 2 orders of magnitude and PWME are found primarily below 75 km height, even in conditions when a large proportion of negative ions is expected. There is also a strong dawn–dusk asymmetry with PWME detected very rarely during morning twilight but often during evening twilight. This behaviour cannot be

High-speed solar wind streams and polar mesosphere winter echoes at Troll, Antarctica

Energy Technology Data Exchange (ETDEWEB)

Kirkwood, S.; Belova, E. [Swedish Institute of Space Physics, Kiruna (Sweden). Polar Atmospheric Research; Osepian, A. [Polar Geophysical Institute, Murmansk (Russian Federation); Lee, Y.S. [Korea Astronomy and Space Science Institute, Daejeon (Korea, Republic of)

2015-10-01

A small, 54 MHz wind-profiler radar, MARA, was operated at Troll, Antarctica (72 S, 2.5 E), continuously from November 2011 to January 2014, covering two complete Antarctic winters. Despite very low power, MARA observed echoes from heights of 55-80 km (polar mesosphere winter echoes, PMWE) on 60% of all winter days (from March to October). This contrasts with previous reports from radars at high northern latitudes, where PWME have been reported only by very high power radars or during rare periods of unusually high electron density at PMWE heights, such as during solar proton events. Analysis shows that PWME at Troll were not related to solar proton events but were often closely related to the arrival of high-speed solar wind streams (HSS) at the Earth, with PWME appearing at heights as low as 56 km and persisting for up to 15 days following HSS arrival. This demonstrates that HSS effects penetrate directly to below 60 km height in the polar atmosphere. Using local observations of cosmic-noise absorption (CNA), a theoretical ionization/ion-chemistry model and a statistical model of precipitating energetic electrons associated with HSS, the electron density conditions during the HSS events are estimated. We find that PMWE detectability cannot be explained by these variations in electron density and molecular-ion chemistry alone. PWME become detectable at different thresholds depending on solar illumination and height. In darkness, PWME are detected only when the modelled electron density is above a threshold of about 1000 cm{sup -3}, and only above 75 km height, where negative ions are few. In daylight, the electron density threshold falls by at least 2 orders of magnitude and PWME are found primarily below 75 km height, even in conditions when a large proportion of negative ions is expected. There is also a strong dawn-dusk asymmetry with PWME detected very rarely during morning twilight but often during evening twilight. This behaviour cannot be explained if PMWE

Price Forecasting of Electricity Markets in the Presence of a High Penetration of Wind Power Generators

OpenAIRE

Saber Talari; Miadreza Shafie-khah; Gerardo J. Osório; Fei Wang; Alireza Heidari; João P. S. Catalão

2017-01-01

Price forecasting plays a vital role in the day-ahead markets. Once sellers and buyers access an accurate price forecasting, managing the economic risk can be conducted appropriately through offering or bidding suitable prices. In networks with high wind power penetration, the electricity price is influenced by wind energy; therefore, price forecasting can be more complicated. This paper proposes a novel hybrid approach for price forecasting of day-ahead markets, with high penetration of wind...

Final Technical Report for Contract No. DE-EE0006332, "Integrated Simulation Development and Decision Support Tool-Set for Utility Market and Distributed Solar Power Generation"

Energy Technology Data Exchange (ETDEWEB)

Cormier, Dallas [San Diego Gas & Electric, CA (United States); Edra, Sherwin [San Diego Gas & Electric, CA (United States); Espinoza, Michael [San Diego Gas & Electric, CA (United States); Daye, Tony [Green Power Labs, San Diego, CA (United States); Kostylev, Vladimir [Green Power Labs, San Diego, CA (United States); Pavlovski, Alexandre [Green Power Labs, San Diego, CA (United States); Jelen, Deborah [Electricore, Inc., Valencia, CA (United States)

2014-12-29

This project will enable utilities to develop long-term strategic plans that integrate high levels of renewable energy generation, and to better plan power system operations under high renewable penetration. The program developed forecast data streams for decision support and effective integration of centralized and distributed solar power generation in utility operations. This toolset focused on real time simulation of distributed power generation within utility grids with the emphasis on potential applications in day ahead (market) and real time (reliability) utility operations. The project team developed and demonstrated methodologies for quantifying the impact of distributed solar generation on core utility operations, identified protocols for internal data communication requirements, and worked with utility personnel to adapt the new distributed generation (DG) forecasts seamlessly within existing Load and Generation procedures through a sophisticated DMS. This project supported the objectives of the SunShot Initiative and SUNRISE by enabling core utility operations to enhance their simulation capability to analyze and prepare for the impacts of high penetrations of solar on the power grid. The impact of high penetration solar PV on utility operations is not only limited to control centers, but across many core operations. Benefits of an enhanced DMS using state-of-the-art solar forecast data were demonstrated within this project and have had an immediate direct operational cost savings for Energy Marketing for Day Ahead generation commitments, Real Time Operations, Load Forecasting (at an aggregate system level for Day Ahead), Demand Response, Long term Planning (asset management), Distribution Operations, and core ancillary services as required for balancing and reliability. This provided power system operators with the necessary tools and processes to operate the grid in a reliable manner under high renewable penetration.

High-strength uranium-0.8 weight percent titanium alloy penetrators

International Nuclear Information System (INIS)

Northcutt, W.G.

1978-09-01

Long-rod kinetic-energy penetrators, produced from a uranium-0.8 titanium (U-0.8 Ti) alloy, are normally water quenched from the gamma phase (approximately 800 0 C) and aged to the desired hardness and strength levels. High cooling rates from 800 0 C in U-0.8 Ti alloy cylindrical bodies larger than about 13 mm in diameter cause internal voids, while slower rates of cooling can produce material that is unresponsive to aging. For the present study, elimination of quenching voids was of paramount importance; therefore, a process including the quenching of plate was explored. Vacuum-induction-cast ingots were forged and rolled into plate and cut into blanks from which the penetrators were obtained. Quenched U-0.8 Ti alloy blanks were aged at 350 to 500 0 C to determine the treatment that would provide maximum tensile and impact strengths. Both tensile and impact strengths were maximized by aging in vacuum for six hours at 450 0 C

High efficiency, long life terrestrial solar panel

Science.gov (United States)

Chao, T.; Khemthong, S.; Ling, R.; Olah, S.

1977-01-01

The design of a high efficiency, long life terrestrial module was completed. It utilized 256 rectangular, high efficiency solar cells to achieve high packing density and electrical output. Tooling for the fabrication of solar cells was in house and evaluation of the cell performance was begun. Based on the power output analysis, the goal of a 13% efficiency module was achievable.

Applications of nonimaging optics for very high solar concentrations

International Nuclear Information System (INIS)

O'Gallagher, J.; Winston, R.

1997-01-01

Using the principles and techniques of nonimaging optics, solar concentrations that approach the theoretical maximum can be achieved. This has applications in solar energy collection wherever concentration is desired. In this paper, we survey recent progress in attaining and using high and ultrahigh solar fluxes. We review a number of potential applications for highly concentrated solar energy and the current status of the associated technology. By making possible new and unique applications for intense solar flux, these techniques have opened a whole new frontier for research and development of potentially economic uses of solar energy

An illustrative note on the system price effect of wind and solar power. The German case

Energy Technology Data Exchange (ETDEWEB)

Jaegemann, Cosima

2014-07-15

Exposing wind and solar power to the market price signal allows for cost-efficient investment decisions, as it incentivizes investors to account for the marginal value (MV{sup el}) of renewable energy technologies. As shown by Lamont (2008), the MV{sup el} of wind and solar power units depends on their penetration level. More specifically, the MV el of wind and solar power units is a function of the respective unit's capacity factor and the covariance between its generation profile and the system marginal costs. The latter component of the MV{sup el} (i.e., the covariance) is found to decline as the wind and solar power penetration increases, displacing dispatchable power plants with higher short-run marginal costs of power production and thus reducing the system marginal costs in all generation hours. This so called 'system price effect' is analyzed in more detail in this paper. The analysis complements the work Lamont (2008) in two regards. First of all, an alternative expression for the MV{sup el} of wind and solar power units is derived, which shows that the MV{sup el} of fluctuating renewable energy technologies depends not only on their own penetration level but also on a variety of other parameters that are specific to the electricity system. Second, based on historical wholesale prices and wind and solar power generation data for Germany, a numerical 'ceteris paribus' example for Germany is presented which illustrates that the system price effect is already highly relevant for both wind and solar power generation in Germany.

An illustrative note on the system price effect of wind and solar power. The German case

International Nuclear Information System (INIS)

Jaegemann, Cosima

2014-01-01

Exposing wind and solar power to the market price signal allows for cost-efficient investment decisions, as it incentivizes investors to account for the marginal value (MV el ) of renewable energy technologies. As shown by Lamont (2008), the MV el of wind and solar power units depends on their penetration level. More specifically, the MV el of wind and solar power units is a function of the respective unit's capacity factor and the covariance between its generation profile and the system marginal costs. The latter component of the MV el (i.e., the covariance) is found to decline as the wind and solar power penetration increases, displacing dispatchable power plants with higher short-run marginal costs of power production and thus reducing the system marginal costs in all generation hours. This so called 'system price effect' is analyzed in more detail in this paper. The analysis complements the work Lamont (2008) in two regards. First of all, an alternative expression for the MV el of wind and solar power units is derived, which shows that the MV el of fluctuating renewable energy technologies depends not only on their own penetration level but also on a variety of other parameters that are specific to the electricity system. Second, based on historical wholesale prices and wind and solar power generation data for Germany, a numerical 'ceteris paribus' example for Germany is presented which illustrates that the system price effect is already highly relevant for both wind and solar power generation in Germany.

Destruction of Sun-Grazing Comet C-2011 N3 (SOHO) Within the Low Solar Corona

Science.gov (United States)

Schrijver, C. J.; Brown, J. C.; Battams, K.; Saint-Hilaire, P.; Liu, W.; Hudson, H.; Pesnell, W. D.

2012-01-01

Observations of comets in Sun-grazing orbits that survive solar insolation long enough to penetrate into the Suns inner corona provide information on the solar atmosphere and magnetic field as well as on the makeup of the comet. On 6 July 2011, the Solar Dynamics Observatory (SDO) observed the demise of comet C2011 N3 (SOHO) within the low solar corona in five wavelength bands in the extreme ultraviolet (EUV). The comet penetrated to within 0.146 solarradius (100,000 kilometers) of the solar surface before its EUV signal disappeared.

Facile synthesis of highly branched jacks-like ZnO nanorods and their applications in dye-sensitized solar cells

International Nuclear Information System (INIS)

Sudhagar, P.; Kumar, R. Saravana; Jung, June Hyuk; Cho, Woohyung; Sathyamoorthy, R.; Won, Jongok; Kang, Yong Soo

2011-01-01

Graphical abstract: -- Abstract: Highly branched, jacks-like ZnO nanorods architecture were explored as a photoanode in dye-sensitized solar cells, and their photovoltaic performance was compared with that of branch-free ZnO nanorods photoanodes. The highly branched network and large pores of the jacks-like ZnO nanorods electrodes enhances the charge transport, and electrolyte penetration. Thus, the jacks-like ZnO nanorods DSSCs render a higher conversion efficiency of η = 1.82% (V oc = 0.59 V, J sc = 5.52 mA cm -2 ) than that of the branch-free ZnO nanorods electrodes (η = 1.08%, V oc = 0.49 V, J sc = 4.02 mA cm -2 ). The incident photon-to-current conversion efficiency measurements reveal that the jacks-like ZnO nanorods DSSCs exhibit higher internal quantum efficiency (∼59.1%) than do the branch-free ZnO nanorods DSSC (∼52.5%). The charge transfer resistances at the ZnO/dye/electrolyte interfaces investigated using electrochemical impedance spectroscopy showed that the jacks-like ZnO nanorods DSSC had high charge transfer resistance and a slightly longer electron lifetime, thus improving the solar-cell performance.

Facile synthesis of highly branched jacks-like ZnO nanorods and their applications in dye-sensitized solar cells

Energy Technology Data Exchange (ETDEWEB)

Sudhagar, P. [Center for Next Generation Dye-sensitized Solar Cells, WCU Program Department of Energy Engineering, Hanyang University, Seongdong-gu, Seoul- 133 791 (Korea, Republic of); Kumar, R. Saravana [R and D Department of Physics, Kongunadu Arts and Science College, Coimbatore 641 029, Tamilnadu (India); Jung, June Hyuk; Cho, Woohyung [Center for Next Generation Dye-sensitized Solar Cells, WCU Program Department of Energy Engineering, Hanyang University, Seongdong-gu, Seoul- 133 791 (Korea, Republic of); Sathyamoorthy, R. [R and D Department of Physics, Kongunadu Arts and Science College, Coimbatore 641 029, Tamilnadu (India); Won, Jongok [Department of Chemistry, Sejong University, Gwangjin-gu, Seoul 143-747 (Korea, Republic of); Kang, Yong Soo, E-mail: kangys@hanyang.ac.kr [Center for Next Generation Dye-sensitized Solar Cells, WCU Program Department of Energy Engineering, Hanyang University, Seongdong-gu, Seoul- 133 791 (Korea, Republic of)

2011-09-15

Graphical abstract: -- Abstract: Highly branched, jacks-like ZnO nanorods architecture were explored as a photoanode in dye-sensitized solar cells, and their photovoltaic performance was compared with that of branch-free ZnO nanorods photoanodes. The highly branched network and large pores of the jacks-like ZnO nanorods electrodes enhances the charge transport, and electrolyte penetration. Thus, the jacks-like ZnO nanorods DSSCs render a higher conversion efficiency of {eta} = 1.82% (V{sub oc} = 0.59 V, J{sub sc} = 5.52 mA cm{sup -2}) than that of the branch-free ZnO nanorods electrodes ({eta} = 1.08%, V{sub oc} = 0.49 V, J{sub sc} = 4.02 mA cm{sup -2}). The incident photon-to-current conversion efficiency measurements reveal that the jacks-like ZnO nanorods DSSCs exhibit higher internal quantum efficiency ({approx}59.1%) than do the branch-free ZnO nanorods DSSC ({approx}52.5%). The charge transfer resistances at the ZnO/dye/electrolyte interfaces investigated using electrochemical impedance spectroscopy showed that the jacks-like ZnO nanorods DSSC had high charge transfer resistance and a slightly longer electron lifetime, thus improving the solar-cell performance.

Convective overshoot at the solar tachocline

Science.gov (United States)

Brown, Benjamin; Oishi, Jeffrey S.; Anders, Evan H.; Lecoanet, Daniel; Burns, Keaton; Vasil, Geoffrey M.

2017-08-01

At the base of the solar convection zone lies the solar tachocline. This internal interface is where motions from the unstable convection zone above overshoot and penetrate downward into the stiffly stable radiative zone below, driving gravity waves, mixing, and possibly pumping and storing magnetic fields. Here we study the dynamics of convective overshoot across very stiff interfaces with some properties similar to the internal boundary layer within the Sun. We use the Dedalus pseudospectral framework and study fully compressible dynamics at moderate to high Peclet number and low Mach number, probing a regime where turbulent transport is important, and where the compressible dynamics are similar to those of convective motions in the deep solar interior. We find that the depth of convective overshoot is well described by a simple buoyancy equilibration model, and we consider implications for dynamics at the solar tachocline and for the storage of magnetic fields there by overshooting convection.

Highly efficient light management for perovskite solar cells.

Science.gov (United States)

Wang, Dong-Lin; Cui, Hui-Juan; Hou, Guo-Jiao; Zhu, Zhen-Gang; Yan, Qing-Bo; Su, Gang

2016-01-06

Organic-inorganic halide perovskite solar cells have enormous potential to impact the existing photovoltaic industry. As realizing a higher conversion efficiency of the solar cell is still the most crucial task, a great number of schemes were proposed to minimize the carrier loss by optimizing the electrical properties of the perovskite solar cells. Here, we focus on another significant aspect that is to minimize the light loss by optimizing the light management to gain a high efficiency for perovskite solar cells. In our scheme, the slotted and inverted prism structured SiO2 layers are adopted to trap more light into the solar cells, and a better transparent conducting oxide layer is employed to reduce the parasitic absorption. For such an implementation, the efficiency and the serviceable angle of the perovskite solar cell can be promoted impressively. This proposal would shed new light on developing the high-performance perovskite solar cells.

The CRRES high efficiency solar panel

International Nuclear Information System (INIS)

Trumble, T.M.

1991-01-01

This paper reports on the High Efficiency Solar Panel (HESP) experiments which is to provide both engineering and scientific information concerning the effects of space radiation on advanced gallium arsenide (GaAs) solar cells. The HESP experiment consists of an ambient panel, and annealing panel and a programmable load. This experiment, in conjunction with the radiation measurement experiments abroad the CREES, provides the first opportunity to simultaneously measure the trapped radiation belts and the results of radiation damage to solar cells. The engineering information will result in a design guide for selecting the optimum solar array characteristics for different orbits and different lifetimes. The scientific information will provide both correlation of laboratory damage effects to space damage effects and a better model for predicting effective solar cell panel lifetimes

Solar Thermal Energy; Energia Solar Termica

Energy Technology Data Exchange (ETDEWEB)

Perez-Martinez, M; Cuesta-Santianes, M J; Cabrera Jimenez, J A

2008-07-01

Approximately, 50 % of worldwide primary energy consumption is done in the form of heat in applications with a temperature lower than 250 degree centigree (low-medium temperature heat). These data clearly demonstrate the great potential of solar thermal energy to substitute conventional fossil fuels, which are becoming more expensive and are responsible for global warming. Low-medium temperature solar thermal energy is mainly used to obtain domestic hot water and provide space heating. Active solar thermal systems are those related to the use of solar thermal collectors. This study is dealing with low temperature solar thermal applications, mainly focusing on active solar thermal systems. This kind of systems has been extensively growing worldwide during the last years. At the end of 2006, the collector capacity in operation worldwide equalled 127.8 GWth. The technology is considered to be already developed and actions should be aimed at favouring a greater market penetration: diffusion, financial support, regulations establishment, etc. China and USA are the leading countries with a technology based on evacuated tube collectors and unglazed collectors, respectively. The rest of the world markets are dominated by the flat glazed collectors technology. (Author) 15 refs.

High-efficient solar cells with porous silicon

International Nuclear Information System (INIS)

Migunova, A.A.

2002-01-01

It has been shown that the porous silicon is multifunctional high-efficient coating on silicon solar cells, modifies its surface and combines in it self antireflection and passivation properties., The different optoelectronic effects in solar cells with porous silicon were considered. The comparative parameters of uncovered photodetectors also solar cells with porous silicon and other coatings were resulted. (author)

Long-rod penetration: the transition zone between rigid and hydrodynamic penetration modes

Directory of Open Access Journals (Sweden)

Jian-feng Lou

2014-06-01

Full Text Available Long-rod penetration in a wide range of velocity means that the initial impact velocity varies in a range from tens of meters per second to several kilometers per second. The long rods maintain rigid state when the impact velocity is low, the nose of rod deforms and even is blunted when the velocity gets higher, and the nose erodes and fails to lead to the consumption of long projectile when the velocity is very high due to instantaneous high pressure. That is, from low velocity to high velocity, the projectile undergoes rigid rods, deforming non-erosive rods, and erosive rods. Because of the complicated changes of the projectile, no well-established theoretical model and numerical simulation have been used to study the transition zone. Based on the analysis of penetration behavior in the transition zone, a phenomenological model to describe target resistance and a formula to calculate penetration depth in transition zone are proposed, and a method to obtain the boundary velocity of transition zone is determined. A combined theoretical analysis model for three response regions is built by analyzing the characteristics in these regions. The penetration depth predicted by this combined model is in good agreement with experimental result.

High-power, ultralow-mass solar arrays: FY-77 solar arrays technology readiness assessment report, volume 2

Science.gov (United States)

Costogue, E. N.; Young, L. E.; Brandhorst, H. W., Jr.

1978-01-01

Development efforts are reported in detail for: (1) a lightweight solar array system for solar electric propulsion; (2) a high efficiency thin silicon solar cell; (3) conceptual design of 200 W/kg solar arrays; (4) fluorocarbon encapsulation for silicon solar cell array; and (5) technology assessment of concentrator solar arrays.

Electricity markets evolution with the changing generation mix: An empirical analysis based on China 2050 High Renewable Energy Penetration Roadmap

International Nuclear Information System (INIS)

Zou, Peng; Chen, Qixin; Yu, Yang; Xia, Qing; Kang, Chongqing

2017-01-01

Highlights: • How electricity markets are evolving with the changing generation mix is studied. • China 2050 High Renewable Energy Penetration Roadmap are empirically analysed. • A multi-period Nash-Cournot model is established to study the market equilibrium. • Energy storages are analysed and compared to reveal their impacts on the equilibrium. - Abstract: The power generation mix are significantly changing due to the growth of stricter energy policies. The renewables are increasingly penetrating the power systems and leading to more clean energy and lower energy prices. However, they also require much more flexibilities and ancillary services to handle their uncertainties and variabilities. Thus, the requirements for regulation and reserve services may dramatically increase while the supplies of these services, which are mainly from the traditional thermal plants, remain almost invariant. This changing situation will cause higher regulation and reserve prices and impact the profit models and revenue structures of the traditional plants. How electricity markets are actually evolving with the changing generation mix? Can enough backup power plants be given adequate economic incentives and thus remained with the increasing renewables and the decreasing energy prices and productions? Can de-carbonization be fully performed in power systems? To explicitly answer the question, this paper uses a multi-period Nash-Cournot equilibrium model to formulate the evolution of power markets incorporating different types of generators, including thermal units, hydro units, wind farms, solar stations and energy storage systems. The price changes in the co-optimized energy, regulation and reserve markets, and the profit changes of various generators are studied. And the variabilities and uncertainties of renewable generation sources are considered in dynamically determining the requirements of regulation and reserve services. Based on the China 2050 High Renewable Energy

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

Science.gov (United States)

Kurtz, Sarah

2006-03-01

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

Operational Simulation Tools and Long Term Strategic Planning for High Penetrations of PV in the Southeastern United States

Energy Technology Data Exchange (ETDEWEB)

Tuohy, Aidan [Electric Power Research Institute, Knoxville, TN (United States); Smith, Jeff [Electric Power Research Institute, Knoxville, TN (United States); Rylander, Matt [Electric Power Research Institute, Knoxville, TN (United States); Singhvi, Vikas [Electric Power Research Institute, Knoxville, TN (United States); Enbar, Nadav [Electric Power Research Institute, Knoxville, TN (United States); Coley, Steven [Electric Power Research Institute, Knoxville, TN (United States); Roark, Jeff [Electric Power Research Institute, Knoxville, TN (United States); Ela, Erik [Electric Power Research Institute, Knoxville, TN (United States); Lannoye, Eamonn [Electric Power Research Institute, Knoxville, TN (United States); Pilbrick, Charles Russ [Electric Power Research Institute, Knoxville, TN (United States); Rudkevich, Alex [Electric Power Research Institute, Knoxville, TN (United States); Hansen, Cliff [Electric Power Research Institute, Knoxville, TN (United States)

2016-07-11

Increasing levels of distributed and utility scale Solar Photovoltaics (PV) will have an impact on many utility functions, including distribution system operations, bulk system performance, business models and scheduling of generation. In this project, EPRI worked with Southern Company Services and its affiliates and the Tennessee Valley Authority to assist these utilities in their strategic planning efforts for integrating PV, based on modeling, simulation and analysis using a set of innovative tools. Advanced production simulation models were used to investigate operating reserve requirements. To leverage existing work and datasets, this last task was carried out on the California system. Overall, the project resulted in providing useful information to both of the utilities involved and through the final reports and interactions during the project. The results from this project can be used to inform the industry about new and improved methodologies for understanding solar PV penetration, and will influence ongoing and future research. This report summarizes each of the topics investigated over the 2.5-year project period.

A Short Progress Report on High-Efficiency Perovskite Solar Cells.

Science.gov (United States)

Tang, He; He, Shengsheng; Peng, Chuangwei

2017-12-01

Faced with the increasingly serious energy and environmental crisis in the world nowadays, the development of renewable energy has attracted increasingly more attention of all countries. Solar energy as an abundant and cheap energy is one of the most promising renewable energy sources. While high-performance solar cells have been well developed in the last couple of decades, the high module cost largely hinders wide deployment of photovoltaic devices. In the last 10 years, this urgent demand for cost-effective solar cells greatly facilitates the research of solar cells. This paper reviews the recent development of cost-effective and high-efficient solar cell technologies. This report paper covers low-cost and high-efficiency perovskite solar cells. The development and the state-of-the-art results of perovskite solar cell technologies are also introduced.

The high-resolution extraterrestrial solar spectrum (QASUMEFTS determined from ground-based solar irradiance measurements

Directory of Open Access Journals (Sweden)

J. Gröbner

2017-09-01

Full Text Available A high-resolution extraterrestrial solar spectrum has been determined from ground-based measurements of direct solar spectral irradiance (SSI over the wavelength range from 300 to 500 nm using the Langley-plot technique. The measurements were obtained at the Izaña Atmospheric Research Centre from the Agencia Estatal de Meteorología, Tenerife, Spain, during the period 12 to 24 September 2016. This solar spectrum (QASUMEFTS was combined from medium-resolution (bandpass of 0.86 nm measurements of the QASUME (Quality Assurance of Spectral Ultraviolet Measurements in Europe spectroradiometer in the wavelength range from 300 to 500 nm and high-resolution measurements (0.025 nm from a Fourier transform spectroradiometer (FTS over the wavelength range from 305 to 380 nm. The Kitt Peak solar flux atlas was used to extend this high-resolution solar spectrum to 500 nm. The expanded uncertainties of this solar spectrum are 2 % between 310 and 500 nm and 4 % at 300 nm. The comparison of this solar spectrum with solar spectra measured in space (top of the atmosphere gave very good agreements in some cases, while in some other cases discrepancies of up to 5 % were observed. The QASUMEFTS solar spectrum represents a benchmark dataset with uncertainties lower than anything previously published. The metrological traceability of the measurements to the International System of Units (SI is assured by an unbroken chain of calibrations leading to the primary spectral irradiance standard of the Physikalisch-Technische Bundesanstalt in Germany.

Differences in Femoral Head Penetration Between Highly Cross-Linked Polyethylene Cemented Sockets and Uncemented Liners.

Science.gov (United States)

Morita, Daigo; Seki, Taisuke; Higuchi, Yoshitoshi; Takegami, Yasuhiko; Ishiguro, Naoki

2017-12-01

This study aimed at investigating differences in femoral head penetration between highly cross-linked polyethylene (HXLPE) cemented sockets and uncemented liners during 5 years postoperatively. Ninety-six patients (106 hips) with a mean age of 64.4 (range, 35-83) years underwent total hip arthroplasty using a HXLPE cemented socket or liner and were respectively divided into cemented (35 patients [37 hips]) and uncemented (61 patients [69 hips]) groups. Femoral head penetrations were evaluated on both anteroposterior (AP)-view and Lauenstein-view radiographs, and mean polyethylene (PE) wear rates were calculated based on femoral head penetration from 2 to 5 years. Multivariate analyses were performed to assess risk factors for PE wear. At 5 years postoperatively, the cemented and uncemented groups exhibited proximal direction femoral head penetrations of 0.103 mm and 0.124 mm (P = .226) and anterior direction penetrations of 0.090 mm and 0.151 mm (P = .002), respectively. The corresponding mean PE wear rates were 0.004 mm/y and 0.009 mm/y in the AP-view (P = .286) and 0.005 mm/y and 0.012 mm/y in the Lauenstein-view (P = .168), respectively. Left-side operation and high activity were independent risk factors for PE wear on AP-view. When HXLPE was used, all mean PE wear rates were very low and those of cemented sockets and uncemented liners were very similar. PE particle theory suggests that the occurrence of osteolysis and related aseptic loosening might consequently decrease. Copyright © 2017 Elsevier Inc. All rights reserved.

A novel design for a cheap high temperature solar collector: The rotating solar boiler

NARCIS (Netherlands)

Luijtelaer, van J.P.H.; Kroon, M.C.

2009-01-01

In this work a novel type of high temperature solar collector is designed: the rotating solar boiler. This rotating solar boiler consists of two concentric tubes. The inner tube, called absorber, absorbs sunlight and boils water. The outer transparent tube, called cover, is filled with air. The

High-Penetration PV Integration Handbook for Distribution Engineers

Energy Technology Data Exchange (ETDEWEB)

Seguin, Rich [Electrical Distribution Design, Blacksburg, VA (United States); Woyak, Jeremy [Electrical Distribution Design, Blacksburg, VA (United States); Costyk, David [Electrical Distribution Design, Blacksburg, VA (United States); Hambrick, Josh [Electrical Distribution Design, Blacksburg, VA (United States); Mather, Barry [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-01-01

This handbook has been developed as part of a five-year research project which began in 2010. The National Renewable Energy Laboratory (NREL), Southern California Edison (SCE), Quanta Technology, Satcon Technology Corporation, Electrical Distribution Design (EDD), and Clean Power Research (CPR) teamed together to analyze the impacts of high-penetration levels of photovoltaic (PV) systems interconnected onto the SCE distribution system. This project was designed specifically to leverage the experience that SCE and the project team would gain during the significant installation of 500 MW of commercial scale PV systems (1-5 MW typically) starting in 2010 and completing in 2015 within SCE’s service territory through a program approved by the California Public Utility Commission (CPUC).

High performance ground penetrating radar survey of TA-49/Area 2. Final report

International Nuclear Information System (INIS)

Hoeberling, R.F.; Rangel, M.J. III

1994-09-01

The results of high performance ground penetrating radar study of Area 2 at Technical Area 49 are presented. The survey was commissioned as part of Los Alamos Laboratory's continuing Environmental Remediation program and was completed and analyzed before borehole studies in Area 2 were started. Based upon the ground penetrating radar results, the location of one of the planned boreholes was moved to assure the drilling area was as safe as possible. While earlier attempts to use commercial radar devices at this facility had not been successful, the radar and digital processing system developed at Los Alamos were able to significantly improve the buried physical detail of the site

High-resolution mapping, modeling, and evolution of subsurface geomorphology using ground-penetrating radar techniques

Digital Repository Service at National Institute of Oceanography (India)

Loveson, V.J.; Gujar, A.R.

subsurface. It has been useful to decipher shallow geomorphic structures having various options to use different antennas for different depth penetration (0-30 m) with higher resolution.   7.2 Principles of GPR  Ground Penetrating Radar (GPR) was invented... about 90m. Flat and plain land is being used, at present, for agriculture (paddy cultivation) practice. Sand dunes are low lying and highly reworked due to social forestry plantation (acacia) activities. 13    7.8.6 Paleo­Lagoon  GPR data shows two...

Potential of ultrafine grained materials as high performance penetrator materials

Directory of Open Access Journals (Sweden)

Lee C.S.

2012-08-01

Full Text Available The shear formability and the metal jet formability are important for the kinetic energy penetrator and the chemical energy penetrator, respectively. The shear formability of ultrafine grained (UFG steel was examined, mainly focusing on the effects of the grain shape on the shear characteristics. For this purpose, UFG 4130 steel having the different UFG structures, the lamellar UFG and the equiaxed UFG, was prepared by equal channel angular pressing (ECAP. The lamellar UFG steel exhibited more sharper and localized shear band formation than the equiaxed UFG steel. This is because a lamellar UFG structure was unfavourable against grain rotation which is a main mechanism of the band propagation in UFG materials. Meanwhile, the metal jet formability of UFG OFHC Cu also processed by ECAP was compared to that of coarse grained (CG one by means of dynamic tensile extrusion (DTE tests. CG OFHC Cu exhibited the higher DTE ductility, i.e. better metal jet stability, than UFG OFHC Cu. The initial high strength and the lack of strain hardenability of UFG OFHC Cu were harmful to the metal jet formability.

Energy Non-Availability in Distribution Grids with Heavy Penetration of Solar Power: Assessment and Mitigation through Solar Smoother

Directory of Open Access Journals (Sweden)

Tathagata Sarkar

2018-03-01

Full Text Available Rapid fluctuation of solar irradiance due to cloud passage causes corresponding variations in the power output of solar PV power plants. This leads to rapid voltage instability at the point of common coupling (PCC of the connected grid which may cause temporary shutdown of the plant leading to non-availability of energy in the connected load and distribution grid. An estimate of the duration and frequency of this outage is important for solar energy generators to ensure the generation and performance of the solar power plant. A methodology using PVsyst (6.6.4, University of Geneva, Geneva, Switzerland and PSCAD (4.5, Manitoba HVDC Research Centre, Winnipeg, MB, Canada simulation has been developed to estimate the duration and frequency of power outages due to rapid fluctuation of solar irradiance throughout the year. It is shown that the outage depends not only on the solar irradiance fluctuation, but also on the grid parameters of the connected distribution grid. A practical case study has been done on a 500 kilo Watt peak (kWp solar PV power plant for validation of the proposed methodology. It is observed that the energy non-availability for this plant is about 13% per year. This can be reduced to 8% by incorporating a solar smoother. A financial analysis of this outage and its mitigation has also been carried out.

Synthesis of calcium aluminates on the big solar furnace

International Nuclear Information System (INIS)

Abdurakhmanov, A. A.; Paizullakhanov, M. S.; Akhadov, Zh.

2012-01-01

The processes of synthesizing calcium aluminate in the flow of concentrated solar radiation on Large Solar Furnace are studied. It is shown that the synthesis of calcium aluminate takes place through a process of melting of a mixture of aluminum oxides and calcium (Al 2 O 3 + CaO). At values of power of the concentrated flow of 200 W/cm 2 , thermodynamic conditions for melting of the materials studied were implemented. Full fusion penetration is achieved at a power flow of 400 W/cm 2 . The resulting material exhibits high mechanical properties (the modulus of rupture upon bending is 40 MPa). (author)

Penetrating bladder trauma: a high risk factor for associated rectal injury.

Science.gov (United States)

Pereira, B M; Reis, L O; Calderan, T R; de Campos, C C; Fraga, G P

2014-01-01

Demographics and mechanisms were analyzed in prospectively maintained level one trauma center database 1990-2012. Among 2,693 trauma laparotomies, 113 (4.1%) presented bladder lesions; 51.3% with penetrating injuries (n = 58); 41.3% (n = 24) with rectal injuries, males corresponding to 95.8%, mean age 29.8 years; 79.1% with gunshot wounds and 20.9% with impalement; 91.6% arriving the emergence room awake (Glasgow 14-15), hemodynamically stable (average systolic blood pressure 119.5 mmHg); 95.8% with macroscopic hematuria; and 100% with penetrating stigmata. Physical exam was not sensitive for rectal injuries, showing only 25% positivity in patients. While 60% of intraperitoneal bladder injuries were surgically repaired, extraperitoneal ones were mainly repaired using Foley catheter alone (87.6%). Rectal injuries, intraperitoneal in 66.6% of the cases and AAST-OIS grade II in 45.8%, were treated with primary suture plus protective colostomy; 8.3% were sigmoid injuries, and 70.8% of all injuries had a minimum stool spillage. Mean injury severity score was 19; mean length of stay 10 days; 20% of complications with no death. Concomitant rectal injuries were not a determinant prognosis factor. Penetrating bladder injuries are highly associated with rectal injuries (41.3%). Heme-negative rectal examination should not preclude proctoscopy and eventually rectal surgical exploration (only 25% sensitivity).

High efficiency double sided solar cells

International Nuclear Information System (INIS)

Seddik, M.M.

1990-06-01

Silicon technology state of the art for single crystalline was given to be limited to less than 20% efficiency. A proposed new form of photovoltaic solar cell of high current high efficiency with double sided structures has been given. The new forms could be n ++ pn ++ or p ++ np ++ double side junctions. The idea of double sided devices could be understood as two solar cells connected back-to-back in parallel electrical connection, in which the current is doubled if the cell is illuminated from both sides by a V-shaped reflector. The cell is mounted to the reflector such that each face is inclined at an angle of 45 deg. C to each side of the reflector. The advantages of the new structure are: a) High power devices. b) Easy to fabricate. c) The cells are used vertically instead of horizontal use of regular solar cell which require large area to install. This is very important in power stations and especially for satellite installation. If the proposal is made real and proved to be experimentally feasible, it would be a new era for photovoltaic solar cells since the proposal has already been extended to even higher currents. The suggested structures could be stated as: n ++ pn ++ Vp ++ np ++ ;n ++ pn ++ Vn ++ pn ++ ORp ++ np ++ Vp ++ np ++ . These types of structures are formed in wedged shape to employ indirect illumination by either parabolic; conic or V-shaped reflectors. The advantages of these new forms are low cost; high power; less in size and space; self concentrating; ... etc. These proposals if it happens to find their ways to be achieved experimentally, I think they will offer a short path to commercial market and would have an incredible impact on solar cell technology and applications. (author). 12 refs, 5 figs

High-Temperature High-Efficiency Solar Thermoelectric Generators

Energy Technology Data Exchange (ETDEWEB)

Baranowski, LL; Warren, EL; Toberer, ES

2014-03-01

Inspired by recent high-efficiency thermoelectric modules, we consider thermoelectrics for terrestrial applications in concentrated solar thermoelectric generators (STEGs). The STEG is modeled as two subsystems: a TEG, and a solar absorber that efficiently captures the concentrated sunlight and limits radiative losses from the system. The TEG subsystem is modeled using thermoelectric compatibility theory; this model does not constrain the material properties to be constant with temperature. Considering a three-stage TEG based on current record modules, this model suggests that 18% efficiency could be experimentally expected with a temperature gradient of 1000A degrees C to 100A degrees C. Achieving 15% overall STEG efficiency thus requires an absorber efficiency above 85%, and we consider two methods to achieve this: solar-selective absorbers and thermally insulating cavities. When the TEG and absorber subsystem models are combined, we expect that the STEG modeled here could achieve 15% efficiency with optical concentration between 250 and 300 suns.

High penetration wind generation impacts on spot prices in the Australian national electricity market

International Nuclear Information System (INIS)

Cutler, Nicholas J.; Boerema, Nicholas D.; MacGill, Iain F.; Outhred, Hugh R.

2011-01-01

This paper explores wind power integration issues for the South Australian (SA) region of the Australian National Electricity Market (NEM) by assessing the interaction of regional wind generation, electricity demand and spot prices over 2 recent years of market operation. SA's wind energy penetration has recently surpassed 20% and it has only a limited interconnection with other regions of the NEM. As such, it represents an interesting example of high wind penetration in a gross wholesale pool market electricity industry. Our findings suggest that while electricity demand continues to have the greatest influence on spot prices in SA, wind generation levels have become a significant secondary influence, and there is an inverse relationship between wind generation and price. No clear relationship between wind generation and demand has been identified although some periods of extremely high demand may coincide with lower wind generation. Periods of high wind output are associated with generally lower market prices, and also appear to contribute to extreme negative price events. The results highlight the importance of electricity market and renewable policy design in facilitating economically efficient high wind penetrations. - Highlights: → In South Australia (SA) wind generation is having an influence on market prices. → Little or no correlation is found between wind generation and demand. → Wind farms in SA are receiving a lower average price than in other States. → The results highlight the importance of appropriate electricity market design.

Highly Flexible and Efficient Solar Steam Generation Device.

Science.gov (United States)

Chen, Chaoji; Li, Yiju; Song, Jianwei; Yang, Zhi; Kuang, Yudi; Hitz, Emily; Jia, Chao; Gong, Amy; Jiang, Feng; Zhu, J Y; Yang, Bao; Xie, Jia; Hu, Liangbing

2017-08-01

Solar steam generation with subsequent steam recondensation has been regarded as one of the most promising techniques to utilize the abundant solar energy and sea water or other unpurified water through water purification, desalination, and distillation. Although tremendous efforts have been dedicated to developing high-efficiency solar steam generation devices, challenges remain in terms of the relatively low efficiency, complicated fabrications, high cost, and inability to scale up. Here, inspired by the water transpiration behavior of trees, the use of carbon nanotube (CNT)-modified flexible wood membrane (F-Wood/CNTs) is demonstrated as a flexible, portable, recyclable, and efficient solar steam generation device for low-cost and scalable solar steam generation applications. Benefitting from the unique structural merits of the F-Wood/CNTs membrane-a black CNT-coated hair-like surface with excellent light absorbability, wood matrix with low thermal conductivity, hierarchical micro- and nanochannels for water pumping and escaping, solar steam generation device based on the F-Wood/CNTs membrane demonstrates a high efficiency of 81% at 10 kW cm -2 , representing one of the highest values ever-reported. The nature-inspired design concept in this study is straightforward and easily scalable, representing one of the most promising solutions for renewable and portable solar energy generation and other related phase-change applications. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Review of Mid- to High-Temperature Solar Selective Absorber Materials

Energy Technology Data Exchange (ETDEWEB)

Kennedy, C. E.

2002-07-01

This report describes the concentrating solar power (CSP) systems using solar absorbers to convert concentrated sunlight to thermal electric power. It is possible to achieve solar absorber surfaces for efficient photothermal conversion having high solar absorptance (a) for solar radiation and a low thermal emittance (e) at the operational temperature. A low reflectance (?'' 0) at wavelengths (?) 3 mm and a high reflectance (?'' 1) at l 3 mm characterize spectrally selective surfaces. The operational temperature ranges of these materials for solar applications can be categorized as low temperature (T< 100 C), mid-temperature (100 C< T< 400 C), and high-temperature (T> 400 C). High- and mid-temperature applications are needed for CSP applications. For CSP applications, the ideal spectrally selective surface would be low-cost and easy to manufacture, chemically and thermally stable in air at elevated operating temperatures (T= 500 C), and have a solar absorptance= 0.98 and a thermal emittance= 0.05 at 500 C.

Effect of Using Metakaolin on Chloride Ion Penetration in High Performance Steel Fiber Reinforced Concrete

Directory of Open Access Journals (Sweden)

Adnan Mohammed Shihab

2016-03-01

Full Text Available This paper attempts to reduce the penetrability of high performance steel fiber reinforced concrete to chloride ions originating from external sources, by using High Reactivity Metakaolin (HRM as a highly active pozzolanic material, in order to prolong the time to initiation of the steel fibers corrosion and to minimize concrete damage that may occur due to the exposure to chloride ion penetration. According to pozzolanic activity index (P.A.I., 8% content of HRM was used as a partial replacement by weight of cement with 2% steel fibers by volume of concrete. During the exposure period of 300 days in 4.5% of NaCl solution, the total and free chloride contents (Cltotal, Clfree with the chloride profiles at the ages of 28 and 300 days were investigated. Also the rapid chloride penetrability test (RCPT, compressive and flexural strengths tests were conducted at the ages of 28, 90, 180 and 300 days. Results showed that the incorporation of 8% HRM caused a reduction in the (Clfree/Cltota ratio, the chloride penetration depth and the electrical conductivity with percentages of 21%, 40% and 43% respectively after 300 days exposure to chloride solution in comparing with the mix of 0% HRM. Results also indicated that the losses in compressive and flexural strengths after exposure of 300 days to chloride solution for the mix incorporating 8% HRM were by 5% and 5.8% respectively while they reached 9.5% and 11% respectively for the mix without HRM in relation to the correspondent test specimens cured in tap water.

High-efficiency silicon solar cells for low-illumination applications

OpenAIRE

Glunz, S.W.; Dicker, J.; Esterle, M.; Hermle, M.; Isenberg, J.; Kamerewerd, F.; Knobloch, J.; Kray, D.; Leimenstoll, A.; Lutz, F.; Oßwald, D.; Preu, R.; Rein, S.; Schäffer, E.; Schetter, C.

2002-01-01

At Fraunhofer ISE the fabrication of high-efficiency solar cells was extended from a laboratory scale to a small pilot-line production. Primarily, the fabricated cells are used in small high-efficiency modules integrated in prototypes of solar-powered portable electronic devices such as cellular phones, handheld computers etc. Compared to other applications of high-efficiency cells such as solar cars and planes, the illumination densities found in these mainly indoor applications are signific...

Update on the Management of High-Risk Penetrating Keratoplasty.

Science.gov (United States)

Jabbehdari, Sayena; Rafii, Alireza Baradaran; Yazdanpanah, Ghasem; Hamrah, Pedram; Holland, Edward J; Djalilian, Ali R

2017-03-01

In this article, we review the indications and latest management of high-risk penetrating keratoplasty. Despite the immune-privilege status of the cornea, immune-mediated graft rejection still remains the leading cause of corneal graft failure. This is particularly a problem in the high-risk graft recipients, namely patients with previous graft failure due to rejection and those with inflamed and vascularized corneal beds. A number of strategies including both local and systemic immunosuppression are currently used to increase the success rate of high-risk corneal grafts. Moreover, in cases of limbal stem cell deficiency, limbal stem cells transplantation is employed. Corticosteroids are still the top medication for prevention and treatment in cases of corneal graft rejection. Single and combined administration of immunosuppressive agents e.g. tacrolimus, cyclosporine and mycophenolate are promising adjunctive therapies for prolonging graft survival. In the future, cellular and molecular therapies should allow us to achieve immunologic tolerance even in high-risk grafts.

High-energy particles associated with solar flares

International Nuclear Information System (INIS)

Sakurai, K.; Klimas, A.J.

1974-05-01

High energy particles, the so-called solar cosmic rays, are often generated in association with solar flares, and then emitted into interplanetary space. These particles, consisting of electrons, protons, and other heavier nuclei, including the iron-group, are accelerated in the vicinity of the flare. By studying the temporal and spatial variation of these particles near the earth's orbit, their storage and release mechanisms in the solar corona and their propagation mechanism can be understood. The details of the nuclear composition and the rigidity spectrum for each nuclear component of the solar cosmic rays are important for investigating the acceleration mechanism in solar flares. The timing and efficiency of the acceleration process can also be investigated by using this information. These problems are described in some detail by using observational results on solar cosmic rays and associated phenomena. (U.S.)

In-place HEPA filter penetration test

International Nuclear Information System (INIS)

Bergman, W.; Wilson, K.; Elliott, J.; Bettencourt, B.; Slawski, J.W.

1997-01-01

We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in- place penetration test is practical

Wind and solar energy curtailment: A review of international experience

DEFF Research Database (Denmark)

Bird, Lori; Lew, Debra; Milligan, Michael

2016-01-01

Greater penetrations of variable renewable generation on some electric grids have resulted in increased levels of curtailment in recent years. Studies of renewable energy grid integration have found that curtailment levels may grow as the penetration of wind and solar energy generation increases....

Solar power generation in the US: Too expensive, or a bargain?

International Nuclear Information System (INIS)

Perez, Richard; Zweibel, Ken; Hoff, Thomas E.

2011-01-01

This article identifies the combined value that solar electric power plants deliver to utilities' rate payers and society's tax payers. Benefits that are relevant to utilities and their rate payers include traditional, measures of energy and capacity. Benefits that are tangible to tax payers include environmental, fuel price mitigation, outage risk protection, and long-term economic growth components. Results for the state of New York suggest that solar electric installations deliver between 15 and 40 cents /kWh to ratepayers and tax payers. These results provide economic justification for the existence of payment structures (often referred to as incentives) that transfer value from those who benefit from solar electric generation to those who invest in solar electric generation. - Highlights: → The article presents a valuation of the energy produced by solar generators. → Valuation accounts for physical, socio economic, and environmental attributes. → Value depends upon solar penetration and location and is likely to exceed cost. → The article shows that incentives for solar deployment are justified. → Incentives should be a function of solar energy's site and penetration dependent value.

Peak shifting and cross-class subsidization: The impacts of solar PV on changes in electricity costs

International Nuclear Information System (INIS)

Johnson, Erik; Beppler, Ross; Blackburn, Chris; Staver, Benjamin; Brown, Marilyn; Matisoff, Daniel

2017-01-01

The expansion of distributed solar necessitates additional research into the impacts on both utilities and their customers. In this paper we use New Jersey solar data, PJM market data, and demand profiles from a PJM utility to investigate rate and bill impacts of large-scale solar penetration. In addition to the subsidization of solar adopters by non-participants, we highlight the channels through which cross-subsidization of rate classes can arise in practice. The results of our study indicate that the fear of a utility “death spiral” may be exaggerated. Significant solar can be incorporated with only a 2% increase in non-participant bills. At high levels of penetration, distributed solar has the potential to alter the system peak hour which affects the allocation of costs across rate-classes. As the peak hour shifts to the evening when solar production diminishes, residential customers face higher distribution costs. Policy makers and utilities need to be aware of these challenges in designing the next generation of rates that are better aligned with cost causality. - Highlights: • We develop a model of electricity costs with large amounts of solar adoption. • Solar adoption leads to cost redistribution across customer classes. • Costs are redistributed partially because peak utility load shifts later in the day. • Residential distributed solar generation affects electricity bills the most. • We confirm the subsidy of participants by non-participants in net metering programs.

Transport mean free path related to trajectory patterns: Comparison of nonrelativistic and highly relativistic electron penetration through matter

International Nuclear Information System (INIS)

Liljequist, D.; Ismail, M.

1987-01-01

This analysis is based on the similarity between multiple scattering and slowing down (random walk) processes described by the same transport mean-free-path function λ/sub tr/(s) (s = path length). We discuss the connection between λ/sub tr/(s) and the characteristic appearance and scale of the trajectory pattern. Straggling is considered by means by stochastically discontinuous λ/sub tr/(s) functions. In the application to electron penetration, we show that while nonrelativistic electron penetration is modeled by λ/sub tr/ = (r-s)/α, where r is the range and α is a material-dependent dimensionless constant, highly relativistic electron penetration is modeled by λ/sub tr/proportionalexp(-s/Λ), where Λ is a length characteristic for the penetrated material. The respective trajectory patterns are distinctly different. The effect of straggling on the trajectory pattern in the highly relativistic case is demonstrated by means of a simple model of the stochastic λ/sub tr/(s) behavior

Estimating the Value of Utility-Scale Solar Technologies in California Under a 40% Renewable Portfolio Standard

Energy Technology Data Exchange (ETDEWEB)

Jorgenson, J.; Denholm, P.; Mehos, M.

2014-05-01

Concentrating solar power with thermal energy storage (CSP-TES) is a unique source of solar energy in that its output can be shifted over time. The ability of CSP-TES to be a flexible source of generation may be particularly valuable in regions with high overall penetration of solar energy, such as the state of California. California's Renewable Portfolio Standard (RPS) requires the state to increase generation from eligible renewable energy resources to reach 33% of retail electricity sales by 2020. Beyond 2020, California targets a further reduction in greenhouse gas emissions. To help reach this goal, current California governor Jerry Brown has stated that a higher 40% RPS might be reachable in the near term. The levelized cost of energy is generally emphasized when assessing the economic viability of renewable energy systems implemented to achieve the RPS. However, the operational and capacity benefits of such systems are often ignored, which can lead to incorrect economic comparisons between CSP-TES and variable renewable generation technologies such as solar photovoltaics (PV). Here we evaluate a 40% RPS scenario in a California grid model with PV or CSP-TES providing the last 1% of RPS energy. We compare the technical and economic implications of integrating either solar technology under several sensitivities, finding that the ability to displace new conventional thermal generation capacity may be the largest source of value of CSP-TES compared to PV at high solar penetrations.

The north-south asymmetry of solar filaments separately at low and high latitudes in solar cycle 23

International Nuclear Information System (INIS)

Kong De-Fang; Qu Zhi-Ning; Guo Qiao-Ling

2015-01-01

We present the results of a study on the north-south asymmetry of solar filaments at low (<50°) and high (>60°) latitudes using daily filament numbers from January 1998 to November 2008 (solar cycle 23). It is found that the northern hemisphere is dominant at low latitudes for cycle 23. However, a similar asymmetry does not occur for solar filaments at high latitudes. The present study indicates that the hemispheric asymmetry of solar filaments at high latitudes in a cycle appears to have little connection with that at low latitudes. Our results support that the observed magnetic fields at high latitudes include two components: one comes from the emergence of the magnetic fields from the solar interior and the other comes from the drift of the magnetic activity at low latitudes. (research papers)

Outlook and application analysis of energy storage in power system with high renewable energy penetration

Science.gov (United States)

Feng, Junshu; Zhang, Fuqiang

2018-02-01

To realize low-emission and low-carbon energy production and consumption, large-scale development and utilization of renewable energy has been put into practice in China. And it has been recognized that power system of future high renewable energy shares can operate more reliably with the participation of energy storage. Considering the significant role of storage playing in the future power system, this paper focuses on the application of energy storage with high renewable energy penetration. Firstly, two application modes are given, including demand side application mode and centralized renewable energy farm application mode. Afterwards, a high renewable energy penetration scenario of northwest region in China is designed, and its production simulation with application of energy storage in 2050 has been calculated and analysed. Finally, a development path and outlook of energy storage is given.

Gas Turbine/Solar Parabolic Trough Hybrid Designs: Preprint

Energy Technology Data Exchange (ETDEWEB)

Turchi, C. S.; Ma, Z.; Erbes, M.

2011-03-01

A strength of parabolic trough concentrating solar power (CSP) plants is the ability to provide reliable power by incorporating either thermal energy storage or backup heat from fossil fuels. Yet these benefits have not been fully realized because thermal energy storage remains expensive at trough operating temperatures and gas usage in CSP plants is less efficient than in dedicated combined cycle plants. For example, while a modern combined cycle plant can achieve an overall efficiency in excess of 55%; auxiliary heaters in a parabolic trough plant convert gas to electricity at below 40%. Thus, one can argue the more effective use of natural gas is in a combined cycle plant, not as backup to a CSP plant. Integrated solar combined cycle (ISCC) systems avoid this pitfall by injecting solar steam into the fossil power cycle; however, these designs are limited to about 10% total solar enhancement. Without reliable, cost-effective energy storage or backup power, renewable sources will struggle to achieve a high penetration in the electric grid. This paper describes a novel gas turbine / parabolic trough hybrid design that combines solar contribution of 57% and higher with gas heat rates that rival that for combined cycle natural gas plants. The design integrates proven solar and fossil technologies, thereby offering high reliability and low financial risk while promoting deployment of solar thermal power.

Solar low energy dwellings

International Nuclear Information System (INIS)

Hestnes, Anne Grete

2000-01-01

By now, a lot has been learnt about how to reduce energy use in dwellings using solar and low energy technologies, and many good examples can be found throughout Europe. Still, they are not quite the common feature we would expect them to be, i.e. they have not really penetrated the market. The reason for this is in part a result of the fact that the designers and developers of these buildings have not looked at what the market wants and needs, but rather at how to use a set of given technologies. The buildings are the result of a technology push rather than a market pull and have therefore, often, been detached or semidetached dwellings with different solar technologies added on in less than optimal ways. In order to increase market penetration, it is time to look at the market trends and relate to these. Fortunately, quite a few European architects have realized this and have started designing somewhat different residential buildings. The paper focuses on examples of the new trends in solar residential architecture and by that, hopefully, it shows that we are on the right track. (au)

On the Path to SunShot - The Environmental and Public Health Benefits of Achieving High Penetrations of Solar Energy in the United States

Energy Technology Data Exchange (ETDEWEB)

Wiser, Ryan [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mai, Trieu [National Renewable Energy Lab. (NREL), Golden, CO (United States); Millstein, Dev [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Macknick, Jordan [National Renewable Energy Lab. (NREL), Golden, CO (United States); Carpenter, Alberta [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cohen, Stuart [National Renewable Energy Lab. (NREL), Golden, CO (United States); Cole, Wesley [National Renewable Energy Lab. (NREL), Golden, CO (United States); Frew, Bethany [National Renewable Energy Lab. (NREL), Golden, CO (United States); Heath, Garvin [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-05-01

Monetizing the environmental health benefits of solar could add ~3.5¢/kWh to the value of solar energy (see Wiser et al. 2016). The monetary impacts due to environmental degradation and public health impacts seem far removed from the apparent “sticker price” of electricity. Yet quantifying these impacts is essential to understanding the true costs and benefits of solar and conventional generating technologies. Compared with fossil fuel generators, PV and CSP produce far lower lifecycle levels of greenhouse gas (GHG) emissions and harmful pollutants including fine particular matter (PM2.5), sulfur dioxide (SO2), and nitrogen oxides (NOx). Achieving the SunShot-level solar deployment targets—14% of U.S. electricity demand met by solar in 2030 and 27% in 2050—could reduce cumulative power-sector GHG emissions by 10% between 2015 and 2050, resulting in savings of $238–$252 billion. This is equivalent to 2.0–2.2 cents per kilowatt-hour of solar installed (¢/kWh-solar). Similarly, realizing these levels of solar deployment could reduce cumulative power-sector emissions of PM2.5 by 8%, SO2 by 9%, and NOx by 11% between 2015 and 2050. This could produce $167 billion in savings from lower future health and environmental damages, or 1.4¢/kWh-solar—while also preventing 25,000–59,000 premature deaths. To put this in perspective, the estimated 3.5¢/kWh-solar in benefits due to SunShot-level solar deployment is approximately equal to the additional LCOE reduction needed to make unsubsidized utility-scale solar competitive with conventional generators today. In addition, water savings from achieving the SunShot goals, could result in the 2015–2050 cumulative savings of 4% of total power-sector withdrawals and 9% of total power-sector consumption—a particularly important consideration for arid states where substantial solar will be deployed. Improving public health and the environment is but one aspect of solar’s many costs and benefits. Clearly, however

Customer-economics of residential photovoltaic systems (Part 1): The impact of high renewable energy penetrations on electricity bill savings with net metering

International Nuclear Information System (INIS)

Darghouth, Naïm R.; Barbose, Galen; Wiser, Ryan H.

2014-01-01

Residential photovoltaic (PV) systems in the US are often compensated at the customer's underlying retail electricity rate through net metering. Given the uncertainty in future retail rates and the inherent links between rates and the customer–economics of behind-the-meter PV, there is growing interest in understanding how potential changes in rates may impact the value of bill savings from PV. In this article, we first use a production cost and capacity expansion model to project California hourly wholesale electricity market prices under two potential electricity market scenarios, including a reference and a 33% renewables scenario. Second, based on the wholesale electricity market prices generated by the model, we develop retail rates (i.e., flat, time-of-use, and real-time pricing) for each future scenario based on standard retail rate design principles. Finally, based on these retail rates, the bill savings from PV is estimated for 226 California residential customers under two types of net metering, for each scenario. We find that high renewable penetrations can drive substantial changes in residential retail rates and that these changes, together with variations in retail rate structures and PV compensation mechanisms, interact to place substantial uncertainty on the future value of bill savings from residential PV. - Highlights: • We investigate the impact of high renewables on customer economics of solar. • We model three types of residential retail electricity rates. • Based on the rates, we calculate the bill savings from photovoltaic (PV) generation. • High renewables penetration can lead to lower bill savings with time-varying rates. • There is substantial uncertainty in the future bill savings from residential PV

Evaluating the limits of solar photovoltaics (PV) in traditional electric power systems

International Nuclear Information System (INIS)

Denholm, Paul; Margolis, Robert M.

2007-01-01

In this work, we examine some of the limits to large-scale deployment of solar photovoltaics (PV) in traditional electric power systems. Specifically, we evaluate the ability of PV to provide a large fraction (up to 50%) of a utility system's energy by comparing hourly output of a simulated large PV system to the amount of electricity actually usable. The simulations use hourly recorded solar insolation and load data for Texas in the year 2000 and consider the constraints of traditional electricity generation plants to reduce output and accommodate intermittent PV generation. We find that under high penetration levels and existing grid-operation procedures and rules, the system will have excess PV generation during certain periods of the year. Several metrics are developed to examine this excess PV generation and resulting costs as a function of PV penetration at different levels of system flexibility. The limited flexibility of base load generators produces increasingly large amounts of unusable PV generation when PV provides perhaps 10-20% of a system's energy. Measures to increase PV penetration beyond this range will be discussed and quantified in a follow-up analysis

In-place HEPA filter penetration test

Energy Technology Data Exchange (ETDEWEB)

Bergman, W.; Wilson, K.; Elliott, J. [Lawrence Livermore National Lab., CA (United States)] [and others

1997-08-01

We have demonstrated the feasibility of conducting penetration tests on high efficiency particulate air (HEPA) filters as installed in nuclear ventilation systems. The in-place penetration test, which is designed to yield equivalent penetration measurements as the standard DOP efficiency test, is based on measuring the aerosol penetration of the filter installation as a function of particle size using a portable laser particle counter. This in-place penetration test is compared to the current in-place leak test using light scattering photometers for single HEPA filter installations and for HEPA filter plenums using the shroud method. Test results show the in-place penetration test is more sensitive than the in-place leak test, has a similar operating procedure, but takes longer to conduct. Additional tests are required to confirm that the in-place penetration test yields identical results as the standard dioctyl phthalate (DOP) penetration test for HEPA filters with controlled leaks in the filter and gasket and duct by-pass leaks. Further development of the procedure is also required to reduce the test time before the in-place penetration test is practical. 14 refs., 14 figs., 3 tabs.

Ensemble Solar Forecasting Statistical Quantification and Sensitivity Analysis: Preprint

Energy Technology Data Exchange (ETDEWEB)

Cheung, WanYin; Zhang, Jie; Florita, Anthony; Hodge, Bri-Mathias; Lu, Siyuan; Hamann, Hendrik F.; Sun, Qian; Lehman, Brad

2015-12-08

Uncertainties associated with solar forecasts present challenges to maintain grid reliability, especially at high solar penetrations. This study aims to quantify the errors associated with the day-ahead solar forecast parameters and the theoretical solar power output for a 51-kW solar power plant in a utility area in the state of Vermont, U.S. Forecasts were generated by three numerical weather prediction (NWP) models, including the Rapid Refresh, the High Resolution Rapid Refresh, and the North American Model, and a machine-learning ensemble model. A photovoltaic (PV) performance model was adopted to calculate theoretical solar power generation using the forecast parameters (e.g., irradiance, cell temperature, and wind speed). Errors of the power outputs were quantified using statistical moments and a suite of metrics, such as the normalized root mean squared error (NRMSE). In addition, the PV model's sensitivity to different forecast parameters was quantified and analyzed. Results showed that the ensemble model yielded forecasts in all parameters with the smallest NRMSE. The NRMSE of solar irradiance forecasts of the ensemble NWP model was reduced by 28.10% compared to the best of the three NWP models. Further, the sensitivity analysis indicated that the errors of the forecasted cell temperature attributed only approximately 0.12% to the NRMSE of the power output as opposed to 7.44% from the forecasted solar irradiance.

Wind power bidding in electricity markets with high wind penetration

International Nuclear Information System (INIS)

Vilim, Michael; Botterud, Audun

2014-01-01

Highlights: • We analyze the pricing systems and wind power trading in electricity markets. • We propose a model that captures the relation between market prices and wind power. • A probabilistic bidding model can increase profits for wind power producers. • Profit maximizing bidding strategies carry risks for power system operators. • We conclude that modifications of current market designs may be needed. - Abstract: Objective: The optimal day-ahead bidding strategy is studied for a wind power producer operating in an electricity market with high wind penetration. Methods: A generalized electricity market is studied with minimal assumptions about the structure of the production, bidding, or consumption of electricity. Two electricity imbalance pricing schemes are investigated, the one price and the two price scheme. A stochastic market model is created to capture the price effects of wind power production and consumption. A bidding algorithm called SCOPES (Supply Curve One Price Estimation Strategy) is developed for the one price system. A bidding algorithm called MIMICS (Multivariate Interdependence Minimizing Imbalance Cost Strategy) is developed for the two price system. Results: Both bidding strategies are shown to have advantages over the assumed “default” bidding strategy, the point forecast. Conclusion: The success of these strategies even in the case of high deviation penalties in a one price system and the implicit deviation penalties of the two price system has substantial implications for power producers and system operators in electricity markets with a high level of wind penetration. Practice implications: From an electricity market design perspective, the results indicate that further penalties or regulations may be needed to reduce system imbalance

Integration of electric drive vehicles in the Danish electricity network with high wind power penetration

DEFF Research Database (Denmark)

Chandrashekhara, Divya K; Østergaard, Jacob; Larsen, Esben

2010-01-01

/conventional) which are likely to fuel these cars. The study was carried out considering the Danish electricity network state around 2025, when the EDV penetration levels would be significant enough to have an impact on the power system. Some of the interesting findings of this study are - EDV have the potential......This paper presents the results of a study carried out to examine the feasibility of integrating electric drive vehicles (EDV) in the Danish electricity network which is characterised by high wind power penetration. One of the main aims of this study was to examine the effect of electric drive...... vehicles on the Danish electricity network, wind power penetration and electricity market. In particular the study examined the effect of electric drive vehicles on the generation capacity constraints, load curve, cross border transmission capacity and the type of generating sources (renewable...

A simulation study of impulsive penetration of solar wind irregularities into the magnetosphere at the dayside magnetopause

International Nuclear Information System (INIS)

Ma, Z.W.; Hawkins, J.G.; Lee, L.C.

1991-01-01

A two-dimensional magnetohydrodynamic code is used to study impulsive penetration processes that occur when a plasma irregularity in the magnetosheath, modeled as a field-aligned filament, impinges on the dayside magnetopause. If the magnetic fields in the magnetosheath and magnetosphere are parallel or antiparallel, then a filament in the magnetosheath can always penetrate into the magnetosphere. However, if the fields in the magnetosheath and magnetosphere are not aligned, then a filament can only penetrate into the magnetosphere when its initial kinetic energy density exceeds the magnetic energy density attributed to the transverse component of the magnetic field by a factor of 50. In this case, the magnetospheric field lines reconnect behind the filament, thereby trapping it within the magnetosphere. Otherwise, the increasing magnetic stress in front of the filament will eventually stop the filament from further penetration. For typical parameters found at the dayside magnetopause, the threshold condition obtained from this two-dimensional model predicts that penetration is possible only when the angle between the fields is within approximately 5 of parallel or antiparallel. During the penetration process, velocity vortices are observed both inside the filament and in the external plasma. Either increased β within the magnetosphere, or the larger plasma density at the magnetopause associated with antiparallel magnetic fields, will act to reduce the penetration velocity

Technology assessment of solar energy utilization

Science.gov (United States)

Jaeger, F.

1985-11-01

The general objectives and methods of Technology Assessment (TA) are outlined. Typical analysis steps of a TA for solar energy are reviewed: description of the technology and its further development; identification of impact areas; analysis of boundary conditions and definition of scenarios; market penetration of solar technologies; projection of consequences in areas of impact; and assessment of impacts and identification of options for action.

Solar results purchasing

International Nuclear Information System (INIS)

Sanders, J.

2001-01-01

Solar Thermal water heating has made little market penetration in some European countries. The main barriers to market development are: Long payback periods for the technology; Difficulties for the end-user in meeting the initial capital costs of the installation; Lack of confidence in the delivered energy that can be expected from the technology. The third barrier has been addressed using the concept of Guaranteed Solar Results (GSR). This project has addressed the other two main barriers using the concept of Solar Results Purchasing, (SRP) which combines GSR with Third Party Financing. The work was carried out in the UK, France, and Spain. The project used a uniform approach across the three countries. Each team calculated solar performance using an English version of the SOLO programme developed by TECSOL in France to encode the methodology for GSR model contracts. (author)

Solar results purchasing

Energy Technology Data Exchange (ETDEWEB)

Sanders, J.

2001-07-01

Solar Thermal water heating has made little market penetration in some European countries. The main barriers to market development are: Long payback periods for the technology; Difficulties for the end-user in meeting the initial capital costs of the installation; Lack of confidence in the delivered energy that can be expected from the technology. The third barrier has been addressed using the concept of Guaranteed Solar Results (GSR). This project has addressed the other two main barriers using the concept of Solar Results Purchasing, (SRP) which combines GSR with Third Party Financing. The work was carried out in the UK, France, and Spain. The project used a uniform approach across the three countries. Each team calculated solar performance using an English version of the SOLO programme developed by TECSOL in France to encode the methodology for GSR model contracts. (author)

Environmental acceptability of high-performance alternatives for depleted uranium penetrators

Energy Technology Data Exchange (ETDEWEB)

Kerley, C.R.; Easterly, C.E.; Eckerman, K.F. [and others

1996-08-01

The Army`s environmental strategy for investigating material substitution and management is to measure system environmental gains/losses in all phases of the material management life cycle from cradle to grave. This study is the first in a series of new investigations, applying material life cycle concepts, to evaluate whether there are environmental benefits from increasing the use of tungsten as an alternative to depleted uranium (DU) in Kinetic Energy Penetrators (KEPs). Current military armor penetrators use DU and tungsten as base materials. Although DU alloys have provided the highest performance of any high-density alloy deployed against enemy heavy armor, its low-level radioactivity poses a number of environmental risks. These risks include exposures to the military and civilian population from inhalation, ingestion, and injection of particles. Depleted uranium is well known to be chemically toxic (kidney toxicity), and workplace exposure levels are based on its renal toxicity. Waste materials containing DU fragments are classified as low-level radioactive waste and are regulated by the Nuclear Regulatory Commission. These characteristics of DU do not preclude its use in KEPs. However, long-term management challenges associated with KEP deployment and improved public perceptions about environmental risks from military activities might be well served by a serious effort to identify, develop, and substitute alternative materials that meet performance objectives and involve fewer environmental risks. Tungsten, a leading candidate base material for KEPS, is potentially such a material because it is not radioactive. Tungsten is less well studied, however, with respect to health impacts and other environmental risks. The present study is designed to contribute to the understanding of the environmental behavior of tungsten by synthesizing available information that is relevant to its potential use as a penetrator.

Mastering wireless penetration testing for highly secured environments

CERN Document Server

Johns, Aaron

2015-01-01

This book is intended for security professionals who want to enhance their wireless penetration testing skills and knowledge. Since this book covers advanced techniques, you will need some previous experience in computer security and networking.

Economic viability of transmission capacity expansion at high wind penetrations

DEFF Research Database (Denmark)

Østergaard, Poul Alberg

2005-01-01

investments and analyses of the Nord Pool price variations. The analyses are done for varying degrees of wind power penetrations ranging from 20% of the West Danish electricity demand up to 100% of the demand. The analyses demonstrate, that while there is an economic potential for some expansion in some years......With growing wind power penetrations in many countries, grid and system integration becomes more and more important issues. This is particularly the case in countries or regions with good wind resources as well as substantial installed wind power capacity as found in e.g. Northern Europe. At 20......% penetration in Western Denmark, the issue is pertinent here in relation to future plans of further expansion which is planned in accordance with the Danish Government’s climate change mitigation initiatives. This paper analyses the potential economic benefit of selling excess electricity production...

Serially Connected Micro Amorphous Silicon Solar Cells for Compact High-Voltage Sources

Directory of Open Access Journals (Sweden)

Jiyoon Nam

2016-01-01

Full Text Available We demonstrate a compact amorphous silicon (a-Si solar module to be used as high-voltage power supply. In comparison with the organic solar module, the main advantages of the a-Si solar module are its compatibility with photolithography techniques and relatively high power conversion efficiency. The open circuit voltage of a-Si solar cells can be easily controlled by serially interconnecting a-Si solar cells. Moreover, the a-Si solar module can be easily patterned by photolithography in any desired shapes with high areal densities. Using the photolithographic technique, we fabricate a compact a-Si solar module with noticeable photovoltaic characteristics as compared with the reported values for high-voltage power supplies.

Retrofitting a Geothermal Plant with Solar and Storage to Increase Power Generation

Energy Technology Data Exchange (ETDEWEB)

Zhu, Guangdong [National Renewable Energy Laboratory (NREL), Golden, CO (United States); McTigue, Joshua Dominic P [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Turchi, Craig S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Castro, Jose [Coso Operating Co.; Mungas, Greg [Hyperlight Energy; Kramer, Nick [Hyperlight Energy; King, John [Hyperlight Energy

2017-10-04

Solar hybridization using concentrating solar power (CSP) can be an effective approach to augment the power generation and power cycle efficiency of a geothermal power plant with a declining resource. Thermal storage can further increase the dispatchability of a geothermal/solar hybrid system, which is particularly valued for a national grid with high renewable penetration. In this paper, a hybrid plant design with thermal storage is proposed based on the requirements of the Coso geothermal field in China Lake, California. The objective is to increase the power production by 4 MWe. In this system, a portion of the injection brine is recirculated through a heat exchanger with the solar heat transfer fluid, before being mixed with the production well brine. In the solar heating loop the brine should be heated to at least 155 degrees C to increase the net power. The solar field and storage were sized based on solar data for China Lake. Thermal storage is used to store excess power at the high-solar-irradiation hours and generate additional power during the evenings. The solar field size, the type and capacity of thermal storage and the operating temperatures are critical factors in determining the most economic hybrid system. Further investigations are required to optimize the hybrid system and evaluate its economic feasibility.

A Dynamic Programming based method for optimizing power system restoration with high wind power penetration

DEFF Research Database (Denmark)

Hu, Rui; Hu, Weihao; Li, Pengfei

2016-01-01

and relatively low cost. Thus, many countries are increasing the wind power penetration in their power system step by step, such as Denmark, Spain and Germany. The incremental wind power penetration brings a lot of new issues in operation and programming. The power system sometimes will operate close to its...... stable limits. Once the blackout happens, a well-designed restoration strategy is significant. This paper focuses on how to ameliorate the power system restoration procedures to adapt the high wind power penetration and how to take full advantages of the wind power plants during the restoration....... In this paper, the possibility to exploit the stochastic wind power during restoration was discussed, and a Dynamic Programming (DP) method was proposed to make wind power contribute in the restoration rationally as far as possible. In this paper, the method is tested and verified by a modified IEEE 30 Buses...

Education effect of solar car for technical high school student; Kogyo kokosei ni taisuru solar car no kyoiku koka

Energy Technology Data Exchange (ETDEWEB)

Inoue, T.

1998-09-30

The solar car race which technical high school students can join in was determined to be held at Ogata village, Akita prefecture. To join in the solar bicycle race, the author working in Ofuna technical high school called on 3 schools of Yokosuka, Fujisawa and Kanagawa technical high schools which joined in World Solar-Car Rally in Akita (WSR) in 1997, before fabrication of a racing bicycle. This paper describes the survey results at the above technical high schools, and the spirit as the teacher of Ofuna technical high school on joining in the race and fabrication of the solar bicycle, and the past, current and future situations. Club activities of high school students incline too toward sports such as soccer, baseball, volleyball and rugby, and are apt to keep honest cultural events and technical events at a distance. The author says that the challenge spirit to the solar car race using environment-friendly solar energy by both dedicated teachers and students of technical high schools summoned up the author`s courage. 15 figs.

High resolution solar observations from first principles to applications

Science.gov (United States)

Verdoni, Angelo P.

2009-10-01

The expression "high-resolution observations" in Solar Physics refers to the spatial, temporal and spectral domains in their entirety. High-resolution observations of solar fine structure are a necessity to answer many of the intriguing questions related to solar activity. However, a researcher building instruments for high-resolution observations has to cope with the fact that these three domains often have diametrically opposed boundary conditions. Many factors have to be considered in the design of a successful instrument. Modern post-focus instruments are more closely linked with the solar telescopes that they serve than in past. In principle, the quest for high-resolution observations already starts with the selection of the observatory site. The site survey of the Advanced Technology Solar Telescope (ATST) under the stewardship of the National Solar Observatory (NSO) has identified Big Bear Solar Observatory (BBSO) as one of the best sites for solar observations. In a first step, the seeing characteristics at BBSO based on the data collected for the ATST site survey are described. The analysis will aid in the scheduling of high-resolution observations at BBSO as well as provide useful information concerning the design and implementation of a thermal control system for the New Solar Telescope (NST). NST is an off-axis open-structure Gregorian-style telescope with a 1.6 m aperture. NST will be housed in a newly constructed 5/8-sphere ventilated dome. With optics exposed to the surrounding air, NST's open-structure design makes it particularly vulnerable to the effects of enclosure-related seeing. In an effort to mitigate these effects, the initial design of a thermal control system for the NST dome is presented. The goal is to remediate thermal related seeing effects present within the dome interior. The THermal Control System (THCS) is an essential component for the open-telescope design of NST to work. Following these tasks, a calibration routine for the

High-accuracy defect sizing for CRDM penetration adapters using the ultrasonic TOFD technique

International Nuclear Information System (INIS)

Atkinson, I.

1995-01-01

Ultrasonic time-of-flight diffraction (TOFD) is the preferred technique for critical sizing of throughwall orientated defects in a wide range of components, primarily because it is intrinsically more accurate than amplitude-based techniques. For the same reason, TOFD is the preferred technique for sizing the cracks in control rod drive mechanism (CRDM) penetration adapters, which have been the subject of much recent attention. Once the considerable problem of restricted access for the UT probes has been overcome, this inspection lends itself to very high accuracy defect sizing using TOFD. In qualification trials under industrial conditions, depth sizing to an accuracy of ≤ 0.5 mm has been routinely achieved throughout the full wall thickness (16 mm) of the penetration adapters, using only a single probe pair and without recourse to signal processing. (author)

The penetrating depth analysis of Lunar Penetrating Radar onboard Chang’e-3 rover

Science.gov (United States)

Xing, Shu-Guo; Su, Yan; Feng, Jian-Qing; Dai, Shun; Xiao, Yuan; Ding, Chun-Yu; Li, Chun-Lai

2017-04-01

Lunar Penetrating Radar (LPR) has successfully been used to acquire a large amount of scientific data during its in-situ detection. The analysis of penetrating depth can help to determine whether the target is within the effective detection range and contribute to distinguishing useful echoes from noise. First, this study introduces two traditional methods, both based on a radar transmission equation, to calculate the penetrating depth. The only difference between the two methods is that the first method adopts system calibration parameters given in the calibration report and the second one uses high-voltage-off radar data. However, some prior knowledge and assumptions are needed in the radar equation and the accuracy of assumptions will directly influence the final results. Therefore, a new method termed the Correlation Coefficient Method (CCM) is provided in this study, which is only based on radar data without any a priori assumptions. The CCM can obtain the penetrating depth according to the different correlation between reflected echoes and noise. To be exact, there is a strong correlation in the useful reflected echoes and a random correlation in the noise between adjacent data traces. In addition, this method can acquire a variable penetrating depth along the profile of the rover, but only one single depth value can be obtained from traditional methods. Through a simulation, the CCM has been verified as an effective method to obtain penetration depth. The comparisons and analysis of the calculation results of these three methods are also implemented in this study. Finally, results show that the ultimate penetrating depth of Channel 1 and the estimated penetrating depth of Channel 2 range from 136.9 m to 165.5 m ({\\varepsilon }r=6.6) and from 13.0 m to 17.5 m ({\\varepsilon }r=2.3), respectively.

Solar radiation, phytoplankton pigments and the radiant heating of the equatorial Pacific warm pool

Science.gov (United States)

Siegel, David A.; Ohlmann, J. Carter; Washburn, Libe; Bidigare, Robert R.; Nosse, Craig T.; Fields, Erik; Zhou, Yimei

1995-01-01

Recent optical, physical, and biological oceanographic observations are used to assess the magnitude and variability of the penetrating flux of solar radiation through the mixed layer of the warm water pool (WWP) of the western equatorial Pacific Ocean. Typical values for the penetrative solar flux at the climatological mean mixed layer depth for the WWP (30 m) are approx. 23 W/sq m and are a large fraction of the climatological mean net air-sea heat flux (approx. 40 W/sq m). The penetrating solar flux can vary significantly on synoptic timescales. Following a sustained westerly wind burst in situ solar fluxes were reduced in response to a near tripling of mixed layer phytoplankton pigment concentrations. This results in a reduction in the penetrative flux at depth (5.6 W/sq m at 30 m) and corresponds to a biogeochemically mediated increase in the mixed layer radiant heating rate of 0.13 C per month. These observations demonstrate a significant role of biogeochemical processes on WWP thermal climate. We speculate that this biogeochemically mediated feedback process may play an important role in enhancing the rate at which the WWP climate system returns to normal conditions following a westerly wind burst event.

High temperature solar thermal technology: The North Africa Market

Energy Technology Data Exchange (ETDEWEB)

1990-12-01

High temperature solar thermal (HTST) technology offers an attractive option for both industrialized and non-industrialized countries to generate electricity and industrial process steam. The purpose of this report is to assess the potential market for solar thermal applications in the North African countries of Algeria, Egypt, Morocco and Tunisia. North Africa was selected because of its outstanding solar resource base and the variety of applications to be found there. Diminishing oil and gas resources, coupled with expanding energy needs, opens a large potential market for the US industry. The US high temperature solar trough industry has little competition globally and could build a large market in these areas. The US is already familiar with certain solar markets in North Africa due to the supplying of substantial quantities of US-manufactured flat plate collectors to this region.

Skin penetration and photoprotection of topical formulations containing benzophenone-3 solid lipid microparticles prepared by the solvent-free spray-congealing technique.

Science.gov (United States)

Martins, Rodrigo Molina; Siqueira, Silvia; Fonseca, Maria José Vieira; Freitas, Luis Alexandre Pedro

2014-01-01

Solid-lipid microparticles loaded with high amounts of the sunscreen UV filter benzophenone-3 were prepared by spray congealing with the objective of decreasing its skin penetration and evaluate whether the sunscreen's photoprotection were impaired by the microencapsulation process. The microparticles were produced using the natural lipids carnauba wax or bees wax and three different concentrations of benzophenone-3 (30, 50 and 70%) using spray congealing technique. The microparticles presented properties suitable for topical application, such as spherical morphology, high encapsulation efficiency (95.53-102.2%), average particle sizes between 28.5 and 60.0 µm with polydispersivities from 1.2 to 2.5. In studies of in vitro skin penetration and preliminary stability, formulations of gel cream containing carnauba wax solid lipid microparticles and 70% benzophenone-3 when compared to the formulation added of bees wax solid-lipid microparticles containing 70% benzophenone-3, was stable considering the several parameters evaluated and were able to decrease the penetration of the UV filter into pig skin. Moreover, the formulations containing solid lipid microparticles with 70% benzophenone-3 increased the photoprotective capacity of benzophenone-3 under UV irradiation. The results show that spray-congealed microparticles are interesting solid forms to decrease the penetration solar filters in the skin without compromising their photoprotection.

Highly efficient solar-pumped Nd:YAG laser.

Science.gov (United States)

Liang, Dawei; Almeida, Joana

2011-12-19

The recent progress in solar-pumped laser with Fresnel lens and Cr:Nd:YAG ceramic medium has revitalized solar laser researches, revealing a promising future for renewable reduction of magnesium from magnesium oxide. Here we show a big advance in solar laser collection efficiency by utilizing an economical Fresnel lens and a most widely used Nd:YAG single-crystal rod. The incoming solar radiation from the sun is focused by a 0.9 m diameter Fresnel lens. A dielectric totally internally reflecting secondary concentrator is employed to couple the concentrated solar radiation from the focal zone to a 4 mm diameter Nd:YAG rod within a conical pumping cavity. 12.3 W cw laser power is produced, corresponding to 19.3 W/m(2) collection efficiency, which is 2.9 times larger than the previous results with Nd:YAG single-crystal medium. Record-high slope efficiency of 3.9% is also registered. Laser beam quality is considerably improved by pumping a 3 mm diameter Nd:YAG rod.

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.

Interim Policy Options for Commercialization of Solar Heating and Cooling Systems.

Science.gov (United States)

Bezdek, Roger

This interim report reviews the major incentive policy options available to accelerate market penetration of solar heating and cooling (SHAC) systems. Feasible policy options designed to overcome existing barriers to commercial acceptance and market penetration are identified and evaluated. The report is divided into seven sections, each dealing…

High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrator Application

Energy Technology Data Exchange (ETDEWEB)

Hubbard, Seth

2012-09-12

The High Efficiency Nanostructured III-V Photovoltaics for Solar Concentrators project seeks to provide new photovoltaic cells for Concentrator Photovoltaics (CPV) Systems with higher cell efficiency, more favorable temperature coefficients and less sensitivity to changes in spectral distribution. The main objective of this project is to provide high efficiency III-V solar cells that will reduce the overall cost per Watt for power generation using CPV systems.This work is focused both on a potential near term application, namely the use of indium arsenide (InAs) QDs to spectrally "tune" the middle (GaAs) cell of a SOA triple junction device to a more favorable effective bandgap, as well as the long term goal of demonstrating intermediate band solar cell effects. The QDs are confined within a high electric field i-region of a standard GaAs solar cell. The extended absorption spectrum (and thus enhanced short circuit current) of the QD solar cell results from the increase in the sub GaAs bandgap spectral response that is achievable as quantum dot layers are introduced into the i-region. We have grown InAs quantum dots by OMVPE technique and optimized the QD growth conditions. Arrays of up to 40 layers of strain balanced quantum dots have been experimentally demonstrated with good material quality, low residual stain and high PL intensity. Quantum dot enhanced solar cells were grown and tested under simulated one sun AM1.5 conditions. Concentrator solar cells have been grown and fabricated with 5-40 layers of QDs. Testing of these devices show the QD cells have improved efficiency compared to baseline devices without QDs. Device modeling and measurement of thermal properties were performed using Crosslight APSYS. Improvements in a triple junction solar cell with the insertion of QDs into the middle current limiting junction was shown to be as high as 29% under one sun illumination for a 10 layer stack QD enhanced triple junction solar cell. QD devices have strong

Design of solar systems in high-rise buildings

Science.gov (United States)

Kolosov, Alexander; Chudinov, Dmitry; Yaremenko, Sergey

2018-03-01

Nowadays, the renovation program is being implemented in the megapolises of Russia. Innovative high-rise buildings are built instead of morally and physically obsolete houses, where non-traditional renewable energy sources are used to the fullest extent, under the effect of which they are located. The possibility to use solar systems with variation of their design parameters is considered. It is established that solar systems have high technical potential. The share of heat load, that is provided by using solar energy, varies from 4 to 84% depending on the time of the year. Economic indicators restrain the use of such panels. The payback period is about 8 years at the current cost for thermal energy.

Relative Economic Merits of Storage and Combustion Turbines for Meeting Peak Capacity Requirements under Increased Penetration of Solar Photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Denholm, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States); Diakov, Victor [National Renewable Energy Lab. (NREL), Golden, CO (United States); Margolis, Robert [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2015-09-01

Batteries with several hours of capacity provide an alternative to combustion turbines for meeting peak capacity requirements. Even when compared to state-of-the-art highly flexible combustion turbines, batteries can provide a greater operational value, which is reflected in a lower system-wide production cost. By shifting load and providing operating reserves, batteries can reduce the cost of operating the power system to a traditional electric utility. This added value means that, depending on battery life, batteries can have a higher cost than a combustion turbine of equal capacity and still produce a system with equal or lower overall life-cycle cost. For a utility considering investing in new capacity, the cost premium for batteries is highly sensitive to a variety of factors, including lifetime, natural gas costs, PV penetration, and grid generation mix. In addition, as PV penetration increases, the net electricity demand profile changes, which may reduce the amount of battery energy capacity needed to reliably meet peak demand.

Study on photoelectric parameter measurement method of high capacitance solar cell

Science.gov (United States)

Zhang, Junchao; Xiong, Limin; Meng, Haifeng; He, Yingwei; Cai, Chuan; Zhang, Bifeng; Li, Xiaohui; Wang, Changshi

2018-01-01

The high efficiency solar cells usually have high capacitance characteristic, so the measurement of their photoelectric performance usually requires long pulse width and long sweep time. The effects of irradiance non-uniformity, probe shielding and spectral mismatch on the IV curve measurement are analyzed experimentally. A compensation method for irradiance loss caused by probe shielding is proposed, and the accurate measurement of the irradiance intensity in the IV curve measurement process of solar cell is realized. Based on the characteristics that the open circuit voltage of solar cell is sensitive to the junction temperature, an accurate measurement method of the temperature of solar cell under continuous irradiation condition is proposed. Finally, a measurement method with the characteristic of high accuracy and wide application range for high capacitance solar cell is presented.

External perforated Solar Screens for daylighting in residential desert buildings: Identification of minimum perforation percentages

KAUST Repository

Sherif, Ahmed; Sabry, Hanan; Rakha, Tarek

2012-01-01

and Saudi Arabia, result in the admittance of direct solar radiation, which leads to thermal discomfort and the incidence of undesired glare. One type of shading systems that is used to permit daylight while controlling solar penetration is " Solar Screens

Optimal Capacitor Bank Capacity and Placement in Distribution Systems with High Distributed Solar Power Penetration

Energy Technology Data Exchange (ETDEWEB)

Hodge, Brian S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mather, Barry A [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cho, Gyu-Jung [Sungkyunkwan University, Korea; Oh, Yun-Sik [Sungkyunkwan University, Korea; Kim, Min-Sung [Sungkyunkwan University, Korea; Kim, Ji-Soo [Sungkyunkwan University, Korea; Kim, Chul-Hwan [Sungkyunkwan University, Korea

2018-02-01

Capacitor banks have been generally installed and utilized to support distribution voltage during period of higher load or on longer, higher impedance, feeders. Installations of distributed energy resources in distribution systems are rapidly increasing, and many of these generation resources have variable and uncertain power output. These generators can significantly change the voltage profile across a feeder, and therefore when a new capacitor bank is needed analysis of optimal capacity and location of the capacitor bank is required. In this paper, we model a particular distribution system including essential equipment. An optimization method is adopted to determine the best capacity and location sets of the newly installed capacitor banks, in the presence of distributed solar power generation. Finally we analyze the optimal capacitor banks configuration through the optimization and simulation results.

Impulsive and long duration high-energy gamma-ray emission from the very bright 2012 March 7 solar flares

Energy Technology Data Exchange (ETDEWEB)

Ajello, M. [Space Sciences Laboratory, 7 Gauss Way, University of California, Berkeley, CA 94720-7450 (United States); Albert, A.; Allafort, A.; Caliandro, G. A.; Cameron, R. A.; Charles, E. [W. W. Hansen Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology, Department of Physics and SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305 (United States); Baldini, L. [Università di Pisa and Istituto Nazionale di Fisica Nucleare, Sezione di Pisa I-56127 Pisa (Italy); Barbiellini, G. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, I-34127 Trieste (Italy); Bastieri, D.; Buson, S. [Istituto Nazionale di Fisica Nucleare, Sezione di Padova, I-35131 Padova (Italy); Bellazzini, R.; Bregeon, J. [Istituto Nazionale di Fisica Nucleare, Sezione di Pisa, I-56127 Pisa (Italy); Bissaldi, E. [Istituto Nazionale di Fisica Nucleare, Sezione di Trieste, and Università di Trieste, I-34127 Trieste (Italy); Bonamente, E.; Cecchi, C. [Istituto Nazionale di Fisica Nucleare, Sezione di Perugia, I-06123 Perugia (Italy); Brandt, T. J. [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Brigida, M. [Dipartimento di Fisica " M. Merlin" dell' Università e del Politecnico di Bari, I-70126 Bari (Italy); Bruel, P. [Laboratoire Leprince-Ringuet, École polytechnique, CNRS/IN2P3, Palaiseau (France); Buehler, R. [Deutsches Elektronen Synchrotron DESY, D-15738 Zeuthen (Germany); Caraveo, P. A., E-mail: nicola.omodei@stanford.edu, E-mail: vahep@stanford.edu, E-mail: melissa.pesce.rollins@pi.infn.it [INAF-Istituto di Astrofisica Spaziale e Fisica Cosmica, I-20133 Milano (Italy); and others

2014-07-01

The Fermi Large Area Telescope (LAT) detected gamma-rays up to 4 GeV from two bright X-class solar flares on 2012 March 7, showing both an impulsive and temporally extended emission phases. The gamma-rays appear to originate from the same active region as the X-rays associated with these flares. The >100 MeV gamma-ray flux decreases monotonically during the first hour (impulsive phase) followed by a slower decrease for the next 20 hr. A power law with a high-energy exponential cutoff can adequately describe the photon spectrum. Assuming that the gamma rays result from the decay of pions produced by accelerated protons and ions with a power-law spectrum, we find that the index of that spectrum is ∼3, with minor variations during the impulsive phase. During the extended phase the photon spectrum softens monotonically, requiring the proton index varying from ∼4 to >5. The >30 MeV proton flux observed by the GOES satellites also shows a flux decrease and spectral softening, but with a harder spectrum (index ∼2-3). Based on these observations, we explore the relative merits of prompt or continuous acceleration scenarios, hadronic or leptonic emission processes, and acceleration at the solar corona or by the fast coronal mass ejections. We conclude that the most likely scenario is continuous acceleration of protons in the solar corona that penetrate the lower solar atmosphere and produce pions that decay into gamma rays. However, acceleration in the downstream of the shock cannot be definitely ruled out.

Affordable High Performance Electromagnetically Clean Solar Arrays, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — We propose an Electromagnetically Clean Solar Array (ECSA) with enhanced performance, in Watts/kg and Watts/m2, using flight proven, high efficiency solar cells. For...

Analysis Methodology for Balancing Authority Cooperation in High Penetration of Variable Generation

Energy Technology Data Exchange (ETDEWEB)

Makarov, Yuri V.; Etingov, Pavel V.; Zhou, Ning; Ma, Jian; Samaan, Nader A.; Diao, Ruisheng; Malhara, Sunita V.; Guttromson, Ross T.; Du, Pengwei; Sastry, Chellury

2010-02-01

With the rapidly growing penetration level of wind and solar generation, the challenges of managing variability and the uncertainty of intermittent renewable generation become more and more significant. The problem of power variability and uncertainty gets exacerbated when each balancing authority (BA) works locally and separately to balance its own subsystem. The virtual BA concept means various forms of collaboration between individual BAs must manage power variability and uncertainty. The virtual BA will have a wide area control capability in managing its operational balancing requirements in different time frames. This coordination results in the improvement of efficiency and reliability of power system operation while facilitating the high level integration of green, intermittent energy resources. Several strategies for virtual BA implementation, such as ACE diversity interchange (ADI), wind only BA, BA consolidation, dynamic scheduling, regulation and load following sharing, extreme event impact study are discussed in this report. The objective of such strategies is to allow individual BAs within a large power grid to help each other deal with power variability. Innovative methods have been developed to simulate the balancing operation of BAs. These methods evaluate the BA operation through a number of metrics — such as capacity, ramp rate, ramp duration, energy and cycling requirements — to evaluate the performances of different virtual BA strategies. The report builds a systematic framework for evaluating BA consolidation and coordination. Results for case studies show that significant economic and reliability benefits can be gained. The merits and limitation of each virtual BA strategy are investigated. The report provides guidelines for the power industry to evaluate the coordination or consolidation method. The application of the developed strategies in cooperation with several regional BAs is in progress for several off-spring projects.

Review of status developments of high-efficiency crystalline silicon solar cells

Science.gov (United States)

Liu, Jingjing; Yao, Yao; Xiao, Shaoqing; Gu, Xiaofeng

2018-03-01

In order to further improve cell efficiency and reduce cost in achieving grid parity, a large number of PV manufacturing companies, universities and research institutes have been devoted to a variety of low-cost and high-efficiency crystalline Si solar cells. In this article, the cell structures, characteristics and efficiency progresses of several types of high-efficiency crystalline Si solar cells that have been in small scale production or are promising in mass production are presented, including passivated emitter rear cell, tunnel oxide passivated contact solar cell, interdigitated back contact cell, heterojunction with intrinsic thin-layer cell, and heterojunction solar cells with interdigitated back contacts. Both the industrialization status and future development trend of high-efficiency crystalline silicon solar cells are also pinpointed.

Highly accurate and fast optical penetration-based silkworm gender separation system

Science.gov (United States)

Kamtongdee, Chakkrit; Sumriddetchkajorn, Sarun; Chanhorm, Sataporn

2015-07-01

Based on our research work in the last five years, this paper highlights our innovative optical sensing system that can identify and separate silkworm gender highly suitable for sericulture industry. The key idea relies on our proposed optical penetration concepts and once combined with simple image processing operations leads to high accuracy in identifying of silkworm gender. Inside the system, there are electronic and mechanical parts that assist in controlling the overall system operation, processing the optical signal, and separating the female from male silkworm pupae. With current system performance, we achieve a very highly accurate more than 95% in identifying gender of silkworm pupae with an average system operational speed of 30 silkworm pupae/minute. Three of our systems are already in operation at Thailand's Queen Sirikit Sericulture Centers.

High-speed solar wind flow parameters at 1 AU

International Nuclear Information System (INIS)

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

1976-01-01

To develop a set of constraints for theories of solar wind high-speed streams, a detailed study was made of the fastest streams observed at 1 AU during the time period spanning March 1971 through July 1974. Streams were accepted for study only if (1) the maximum speed exceeded 650 km s -1 ; (2) effects of stream-stream dynamical interaction on the flow parameters could be safely separated from the intrinsic characteristics of the high-speed regions; (3) the full width at half maximum (FWHM) of the stream when mapped back to 20 solar radii by using a constant speed approximation was greater than 45degree in Carrington longitude; and (4) there were no obvious solar-activity-induced contaminating effects. Nineteen streams during this time interval satisfied these criteria. Average parameters at 1 AU for those portions of these streams above V=650 km s -1 are given.Not only is it not presently known why electrons are significantly cooler than the protons within high-speed regions, but also observed particle fluxes and convected energy fluxes for speed greater than 650 km s -1 are substantially larger than those values predicted by any of the existing theories of solar wind high-speed streams. More work is therefore needed in refining present solar wind models to see whether suitable modifications and/or combinations of existing theories based on reasonable coronal conditions can accommodate the above high-speed flow parameters

Characterization of selective solar absorber under high vacuum.

Science.gov (United States)

Russo, Roberto; Monti, Matteo; di Giamberardino, Francesco; Palmieri, Vittorio G

2018-05-14

Total absorption and emission coefficients of selective solar absorbers are measured under high vacuum conditions from room temperature up to stagnation temperature. The sample under investigation is illuminated under vacuum @1000W/m 2 and the sample temperature is recorded during heat up, equilibrium and cool down. During stagnation, the absorber temperature exceeds 300°C without concentration. Data analysis allows evaluating the solar absorptance and thermal emittance at different temperatures. These in turn are useful to predict evacuated solar panel performances at operating conditions.

Simple processing of high efficiency silicon solar cells

International Nuclear Information System (INIS)

Hamammu, I.M.; Ibrahim, K.

2006-01-01

Cost effective photovoltaic devices have been an area research since the development of the first solar cells, as cost is the major factor in their usage. Silicon solar cells have the biggest share in the photovoltaic market, though silicon os not the optimal material for solar cells. This work introduces a simplified approach for high efficiency silicon solar cell processing, by minimizing the processing steps and thereby reducing cost. The suggested procedure might also allow for the usage of lower quality materials compared to the one used today. The main features of the present work fall into: simplifying the diffusion process, edge shunt isolation and using acidic texturing instead of the standard alkaline processing. Solar cells of 17% efficiency have been produced using this procedure. Investigations on the possibility of improving the efficiency and using less quality material are still underway

Adaptive sensor-based ultra-high accuracy solar concentrator tracker

Science.gov (United States)

Brinkley, Jordyn; Hassanzadeh, Ali

2017-09-01

Conventional solar trackers use information of the sun's position, either by direct sensing or by GPS. Our method uses the shading of the receiver. This, coupled with nonimaging optics design allows us to achieve ultra-high concentration. Incorporating a sensor based shadow tracking method with a two stage concentration solar hybrid parabolic trough allows the system to maintain high concentration with acute accuracy.

MDCT diagnosis of penetrating diaphragm injury

Energy Technology Data Exchange (ETDEWEB)

Bodanapally, Uttam K.; Shanmuganathan, Kathirkamanathan; Mirvis, Stuart E.; Sliker, Clint W.; Fleiter, Thorsten R.; Sarada, Kamal; Miller, Lisa A. [University of Maryland School of Medicine, Department of Diagnostic Radiology, Baltimore, MD (United States); Stein, Deborah M. [University of Maryland, Department of Surgery, Shock Trauma Center, Baltimore, MD (United States); Alexander, Melvin [National Study Center for Trauma and Emergency Medical Systems, Baltimore, MD (United States)

2009-08-15

The purpose of the study was to determine the diagnostic sensitivity and specificity of multidetector CT (MDCT) in detection of diaphragmatic injury following penetrating trauma. Chest and abdominal CT examinations performed preoperatively in 136 patients after penetrating trauma to the torso with injury trajectory in close proximity to the diaphragm were reviewed by radiologists unaware of surgical findings. Signs associated with diaphragmatic injuries in penetrating trauma were noted. These signs were correlated with surgical diagnoses, and their sensitivity and specificity in assisting the diagnosis were calculated. CT confirmed diaphragmatic injury in 41 of 47 injuries (sensitivity, 87.2%), and an intact diaphragm in 71 of 98 patients (specificity, 72.4%). The overall accuracy of MDCT was 77%. The most accurate sign helping the diagnosis was contiguous injury on either side of the diaphragm in single-entry penetrating trauma (sensitivity, 88%; specificity, 82%). Thus MDCT has high sensitivity and good specificity in detecting penetrating diaphragmatic injuries. (orig.)

MDCT diagnosis of penetrating diaphragm injury

International Nuclear Information System (INIS)

Bodanapally, Uttam K.; Shanmuganathan, Kathirkamanathan; Mirvis, Stuart E.; Sliker, Clint W.; Fleiter, Thorsten R.; Sarada, Kamal; Miller, Lisa A.; Stein, Deborah M.; Alexander, Melvin

2009-01-01

The purpose of the study was to determine the diagnostic sensitivity and specificity of multidetector CT (MDCT) in detection of diaphragmatic injury following penetrating trauma. Chest and abdominal CT examinations performed preoperatively in 136 patients after penetrating trauma to the torso with injury trajectory in close proximity to the diaphragm were reviewed by radiologists unaware of surgical findings. Signs associated with diaphragmatic injuries in penetrating trauma were noted. These signs were correlated with surgical diagnoses, and their sensitivity and specificity in assisting the diagnosis were calculated. CT confirmed diaphragmatic injury in 41 of 47 injuries (sensitivity, 87.2%), and an intact diaphragm in 71 of 98 patients (specificity, 72.4%). The overall accuracy of MDCT was 77%. The most accurate sign helping the diagnosis was contiguous injury on either side of the diaphragm in single-entry penetrating trauma (sensitivity, 88%; specificity, 82%). Thus MDCT has high sensitivity and good specificity in detecting penetrating diaphragmatic injuries. (orig.)

High-efficiency concentrator silicon solar cells

Energy Technology Data Exchange (ETDEWEB)

Sinton, R.A.; Cuevas, A.; King, R.R.; Swanson, R.M. (Stanford Univ., CA (USA). Solid-State Electronics Lab.)

1990-11-01

This report presents results from extensive process development in high-efficiency Si solar cells. An advanced design for a 1.56-cm{sup 2} cell with front grids achieved 26% efficiency at 90 suns. This is especially significant since this cell does not require a prismatic cover glass. New designs for simplified backside-contact solar cells were advanced from a status of near-nonfunctionality to demonstrated 21--22% for one-sun cells in sizes up to 37.5 cm{sup 2}. An efficiency of 26% was achieved for similar 0.64-cm{sup 2} concentrator cells at 150 suns. More fundamental work on dopant-diffused regions is also presented here. The recombination vs. various process and physical parameters was studied in detail for boron and phosphorous diffusions. Emitter-design studies based solidly upon these new data indicate the performance vs design parameters for a variety of the cases of most interest to solar cell designers. Extractions of p-type bandgap narrowing and the surface recombination for p- and n-type regions from these studies have a generality that extends beyond solar cells into basic device modeling. 68 refs., 50 figs.

Melting Penetration Simulation of Fe-U System at High Temperature Using MPS-LER

International Nuclear Information System (INIS)

Mustari, A P A; Irwanto, Dwi; Yamaji, A

2016-01-01

Melting penetration information of Fe-U system is necessary for simulating the molten core behavior during severe accident in nuclear power plants. For Fe-U system, the information is mainly obtained from experiment, i.e. TREAT experiment. However, there is no reported data on SS304 at temperature above 1350°C. The MPS-LER has been developed and validated to simulate melting penetration on Fe-U system. The MPS-LER modelled the eutectic phenomenon by solving the diffusion process and by applying the binary phase diagram criteria. This study simulates the melting penetration of the system at higher temperature using MPS-LER. Simulations were conducted on SS304 at 1400, 1450 and 1500°C. The simulation results show rapid increase of melting penetration rate. (paper)

High Kinetic Energy Penetrator Shielding and High Wear Resistance Materials Fabricated with Boron Nitride Nanotubes (BNNTS) and BNNT Polymer Composites

Science.gov (United States)

Kang, Jin Ho (Inventor); Sauti, Godfrey (Inventor); Smith, Michael W. (Inventor); Jordan, Kevin C. (Inventor); Park, Cheol (Inventor); Bryant, Robert George (Inventor); Lowther, Sharon E. (Inventor)

2015-01-01

Boron nitride nanotubes (BNNTs), boron nitride nanoparticles (BNNPs), carbon nanotubes (CNTs), graphites, or combinations, are incorporated into matrices of polymer, ceramic or metals. Fibers, yarns, and woven or nonwoven mats of BNNTs are used as toughening layers in penetration resistant materials to maximize energy absorption and/or high hardness layers to rebound or deform penetrators. They can be also used as reinforcing inclusions combining with other polymer matrices to create composite layers like typical reinforcing fibers such as Kevlar.RTM., Spectra.RTM., ceramics and metals. Enhanced wear resistance and usage time are achieved by adding boron nitride nanomaterials, increasing hardness and toughness. Such materials can be used in high temperature environments since the oxidation temperature of BNNTs exceeds 800.degree. C. in air. Boron nitride based composites are useful as strong structural materials for anti-micrometeorite layers for spacecraft and space suits, ultra strong tethers, protective gear, vehicles, helmets, shields and safety suits/helmets for industry.

Optical performance evaluation of a solar furnace by measuring the highly concentrated solar flux

International Nuclear Information System (INIS)

Lee, Hyunjin; Chai, Kwankyo; Kim, Jongkyu; Lee, Sangnam; Yoon, Hwanki; Yu, Changkyun; Kang, Yongheack

2014-01-01

We evaluated optical performance of a solar furnace in the KIER (Korea Institute of Energy Research) by measuring the highly concentrated solar flux with the flux mapping method. We presented and analyzed optical performance in terms of concentrated solar flux distribution and power distribution. We investigated concentration ratio, stagnation temperature, total power, and concentration accuracy with help of a modeling code based on the ray tracing method and thereby compared with other solar furnaces. We also discussed flux changes by shutter opening angles and by position adjustment of reflector facets. In the course of flux analysis, we provided a better understanding of reference flux measurement for calibration, reflectivity measurement with a portable reflectometer, shadowing area consideration for effective irradiation, as well as accuracy and repeatability of flux measurements. The results in the present study will help proper utilization of a solar furnace by facilitating comparison between flux measurements at different conditions and flux estimation during operation

Containment penetration design and analysis by finite element methods

International Nuclear Information System (INIS)

Perry, R.F.; Rigamonti, G.; Dainora, J.

1975-01-01

Containment penetration designs which provide complete support to process piping containing high pressure and high temperature fluids and which do not employ cooling coils, require special provisions to sustain loadings associated with normal/abnormal conditions and to limit maximum temperature transmitted to the containment concrete wall. In order to accommodate piping imposed loads and fluid temperatures within code and regulatory limitations, the containment penetration designs require careful analysis of two critical regions: the portion of the penetration sleeve which is exposed to containment ambient conditions and the portion of the penetration which connects the sleeve to process piping (flued head). The length and thickness of the sleeve must be designed to provide maximum heat dissipation to the atmosphere and minimum heat conduction through the sleeve to meet concrete temperature limitations. The sleeve must have the capability to transmit the postulated piping loads to concrete embedments in the containment shell. The penetration flued head design must be strong enough to transfer high mechanical loads and be flexible enough to accommodate the thermal stresses generated by the high temperature fluid. Analytical models using finite element representations of process piping, penetration flued head, and exposed sleeve were employed to investigate the penetration assembly design. By application of flexible multi-step analyses, different penetration configurations were evaluated to determine the effects of key design parameters. Among the parameters studied were flued head profiles, flued head angles with the process piping, sleeve length and wall thickness. Special designs employing fins welded to the sleeve to lower the temperature at the concrete wall interface were investigated and fin geometry effects reported

Highly doped layer for tunnel junctions in solar cells

Science.gov (United States)

Fetzer, Christopher M.

2017-08-01

A highly doped layer for interconnecting tunnel junctions in multijunction solar cells is presented. The highly doped layer is a delta doped layer in one or both layers of a tunnel diode junction used to connect two or more p-on-n or n-on-p solar cells in a multijunction solar cell. A delta doped layer is made by interrupting the epitaxial growth of one of the layers of the tunnel diode, depositing a delta dopant at a concentration substantially greater than the concentration used in growing the layer of the tunnel diode, and then continuing to epitaxially grow the remaining tunnel diode.

Smart Solar Grid. Integration of high penetration of photovoltaic in municipal low voltage distribution grids; Smart Solar Grid. Integration hoher Anteile von Photovoltaik in kommunalen Niederspannungsverteilnetzen

Energy Technology Data Exchange (ETDEWEB)

Ruf, Holger; Heilscher, Gerd [Hochschule Ulm (Germany); Meier, Florian [SWU Netze GmbH, Ulm (Germany)

2012-07-01

The high rate of decentralized generation in low voltage grids especially photovoltaic (PV) put the distribution grid operators to new challenges. Grid operation and grid planning have to respect the volatility and dynamic of decentralized generation now and in the future and adapt their previous proceedings. In the frame of the project Smart Solar Grid was a test site defined in the grid area of the DSO Stadtwerke Ulm/Neu-Ulm GmbH (SWU) to analyze the impact of the PV rise and possible solutions for the grid planning in the future. The first analysis based upon secondly measurements of the first test site. From this were statistical evaluation of the load flows and power variations done. Furthermore were the roof potential analysis results of the test site validated. These data are the base for the development of a forecast system for grid condition parameter. (orig.)

Final Technical Report: Distributed Controls for High Penetrations of Renewables

Energy Technology Data Exchange (ETDEWEB)

Byrne, Raymond H. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Neely, Jason C. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Rashkin, Lee J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Trudnowski, Daniel J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Wilson, David G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

2015-12-01

The goal of this effort was to apply four potential control analysis/design approaches to the design of distributed grid control systems to address the impact of latency and communications uncertainty with high penetrations of photovoltaic (PV) generation. The four techniques considered were: optimal fixed structure control; Nyquist stability criterion; vector Lyapunov analysis; and Hamiltonian design methods. A reduced order model of the Western Electricity Coordinating Council (WECC) developed for the Matlab Power Systems Toolbox (PST) was employed for the study, as well as representative smaller systems (e.g., a two-area, three-area, and four-area power system). Excellent results were obtained with the optimal fixed structure approach, and the methodology we developed was published in a journal article. This approach is promising because it offers a method for designing optimal control systems with the feedback signals available from Phasor Measurement Unit (PMU) data as opposed to full state feedback or the design of an observer. The Nyquist approach inherently handles time delay and incorporates performance guarantees (e.g., gain and phase margin). We developed a technique that works for moderate sized systems, but the approach does not scale well to extremely large system because of computational complexity. The vector Lyapunov approach was applied to a two area model to demonstrate the utility for modeling communications uncertainty. Application to large power systems requires a method to automatically expand/contract the state space and partition the system so that communications uncertainty can be considered. The Hamiltonian Surface Shaping and Power Flow Control (HSSPFC) design methodology was selected to investigate grid systems for energy storage requirements to support high penetration of variable or stochastic generation (such as wind and PV) and loads. This method was applied to several small system models.

Integrating rooftop solar into a multi-source energy planning optimization model

International Nuclear Information System (INIS)

Arnette, Andrew N.

2013-01-01

Highlights: • There is significant technical capacity for rooftop solar installations. • Rooftop solar generation is heavily dependent on key parameters. • Rooftop solar should be one of several options for increasing renewable energy. • Renewable energy planning should consider both cost and benefits. - Abstract: This research uses an optimization model to compare the role of rooftop solar generation versus large-scale solar and wind farm installations in renewable energy planning. The model consists of competing objectives, minimizing annual generation costs and minimizing annual greenhouse gas emissions. Rather than focus on the individual consumer’s investment decision, over 20 scenarios were developed which explored key input parameters such as the maximum penetration level of rooftop solar installations, pricing of equipment, tax credits, and net-metering policy to determine what role rooftop solar plays in renewable energy investment at an aggregate level. The research finds that at lower levels of penetration, such as those currently found in the United States, other renewable energy sources remain viable options, thus rooftop solar should be just one option considered when increasing development of renewable energy sources. The research also shows that a balanced approach taking into account both of the opposing objectives will lead to greater levels of rooftop solar generation than focusing solely on cost or emissions. Therefore, rooftop solar should be considered as part of an overall balanced approach to increasing renewable energy generation

High-latitude Conic Current Sheets in the Solar Wind

Energy Technology Data Exchange (ETDEWEB)

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

2017-02-10

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

Development of large area, high efficiency amorphous silicon solar cell

Energy Technology Data Exchange (ETDEWEB)

Yoon, K.S.; Kim, S.; Kim, D.W. [Yu Kong Taedok Institute of Technology (Korea, Republic of)

1996-02-01

The objective of the research is to develop the mass-production technologies of high efficiency amorphous silicon solar cells in order to reduce the costs of solar cells and dissemination of solar cells. Amorphous silicon solar cell is the most promising option of thin film solar cells which are relatively easy to reduce the costs. The final goal of the research is to develop amorphous silicon solar cells having the efficiency of 10%, the ratio of light-induced degradation 15% in the area of 1200 cm{sup 2} and test the cells in the form of 2 Kw grid-connected photovoltaic system. (author) 35 refs., 8 tabs., 67 figs.

The Faraday rotation experiment. [solar corona

Science.gov (United States)

Volland, H.; Levy, G. S.; Bird, M. K.; Stelzried, C. T.; Seidel, B. L.

1984-01-01

The magnetized plasma of the solar corona was remotely sounded using the Faraday rotation effect. The solar magnetic field together with the electrons of the coronal plasma cause a measurable Faraday rotation effect, since the radio waves of Helios are linearly polarized. The measurement is performed at the ground stations. Alfven waves traveling from the Sun's surface through the corona into interplanetary space are observed. Helios 2 signals penetrating through a region where coronal mass is ejected show wavelike structures.

Correlation Between Cone Penetration Rate And Measured Cone Penetration Parameters In Silty Soils

DEFF Research Database (Denmark)

Poulsen, Rikke; Nielsen, Benjaminn Nordahl; Ibsen, Lars Bo

2013-01-01

This paper shows, how a change in cone penetration rate affects the cone penetration measurements, hence the cone resistance, pore pressure, and sleeve friction in silty soil. The standard rate of penetration is 20 mm/s, and it is generally accepted that undrained penetration occurs in clay while...... drained penetration occurs in sand. When lowering the penetration rate, the soil pore water starts to dissipate and a change in the drainage condition is seen. In intermediate soils such as silty soils, the standard cone penetration rate may result in a drainage condition that could be undrained......, partially or fully drained. However, lowering the penetration rate in silty soils has a great significance because of the soil permeability, and only a small change in penetration rate will result in changed cone penetration measurements. In this paper, analyses will be done on data from 15 field cone...

Strategy of penetration of renewable power resources in the Granma province, through Analytical Hierarchy Process

International Nuclear Information System (INIS)

Benítez Leyva, Lázaro Ventura; Rosa Andino, Alain Ariel de la; Jácome Cadena, Jaime Fernando; Paredes Palomeque, Cristian Rene

2014-01-01

In selecting new energy sources for a country, region or rural communities, the criteria to be considered conflict and it is difficult to determine the best energetic options as to preference and priority. Therefore, the present work had as objective to define a strategy of penetration of renewable energy sources from consultation of experts and the later application of the mathematical procedure ''Analytic Hierarchy Process''. The obtained results suggest that the energy strategies of better performance for the Granma province are the following: eolian energy for water pumping, solar photovoltaic for water pumping, solar thermal energy for the sector which demands hot water, and solar photovoltaic for the electrical sector, in that order of priority. (author)

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

Institute of Scientific and Technical Information of China (English)

Tim; Mareda; Ludovic; Gaudard; Franco; Romerio

2017-01-01

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

Solar PV resource for higher penetration through a combined spatial aggregation with wind

CSIR Research Space (South Africa)

Bischof-Niemz, ST

2016-06-01

Full Text Available between wind and solar PV and how these would be reflected in the power system. The benefits of spatial distribution of renewables are well understood, but the impact of the combined spatial aggregation of wind and solar PV is central to the design...

Metamaterial Receivers for High Efficiency Concentrated Solar Energy Conversion

Energy Technology Data Exchange (ETDEWEB)

Yellowhair, Julius E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Concentrating Solar Technologies Dept.; Kwon, Hoyeong [Univ. of Texas, Austin, TX (United States). Dept. of Electrical and Computer Engineering; Alu, Andrea [Univ. of Texas, Austin, TX (United States). Dept. of Electrical and Computer Engineering; Jarecki, Robert L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Concentrating Solar Technologies Dept.; Shinde, Subhash L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Concentrating Solar Technologies Dept.

2016-09-01

Operation of concentrated solar power receivers at higher temperatures (>700°C) would enable supercritical carbon dioxide (sCO₂) power cycles for improved power cycle efficiencies (>50%) and cost-effective solar thermal power. Unfortunately, radiative losses at higher temperatures in conventional receivers can negatively impact the system efficiency gains. One approach to improve receiver thermal efficiency is to utilize selective coatings that enhance absorption across the visible solar spectrum while minimizing emission in the infrared to reduce radiative losses. Existing coatings, however, tend to degrade rapidly at elevated temperatures. In this report, we report on the initial designs and fabrication of spectrally selective metamaterial-based absorbers for high-temperature, high-thermal flux environments important for solarized sCO₂ power cycles. Metamaterials are structured media whose optical properties are determined by sub-wavelength structural features instead of bulk material properties, providing unique solutions by decoupling the optical absorption spectrum from thermal stability requirements. The key enabling innovative concept proposed is the use of structured surfaces with spectral responses that can be tailored to optimize the absorption and retention of solar energy for a given temperature range. In this initial study through the Academic Alliance partnership with University of Texas at Austin, we use Tungsten for its stability in expected harsh environments, compatibility with microfabrication techniques, and required optical performance. Our goal is to tailor the optical properties for high (near unity) absorptivity across the majority of the solar spectrum and over a broad range of incidence angles, and at the same time achieve negligible absorptivity in the near infrared to optimize the energy absorbed and retained. To this goal, we apply the recently developed concept of plasmonic Brewster angle to suitably designed

Environmental impacts of high penetration renewable energy scenarios for Europe

International Nuclear Information System (INIS)

Berrill, Peter; Arvesen, Anders; Hertwich, Edgar G; Scholz, Yvonne; Gils, Hans Christian

2016-01-01

The prospect of irreversible environmental alterations and an increasingly volatile climate pressurises societies to reduce greenhouse gas emissions, thereby mitigating climate change impacts. As global electricity demand continues to grow, particularly if considering a future with increased electrification of heat and transport sectors, the imperative to decarbonise our electricity supply becomes more urgent. This letter implements outputs of a detailed power system optimisation model into a prospective life cycle analysis framework in order to present a life cycle analysis of 44 electricity scenarios for Europe in 2050, including analyses of systems based largely on low-carbon fossil energy options (natural gas, and coal with carbon capture and storage (CCS)) as well as systems with high shares of variable renewable energy (VRE) (wind and solar). VRE curtailments and impacts caused by extra energy storage and transmission capabilities necessary in systems based on VRE are taken into account. The results show that systems based largely on VRE perform much better regarding climate change and other impact categories than the investigated systems based on fossil fuels. The climate change impacts from Europe for the year 2050 in a scenario using primarily natural gas are 1400 Tg CO 2 -eq while in a scenario using mostly coal with CCS the impacts are 480 Tg CO 2 -eq. Systems based on renewables with an even mix of wind and solar capacity generate impacts of 120–140 Tg CO 2 -eq. Impacts arising as a result of wind and solar variability do not significantly compromise the climate benefits of utilising these energy resources. VRE systems require more infrastructure leading to much larger mineral resource depletion impacts than fossil fuel systems, and greater land occupation impacts than systems based on natural gas. Emissions and resource requirements from wind power are smaller than from solar power. (letter)

Environmental impacts of high penetration renewable energy scenarios for Europe

Science.gov (United States)

Berrill, Peter; Arvesen, Anders; Scholz, Yvonne; Gils, Hans Christian; Hertwich, Edgar G.

2016-01-01

The prospect of irreversible environmental alterations and an increasingly volatile climate pressurises societies to reduce greenhouse gas emissions, thereby mitigating climate change impacts. As global electricity demand continues to grow, particularly if considering a future with increased electrification of heat and transport sectors, the imperative to decarbonise our electricity supply becomes more urgent. This letter implements outputs of a detailed power system optimisation model into a prospective life cycle analysis framework in order to present a life cycle analysis of 44 electricity scenarios for Europe in 2050, including analyses of systems based largely on low-carbon fossil energy options (natural gas, and coal with carbon capture and storage (CCS)) as well as systems with high shares of variable renewable energy (VRE) (wind and solar). VRE curtailments and impacts caused by extra energy storage and transmission capabilities necessary in systems based on VRE are taken into account. The results show that systems based largely on VRE perform much better regarding climate change and other impact categories than the investigated systems based on fossil fuels. The climate change impacts from Europe for the year 2050 in a scenario using primarily natural gas are 1400 Tg CO2-eq while in a scenario using mostly coal with CCS the impacts are 480 Tg CO2-eq. Systems based on renewables with an even mix of wind and solar capacity generate impacts of 120-140 Tg CO2-eq. Impacts arising as a result of wind and solar variability do not significantly compromise the climate benefits of utilising these energy resources. VRE systems require more infrastructure leading to much larger mineral resource depletion impacts than fossil fuel systems, and greater land occupation impacts than systems based on natural gas. Emissions and resource requirements from wind power are smaller than from solar power.

Containment penetration design and analysis by finite element methods

International Nuclear Information System (INIS)

Perry, R.F.; Rigamonti, G.; Dainora, J.

1975-01-01

Containment penetration designs which provide complete support to process piping containing high pressure and high temperature fluids and which do not employ cooling coils, require special provisions to sustain loadings associated with normal/abnormal conditions and to limit maximum temperature transmitted to the containment concrete wall. In order to accomodate piping loads and fluid temperatures within code and regulatory limitations, the containment penetration designs require careful analysis of two critical regions: 1) the portion of the penetration sleeve which is exposed to containment ambient conditions and 2) the portion of the penetration which connects the sleeve to process piping (flued head). Analytical models using finite element representation of process piping, penetration flued head, and exposed sleeve were employed to investigate the penetration assembly design. By application of flexible multi-step analyses, different penetration configurations were evaluated to determine the effects of key design parameters. Among the parameters studied were flued head angles with the process piping, sleeve length and wall thickness. Special designs employing fins welded to the sleeve to further lower the temperature at the concrete wall interface were also investigated and fin geometry effects reported. (Auth.)

Energy Storage Options for Voltage Support in Low-Voltage Grids with High Penetration of Photovoltaic

DEFF Research Database (Denmark)

Marra, Francesco; Tarek Fawzy, Y.; Bülo, Thorsten

2012-01-01

to be established. In the long term, these solutions should also aim to allow further more PV installed capacity, while meeting the power quality requirements. In this paper, different concepts of energy storage are proposed to ensure the voltage quality requirements in a LV grid with high PV penetration...

Ulysses solar wind plasma observations at high southerly latitudes.

Science.gov (United States)

Phillips, J L; Bame, S J; Feldman, W C; Gosling, J T; Hammond, C M; McComas, D J; Goldstein, B E; Neugebauer, M; Scime, E E; Suess, S T

1995-05-19

Solar wind plasma observations made by the Ulysses spacecraft through -80.2 degrees solar latitude and continuing equatorward to -40.1 degrees are summarized. Recurrent high-speed streams and corotating interaction regions dominated at middle latitudes. The speed of the solar wind was typically 700 to 800 kilometers per second poleward of -35 degrees . Corotating reverse shocks persisted farther south than did forward shocks because of the tilt of the heliomagnetic streamer belt. Sporadic coronal mass ejections were seen as far south as -60.5 degrees . Proton temperature was higher and the electron strahl was broader at higher latitudes. The high-latitude wind contained compressional, pressure-balanced, and Alfvénic structures.

Low Force Penetration of Icy Regolith

Science.gov (United States)

Mantovani, J. G.; Galloway, G. M.; Zacny, K.

2016-01-01

A percussive cone penetrometer measures the strength of granular material by using percussion to deliver mechanical energy into the material. A percussive cone penetrometer was used in this study to penetrate a regolith ice mixture by breaking up ice and decompacting the regolith. As compared to a static cone penetrometer, percussion allows low reaction forces to push a penetrometer probe tip more easily into dry regolith in a low gravity environment from a planetary surface rover or a landed spacecraft. A percussive cone penetrates icy regolith at ice concentrations that a static cone cannot penetrate. In this study, the percussive penetrator was able to penetrate material under 65 N of down-force which could not be penetrated using a static cone under full body weight. This paper discusses using a percussive cone penetrometer to discern changes in the concentration of water-ice in a mixture of lunar regolith simulant and ice to a depth of one meter. The rate of penetration was found to be a function of the ice content and was not significantly affected by the down-force. The test results demonstrate that this method may be ideal for a small platform in a reduced gravity environment. However, there are some cases where the system may not be able to penetrate the icy regolith, and there is some risk of the probe tip becoming stuck so that it cannot be retracted. It is also shown that a percussive cone penetrometer could be used to prospect for water ice in regolith at concentrations as high as 8 by weight.

Studying the Impact of Distributed Solar PV on Power Systems using Integrated Transmission and Distribution Models: Preprint

Energy Technology Data Exchange (ETDEWEB)

Jain, Himanshu [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Palmintier, Bryan S [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Krad, Ibrahim [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Krishnamurthy, Dheepak [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2017-08-24

This paper presents the results of a distributed solar PV impact assessment study that was performed using a synthetic integrated transmission (T) and distribution (D) model. The primary objective of the study was to present a new approach for distributed solar PV impact assessment, where along with detailed models of transmission and distribution networks, consumer loads were modeled using the physics of end-use equipment, and distributed solar PV was geographically dispersed and connected to the secondary distribution networks. The highlights of the study results were (i) increase in the Area Control Error (ACE) at high penetration levels of distributed solar PV; and (ii) differences in distribution voltages profiles and voltage regulator operations between integrated T&D and distribution only simulations.

Can industry afford solar energy

Science.gov (United States)

Kreith, F.; Bezdek, R.

1983-03-01

Falling oil prices and conservation measures have reduced the economic impetus to develop new energy sources, thus decreasing the urgency for bringing solar conversion technologies to commercial readiness at an early date. However, the capability for solar to deliver thermal energy for industrial uses is proven. A year-round operation would be three times as effective as home heating, which is necessary only part of the year. Flat plate, parabolic trough, and solar tower power plant demonstration projects, though uneconomically operated, have revealed engineering factors necessary for successful use of solar-derived heat for industrial applications. Areas of concern have been categorized as technology comparisons, load temperatures, plant size, location, end-use, backup requirements, and storage costs. Tax incentives have, however, supported home heating and not industrial uses, and government subsidies have historically gone to conventional energy sources. Tax credit programs which could lead to a 20% market penetration by solar energy in the industrial sector by the year 2000 are presented.

High performance a-Si solar cells and new fabrication methods for a-Si solar cells

Science.gov (United States)

Nakano, S.; Kuwano, Y.; Ohnishi, M.

1986-12-01

The super chamber, a separated UHV reaction-chamber system has been developed. A conversion efficiency of 11.7% was obtained for an a-Si solar cell using a high-quality i-layer deposited by the super chamber, and a p-layer fabricated by a photo-CVD method. As a new material, amorphous superlattice-structure films were fabricated by the photo-CVD method for the first time. Superlattice structure p-layer a-Si solar cells were fabricated, and a conversion efficiency of 10.5% was obtained. For the fabrication of integrated type a-Si solar cell modules, a laser pattering method was investigated. A thermal analysis of the multilayer structure was done. It was confirmed that selective scribing for a-Si, TCO and metal film is possible by controlling the laser power density. Recently developed a-Si solar power generation systems and a-Si solar cell roofing tiles are also described.

Influence of hole transport material/metal contact interface on perovskite solar cells

Science.gov (United States)

Lei, Lei; Zhang, Shude; Yang, Songwang; Li, Xiaomin; Yu, Yu; Wei, Qingzhu; Ni, Zhichun; Li, Ming

2018-06-01

Interfaces have a significant impact on the performance of perovskite solar cells. This work investigated the influence of hole transport material/metal contact interface on photovoltaic behaviours of perovskite solar devices. Different hole material/metal contact interfaces were obtained by depositing the metal under different conditions. High incident kinetic energy metal particles were proved to penetrate and embed into the hole transport material. These isolated metal particles in hole transport materials capture holes and increase the apparent carrier transport resistance of the hole transport layer. Sample temperature was found to be of great significance in metal deposition. Since metal vapour has a high temperature, the deposition process accumulated a large amount of heat. The heat evaporated the additives in the hole transport layer and decreased the hole conductivity. On the other hand, high temperature may cause iodization of the metal contact.

THE EFFECT OF TURBULENCE INTERMITTENCE ON THE EMISSION OF SOLAR ENERGETIC PARTICLES BY CORONAL AND INTERPLANETARY SHOCKS

International Nuclear Information System (INIS)

Kocharov, Leon; Laitinen, Timo; Vainio, Rami

2013-01-01

Major solar energetic particle events are associated with shock waves in solar corona and solar wind. Fast scattering of charged particles by plasma turbulence near the shock wave increases the efficiency of the particle acceleration in the shock, but prevents particles from escaping ahead of the shock. However, the turbulence energy levels in neighboring magnetic tubes of solar wind may differ from each other by more than one order of magnitude. We present the first theoretical study of accelerated particle emission from an oblique shock wave propagating through an intermittent turbulence background that consists of both highly turbulent magnetic tubes, where particles are accelerated, and quiet tubes, via which the accelerated particles can escape to the non-shocked solar wind. The modeling results imply that the presence of the fast transport channels penetrating the shock and cross-field transport of accelerated particles to those channels may play a key role in high-energy particle emission from distant shocks and can explain the prompt onset of major solar energetic particle events observed near the Earth's orbit

THE EFFECT OF TURBULENCE INTERMITTENCE ON THE EMISSION OF SOLAR ENERGETIC PARTICLES BY CORONAL AND INTERPLANETARY SHOCKS

Energy Technology Data Exchange (ETDEWEB)

Kocharov, Leon [Sodankylä Geophysical Observatory (Oulu Unit), P.O. Box 3000, University of Oulu, FI-90014 Oulu (Finland); Laitinen, Timo [Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE (United Kingdom); Vainio, Rami [Department of Physics, P.O. Box 64, University of Helsinki, FI-00014 Helsinki (Finland)

2013-11-20

Major solar energetic particle events are associated with shock waves in solar corona and solar wind. Fast scattering of charged particles by plasma turbulence near the shock wave increases the efficiency of the particle acceleration in the shock, but prevents particles from escaping ahead of the shock. However, the turbulence energy levels in neighboring magnetic tubes of solar wind may differ from each other by more than one order of magnitude. We present the first theoretical study of accelerated particle emission from an oblique shock wave propagating through an intermittent turbulence background that consists of both highly turbulent magnetic tubes, where particles are accelerated, and quiet tubes, via which the accelerated particles can escape to the non-shocked solar wind. The modeling results imply that the presence of the fast transport channels penetrating the shock and cross-field transport of accelerated particles to those channels may play a key role in high-energy particle emission from distant shocks and can explain the prompt onset of major solar energetic particle events observed near the Earth's orbit.

High-cadence Imaging and Imaging Spectroscopy at the GREGOR Solar Telescope—A Collaborative Research Environment for High-resolution Solar Physics

Science.gov (United States)

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.

Rooftop Solar Technical Potential for Low-to-Moderate Income Households in the United States

Energy Technology Data Exchange (ETDEWEB)

Sigrin, Benjamin O [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Mooney, Meghan E [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-04-17

This report presents a first-of-kind assessment of the technical potential of rooftop solar for low and moderate-income households, as well as providing insight on the distribution of solar potential by tenure, income, and other building characteristics. We find that a substantial fraction of the national rooftop solar potential is located on LMI buildings and, for all incomes, a substantial fraction on multi-family and renter-occupied buildings. We also find that rooftop solar can significantly contribute to long-term penetration targets established by the U.S. DOE, though to do so requires deployment on multi-family and renter-occupied buildings. Traditional deployment models have insufficiently enabled access to solar for these income groups and building types. Without innovation either in regulatory, market, or policy factors, a large fraction of the U.S. potential is unlikely to be addressed, as well as leading to inequalities in solar access. Ironically, potential electric bill savings from rooftop solar would have the greatest material impact on the lives of low-income households as compared to their high-income counterparts.

Projectile Nose Mass Abrasion of High-Speed Penetration into Concrete

Directory of Open Access Journals (Sweden)

Haijun Wu

2012-01-01

Full Text Available Based on the dynamic spherical cavity expansion theory of concrete and the analysis of experimental data, a mass abrasion model of projectile considering the hardness of aggregates, the relative strength of target and projectile, and the initial impact velocity is constructed in this paper. Furthermore, the effect of mass abrasion on the penetration depth of projectile and the influence of hardness of aggregates and strength of projectile on penetration depth and mass loss are also analyzed. The results show that, for the ogive-nose projectile with the CRH of 3 and aspect ratio of 7 penetrating the concrete of 35 MPa, the “rigid-body penetration” model is available when the initial impact velocity is lower than 800 m/s. However, when the initial impact velocity is higher than 800 m/s, the “deforming/eroding body penetration” model should be adopted. Through theoretical analysis and numerical calculation, the results indicate that the initial impact velocity is the most important factor of mass abrasion. The hardness of aggregates and the strength of projectile are also significant factors. But relatively speaking, the sensitivity of strength of projectile to mass abrasion is higher, which indicates that the effect of projectile material on mass abrasion is more dramatic than the hardness of aggregates.

Solar Energy Education. Renewable energy activities for junior high/middle school science

Energy Technology Data Exchange (ETDEWEB)

1985-01-01

Some basic topics on the subject of solar energy are outlined in the form of a teaching manual. The manual is geared toward junior high or middle school science students. Topics include solar collectors, solar water heating, solar radiation, insulation, heat storage, and desalination. Instructions for the construction of apparatus to demonstrate the solar energy topics are provided. (BCS)

CONDITIONED ANALYSIS OF HIGH-LATITUDE SOLAR WIND INTERMITTENCY

International Nuclear Information System (INIS)

D'Amicis, R.; Consolini, G.; Bavassano, B.; Bruno, R.

2012-01-01

The solar wind is a turbulent medium displaying intermittency. Its intermittent features have been widely documented and studied, showing how the intermittent character is different in fast and slow wind. In this paper, a statistical conditioned analysis of the solar wind intermittency for a period of high-latitude fast solar wind is presented. In particular, the intermittent features are investigated as a function of the Alfvénic degree of fluctuations at a given scale. The results show that the main contribution to solar wind intermittency is due to non-Alfvénic structures, while Alfvénic increments are found to be characterized by a smaller level of intermittency than the previous ones. Furthermore, the lifetime statistics of Alfvénic periods are discussed in terms of a multiscale texture of randomly oriented flux tubes.

High-Temperature-Short-Time Annealing Process for High-Performance Large-Area Perovskite Solar Cells.

Science.gov (United States)

Kim, Minjin; Kim, Gi-Hwan; Oh, Kyoung Suk; Jo, Yimhyun; Yoon, Hyun; Kim, Ka-Hyun; Lee, Heon; Kim, Jin Young; Kim, Dong Suk

2017-06-27

Organic-inorganic hybrid metal halide perovskite solar cells (PSCs) are attracting tremendous research interest due to their high solar-to-electric power conversion efficiency with a high possibility of cost-effective fabrication and certified power conversion efficiency now exceeding 22%. Although many effective methods for their application have been developed over the past decade, their practical transition to large-size devices has been restricted by difficulties in achieving high performance. Here we report on the development of a simple and cost-effective production method with high-temperature and short-time annealing processing to obtain uniform, smooth, and large-size grain domains of perovskite films over large areas. With high-temperature short-time annealing at 400 °C for 4 s, the perovskite film with an average domain size of 1 μm was obtained, which resulted in fast solvent evaporation. Solar cells fabricated using this processing technique had a maximum power conversion efficiency exceeding 20% over a 0.1 cm 2 active area and 18% over a 1 cm 2 active area. We believe our approach will enable the realization of highly efficient large-area PCSs for practical development with a very simple and short-time procedure. This simple method should lead the field toward the fabrication of uniform large-scale perovskite films, which are necessary for the production of high-efficiency solar cells that may also be applicable to several other material systems for more widespread practical deployment.

Streaming of interstellar grains in the solar system

Science.gov (United States)

Gustafson, B. A. S.; Misconi, N. Y.

1979-01-01

Results of a theoretical study of the interactions between interstellar grains streaming through the solar system and the solar wind are presented. It is shown that although elongated core-mantle interstellar particles of a characteristic radius of about 0.12 microns are subject to a greater force due to radiation pressure than to gravitational attraction, they are still able to penetrate deep inside the solar system. Calculations of particle trajectories within the solar system indicate substantial effects of the solar activity cycle as reflected in the interplanetary magnetic field on the distribution of 0.12- and 0.0005-micron interstellar grains streaming through the solar system, leading to a 50-fold increase in interstellar grain densities 3 to 4 AU ahead of the sun during years 8 to 17 of the solar cycle. It is noted that during the Solar Polar Mission, concentrations are expected which will offer the opportunity of detecting interstellar grains in the solar system.

Cryo-braking using penetrators for enhanced capabilities for the potential landing of payloads on icy solar system objects

Science.gov (United States)

Winglee, R. M.; Robinson, T.; Danner, M.; Koch, J.

2018-03-01

The icy moons of Jupiter and Saturn are important astrobiology targets. Access to the surface of these worlds is made difficult by the high ΔV requirements which is typically in the hypervelocity range. Passive braking systems cannot be used due to the lack of an atmosphere, and active braking by rockets significantly adds to the missions costs. This paper demonstrates that a two-stage landing system can overcome these problems and provide significant improvements in the payload fraction that can be landed The first stage involves a hypervelocity impactor which is designed to penetrate to a depth of a few tens of meters. This interaction is the cryo-breaking component and is examined through laboratory experiments, empirical relations and modeling. The resultant ice-particle cloud creates a transient artificial atmosphere that can be used to enable passive braking of the second stage payload dd, with a substantially higher mass payload fraction than possible with a rocket landing system. It is shown that a hollow cylinder design for the impactor can more efficiently eject the material upwards in a solid cone of ice particles relative to solid impactors such as spheres or spikes. The ejected mass is shown to be of the order of 103 to 104 times the mass of the impactor. The modeling indicates that a 10 kg payload with a braking system of 3 m2 (i.e. an areal density of 0.3 kg/m2) is sufficient to allow the landing of the payload with the deceleration limited to less than 2000 g's. Modern electronics can withstand this deceleration and as such the system provides an important alternative to landing payloads on icy solar system objects.

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

Investigating the real situation of Greek solar water heating market

International Nuclear Information System (INIS)

Kaldellis, J.K.; Kavadias, K.A.; Spyropoulos, G.

2005-01-01

Solar thermal applications have been acknowledged among the leading alternative solutions endeavouring to face the uncontrollable oil price variations, the gradual depletion of fossil fuel reserves and the chain environmental consequences caused by its excessive usage. Almost 30 years after the initial emergence of the commercial domestic solar water heating system (DSWHS) in the European market, the corresponding technology is qualified as quite mature. On top of this, the European Commission expects that 100,000,000 m 2 of solar collectors are to be installed in Europe by the year 2010 to facilitate durable and environment-friendly heat. In this context, the Greek DSWHSs market is highly developed worldwide, having a great experience in this major energy market segment. The present study is devoted to an extensive evaluation of the local DSWHSs market, including a discerning analysis of its time variation, taking seriously into account the corresponding annual replacement rate. Accordingly, the crucial techno-economic reasons, limiting the DSWHSs penetration in the local heat production market, are summarized and elaborated. Subsequently, the national policy measures - aiming to support the DSWHSs in the course of time - are cited, in comparison with those applied in other European countries. Next, the financial attractiveness of a DSWHS for Greek citizens is examined in the local socio-economic environment. The present work is integrated by reciting the prospects and mustering certain proposals that, if applied, could stimulate the local market. As a general comment, the outlook for penetration of new DSWHSs in the local market is rather grim, as the current techno-economic situation of solar heat cannot compete with oil and natural gas heat production, unless the remarkable social and environmental benefits of solar energy are seriously considered. Hence, the Greek State lacks stimulus to further DSWHSs installations, being strongly in support of the imported

High resolution solar observations

International Nuclear Information System (INIS)

Title, A.

1985-01-01

Currently there is a world-wide effort to develop optical technology required for large diffraction limited telescopes that must operate with high optical fluxes. These developments can be used to significantly improve high resolution solar telescopes both on the ground and in space. When looking at the problem of high resolution observations it is essential to keep in mind that a diffraction limited telescope is an interferometer. Even a 30 cm aperture telescope, which is small for high resolution observations, is a big interferometer. Meter class and above diffraction limited telescopes can be expected to be very unforgiving of inattention to details. Unfortunately, even when an earth based telescope has perfect optics there are still problems with the quality of its optical path. The optical path includes not only the interior of the telescope, but also the immediate interface between the telescope and the atmosphere, and finally the atmosphere itself

Superlattice photonic crystal as broadband solar absorber for high temperature operation.

Science.gov (United States)

Rinnerbauer, Veronika; Shen, Yichen; Joannopoulos, John D; Soljačić, Marin; Schäffler, Friedrich; Celanovic, Ivan

2014-12-15

A high performance solar absorber using a 2D tantalum superlattice photonic crystal (PhC) is proposed and its design is optimized for high-temperature energy conversion. In contrast to the simple lattice PhC, which is limited by diffraction in the short wavelength range, the superlattice PhC achieves solar absorption over broadband spectral range due to the contribution from two superposed lattices with different cavity radii. The superlattice PhC geometry is tailored to achieve maximum thermal transfer efficiency for a low concentration system of 250 suns at 1500 K reaching 85.0% solar absorptivity. In the high concentration case of 1000 suns, the superlattice PhC absorber achieves a solar absorptivity of 96.2% and a thermal transfer efficiency of 82.9% at 1500 K, amounting to an improvement of 10% and 5%, respectively, versus the simple square lattice PhC absorber. In addition, the performance of the superlattice PhC absorber is studied in a solar thermophotovoltaic system which is optimized to minimize absorber re-emission by reducing the absorber-to-emitter area ratio and using a highly reflective silver aperture.

Influence of the mole penetrator on measurements of heat flow in lunar subsurface layers

Science.gov (United States)

Wawrzaszek, Roman; Drogosz, Michal; Seweryn, Karol; Banaszkiewicz, Marek; Grygorczuk, Jerzy

Measuring the thermal gradient in subsurface layers is a basic method of determination the heat flux from the interior of a planetary body to its surface. In case of the Moon, such measurements complemented with the results of theoretical analysis and modeling can significantly improve our understanding of the thermal and geological evolution of the Moon. In practice, temperature gradient measurements are performed by at least two sensors located at different depths under the surface. These sensors will be attached to a penetrator [1] or to a cable pulled behind the penetrator. In both cases the object that carries the sensors, e.g. penetrator, perturb temperature measurements. In our study we analyze a case of two thermal sensors attached to the ends of 350mm long penetrator made of a composite material. In agreement with the studies of other authors we have found that the penetrator should be placed at the depth of 2-3 meters, where periodic changes of the temperature due to variation of solar flux at the surface are significantly smaller than the error of temperature measurement. The most important result of our analysis is to show how to deconvolve the real gradient of the temperature from the measurements perturbed by the penetrator body. In this way it will be possible to more accurately determine heat flux in the lunar regolith. [1] Grygorczuk J., Seweryn K., Wawrzaszek R., Banaszkiewicz M., Insertion of a Mole Pene-trator -Experimental Results, /39th Lunar and Planetary Science Conference /League City, Texas 2008

Penetrating ureteral trauma

Directory of Open Access Journals (Sweden)

Gustavo P. Fraga

2007-04-01

Full Text Available OBJECTIVE: The purpose of this series is to report our experience in managing ureteral trauma, focusing on the importance of early diagnosis, correct treatment, and the impact of associated injuries on the management and morbid-mortality. MATERIALS AND METHODS: From January 1994 to December 2002, 1487 laparotomies for abdominal trauma were performed and 20 patients with ureteral lesions were identified, all of them secondary to penetrating injury. Medical charts were analyzed as well as information about trauma mechanisms, diagnostic routine, treatment and outcome. RESULTS: All patients were men. Mean age was 27 years. The mechanisms of injury were gunshot wounds in 18 cases (90% and stab wounds in two (10%. All penetrating abdominal injuries had primary indication of laparotomy, and neither excretory urography nor computed tomography were used in any case before surgery. The diagnosis of ureteric injury was made intra-operatively in 17 cases (85%. Two ureteral injuries (10% were initially missed. All patients had associated injuries. The treatment was dictated by the location, extension and time necessary to identify the injury. The overall incidence of complications was 55%. The presence of shock on admission, delayed diagnosis, Abdominal Trauma Index > 25, Injury Severity Score > 25 and colon injuries were associated to a high complication rate, however, there was no statistically significant difference. There were no mortalities in this group. CONCLUSIONS: A high index of suspicion is required for diagnosis of ureteral injuries. A thorough exploration of all retroperitoneal hematoma after penetrating trauma should be an accurate method of diagnosis; even though it failed in 10% of our cases.

LCA of electricity systems with high wind power penetration

DEFF Research Database (Denmark)

Turconi, Roberto; O' Dwyer, C. O.; Flynn, D.

Electricity systems are shifting from being based on fossil fuels towards renewable sources to enhance energy security and mitigate climate change. However, by introducing high shares of variable renewables - such as wind and solar - dispatchable power plants are required to vary their output...... to fulfill the remaining electrical demand, potentially increasing their environmental impacts [1,2]. In this study the environmental impacts of potential short-term future electricity systems in Ireland with high shares of wind power (35-50% of total installed capacity) were evaluated using life cycle...... considered: while not outweighing the benefits from increasing wind energy, cycling emissions are not negligible and should thus be systematically included (i.e. by using emission factors per unit of fuel input rather than per unit of power generated). Cycling emissions increased with the installed wind...

Radiation hardened high efficiency silicon space solar cell

International Nuclear Information System (INIS)

Garboushian, V.; Yoon, S.; Turner, J.

1993-01-01

A silicon solar cell with AMO 19% Beginning of Life (BOL) efficiency is reported. The cell has demonstrated equal or better radiation resistance when compared to conventional silicon space solar cells. Conventional silicon space solar cell performance is generally ∼ 14% at BOL. The Radiation Hardened High Efficiency Silicon (RHHES) cell is thinned for high specific power (watts/kilogram). The RHHES space cell provides compatibility with automatic surface mounting technology. The cells can be easily combined to provide desired power levels and voltages. The RHHES space cell is more resistant to mechanical damage due to micrometeorites. Micro-meteorites which impinge upon conventional cells can crack the cell which, in turn, may cause string failure. The RHHES, operating in the same environment, can continue to function with a similar crack. The RHHES cell allows for very efficient thermal management which is essential for space cells generating higher specific power levels. The cell eliminates the need for electrical insulation layers which would otherwise increase the thermal resistance for conventional space panels. The RHHES cell can be applied to a space concentrator panel system without abandoning any of the attributes discussed. The power handling capability of the RHHES cell is approximately five times more than conventional space concentrator solar cells

High-energy solar flare observations at the Y2K maximum

Science.gov (United States)

Emslie, A. Gordon

2000-04-01

Solar flares afford an opportunity to observe processes associated with the acceleration and propagation of high-energy particles at a level of detail not accessible in any other astrophysical source. I will review some key results from previous high-energy solar flare observations, including those from the Compton Gamma-Ray Observatory, and the problems that they pose for our understanding of energy release and particle acceleration processes in the astrophysical environment. I will then discuss a program of high-energy observations to be carried out during the upcoming 2000-2001 solar maximum that is aimed at addressing and resolving these issues. A key element in this observational program is the High Energy Solar Spectroscopic Imager (HESSI) spacecraft, which will provide imaging spectroscopic observations with spatial, temporal, and energy resolutions commensurate with the physical processes believed to be operating, and will in addition provide the first true gamma-ray spectroscopy of an astrophysical source. .

Corrugation Architecture Enabled Ultraflexible Wafer-Scale High-Efficiency Monocrystalline Silicon Solar Cell

KAUST Repository

Bahabry, Rabab R.

2018-01-02

Advanced classes of modern application require new generation of versatile solar cells showcasing extreme mechanical resilience, large-scale, low cost, and excellent power conversion efficiency. Conventional crystalline silicon-based solar cells offer one of the most highly efficient power sources, but a key challenge remains to attain mechanical resilience while preserving electrical performance. A complementary metal oxide semiconductor-based integration strategy where corrugation architecture enables ultraflexible and low-cost solar cell modules from bulk monocrystalline large-scale (127 × 127 cm) silicon solar wafers with a 17% power conversion efficiency. This periodic corrugated array benefits from an interchangeable solar cell segmentation scheme which preserves the active silicon thickness of 240 μm and achieves flexibility via interdigitated back contacts. These cells can reversibly withstand high mechanical stress and can be deformed to zigzag and bifacial modules. These corrugation silicon-based solar cells offer ultraflexibility with high stability over 1000 bending cycles including convex and concave bending to broaden the application spectrum. Finally, the smallest bending radius of curvature lower than 140 μm of the back contacts is shown that carries the solar cells segments.

Corrugation Architecture Enabled Ultraflexible Wafer-Scale High-Efficiency Monocrystalline Silicon Solar Cell

KAUST Repository

Bahabry, Rabab R.; Kutbee, Arwa T.; Khan, Sherjeel M.; Sepulveda, Adrian C.; Wicaksono, Irmandy; Nour, Maha A.; Wehbe, Nimer; Almislem, Amani Saleh Saad; Ghoneim, Mohamed T.; Sevilla, Galo T.; Syed, Ahad; Shaikh, Sohail F.; Hussain, Muhammad Mustafa

2018-01-01

Advanced classes of modern application require new generation of versatile solar cells showcasing extreme mechanical resilience, large-scale, low cost, and excellent power conversion efficiency. Conventional crystalline silicon-based solar cells offer one of the most highly efficient power sources, but a key challenge remains to attain mechanical resilience while preserving electrical performance. A complementary metal oxide semiconductor-based integration strategy where corrugation architecture enables ultraflexible and low-cost solar cell modules from bulk monocrystalline large-scale (127 × 127 cm) silicon solar wafers with a 17% power conversion efficiency. This periodic corrugated array benefits from an interchangeable solar cell segmentation scheme which preserves the active silicon thickness of 240 μm and achieves flexibility via interdigitated back contacts. These cells can reversibly withstand high mechanical stress and can be deformed to zigzag and bifacial modules. These corrugation silicon-based solar cells offer ultraflexibility with high stability over 1000 bending cycles including convex and concave bending to broaden the application spectrum. Finally, the smallest bending radius of curvature lower than 140 μm of the back contacts is shown that carries the solar cells segments.

Evaluating the limits of solar photovoltaics (PV) in electric power systems utilizing energy storage and other enabling technologies

International Nuclear Information System (INIS)

Denholm, Paul; Margolis, Robert M.

2007-01-01

In this work, we evaluate technologies that will enable solar photovoltaics (PV) to overcome the limits of traditional electric power systems. We performed simulations of a large utility system using hourly solar insolation and load data and attempted to provide up to 50% of this system's energy from PV. We considered several methods to avoid the limits of unusable PV that result at high penetration due to the use of inflexible baseload generators. The enabling technologies considered in this work are increased system flexibility, load shifting via demand responsive appliances, and energy storage

Simulation of the charging process of the LISA test masses due to solar flares

International Nuclear Information System (INIS)

Vocca, H; Grimani, C; Amico, P; Bosi, L; Marchesoni, F; Punturo, M; Travasso, F; Barone, M; Stanga, R; Vetrano, F; Vicere, A

2004-01-01

Cosmic-ray and solar high energy particles penetrate the LISA experiment test masses. Consequently, an electric charge accumulates in the bodies of the masses, generating spurious Coulomb forces between the masses and the surrounding electrodes. This process increases the noise level of the experiment. We have estimated the amount of charge deposited per second on the LISA test masses by solar flares and primary cosmic-ray protons at solar minimum. The simulation has been carried out with the Fluka Monte Carlo program. A simplified geometry for the experiment has been considered. We have found a net charging rate of 37 ± 1 e + /s for primary protons at solar minimum between 0.1 and 1000 GeV/n. The amount of charge released by a medium-strong solar flare, like that of 16 February 1984, is 10 732 ± 30 e + /s in the energy range 0.1-10 GeV/n. This value increases or decreases by approximately one order of magnitude for strong (weak) solar flares

Profit-based conventional resource scheduling with renewable energy penetration

Science.gov (United States)

Reddy, K. Srikanth; Panwar, Lokesh Kumar; Kumar, Rajesh; Panigrahi, B. K.

2017-08-01

Technological breakthroughs in renewable energy technologies (RETs) enabled them to attain grid parity thereby making them potential contenders for existing conventional resources. To examine the market participation of RETs, this paper formulates a scheduling problem accommodating energy market participation of wind- and solar-independent power producers (IPPs) treating both conventional and RETs as identical entities. Furthermore, constraints pertaining to penetration and curtailments of RETs are restructured. Additionally, an appropriate objective function for profit incurred by conventional resource IPPs through reserve market participation as a function of renewable energy curtailment is also proposed. The proposed concept is simulated with a test system comprising 10 conventional generation units in conjunction with solar photovoltaic (SPV) and wind energy generators (WEG). The simulation results indicate that renewable energy integration and its curtailment limits influence the market participation or scheduling strategies of conventional resources in both energy and reserve markets. Furthermore, load and reliability parameters are also affected.

Electric Vehicles for Improved Operation of Power Systems with High Wind Power Penetration

OpenAIRE

Larsen, Esben; Chandrashekhara, Divya K; Østergaard, Jacob

2008-01-01

In a power system with a high share of wind energy the wind fluctuation causes a variation in the power generation, which must be compensated from other sources. The situation in Denmark with a penetration of more than 20% wind in yearly average is presented. The introduction of electric drive vehicles (EDV) as flexible loads can improve the system operation. Bidirectional power exchange through batteries (vehicle to grid) can be seen as a storage system in the grid. An analysis of possible e...

SunShot solar power reduces costs and uncertainty in future low-carbon electricity systems.

Science.gov (United States)

Mileva, Ana; Nelson, James H; Johnston, Josiah; Kammen, Daniel M

2013-08-20

The United States Department of Energy's SunShot Initiative has set cost-reduction targets of $1/watt for central-station solar technologies. We use SWITCH, a high-resolution electricity system planning model, to study the implications of achieving these targets for technology deployment and electricity costs in western North America, focusing on scenarios limiting carbon emissions to 80% below 1990 levels by 2050. We find that achieving the SunShot target for solar photovoltaics would allow this technology to provide more than a third of electric power in the region, displacing natural gas in the medium term and reducing the need for nuclear and carbon capture and sequestration (CCS) technologies, which face technological and cost uncertainties, by 2050. We demonstrate that a diverse portfolio of technological options can help integrate high levels of solar generation successfully and cost-effectively. The deployment of GW-scale storage plays a central role in facilitating solar deployment and the availability of flexible loads could increase the solar penetration level further. In the scenarios investigated, achieving the SunShot target can substantially mitigate the cost of implementing a carbon cap, decreasing power costs by up to 14% and saving up to $20 billion ($2010) annually by 2050 relative to scenarios with Reference solar costs.

High Voltage Solar Concentrator Experiment with Implications for Future Space Missions

Science.gov (United States)

Mehdi, Ishaque S.; George, Patrick J.; O'Neill, Mark; Matson, Robert; Brockschmidt, Arthur

2004-01-01

This paper describes the design, development, fabrication, and test of a high performance, high voltage solar concentrator array. This assembly is believed to be the first ever terrestrial triple-junction-cell solar array rated at over 1 kW. The concentrator provides over 200 W/square meter power output at a nominal 600 Vdc while operating under terrestrial sunlight. Space-quality materials and fabrication techniques were used for the array, and the 3005 meter elevation installation below the Tropic of Cancer allowed testing as close as possible to space deployment without an actual launch. The array includes two concentrator modules, each with a 3 square meter aperture area. Each concentrator module uses a linear Fresnel lens to focus sunlight onto a photovoltaic receiver that uses 240 series-connected triple-junction solar cells. Operation of the two receivers in series can provide 1200 Vdc which would be adequate for the 'direct drive' of some ion engines or microwave transmitters in space. Lens aperture width is 84 cm and the cell active width is 3.2 cm, corresponding to a geometric concentration ratio of 26X. The evaluation includes the concentrator modules, the solar cells, and the materials and techniques used to attach the solar cells to the receiver heat sink. For terrestrial applications, a finned aluminum extrusion was used for the heat sink for the solar cells, maintaining a low cell temperature so that solar cell efficiency remains high.

Bias-dependent high saturation solar LBIC scanning of solar cells

Energy Technology Data Exchange (ETDEWEB)

Vorster, F.J.; van Dyk, E.E. [Department of Physics, Nelson Mandela Metropolitan University, P.O. Box 77000, Port Elizabeth 6031 (South Africa)

2007-06-15

A light beam-induced current measurement system that uses concentrated solar radiation as a beam probe to map spatially distributed defects on a solar cell has been developed and tested [F.J. Vorster, E.E. van Dyk, Rev. Sci. Instrum., submitted for review]. The induced current response from a flat plate EFG Si solar cell was mapped as a function of surface position and cell bias by using a solar light beam induced current (S-LBIC) mapping system while at the same time dynamically biasing the whole cell with an external voltage. This paper examines the issues relating to transient capacitive effects as well as the electrical behaviour of typical solar cell defect mechanisms under spot illumination. By examining the bias dependence of the S-LBIC maps, various defect mechanisms of photovoltaic (PV) cells under concentrated solar irradiance may be identified. The techniques employed to interpret the spatially distributed IV curves as well as initial results are discussed. (author)

Solar thermal energy in Latin America and the Caribbean: Status, barriers and solutions

International Nuclear Information System (INIS)

Avalos, C.

1991-01-01

The intention of this paper is to provide an overview of the status of solar development and use in the Region to pinpoint, as best as possible, the causes for solar energy market penetration at less than expected levels, and to suggest solutions for the future. 2 refs, 2 tabs

NREL/SCE High Penetration PV Integration Project: FY13 Annual Report

Energy Technology Data Exchange (ETDEWEB)

Mather, B. A.; Shah, S.; Norris, B. L.; Dise, J. H.; Yu, L.; Paradis, D.; Katiraei, F.; Seguin, R.; Costyk, D.; Woyak, J.; Jung, J.; Russell, K.; Broadwater, R.

2014-06-01

In 2010, the National Renewable Energy Laboratory (NREL), Southern California Edison (SCE), Quanta Technology, Satcon Technology Corporation, Electrical Distribution Design (EDD), and Clean Power Research (CPR) teamed to analyze the impacts of high penetration levels of photovoltaic (PV) systems interconnected onto the SCE distribution system. This project was designed specifically to benefit from the experience that SCE and the project team would gain during the installation of 500 megawatts (MW) of utility-scale PV systems (with 1-5 MW typical ratings) starting in 2010 and completing in 2015 within SCE's service territory through a program approved by the California Public Utility Commission (CPUC). This report provides the findings of the research completed under the project to date.

SOLAR ROTATION EFFECTS ON THE HELIOSHEATH FLOW NEAR SOLAR MINIMA

International Nuclear Information System (INIS)

Borovikov, Sergey N.; Pogorelov, Nikolai V.; Ebert, Robert W.

2012-01-01

The interaction between fast and slow solar wind (SW) due to the Sun's rotation creates corotating interaction regions (CIRs), which further interact with each other creating complex plasma structures at large heliospheric distances. We investigate the global influence of CIRs on the SW flow in the inner heliosheath between the heliospheric termination shock (TS) and the heliopause. The stream interaction model takes into account the major global effects due to slow-fast stream interaction near solar minima. The fast and slow wind parameters are derived from the Ulysses observations. We investigate the penetration of corotating structures through the TS and their further propagation through the heliosheath. It is shown that the heliosheath flow structure may experience substantial modifications, including local decreases in the radial velocity component observed by Voyager 1.

Long range surface plasmon resonance with ultra-high penetration depth for self-referenced sensing and ultra-low detection limit using diverging beam approach

Energy Technology Data Exchange (ETDEWEB)

Isaacs, Sivan, E-mail: sivan.isaacs@gmail.com; Abdulhalim, Ibrahim [Department of Electro-Optical Engineering and TheIlse Katz Institute for Nanoscale Science and Technology, Ben Gurion University of the Negev, Beer Sheva 84105 (Israel); NEW CREATE Programme, School of Materials Science and Engineering, 1 CREATE Way, Research Wing, #02-06/08, Singapore 138602 (Singapore)

2015-05-11

Using an insulator-metal-insulator structure with dielectric having refractive index (RI) larger than the analyte, long range surface plasmon (SP) resonance exhibiting ultra-high penetration depth is demonstrated for sensing applications of large bioentities at wavelengths in the visible range. Based on the diverging beam approach in Kretschmann-Raether configuration, one of the SP resonances is shown to shift in response to changes in the analyte RI while the other is fixed; thus, it can be used as a built in reference. The combination of the high sensitivity, high penetration depth and self-reference using the diverging beam approach in which a dark line is detected of the high sensitivity, high penetration depth, self-reference, and the diverging beam approach in which a dark line is detected using large number of camera pixels with a smart algorithm for sub-pixel resolution, a sensor with ultra-low detection limit is demonstrated suitable for large bioentities.

Greening the Grid: Solar and Wind Grid Integration Study for the Luzon-Visayas System of the Philippines

Energy Technology Data Exchange (ETDEWEB)

Barrows, Clayton P. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Katz, Jessica R. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Cochran, Jaquelin M. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Maclaurin, Galen J. [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Marollano, Mark C. [Dept. of Energy of the Philippines, Taguig (Philippines); Gabis, Mary G. [Dept. of Energy of the Philippines, Taguig (Philippines); Reyes, Noriel C. [Dept. of Energy of the Philippines, Taguig (Philippines); Munoz, Kenneth J. [Dept. of Energy of the Philippines, Taguig (Philippines); Jesus, Clarita D. [Dept. of Energy of the Philippines, Taguig (Philippines); Asedillo, Nielson [Grid Management Committee (GMC), Inc., Pasig City (Philipines); Binayug, Jake [Grid Management Committee (GMC), Inc., Pasig City (Philipines); Cubangbang, Hanzel [National Grid Corporation of the Philippines, Metro Manila (Philippines); Reyes, Rommel [National Grid Corporation of the Philippines, Metro Manila (Philippines); de la Vina, Jonathan [Philippine Electricity Market Corporation, Pasig City (Phillipines); Olmedo, Edward [Philippine Electricity Market Corporation, Pasig City (Phillipines); Leisch, Jennifer [United States Agency for International Development, Washington DC (United States)

2018-01-24

The Republic of the Philippines is home to abundant solar, wind, and other renewable energy (RE) resources that contribute to the national government's vision to ensure sustainable, secure, sufficient, accessible, and affordable energy. Because solar and wind resources are variable and uncertain, significant generation from these resources necessitates an evolution in power system planning and operation. To support Philippine power sector planners in evaluating the impacts and opportunities associated with achieving high levels of variable RE penetration, the Department of Energy of the Philippines (DOE) and the United States Agency for International Development (USAID) have spearheaded this study along with a group of modeling representatives from across the Philippine electricity industry, which seeks to characterize the operational impacts of reaching high solar and wind targets in the Philippine power system, with a specific focus on the integrated Luzon-Visayas grids.

Selectively coated high efficiency glazing for solar-thermal flat-plate collectors

International Nuclear Information System (INIS)

Ehrmann, N.; Reineke-Koch, R.

2012-01-01

In order to increase the efficiency of solar-thermal flat-plate collectors at temperatures above 100 °C or with low solar irradiation, we implement a double glazing with a low-emitting (low-e) coating on the inner pane to improve the insulation of the transparent cover. Since commercially available low-e glazing provides only insufficient solar transmittance for the application in thermal flat-plate collectors we are developing a sputter-deposited low e-coating system based on transparent conductive oxides which provides a high solar transmittance of 85% due to additional antireflective coatings and the use of low-iron glass substrates. Durability tests of the developed coating system show that our low e-coating system is well suitable even at high temperatures, humidity and condensation.

Revisiting long-run relations in power markets with high RES penetration

International Nuclear Information System (INIS)

Gianfreda, Angelica; Parisio, Lucia; Pelagatti, Matteo

2016-01-01

Electricity generation from renewable energy resources (RES) has become increasingly significant to reach EU and emissions reduction targets. At the same time, one of the main EU policy goals has been the creation of a common internal energy market for Europe. In this paper, we focus on these two issues previously studied separately, considering their possible interactions. We first analyze the long-run relationship between day-ahead electricity prices and fuel prices (natural gas and coal) looking at two samples of years characterized by low and high RES penetration, then we explore the integration of EU markets. We show that the electricity–fuel nexus found over 2006–2008 changed dramatically over 2010–2014 for the majority of countries considered. In particular, the long-run dependence of electricity from gas and coal prices is much lower in recent years. Furthermore, our results confirm that the considered EU countries are becoming less integrated as RES-E increases. Our findings suggest that nationally implemented policies to support renewables are successful in increasing RES penetration, but they have lessened the linkage among EU markets, then making integration more difficult to obtain. - Highlights: •RES lower the intra-daily electricity dependence from coal and natural gas. •RES affect the EU wholesale electricity market integration, studied at hourly level. •Overlapping national and supranational policies tackle the achievement of EU targets. •Strong policy coordination is required to avoid that the “greens” promote the “dirtiest”.

Magnetic Fields in the Solar Convection Zone

Directory of Open Access Journals (Sweden)

Fan Yuhong

2004-07-01

Full Text Available Recent studies of the dynamic evolution of magnetic flux tubes in the solar convection zone are reviewed with focus on emerging flux tubes responsible for the formation of solar active regions. The current prevailing picture is that active regions on the solar surface originate from strong toroidal magnetic fields generated by the solar dynamo mechanism at the thin tachocline layer at the base of the solar convection zone. Thus the magnetic fields need to traverse the entire convection zone before they reach the photosphere to form the observed solar active regions. This review discusses results with regard to the following major topics: 1. the equilibrium properties of the toroidal magnetic fields stored in the stable overshoot region at the base of the convection zone, 2. the buoyancy instability associated with the toroidal magnetic fields and the formation of buoyant magnetic flux tubes, 3. the rise of emerging flux loops through the solar convective envelope as modeled by the thin flux tube calculations which infer that the field strength of the toroidal magnetic fields at the base of the solar convection zone is significantly higher than the value in equipartition with convection, 4. the minimum twist needed for maintaining cohesion of the rising flux tubes, 5. the rise of highly twisted kink unstable flux tubes as a possible origin of d -sunspots, 6. the evolution of buoyant magnetic flux tubes in 3D stratified convection, 7. turbulent pumping of magnetic flux by penetrative compressible convection, 8. an alternative mechanism for intensifying toroidal magnetic fields to significantly super-equipartition field strengths by conversion of the potential energy associated with the superadiabatic stratification of the solar convection zone, and finally 9. a brief overview of our current understanding of flux emergence at the surface and post-emergence evolution of the subsurface magnetic fields.

Europa Kinetic Ice Penetrator (EKIP)

Data.gov (United States)

National Aeronautics and Space Administration — The goal of the proposed work is to validate an initial design for a Europa penetrator that can withstand the high g load associated with the expected hypervelocity...

Photo-degradation of high efficiency fullerene-free polymer solar cells.

Science.gov (United States)

Upama, Mushfika Baishakhi; Wright, Matthew; Mahmud, Md Arafat; Elumalai, Naveen Kumar; Mahboubi Soufiani, Arman; Wang, Dian; Xu, Cheng; Uddin, Ashraf

2017-12-07

Polymer solar cells are a promising technology for the commercialization of low cost, large scale organic solar cells. With the evolution of high efficiency (>13%) non-fullerene polymer solar cells, the stability of the cells has become a crucial parameter to be considered. Among the several degradation mechanisms of polymer solar cells, burn-in photo-degradation is relatively less studied. Herein, we present the first systematic study of photo-degradation of novel PBDB-T:ITIC fullerene-free polymer solar cells. The thermally treated and as-prepared PBDB-T:ITIC solar cells were exposed to continuous 1 sun illumination for 5 hours. The aged devices exhibited rapid losses in the short-circuit current density and fill factor. The severe short-circuit current and fill factor burn in losses were attributed to trap mediated charge recombination, as evidenced by an increase in Urbach energy for aged devices.

Solar Flares Observed with the Ramaty High Energy Solar Spectroscopic Imager (RHESSI)

Science.gov (United States)

Holman, Gordon D.

2004-01-01

Solar flares are impressive examples of explosive energy release in unconfined, magnetized plasma. It is generally believed that the flare energy is derived from the coronal magnetic field. However, we have not been able to establish the specific energy release mechanism(s) or the relative partitioning of the released energy between heating, particle acceleration (electrons and ions), and mass motions. NASA's RHESSI Mission was designed to study the acceleration and evolution of electrons and ions in flares by observing the X-ray and gamma-ray emissions these energetic particles produce. This is accomplished through the combination of high-resolution spectroscopy and spectroscopic imaging, including the first images of flares in gamma rays. RHESSI has observed over 12,000 solar flares since its launch on February 5, 2002. I will demonstrate how we use the RHESSI spectra to deduce physical properties of accelerated electrons and hot plasma in flares. Using images to estimate volumes, w e typically find that the total energy in accelerated electrons is comparable to that in the thermal plasma. I will also present flare observations that provide strong support for the presence of magnetic reconnection in a large-scale, vertical current sheet in the solar corona. RHESSI observations such as these are allowing us to probe more deeply into the physics of solar flares.

Penetration of hydrogen isotopes through EhI 698 alloy at high pressure and temperature

International Nuclear Information System (INIS)

Bystritskij, V.M.; Voznyak, Ya.; Granovskij, V.B.

1986-01-01

The paper deals with investigations of the process of hydrogen and deuterium penetration through the high-temperature alloy EhI-698 at a pressure up to 1 kbar and temperature up to 1050 K. Parameters of the process obey Sieverts's law and can be described by Arrenius's and Vant-Goff's equations. The obtained results lead to a conclusion that the alloy EhI-698 is good for vessels to be employed in hydrogen media

High efficiency thin-film solar cells

Energy Technology Data Exchange (ETDEWEB)

Schock, Hans-Werner [Helmholtz Zentrum Berlin (Germany). Solar Energy

2012-11-01

Production of photovoltaics is growing worldwide on a gigawatt scale. Among the thin film technologies, Cu(In,Ga)S,Se{sub 2} (CIS or CIGS) based solar cells have been the focus of more and more attention. This paper aims to analyze the success of CIGS based solar cells and the potential of this technology for future photovoltaics large-scale production. Specific material properties make CIS unique and allow the preparation of the material with a wide range of processing options. The huge potential lies in the possibility to take advantage of modern thin film processing equipment and combine it with very high efficiencies beyond 20% already achieved on the laboratory scale. A sustainable development of this technology could be realized by modifying the materials and replacing indium by abundant elements. (orig.)

High efficiency thin-film solar cells for space applications: challenges and opportunities

NARCIS (Netherlands)

Leest, R.H. van

2017-01-01

In theory high efficiency thin-film III-V solar cells obtained by the epitaxial lift-off (ELO) technique offer excellent characteristics for application in space solar panels. The thesis describes several studies that investigate the space compatibility of the thin-film solar cell design developed

High Efficiency Multijunction Solar Cells with Finely-Tuned Quantum Wells

Science.gov (United States)

Varonides, Argyrios C.

The field of high efficiency (inorganic) photovoltaics (PV) is rapidly maturing in both efficiency goals and cover all cost reduction of fabrication. On one hand, know-how from space industry in new solar cell design configurations and on the other, fabrication cost reduction challenges for terrestrial uses of solar energy, have paved the way to a new generation of PV devices, capable of capturing most of the solar spectrum. For quite a while now, the goal of inorganic solar cell design has been the total (if possible) capture-absorption of the solar spectrum from a single solar cell, designed in such a way that a multiple of incident wavelengths could be simultaneously absorbed. Multi-absorption in device physics indicates parallel existence of different materials that absorb solar photons of different energies. Bulk solid state devices absorb at specific energy thresholds, depending on their respective energy gap (EG). More than one energy gaps would on principle offer new ways of photon absorption: if such a structure could be fabricated, two or more groups of photons could be absorbed simultaneously. The point became then what lattice-matched semiconductor materials could offer such multiple levels of absorption without much recombination losses. It was soon realized that such layer multiplicity combined with quantum size effects could lead to higher efficiency collection of photo-excited carriers. At the moment, the main reason that slows down quantum effect solar cell production is high fabrication cost, since it involves primarily expensive methods of multilayer growth. Existing multi-layer cells are fabricated in the bulk, with three (mostly) layers of lattice-matched and non-lattice-matched (pseudo-morphic) semiconductor materials (GaInP/InGaN etc), where photo-carrier collection occurs in the bulk of the base (coming from the emitter which lies right under the window layer). These carriers are given excess to conduction via tunnel junction (grown between

Towards Building Reliable, High-Accuracy Solar Irradiance Database For Arid Climates

Science.gov (United States)

Munawwar, S.; Ghedira, H.

2012-12-01

Middle East's growing interest in renewable energy has led to increased activity in solar technology development with the recent commissioning of several utility-scale solar power projects and many other commercial installations across the Arabian Peninsula. The region, lying in a virtually rainless sunny belt with a typical daily average solar radiation exceeding 6 kWh/m2, is also one of the most promising candidates for solar energy deployment. However, it is not the availability of resource, but its characterization and reasonably accurate assessment that determines the application potential. Solar irradiance, magnitude and variability inclusive, is the key input in assessing the economic feasibility of a solar system. The accuracy of such data is of critical importance for realistic on-site performance estimates. This contribution aims to identify the key stages in developing a robust solar database for desert climate by focusing on the challenges that an arid environment presents to parameterization of solar irradiance attenuating factors. Adjustments are proposed based on the currently available resource assessment tools to produce high quality data for assessing bankability. Establishing and maintaining ground solar irradiance measurements is an expensive affair and fairly limited in time (recently operational) and space (fewer sites) in the Gulf region. Developers within solar technology industry, therefore, rely on solar radiation models and satellite-derived data for prompt resource assessment needs. It is imperative that such estimation tools are as accurate as possible. While purely empirical models have been widely researched and validated in the Arabian Peninsula's solar modeling history, they are known to be intrinsically site-specific. A primal step to modeling is an in-depth understanding of the region's climate, identifying the key players attenuating radiation and their appropriate characterization to determine solar irradiance. Physical approach

Intra-Hour Dispatch and Automatic Generator Control Demonstration with Solar Forecasting - Final Report

Energy Technology Data Exchange (ETDEWEB)

Coimbra, Carlos F. M. [Univ. of California, San Diego, CA (United States

2016-02-25

In this project we address multiple resource integration challenges associated with increasing levels of solar penetration that arise from the variability and uncertainty in solar irradiance. We will model the SMUD service region as its own balancing region, and develop an integrated, real-time operational tool that takes solar-load forecast uncertainties into consideration and commits optimal energy resources and reserves for intra-hour and intra-day decisions. The primary objectives of this effort are to reduce power system operation cost by committing appropriate amount of energy resources and reserves, as well as to provide operators a prediction of the generation fleet’s behavior in real time for realistic PV penetration scenarios. The proposed methodology includes the following steps: clustering analysis on the expected solar variability per region for the SMUD system, Day-ahead (DA) and real-time (RT) load forecasts for the entire service areas, 1-year of intra-hour CPR forecasts for cluster centers, 1-year of smart re-forecasting CPR forecasts in real-time for determination of irreducible errors, and uncertainty quantification for integrated solar-load for both distributed and central stations (selected locations within service region) PV generation.

Azobenzene-functionalized carbon nanotubes as high-energy density solar thermal fuels.

Science.gov (United States)

Kolpak, Alexie M; Grossman, Jeffrey C

2011-08-10

Solar thermal fuels, which reversibly store solar energy in molecular bonds, are a tantalizing prospect for clean, renewable, and transportable energy conversion/storage. However, large-scale adoption requires enhanced energy storage capacity and thermal stability. Here we present a novel solar thermal fuel, composed of azobenzene-functionalized carbon nanotubes, with the volumetric energy density of Li-ion batteries. Our work also demonstrates that the inclusion of nanoscale templates is an effective strategy for design of highly cyclable, thermally stable, and energy-dense solar thermal fuels.

Technical impacts of high penetration levels of wind power on power system stability

OpenAIRE

Flynn, Damian; Rather, Z.; Ardal, Atle; Darco, Salvatore; Hansen, Anca Daniela; Cutululis, Nicolaos Antonio; Sørensen, Poul Ejnar; Estanqueiro, Ana; Gomez, Emilio; Menemenlis, Nickie; Smith, Charlie; Wang, Ye

2017-01-01

With increasing penetrations of wind generation, based on power-electronic converters, power systems are transitioning away from well-understood synchronous generator-based systems, with growing implications for their stability. Issues of concern will vary with system size, wind penetration level, geographical distribution and turbine type, network topology, electricity market structure, unit commitment procedures, and other factors. However, variable-speed wind turbines, both onshore and con...

Fabrication of high efficacy selective solar absorbers

CSIR Research Space (South Africa)

Tile, N

2012-03-01

Full Text Available High efficiency tandem selective solar absorber materials of carbon in nickel oxide (C-NiO) composite were fabricated on an aluminium substrate using a simple and cost effective sol-gel process. The process involved preparation of carbon and nickel...

Development of high-performance solar LED lighting system

KAUST Repository

Huang, B.J.; Wu, M.S.; Hsu, P.C.; Chen, J.W.; Chen, K.Y.

2010-01-01

The present study developed a high-performance charge/discharge controller for stand-alone solar LED lighting system by incorporating an nMPPO system design, a PWM battery charge control, and a PWM battery discharge control to directly drive the LED. The MPPT controller can then be removed from the stand-alone solar system and the charged capacity of the battery increases 9.7%. For LED driven by PWM current directly from battery, a reliability test for the light decay of LED lamps was performed continuously for 13,200 h. It has shown that the light decay of PWM-driven LED is the same as that of constant-current driven LED. The switching energy loss of the MOSFET in the PWM battery discharge control is less than 1%. Three solar-powered LED lighting systems (18 W, 100 W and 150 W LED) were designed and built. The long-term outdoor field test results have shown that the system performance is satisfactory with the control system developed in the present study. The loss of load probability for the 18 W solar LED system is 14.1% in winter and zero in summer. For the 100 W solar LED system, the loss of load probability is 3.6% in spring. © 2009 Elsevier Ltd. All rights reserved.

Development of high-performance solar LED lighting system

International Nuclear Information System (INIS)

Huang, B.J.; Wu, M.S.; Hsu, P.C.; Chen, J.W.; Chen, K.Y.

2010-01-01

The present study developed a high-performance charge/discharge controller for stand-alone solar LED lighting system by incorporating an nMPPO system design, a PWM battery charge control, and a PWM battery discharge control to directly drive the LED. The MPPT controller can then be removed from the stand-alone solar system and the charged capacity of the battery increases 9.7%. For LED driven by PWM current directly from battery, a reliability test for the light decay of LED lamps was performed continuously for 13,200 h. It has shown that the light decay of PWM-driven LED is the same as that of constant-current driven LED. The switching energy loss of the MOSFET in the PWM battery discharge control is less than 1%. Three solar-powered LED lighting systems (18 W, 100 W and 150 W LED) were designed and built. The long-term outdoor field test results have shown that the system performance is satisfactory with the control system developed in the present study. The loss of load probability for the 18 W solar LED system is 14.1% in winter and zero in summer. For the 100 W solar LED system, the loss of load probability is 3.6% in spring.

Development of high-performance solar LED lighting system

KAUST Repository

Huang, B.J.

2010-08-01

The present study developed a high-performance charge/discharge controller for stand-alone solar LED lighting system by incorporating an nMPPO system design, a PWM battery charge control, and a PWM battery discharge control to directly drive the LED. The MPPT controller can then be removed from the stand-alone solar system and the charged capacity of the battery increases 9.7%. For LED driven by PWM current directly from battery, a reliability test for the light decay of LED lamps was performed continuously for 13,200 h. It has shown that the light decay of PWM-driven LED is the same as that of constant-current driven LED. The switching energy loss of the MOSFET in the PWM battery discharge control is less than 1%. Three solar-powered LED lighting systems (18 W, 100 W and 150 W LED) were designed and built. The long-term outdoor field test results have shown that the system performance is satisfactory with the control system developed in the present study. The loss of load probability for the 18 W solar LED system is 14.1% in winter and zero in summer. For the 100 W solar LED system, the loss of load probability is 3.6% in spring. © 2009 Elsevier Ltd. All rights reserved.

Macroporous Double-Network Hydrogel for High-Efficiency Solar Steam Generation Under 1 sun Illumination.

Science.gov (United States)

Yin, Xiangyu; Zhang, Yue; Guo, Qiuquan; Cai, Xiaobing; Xiao, Junfeng; Ding, Zhifeng; Yang, Jun

2018-04-04

Solar steam generation is one of the most promising solar-energy-harvesting technologies to address the issue of water shortage. Despite intensive efforts to develop high-efficiency solar steam generation devices, challenges remain in terms of the relatively low solar thermal efficiency, complicated fabrications, high cost, and difficulty in scaling up. Herein, a double-network hydrogel with a porous structure (p-PEGDA-PANi) is demonstrated for the first time as a flexible, recyclable, and efficient photothermal platform for low-cost and scalable solar steam generation. As a novel photothermal platform, the p-PEGDA-PANi involves all necessary properties of efficient broadband solar absorption, exceptional hydrophilicity, low heat conductivity, and porous structure for high-efficiency solar steam generation. As a result, the hydrogel-based solar steam generator exhibits a maximum solar thermal efficiency of 91.5% with an evaporation rate of 1.40 kg m -2 h -1 under 1 sun illumination, which is comparable to state-of-the-art solar steam generation devices. Furthermore, the good durability and environmental stability of the p-PEGDA-PANi hydrogel enables a convenient recycling and reusing process toward real-life applications. The present research not only provides a novel photothermal platform for solar energy harvest but also opens a new avenue for the application of the hydrogel materials in solar steam generation.

Lightweight, Mesoporous, and Highly Absorptive All-Nanofiber Aerogel for Efficient Solar Steam Generation.

Science.gov (United States)

Jiang, Feng; Liu, He; Li, Yiju; Kuang, Yudi; Xu, Xu; Chen, Chaoji; Huang, Hao; Jia, Chao; Zhao, Xinpeng; Hitz, Emily; Zhou, Yubing; Yang, Ronggui; Cui, Lifeng; Hu, Liangbing

2018-01-10

The global fresh water shortage has driven enormous endeavors in seawater desalination and wastewater purification; among these, solar steam generation is effective in extracting fresh water by efficient utilization of naturally abundant solar energy. For solar steam generation, the primary focus is to design new materials that are biodegradable, sustainable, of low cost, and have high solar steam generation efficiency. Here, we designed a bilayer aerogel structure employing naturally abundant cellulose nanofibrils (CNFs) as basic building blocks to achieve sustainability and biodegradability as well as employing a carbon nanotube (CNT) layer for efficient solar utilization with over 97.5% of light absorbance from 300 to 1200 nm wavelength. The ultralow density (0.0096 g/cm 3 ) of the aerogel ensures that minimal material is required, reducing the production cost while at the same time satisfying the water transport and thermal-insulation requirements due to its highly porous structure (99.4% porosity). Owing to its rationally designed structure and thermal-regulation performance, the bilayer CNF-CNT aerogel exhibits a high solar-energy conversion efficiency of 76.3% and 1.11 kg m -2 h -1 at 1 kW m -2 (1 Sun) solar irradiation, comparable or even higher than most of the reported solar steam generation devices. Therefore, the all-nanofiber aerogel presents a new route for designing biodegradable, sustainable, and scalable solar steam generation devices with superb performance.

Evaluation of the National Solar Radiation Database (NSRDB): 1998-2015

Energy Technology Data Exchange (ETDEWEB)

Habte, Aron [National Renewable Energy Lab. (NREL), Golden, CO (United States); Sengupta, Manajit [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lopez, Anthony [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2017-04-01

This paper validates the performance of the physics-based Physical Solar Model (PSM) data set in the National Solar Radiation Data Base (NSRDB) to quantify the accuracy of the magnitude and the spatial and temporal variability of the solar radiation data. Achieving higher penetrations of solar energy on the electric grid and reducing integration costs requires accurate knowledge of the available solar resource. Understanding the impacts of clouds and other meteorological constituents on the solar resource and quantifying intra-/inter-hour, seasonal, and interannual variability are essential for accurately designing utility-scale solar energy projects. Solar resource information can be obtained from ground-based measurement stations and/or from modeled data sets. The availability of measurements is scarce, both temporally and spatially, because it is expensive to maintain a high-density solar radiation measurement network that collects good quality data for long periods of time. On the other hand, high temporal and spatial resolution gridded satellite data can be used to estimate surface radiation for long periods of time and is extremely useful for solar energy development. Because of the advantages of satellite-based solar resource assessment, the National Renewable Energy Laboratory developed the PSM. The PSM produced gridded solar irradiance -- global horizontal irradiance (GHI), direct normal irradiance (DNI), and diffuse horizontal irradiance -- for the NSRDB at a 4-km by 4-km spatial resolution and half-hourly temporal resolution covering the 18 years from 1998-2015. The NSRDB also contains additional ancillary meteorological data sets, such as temperature, relative humidity, surface pressure, dew point, and wind speed. Details of the model and data are available at https://nsrdb.nrel.gov. The results described in this paper show that the hourly-averaged satellite-derived data have a systematic (bias) error of approximately +5% for GHI and less than +10% for

Residential heating costs: A comparison of geothermal solar and conventional resources

Science.gov (United States)

Bloomster, C. H.; Garrett-Price, B. A.; Fassbender, L. L.

1980-08-01

The costs of residential heating throughout the United States using conventional, solar, and geothermal energy were determined under current and projected conditions. These costs are very sensitive to location, being dependent on the local prices of conventional energy supplies, local solar insolation, climate, and the proximity and temperature of potential geothermal resources. The sharp price increases in imported fuels during 1979 and the planned decontrol of domestic oil and natural gas prices have set the stage for geothermal and solar market penetration in the 1980's.

Building application of solar energy. Study no. 2: Representative buildings for solar energy performance analysis and market penetration

Science.gov (United States)

Hirshberg, A. S.

1975-01-01

The following topics are discussed: (1) Assignment of population to microclimatic zones; (2) specifications of the mix of buildings in the SCE territory; (3) specification of four typical buildings for thermal analysis and market penetration studies; (4) identification of the materials and energy conserving characteristics of these typical buildings; (5) specifications of the HVAC functions used in each typical building, and determination of the HVAC systems used in each building; and (6) identification of the type of fuel used in each building.

Voltage magnitude and margin controller for remote industrial microgrid with high wind penetration

DEFF Research Database (Denmark)

Cai, Yu; Lin, Jin; Song, Yonghua

2013-01-01

It is well known that the remote industrial microgrid is located at the periphery of the grid, which is weakly connected to the main grid. In order to enhance the voltage stability and ensure a good power quality for industries, a voltage magnitude and margin controller based on wind turbines...... is proposed in this paper. This controller includes two parts to improve voltage stability in different time scales by using local measurements. Case studies conducted for a remote microgrid with high wind penetration have proved the effectiveness of the proposed control scheme....

MEPSOCON project: Calibration of Radiometers for High Solar Irradiance; Proyecto MEPSOCON: Calibracion de Radiometros de Alta Irradiancia Solar

Energy Technology Data Exchange (ETDEWEB)

Ballestrin, J.; Rodriguez-Alonso, M.

2006-07-01

The development of central receiver solar plants is a currently emerging field into renewable energies. For several years various receiver prototypes have been evaluated at the Plataforma Solar de Almeria (PSA). The measurement of the incident solar power on the receiver aperture is fundamental to the estimation of its efficiency. Many factors interfere with this measurement and consequently accuracy is very low. This uncertainty is transmitted to the design of the final solar plant and thereby to its price. The sensors used for this measurement are of small size in comparison with the receiver apertures, therefore different systems are necessary to obtain the incident solar power on the receiver aperture from the individual radiometer measurements. This report presents calibration procedures for the sensor used on the measurement of high solar irradiance and the analysis of the different factors affecting the incident power measurement to significantly reduce its uncertainty. (Author) 16 refs.

Proceedings of the Flat-Plate Solar Array Project Workshop on Crystal Gowth for High-Efficiency Silicon Solar Cells

Science.gov (United States)

Dumas, K. A. (Editor)

1985-01-01

A Workshop on Crystal Growth for High-Efficiency Silicon Solar Cells was held December 3 and 4, 1984, in San Diego, California. The Workshop offered a day and a half of technical presentations and discussions and an afternoon session that involved a panel discussion and general discussion of areas of research that are necessary to the development of materials for high-efficiency solar cells. Topics included the theoretical and experimental aspects of growing high-quality silicon crystals, the effects of growth-process-related defects on photovoltaic devices, and the suitability of various growth technologies as cost-effective processes. Fifteen invited papers were presented, with a discussion period following each presentation. The meeting was organized by the Flat-Plate Solar Array Project of the Jet Propulsion Laboratory. These Proceedings are a record of the presentations and discussions, edited for clarity and continuity.

Design of DSP-based high-power digital solar array simulator

Science.gov (United States)

Zhang, Yang; Liu, Zhilong; Tong, Weichao; Feng, Jian; Ji, Yibo

2013-12-01

To satisfy rigid performance specifications, a feedback control was presented for zoom optical lens plants. With the increasing of global energy consumption, research of the photovoltaic(PV) systems get more and more attention. Research of the digital high-power solar array simulator provides technical support for high-power grid-connected PV systems research.This paper introduces a design scheme of the high-power digital solar array simulator based on TMS320F28335. A DC-DC full-bridge topology was used in the system's main circuit. The switching frequency of IGBT is 25kHz.Maximum output voltage is 900V. Maximum output current is 20A. Simulator can be pre-stored solar panel IV curves.The curve is composed of 128 discrete points .When the system was running, the main circuit voltage and current values was feedback to the DSP by the voltage and current sensors in real-time. Through incremental PI,DSP control the simulator in the closed-loop control system. Experimental data show that Simulator output voltage and current follow a preset solar panels IV curve. In connection with the formation of high-power inverter, the system becomes gridconnected PV system. The inverter can find the simulator's maximum power point and the output power can be stabilized at the maximum power point (MPP).

Physical Penetration Testing: A Whole New Story in Penetration Testing

NARCIS (Netherlands)

Dimkov, T.; Pieters, Wolter

2011-01-01

Physical penetration testing plays an important role in assuring a company that the security policies are properly enforced and that the security awareness of the employees is on the appropriate level. In physical penetration tests the tester physically enters restricted locations and directly

Hardened Solar Array High Temperature Adhesive.

Science.gov (United States)

1981-04-01

SHERWOOO. D SASIU.IS F3361S-0-C-201S UNCLASSI ED 1AC-SCG-IOOIIR AFVAL-TR-OL-201? NLm,,hinii EhhhEE11I1 AFWAL-TR-81- 2017 i : HARDENED SOLAR ARRAY D HIGH...Tg and as a consequence forms a film on the container and also precipitates as tacky waxlike particles, rather than the desired flocullated

Interfacial Layer Engineering for Performance Enhancement in Polymer Solar Cells

Directory of Open Access Journals (Sweden)

Hao Zeng

2015-02-01

Full Text Available Improving power conversion efficiency and device performance stability is the most critical challenge in polymer solar cells for fulfilling their applications in industry at large scale. Various methodologies have been developed for realizing this goal, among them interfacial layer engineering has shown great success, which can optimize the electrical contacts between active layers and electrodes and lead to enhanced charge transport and collection. Interfacial layers also show profound impacts on light absorption and optical distribution of solar irradiation in the active layer and film morphology of the subsequently deposited active layer due to the accompanied surface energy change. Interfacial layer engineering enables the use of high work function metal electrodes without sacrificing device performance, which in combination with the favored kinetic barriers against water and oxygen penetration leads to polymer solar cells with enhanced performance stability. This review provides an overview of the recent progress of different types of interfacial layer materials, including polymers, small molecules, graphene oxides, fullerene derivatives, and metal oxides. Device performance enhancement of the resulting solar cells will be elucidated and the function and operation mechanism of the interfacial layers will be discussed.

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

International Nuclear Information System (INIS)

Bavassano, B.; Bruno, R.

1991-01-01

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

Experimental Study of Arcing on High-voltage Solar Arrays

Science.gov (United States)

Vayner, Boris; Galofaro, Joel; Ferguson, Dale

2005-01-01

The main obstacle to the implementation of a high-voltage solar array in space is arcing on the conductor-dielectric junctions exposed to the surrounding plasma. One obvious solution to this problem would be the installation of fully encapsulated solar arrays which were not having exposed conductors at all. However, there are many technological difficulties that must be overcome before the employment of fully encapsulated arrays will turn into reality. An alternative solution to raise arc threshold by modifications of conventionally designed solar arrays looks more appealing, at least in the nearest future. A comprehensive study of arc inception mechanism [1-4] suggests that such modifications can be done in the following directions: i) to insulate conductor-dielectric junction from a plasma environment (wrapthrough interconnects); ii) to change a coverglass geometry (overhang); iii) to increase a coverglass thickness; iiii) to outgas areas of conductor-dielectric junctions. The operation of high-voltage array in LEO produces also the parasitic current power drain on the electrical system. Moreover, the current collected from space plasma by solar arrays determines the spacecraft floating potential that is very important for the design of spacecraft and its scientific apparatus. In order to verify the validity of suggested modifications and to measure current collection five different solar array samples have been tested in large vacuum chamber. Each sample (36 silicon based cells) consists of three strings containing 12 cells connected in series. Thus, arc rate and current collection can be measured on every string independently, or on a whole sample when strings are connected in parallel. The heater installed in the chamber provides the possibility to test samples under temperature as high as 80 C that simulates the LEO operational temperature. The experimental setup is described below.

High Performance Flat Plate Solar Thermal Collector Evaluation

Energy Technology Data Exchange (ETDEWEB)

Rockenbaugh, Caleb [National Renewable Energy Lab. (NREL), Golden, CO (United States); Dean, Jesse [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lovullo, David [National Renewable Energy Lab. (NREL), Golden, CO (United States); Lisell, Lars [National Renewable Energy Lab. (NREL), Golden, CO (United States); Barker, Greg [National Renewable Energy Lab. (NREL), Golden, CO (United States); Hanckock, Ed [National Renewable Energy Lab. (NREL), Golden, CO (United States); Norton, Paul [National Renewable Energy Lab. (NREL), Golden, CO (United States)

2016-09-01

This report was prepared for the General Services Administration by the National Renewable Energy Laboratory. The Honeycomb Solar Thermal Collector (HSTC) is a flat plate solar thermal collector that shows promising high efficiencies over a wide range of climate zones. The technical objectives of this study are to: 1) verify collector performance, 2) compare that performance to other market-available collectors, 3) verify overheat protection, and 4) analyze the economic performance of the HSTC both at the demonstration sites and across a matrix of climate zones and utility markets.

High-flux solar photon processes: Opportunities for applications

Energy Technology Data Exchange (ETDEWEB)

Steinfeld, J.I.; Coy, S.L.; Herzog, H.; Shorter, J.A.; Schlamp, M.; Tester, J.W.; Peters, W.A. [Massachusetts Inst. of Tech., Cambridge, MA (United States)

1992-06-01

The overall goal of this study was to identify new high-flux solar photon (HFSP) processes that show promise of being feasible and in the national interest. Electric power generation and hazardous waste destruction were excluded from this study at sponsor request. Our overall conclusion is that there is promise for new applications of concentrated solar photons, especially in certain aspects of materials processing and premium materials synthesis. Evaluation of the full potential of these and other possible applications, including opportunities for commercialization, requires further research and testing. 100 refs.

Interstellar gas near and within the solar system

International Nuclear Information System (INIS)

Burgin, M.S.

1981-01-01

The picture of the interaction between the local interstellar medium (LISM) and the solar environment developed in recent years is described, and prospects are discussed for obtaining complete information about the LISM. Special attention is given to the neutral component of the LISM, particularly to the results of observations of the uv radiation scattered from hydrogen and helium atoms penetrating the solar system from interstellar space. The properties of the LISM plasma are considered only as they pertain to the interaction with the neutral component

Solar Cell Short Circuit Current Errors and Uncertainties During High Altitude Calibrations

Science.gov (United States)

Snyder, David D.

2012-01-01

High altitude balloon based facilities can make solar cell calibration measurements above 99.5% of the atmosphere to use for adjusting laboratory solar simulators. While close to on-orbit illumination, the small attenuation to the spectra may result in under measurements of solar cell parameters. Variations of stratospheric weather, may produce flight-to-flight measurement variations. To support the NSCAP effort, this work quantifies some of the effects on solar cell short circuit current (Isc) measurements on triple junction sub-cells. This work looks at several types of high altitude methods, direct high altitude meas urements near 120 kft, and lower stratospheric Langley plots from aircraft. It also looks at Langley extrapolation from altitudes above most of the ozone, for potential small balloon payloads. A convolution of the sub-cell spectral response with the standard solar spectrum modified by several absorption processes is used to determine the relative change from AMO, lscllsc(AMO). Rayleigh scattering, molecular scatterin g from uniformly mixed gases, Ozone, and water vapor, are included in this analysis. A range of atmosph eric pressures are examined, from 0. 05 to 0.25 Atm to cover the range of atmospheric altitudes where solar cell calibrations a reperformed. Generally these errors and uncertainties are less than 0.2%

7Be(p, γ)8B and the high-energy solar neutrino flux

International Nuclear Information System (INIS)

Csoto, A.

1997-01-01

Despite thirty years of extensive experimental and theoretical work, the predicted solar neutrino flux is still in sharp disagreement with measurements. The solar neutrino measurements strongly suggest that the problem cannot be solved within the standard electroweak and astrophysical theories. Thus, the solar neutrino problem constitutes the strongest evidence for physics beyond the Standard Model. Whatever the solution of the solar neutrino problem turns out to be, it is of paramount importance that the input parameters of the underlying electroweak and solar theories rest upon solid ground. The most uncertain nuclear input parameter in standard solar models is the low-energy 7 Be(p, γ) 8 B radiative capture cross section. This reaction produces 8 B in the Sun, whose β + decay is the main source of the high-energy solar neutrinos. Here, the importance of the 7 Be(p, γ) 8 B reaction in predicting the high energy solar neutrino flux is discussed. The author presents a microscopic eight-body model and a potential model for the calculation of the 7 Be(p, γ) 8 B cross section

The role of hydrogen in high wind energy penetration electricity systems: the Irish case

International Nuclear Information System (INIS)

Gonzalez, A.; McKeogh, E.; Gallachoir, B.O.

2004-01-01

The deployment of wind energy is constrained by wind uncontrollability, which poses operational problems on the electricity supply system at high penetration levels, lessening the value of wind-generated electricity to a significant extent. This paper studies the viability of hydrogen production via electrolysis using wind power that cannot be easily accommodated on the system. The potential benefits of hydrogen and its role in enabling a large penetration of wind energy are assessed, within the context of the enormous wind energy resource in Ireland. The exploitation of this wind resource may in the future give rise to significant amounts of surplus wind electricity, which could be used to produce hydrogen, the zero-emissions fuel that many experts believe will eventually replace fossil fuels in the transport sector. In this paper the operation of a wind powered hydrogen production system is simulated and optimised. The results reveal that, even allowing for significant cost-reductions in electrolyser and associated balance-of-plant equipment, low average surplus wind electricity cost and a high hydrogen market price are also necessary to achieve the economic viability of the technology. These conditions would facilitate the installation of electrolysis units of sufficient capacity to allow an appreciable increase in installed wind power in Ireland. The simulation model was also used to determine the CO 2 abatement potential associated with the wind energy/hydrogen production. (author)

HMO penetration and the geographic mobility of practicing physicians.

Science.gov (United States)

Polsky, D; Kletke, P R; Wozniak, G D; Escarce, J J

2000-09-01

In this study, we assessed the influence of changes in health maintenance organization (HMO) penetration on the probability that established patient care physicians relocated their practices or left patient care altogether. For physicians who relocated their practices, we also assessed the impact of HMO penetration on their destination choices. We found that larger increases in HMO penetration decreased the probability that medical/surgical specialists in early career stayed in patient care in the same market, but had no impact on generalists, hospital-based specialists, or mid career medical/surgical specialists. We also found that physicians who relocated their practices were much more likely to choose destination markets with the same level of HMO penetration or lower HMO penetration compared with their origin markets than they were to choose destination markets with higher HMO penetration. The largely negligible impact of changes in HMO penetration on established physicians' decisions to relocate their practices or leave patient care is consistent with high relocation and switching costs. Relocating physicians' attraction to destination markets with the same level of HMO penetration as their origin markets suggests that, while physicians' styles of medical practice may adapt to changes in market conditions, learning new practice styles is costly.

A Study on Factors Affecting Airborne LiDAR Penetration

Directory of Open Access Journals (Sweden)

Wei-Chen Hsu

2015-01-01

Full Text Available This study uses data from different periods, areas and parameters of airborne LiDAR (light detection and ranging surveys to understand the factors that influence airborne LiDAR penetration rate. A discussion is presented on the relationships between these factors and LiDAR penetration rate. The results show that the flight height above ground level (AGL does not have any relationship with the penetration rate. There are some factors that should have larger influence. For example, the laser is affected by a wet ground surface by reducing the number of return echoes. The field of view (FOV has a slightly negative correlation with the penetration rate, which indicates that the laser incidence angle close to zero should achieve the best penetration. The vegetation cover rate also shows a negative correlation with the penetration rate, thus bare ground and reduced vegetation in the aftermath of a typhoon also cause high penetration rate. More return echoes could be extracted from the full-waveform system, thereby effectively improving the penetration rate. This study shows that full-waveform LiDAR is an effective method for increasing the number of surface reflected echoes. This study suggests avoiding LiDAR survey employment directly following precipitation to prevent laser echo reduction.

Solar photovoltaic power forecasting using optimized modified extreme learning machine technique

Directory of Open Access Journals (Sweden)

Manoja Kumar Behera

2018-06-01

Full Text Available Prediction of photovoltaic power is a significant research area using different forecasting techniques mitigating the effects of the uncertainty of the photovoltaic generation. Increasingly high penetration level of photovoltaic (PV generation arises in smart grid and microgrid concept. Solar source is irregular in nature as a result PV power is intermittent and is highly dependent on irradiance, temperature level and other atmospheric parameters. Large scale photovoltaic generation and penetration to the conventional power system introduces the significant challenges to microgrid a smart grid energy management. It is very critical to do exact forecasting of solar power/irradiance in order to secure the economic operation of the microgrid and smart grid. In this paper an extreme learning machine (ELM technique is used for PV power forecasting of a real time model whose location is given in the Table 1. Here the model is associated with the incremental conductance (IC maximum power point tracking (MPPT technique that is based on proportional integral (PI controller which is simulated in MATLAB/SIMULINK software. To train single layer feed-forward network (SLFN, ELM algorithm is implemented whose weights are updated by different particle swarm optimization (PSO techniques and their performance are compared with existing models like back propagation (BP forecasting model. Keywords: PV array, Extreme learning machine, Maximum power point tracking, Particle swarm optimization, Craziness particle swarm optimization, Accelerate particle swarm optimization, Single layer feed-forward network

Quantitative assessment of liquid Ga penetration into an aluminium alloy by high-resolution X-ray tomography

International Nuclear Information System (INIS)

Ohgaki, T.; Toda, H.; Sinclair, I.; Buffiere, J.-Y.; Ludwig, W.; Kobayashi, T.; Niinomi, M.; Akahori, T.

2005-01-01

We have evaluated the liquid Ga penetration into an aluminium alloy by high-resolution X-ray tomography. The 3D visualization of a crack together with its surrounding grain structure was performed with the help of the Ga penetration technique. It is found that the advance directions of the crack-tip were strongly influenced by the grain microstructure and the branching of the crack is affected by grain distribution. In this study, the liquid Ga not only acts as a contrast agent for grain boundaries, but also expands the volume of the Al alloy due to Ga diffusion and associated processes. The 3D strain between the grains has been determined by microstructural gauging technique, which uses micropores as marker points. The 3D expansion of the sample volume, the volume reduction of micropores and the brittle fracture were evidently observed

Telescoping Solar Array Concept for Achieving High Packaging Efficiency

Science.gov (United States)

Mikulas, Martin; Pappa, Richard; Warren, Jay; Rose, Geoff

2015-01-01

Lightweight, high-efficiency solar arrays are required for future deep space missions using high-power Solar Electric Propulsion (SEP). Structural performance metrics for state-of-the art 30-50 kW flexible blanket arrays recently demonstrated in ground tests are approximately 40 kW/cu m packaging efficiency, 150 W/kg specific power, 0.1 Hz deployed stiffness, and 0.2 g deployed strength. Much larger arrays with up to a megawatt or more of power and improved packaging and specific power are of interest to mission planners for minimizing launch and life cycle costs of Mars exploration. A new concept referred to as the Compact Telescoping Array (CTA) with 60 kW/cu m packaging efficiency at 1 MW of power is described herein. Performance metrics as a function of array size and corresponding power level are derived analytically and validated by finite element analysis. Feasible CTA packaging and deployment approaches are also described. The CTA was developed, in part, to serve as a NASA reference solar array concept against which other proposed designs of 50-1000 kW arrays for future high-power SEP missions could be compared.

Neutrino fluxes produced by high energy solar flare particles

International Nuclear Information System (INIS)

Kolomeets, E.V.; Shmonin, V.L.

1975-01-01

In this work the calculated differential energy spectra of neutrinos poduced by high energy protons accelerated during 'small' solar flares are presented. The muon flux produced by neutrino interactions with the matter at large depths under the ground is calculated. The obtained flux of muons for the total number of solar flare accelerated protons of 10 28 - 10 32 is within 10 9 - 10 13 particles/cm 2 X s x ster. (orig.) [de

A Model for Optimizing the Combination of Solar Electricity Generation, Supply Curtailment, Transmission and Storage

Science.gov (United States)

Perez, Marc J. R.

With extraordinary recent growth of the solar photovoltaic industry, it is paramount to address the biggest barrier to its high-penetration across global electrical grids: the inherent variability of the solar resource. This resource variability arises from largely unpredictable meteorological phenomena and from the predictable rotation of the earth around the sun and about its own axis. To achieve very high photovoltaic penetration, the imbalance between the variable supply of sunlight and demand must be alleviated. The research detailed herein consists of the development of a computational model which seeks to optimize the combination of 3 supply-side solutions to solar variability that minimizes the aggregate cost of electricity generated therefrom: Storage (where excess solar generation is stored when it exceeds demand for utilization when it does not meet demand), interconnection (where solar generation is spread across a large geographic area and electrically interconnected to smooth overall regional output) and smart curtailment (where solar capacity is oversized and excess generation is curtailed at key times to minimize the need for storage.). This model leverages a database created in the context of this doctoral work of satellite-derived photovoltaic output spanning 10 years at a daily interval for 64,000 unique geographic points across the globe. Underpinning the model's design and results, the database was used to further the understanding of solar resource variability at timescales greater than 1-day. It is shown that--as at shorter timescales--cloud/weather-induced solar variability decreases with geographic extent and that the geographic extent at which variability is mitigated increases with timescale and is modulated by the prevailing speed of clouds/weather systems. Unpredictable solar variability up to the timescale of 30 days is shown to be mitigated across a geographic extent of only 1500km if that geographic extent is oriented in a north

Evaluating predictive models for solar energy growth in the US states and identifying the key drivers

Science.gov (United States)

Chakraborty, Joheen; Banerji, Sugata

2018-03-01

Driven by a desire to control climate change and reduce the dependence on fossil fuels, governments around the world are increasing the adoption of renewable energy sources. However, among the US states, we observe a wide disparity in renewable penetration. In this study, we have identified and cleaned over a dozen datasets representing solar energy penetration in each US state, and the potentially relevant socioeconomic and other factors that may be driving the growth in solar. We have applied a number of predictive modeling approaches - including machine learning and regression - on these datasets over a 17-year period and evaluated the relative performance of the models. Our goals were: (1) identify the most important factors that are driving the growth in solar, (2) choose the most effective predictive modeling technique for solar growth, and (3) develop a model for predicting next year’s solar growth using this year’s data. We obtained very promising results with random forests (about 90% efficacy) and varying degrees of success with support vector machines and regression techniques (linear, polynomial, ridge). We also identified states with solar growth slower than expected and representing a potential for stronger growth in future.

Rapid penetration into granular media visualizing the fundamental physics of rapid earth penetration

CERN Document Server

Iskander, Magued

2015-01-01

Rapid Penetration into Granular Media: Visualizing the Fundamental Physics of Rapid Earth Penetration introduces readers to the variety of methods and techniques used to visualize, observe, and model the rapid penetration of natural and man-made projectiles into earth materials. It provides seasoned practitioners with a standard reference that showcases the topic's most recent developments in research and application. The text compiles the findings of new research developments on the subject, outlines the fundamental physics of rapid penetration into granular media, and assembles a com

An investigation of the maximum penetration level of a photovoltaic (PV) system into a traditional distribution grid

Science.gov (United States)

Chalise, Santosh

Although solar photovoltaic (PV) systems have remained the fastest growing renewable power generating technology, variability as well as uncertainty in the output of PV plants is a significant issue. This rapid increase in PV grid-connected generation presents not only progress in clean energy but also challenges in integration with traditional electric power grids which were designed for transmission and distribution of power from central stations. Unlike conventional electric generators, PV panels do not have rotating parts and thus have no inertia. This potentially causes a problem when the solar irradiance incident upon a PV plant changes suddenly, for example, when scattered clouds pass quickly overhead. The output power of the PV plant may fluctuate nearly as rapidly as the incident irradiance. These rapid power output fluctuations may then cause voltage fluctuations, frequency fluctuations, and power quality issues. These power quality issues are more severe with increasing PV plant power output. This limits the maximum power output allowed from interconnected PV plants. Voltage regulation of a distribution system, a focus of this research, is a prime limiting factor in PV penetration levels. The IEEE 13-node test feeder, modeled and tested in the MATLAB/Simulink environment, was used as an example distribution feeder to analyze the maximum acceptable penetration of a PV plant. The effect of the PV plant's location was investigated, along with the addition of a VAR compensating device (a D-STATCOM in this case). The results were used to develop simple guidelines for determining an initial estimate of the maximum PV penetration level on a distribution feeder. For example, when no compensating devices are added to the system, a higher level of PV penetration is generally achieved by installing the PV plant close to the substation. The opposite is true when a VAR compensator is installed with the PV plant. In these cases, PV penetration levels over 50% may be

A dynamic model of an innovative high-temperature solar heating and cooling system

Directory of Open Access Journals (Sweden)

Buonomano Annamaria

2016-01-01

Full Text Available In this paper a new simulation model of a novel solar heating and cooling system based on innovative high temperature flat plate evacuated solar thermal collector is presented. The system configuration includes: flat-plate evacuated solar collectors, a double-stage LiBr-H2O absorption chiller, gas-fired auxiliary heater, a closed loop cooling tower, pumps, heat exchangers, storage tanks, valves, mixers and controllers. The novelty of this study lies in the utilization of flat-plate stationary solar collectors, manufactured by TVP Solar, rather than concentrating ones (typically adopted for driving double-stage absorption chillers. Such devices show ultra-high thermal efficiencies, even at very high (about 200°C operating temperatures, thanks to the high vacuum insulation. Aim of the paper is to analyse the energy and economic feasibility of such novel technology, by including it in a prototypal solar heating and cooling system. For this purpose, the solar heating and cooling system design and performance were analysed by means of a purposely developed dynamic simulation model, implemented in TRNSYS. A suitable case study is also presented. Here, the simulated plant is conceived for the space heating and cooling and the domestic hot water production of a small building, whose energy needs are fulfilled through a real installation (settled also for experimental purposes built up close to Naples (South Italy. Simulation results show that the investigated system is able to reach high thermal efficiencies and very good energy performance. Finally, the economic analysis shows results comparable to those achieved through similar renewable energy systems.

Contribution of Nanostructures in High Performance Solar Cells

Science.gov (United States)

Aly, Abouelmaaty M.; Ebrahim, Essamudin A.; Sweelem, Emad

2017-11-01

Nanotechnology has great contributions in various fields, especially in solar energy conversion through solar cells (SCs). Nanostructured SCs can provide high performance with lower fabrication costs. The transition from fossil fuel energy to renewable sustainable energy represents a major technological challenge for the world. In the last years, the industry of SCs has grown rapidly due to strong attention in renewable energy in order to handle the problem of global climate change that is now believed to occur due to use of the fossil fuels. Cost is an influential factor in the eventual success of any solar technology, since inexpensive SCs are needed to produce electricity, especially for rural areas and for third world countries. Therefore, new developments in nanotechnology may open the door for the production of inexpensive and more efficient SCs by reducing the manufacturing costs of SCs. Utilizing nanotechnology in cheaper SCs will help maintain the environment. This article covers a review of the progress that has been made to-date to enhance efficiencies of various nanostructures used in SCs, including utilizations of all the wavelengths present in of the solar spectrum.

Static Equivalent of Distribution Grids With High Penetration of PV Systems

DEFF Research Database (Denmark)

Samadi, Afshin; Söder, Lennart; Shayesteh, Ebrahim

2015-01-01

High penetrations of photovoltaic (PV) systems within load pockets in distribution grids have changed pure consumers to prosumers. This can cause technical challenges in distribution and transmission grids, such as overvoltage and reverse power flow. Embedding voltage support schemes into PVs...... equivalent that can fairly capture the dominant behavior of the distribution grids. The aim of this paper is to use gray-box modeling concepts to develop a static equivalent of distribution grids comprising a large number of PV systems embedded with voltage support schemes. In the proposed model, the PV...... systems are aggregated as a separate entity, and not as a negative load, which is traditionally done. The results demonstrate the superior quality of the proposed model compared with the model with PV systems as the negative load....

The impact of solar flares and magnetic storms on humans

Energy Technology Data Exchange (ETDEWEB)

Joselyn, J.A. (NOAA, Space Environment Laboratory, Boulder, CO (United States))

1992-03-01

Three classes of solar emanations, namely, photon radiation from solar flares, solar energetic particles, and inhomogeneities in the solar wind that drive magnetic storms, are examined, and their effects on humans and technological systems are discussed. Solar flares may disrupt radio communications in the HF and VLF ranges. Energetic particles pose a special hazard at low-earth orbit and above, where they can penetrate barriers such as spacesuits and aluminum and destroy cells and solid state electronics. Energetic solar particles also influence terrestrial radio waves propagating through polar regions. Magnetic storms may disturb the operation of navigation instruments, power lines and pipelines, and satellites; they give rise to ionospheric storms which affect radio communication at all latitudes. There is also a growing body of evidence that changes in the geomagnetic field affect biological systems. 3 refs.

The impact of solar flares and magnetic storms on humans

International Nuclear Information System (INIS)

Joselyn, J.A.

1992-01-01

Three classes of solar emanations, namely, photon radiation from solar flares, solar energetic particles, and inhomogeneities in the solar wind that drive magnetic storms, are examined, and their effects on humans and technological systems are discussed. Solar flares may disrupt radio communications in the HF and VLF ranges. Energetic particles pose a special hazard at low-earth orbit and above, where they can penetrate barriers such as spacesuits and aluminum and destroy cells and solid state electronics. Energetic solar particles also influence terrestrial radio waves propagating through polar regions. Magnetic storms may disturb the operation of navigation instruments, power lines and pipelines, and satellites; they give rise to ionospheric storms which affect radio communication at all latitudes. There is also a growing body of evidence that changes in the geomagnetic field affect biological systems. 3 refs

The high intensity solar cell: Key to low cost photovoltaic power

Science.gov (United States)

Sater, B. L.; Goradia, C.

1975-01-01

The design considerations and performance characteristics of the 'high intensity' (HI) solar cell are presented. A high intensity solar system was analyzed to determine its cost effectiveness and to assess the benefits of further improving HI cell efficiency. It is shown that residential sized systems can be produced at less than $1000/kW peak electric power. Due to their superior high intensity performance characteristics compared to the conventional and VMJ cells, HI cells and light concentrators may be the key to low cost photovoltaic power.

Perinatal market penetration rate. A tool to evaluate regional perinatal programs.

Science.gov (United States)

Powers, W F; McGill, L

1987-01-01

Very small babies born in tertiary centers fare better than outborn babies referred for tertiary care after birth. Viewing the 1001-1500 gm regional cohort of fetuses as a potential "market" for center delivery, and measuring a center's penetration into this market, quantitates how well a center draws to itself these small, high-risk fetuses for delivery. An Illinois center's annual penetration rate into its regional market for the years 1973-1983 is presented and significant increases are found. The penetration rates of nine Illinois perinatal centers are calculated and wide discrepancies are found. Defining a high-risk regional cohort as a market stresses a perinatal center's obligation to its region. The penetration rate into a defined market measures how well a center fulfills this obligation.

The Norwegian PMS2 founder mutation c.989-1G > T shows high penetrance of microsatellite instable cancers with normal immunohistochemistry.

Science.gov (United States)

Grindedal, Eli Marie; Aarset, Harald; Bjørnevoll, Inga; Røyset, Elin; Mæhle, Lovise; Stormorken, Astrid; Heramb, Cecilie; Medvik, Heidi; Møller, Pål; Sjursen, Wenche

2014-01-01

Using immunohistochemistry (IHC) to select cases for mismatch repair (MMR) genetic testing, we failed to identify a large kindred with the deleterious PMS2 mutation c.989-1G > T. The purpose of the study was to examine the sensitivity of IHC and microsatellite instability-analysis (MSI) to identify carriers of the mutation, and to estimate its penetrance and expressions. All carriers and obligate carriers of the mutation were identified. All cancer diagnoses were confirmed. IHC and MSI-analysis were performed on available tumours. Penetrances of cancers included in the Amsterdam and the Bethesda Criteria, for MSI-high tumours and MSI-high and low tumours were calculated by the Kaplan-Meier algorithm. Probability for co-segregation of the mutation and cancers by chance was 0.000004. Fifty-six carriers or obligate carriers were identified. There was normal staining for PMS2 in 15/18 (83.3%) of tumours included in the AMS1/AMS2/Bethesda criteria. MSI-analysis showed that 15/21 (71.4%) of tumours were MSI-high and 4/21 (19.0%) were MSI-low. Penetrance at 70 years was 30.6% for AMS1 cancers (colorectal cancers), 42.8% for AMS2 cancers, 47.2% for Bethesda cancers, 55.6% for MSI-high and MSI-low cancers and 52.2% for MSI-high cancers. The mutation met class 5 criteria for pathogenicity. IHC was insensitive in detecting tumours caused by the mutation. Penetrance of cancers that displayed MSI was 56% at 70 years. Besides colorectal cancers, the most frequent expressions were carcinoma of the endometrium and breast in females and stomach and prostate in males.

The Potential for Energy Storage to Provide Peaking Capacity in California Under Increased Penetration of Solar Photovoltaics

Energy Technology Data Exchange (ETDEWEB)

Denholm, Paul L [National Renewable Energy Laboratory (NREL), Golden, CO (United States); Margolis, Robert M [National Renewable Energy Laboratory (NREL), Golden, CO (United States)

2018-03-14

In this report, we examine the potential for replacing conventional peaking capacity in California with energy storage, including analysis of the changing technical potential with increased storage deployment and the effect of PV deployment. We examine nine years of historic load data, a range of storage durations (2-8 hours), and a range of PV penetration levels (0%-30%). We demonstrate how PV increases the ability of storage to reduce peak net demand. In the scenarios analyzed, the expected penetration of PV in California in 2020 could more than double the potential for 4-hour energy storage to provide capacity services.

The high intensity solar cell - Key to low cost photovoltaic power

Science.gov (United States)

Sater, B. L.; Goradia, C.

1975-01-01

This paper discusses the problems associated with conventional solar cells at high intensities and presents the design considerations and performance characteristics of the 'high intensity' (HI) solar cell which appears to eliminate the major problems. Test data obtained at greater than 250 AM1 suns gave a peak output power density of 2 W per sq cm at an efficiency exceeding 6% with an unoptimized cell operating at over 100 C. It appears that operation at 1000 AM1 suns at efficiencies greater than 10% is possible. At 1000 AM1 suns and 10% efficiency, the HI cell manufacturing cost is estimated to be $0.25/watt, with multi-megawatt annual production capability already existing within the industrial sector. A high intensity solar system was also analyzed to determine its cost effectiveness and to assess the benefits of further improving HI cell efficiency.

A High-resolution Multi-wavelength Simultaneous Imaging System with Solar Adaptive Optics

Energy Technology Data Exchange (ETDEWEB)

Rao, Changhui; Zhu, Lei; Gu, Naiting; Rao, Xuejun; Zhang, Lanqiang; Bao, Hua; Kong, Lin; Guo, Youming; Zhong, Libo; Ma, Xue’an; Li, Mei; Wang, Cheng; Zhang, Xiaojun; Fan, Xinlong; Chen, Donghong; Feng, Zhongyi; Wang, Xiaoyun; Wang, Zhiyong, E-mail: gunaiting@ioe.ac.cn [The Key Laboratory on Adaptive Optics, Chinese Academy of Sciences, P.O. Box 350, Shuangliu, Chengdu 610209, Sichuan (China)

2017-10-01

A high-resolution multi-wavelength simultaneous imaging system from visible to near-infrared bands with a solar adaptive optics system, in which seven imaging channels, including the G band (430.5 nm), the Na i line (589 nm), the H α line (656.3 nm), the TiO band (705.7 nm), the Ca ii IR line (854.2 nm), the He i line (1083 nm), and the Fe i line (1565.3 nm), are chosen, is developed to image the solar atmosphere from the photosphere layer to the chromosphere layer. To our knowledge, this is the solar high-resolution imaging system with the widest spectral coverage. This system was demonstrated at the 1 m New Vaccum Solar Telescope and the on-sky high-resolution observational results were acquired. In this paper, we will illustrate the design and performance of the imaging system. The calibration and the data reduction of the system are also presented.

Computational design for a wide-angle cermet-based solar selective absorber for high temperature applications

International Nuclear Information System (INIS)

Sakurai, Atsushi; Tanikawa, Hiroya; Yamada, Makoto

2014-01-01

The purpose of this study is to computationally design a wide-angle cermet-based solar selective absorber for high temperature applications by using a characteristic matrix method and a genetic algorithm. The present study investigates a solar selective absorber with tungsten–silica (W–SiO 2 ) cermet. Multilayer structures of 1, 2, 3, and 4 layers and a wide range of metal volume fractions are optimized. The predicted radiative properties show good solar performance, i.e., thermal emittances, especially beyond 2 μm, are quite low, in contrast, solar absorptance levels are successfully high with wide angular range, so that solar photons are effectively absorbed and infrared radiative heat loss can be decreased. -- Highlights: • Electromagnetic simulation of radiative properties by characteristic matrix method. • Optimization for multilayered W–SiO 2 cermet-based absorber by a Genetic Algorithm. • We propose a successfully high solar performance of solar selective absorber

Penetrating Cardiac and Hepatic Injury; Polytrauma of a Child After Bombing

Directory of Open Access Journals (Sweden)

Baris Akca

2013-10-01

Full Text Available After a bombing attack, patients were brought into hospital suffering from a combination of injuries caused by the blast, penetrating injuries and burns which as a case of polytrauma. In penetrating thoracoabdominal injuries due to bombing possibility of cardiac injury should be kept in mind. Penetrating cardiac injuries in children are rare but has a high mortality and morbidity. In some cases there may be difficulty in diagnosis of penetrating cardiac injury. In this case we want to share the diagnosis, treatment and follow-up processes of penetrating cardiac and hepatic injury with burns of a politrauma child due to bombing.

Risk assessment of electric generation systems with high wind penetration

International Nuclear Information System (INIS)

Salgado Duarte, Yorlandys; Castillo Serpa, Alfredo M. del

2017-01-01

The research evaluates the risk function of an Electric Generation System (SGE) with high wind power penetration using the Sequential Monte Carlo Simulation (SMCS) method, which allows calculating indicators that characterize the performance of the SGE with expected average values. The research uses a Markov model of two states or four states according to the characteristics of the generator to simulate the instantaneous capacity. The primary sources of each conventional generator are assumed to be always available; however, wind power depends on the wind behavior in each analyzed region. In this research, the Chronological Series and Weibull models are used to model the wind behavior, and the analyzes are performed in the IEEE-RTS system. The work shows that the behavior of the probabilistic indicators used to analyze the static capacity of the SGE is determined by the model used to simulate the stochastic of the generators and by the primary energy source. (author)

Application of Uintah-MPM to shaped charge jet penetration of aluminum

International Nuclear Information System (INIS)

Burghardt, J; Leavy, B; Brannon, R; Guilkey, J; Xue, Z

2010-01-01

The capability of the generalized interpolation material point (GIMP) method in simulation of penetration events is investigated. A series of experiments was performed wherein a shaped charge jet penetrates into a stack of aluminum plates. Electronic switches were used to measure the penetration time history. Flash x-ray techniques were used to measure the density, length, radius and velocity of the shaped charge jet. Simulations of the penetration event were performed using the Uintah MPM/GIMP code with several different models of the shaped charge jet being used. The predicted penetration time history for each jet model is compared with the experimentally observed penetration history. It was found that the characteristics of the predicted penetration were dependent on the way that the jet data are translated to a discrete description. The discrete jet descriptions were modified such that the predicted penetration histories fell very close to the range of the experimental data. In comparing the various discrete jet descriptions it was found that the cumulative kinetic energy flux curve represents an important way of characterizing the penetration characteristics of the jet. The GIMP method was found to be well suited for simulation of high rate penetration events.

Production of solar radiation bankable datasets from high-resolution solar irradiance derived with dynamical downscaling Numerical Weather prediction model

Directory of Open Access Journals (Sweden)

Yassine Charabi

2016-11-01

Full Text Available A bankable solar radiation database is required for the financial viability of solar energy project. Accurate estimation of solar energy resources in a country is very important for proper siting, sizing and life cycle cost analysis of solar energy systems. During the last decade an important progress has been made to develop multiple solar irradiance database (Global Horizontal Irradiance (GHI and Direct Normal Irradiance (DNI, using satellite of different resolution and sophisticated models. This paper assesses the performance of High-resolution solar irradiance derived with dynamical downscaling Numerical Weather Prediction model with, GIS topographical solar radiation model, satellite data and ground measurements, for the production of bankable solar radiation datasets. For this investigation, NWP model namely Consortium for Small-scale Modeling (COSMO is used for the dynamical downscaling of solar radiation. The obtained results increase confidence in solar radiation data base obtained from dynamical downscaled NWP model. The mean bias of dynamical downscaled NWP model is small, on the order of a few percents for GHI, and it could be ranked as a bankable datasets. Fortunately, these data are usually archived in the meteorological department and gives a good idea of the hourly, monthly, and annual incident energy. Such short time-interval data are valuable in designing and operating the solar energy facility. The advantage of the NWP model is that it can be used for solar radiation forecast since it can estimate the weather condition within the next 72–120 hours. This gives a reasonable estimation of the solar radiation that in turns can be used to forecast the electric power generation by the solar power plant.

Double ionization chamber survey meter for the separate measurement of penetrating and non-penetrating dose

International Nuclear Information System (INIS)

Lucas, A.C.

1987-01-01

The full capabilities of an advanced 8-bit microprocessor have been utilized in construction of a wide range, multiplexing survey meter based on dual electrometers and ionization chambers. The ionization chambers are constructed of modular conducting and non-conducting parts in such a way that the angular dependence for measurement of beta radiation is controlled by design. Display functions for the high range instrument include logarithmic or linear analog display, digital display of rate or dose, SI or English units, optionally for either total, penetrating, or non-penetrating dose. The instrument is presently configured to operate in the range 0.1 R/hr to 50,000 R/hr in support of the requirements of Regulatory Guide 19.7

Price Forecasting of Electricity Markets in the Presence of a High Penetration of Wind Power Generators

Directory of Open Access Journals (Sweden)

Saber Talari

2017-11-01

Full Text Available Price forecasting plays a vital role in the day-ahead markets. Once sellers and buyers access an accurate price forecasting, managing the economic risk can be conducted appropriately through offering or bidding suitable prices. In networks with high wind power penetration, the electricity price is influenced by wind energy; therefore, price forecasting can be more complicated. This paper proposes a novel hybrid approach for price forecasting of day-ahead markets, with high penetration of wind generators based on Wavelet transform, bivariate Auto-Regressive Integrated Moving Average (ARIMA method and Radial Basis Function Neural Network (RBFN. To this end, a weighted time series for wind dominated power systems is calculated and added to a bivariate ARIMA model along with the price time series. Moreover, RBFN is applied as a tool to correct the estimation error, and particle swarm optimization (PSO is used to optimize the structure and adapt the RBFN to the particular training set. This method is evaluated on the Spanish electricity market, which shows the efficiency of this approach. This method has less error compared with other methods especially when it considers the effects of large-scale wind generators.

Penetrating ocular trauma from trampoline spring.

Science.gov (United States)

Spokes, David; Siddiqui, Salina; Vize, Colin

2010-02-01

The case is presented of a 12-year old boy who sustained severe penetrating ocular trauma while playing on a domestic trampoline. A main spring broke under tension and the hook had struck the eye at high velocity and penetrated the sclera. Primary repair was undertaken but on review it became apparent the eye could not be salvaged. Evisceration was carried out and an orbital implant was placed. Post-operative cosmesis is acceptable. This type of injury has not been reported before. Adult supervision of children on trampolines is recommended to minimise the chance of serious injury.

Household Solar Photovoltaics: Supplier of Marginal Abatement, or Primary Source of Low-Emission Power?

Directory of Open Access Journals (Sweden)

Graham Palmer

2013-03-01

Full Text Available With declining system costs and assuming a short energy payback period, photovoltaics (PV should, at face value, be able to make a meaningful contribution to reducing the emission intensity of Australia’s electricity system. However, solar is an intermittent power source and households remain completely dependent on a “less than green” electricity grid for reliable electricity. Further, much of the energy impact of PV occurs outside of the conventional boundaries of PV life-cycle analyses (LCA. This paper examines these competing observations and explores the broader impacts of a high penetration of household PV using Melbourne, Victoria as a reference. It concludes that in a grid dominated by unsequestered coal and gas, PV provides a legitimate source of emission abatement at high, but declining costs, with the potential for network and peak demand support. It may be technically possible to integrate a high penetration of PV, but the economic and energy cost of accommodating high-penetration PV erodes much of the benefits. Future developments in PV, storage, and integration technologies may allow PV to take on a greater long term role, but in the time horizon usually discussed in climate policy, a large-scale expansion of household PV may hinder rather than assist deep cuts to the emission intensity of Australia’s electricity system.

The Solar Textile Challenge: How It Will Not Work and Where It Might

DEFF Research Database (Denmark)

Krebs, Frederik C; Hösel, Markus

2015-01-01

Solar textiles are highlighted as a future technology with transformative power within the fields of both textiles and solar cells provided that developments are made in critical areas. Specifically, these are fundamental solutions to materials and material combinations with mechanical stability......, practical solutions to fast and efficient manufacture and integration. The areas of application and the penetration of solar textiles into our everyday life are expected to be explosive pending efficient developments within these four key areas. A shortcoming in one or more of these will, however, lead...... to the solar textiles being banned to academic existence....

Development Of The Nuclear Optical Penetration

Science.gov (United States)

Inoue, K.; Koike, K.; Imada, Y.

1984-10-01

We have developed the nuclear optical penetration to be incorporated in the wall penetration of the shell to introduce a data transmission system using optical fibers into a nuclear power plant with a pressurized water reactor. Radiation-induced coloration in optical glass seriously affects transmission characteristics of optical fibers, whereas it has been revealed that the pure-silica core optical fiber without any dopant in the core has wide applicability in radiation fields thanks to its very low radiation-induced attenuation. The wall penetration of the shell should have airtightness and resistivity to heat, vibration, and pressure, let alone radiation, excellent enough to be invariable in data transmission efficiency even when subjected to severe environmental tests. The sealing modules of this newly developed nuclear optical penetration are hermetically sealed. The gap between the optical fiber rod (100 pm in core diameter and 5 mm in rod diameter) and stainless steel tube is sealed with lamingted glass layer. As the result of He gas leakage test, high airtightness of less than 10 cc/sec was achieved. No thermal deformation of the core was caused by sealing with laminated glass layer, nor was observed transmission loss. Then the sealiing modules were subjected to the irradiation test using 60 Co gamma ray exposure of 2 x 10 rads. Though silica glass layer supporting the fiber rod and sealing glass portion turned blackish purple, transparency of the fiber was not affected. Only less than 0.5 dB of connecting loss was observed at the connecting point with the optical fiber cable. The sealing modules were also found to have resistivity to vibration and pressure as excellent as that of existing nuclear electric penetrations. We expect the nuclear optical fiber penetration will be much effective in improving reliability of data transmission systems using optical fibers in radiation fields.

Tumor penetrating peptides

Directory of Open Access Journals (Sweden)

Tambet eTeesalu

2013-08-01

Full Text Available Tumor-homing peptides can be used to deliver drugs into tumors. Phage library screening in live mice has recently identified homing peptides that specifically recognize the endothelium of tumor vessels, extravasate, and penetrate deep into the extravascular tumor tissue. The prototypic peptide of this class, iRGD (CRGDKGPDC, contains the integrin-binding RGD motif. RGD mediates tumor homing through binding to αv integrins, which are selectively expressed on various cells in tumors, including tumor endothelial cells. The tumor-penetrating properties of iRGD are mediated by a second sequence motif, R/KXXR/K. This C-end Rule (or CendR motif is active only when the second basic residue is exposed at the C-terminus of the peptide. Proteolytic processing of iRGD in tumors activates the cryptic CendR motif, which then binds to neuropilin-1 activating an endocytic bulk transport pathway through tumor tissue. Phage screening has also yielded tumor-penetrating peptides that function like iRGD in activating the CendR pathway, but bind to a different primary receptor. Moreover, novel tumor-homing peptides can be constructed from tumor-homing motifs, CendR elements and protease cleavage sites. Pathologies other than tumors can be targeted with tissue-penetrating peptides, and the primary receptor can also be a vascular zip code of a normal tissue. The CendR technology provides a solution to a major problem in tumor therapy, poor penetration of drugs into tumors. The tumor-penetrating peptides are capable of taking a payload deep into tumor tissue in mice, and they also penetrate into human tumors ex vivo. Targeting with these peptides specifically increases the accumulation in tumors of a variety of drugs and contrast agents, such as doxorubicin, antibodies and nanoparticle-based compounds. Remarkably the drug to be targeted does not have to be coupled to the peptide; the bulk transport system activated by the peptide sweeps along any compound that is

The impact of changing solar screen rotation angle and its opening aspect ratios on Daylight Availability in residential desert buildings

KAUST Repository

Sherif, Ahmed H.; Sabry, Hanan M.; Gadelhak, Mahmoud I.

2012-01-01

usually used to diffuse and prevent direct solar penetration into spaces. This paper investigates the impact of changing solar screen axial rotation angle and screen opening aspect ratio on daylighting performance in a typical residential living room space

HIGH SPATIAL RESOLUTION OBSERVATIONS OF LOOPS IN THE SOLAR CORONA

Energy Technology Data Exchange (ETDEWEB)

Brooks, David H.; Ugarte-Urra, Ignacio [College of Science, George Mason University, 4400 University Drive, Fairfax, VA 22030 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Winebarger, Amy R. [NASA Marshall Space Flight Center, ZP 13, Huntsville, AL 35812 (United States)

2013-08-01

Understanding how the solar corona is structured is of fundamental importance to determine how the Sun's upper atmosphere is heated to high temperatures. Recent spectroscopic studies have suggested that an instrument with a spatial resolution of 200 km or better is necessary to resolve coronal loops. The High Resolution Coronal Imager (Hi-C) achieved this performance on a rocket flight in 2012 July. We use Hi-C data to measure the Gaussian widths of 91 loops observed in the solar corona and find a distribution that peaks at about 270 km. We also use Atmospheric Imaging Assembly data for a subset of these loops and find temperature distributions that are generally very narrow. These observations provide further evidence that loops in the solar corona are often structured at a scale of several hundred kilometers, well above the spatial scale of many proposed physical mechanisms.

3D-Printed, All-in-One Evaporator for High-Efficiency Solar Steam Generation under 1 Sun Illumination.

Science.gov (United States)

Li, Yiju; Gao, Tingting; Yang, Zhi; Chen, Chaoji; Luo, Wei; Song, Jianwei; Hitz, Emily; Jia, Chao; Zhou, Yubing; Liu, Boyang; Yang, Bao; Hu, Liangbing

2017-07-01

Using solar energy to generate steam is a clean and sustainable approach to addressing the issue of water shortage. The current challenge for solar steam generation is to develop easy-to-manufacture and scalable methods which can convert solar irradiation into exploitable thermal energy with high efficiency. Although various material and structure designs have been reported, high efficiency in solar steam generation usually can be achieved only at concentrated solar illumination. For the first time, 3D printing to construct an all-in-one evaporator with a concave structure for high-efficiency solar steam generation under 1 sun illumination is used. The solar-steam-generation device has a high porosity (97.3%) and efficient broadband solar absorption (>97%). The 3D-printed porous evaporator with intrinsic low thermal conductivity enables heat localization and effectively alleviates thermal dissipation to the bulk water. As a result, the 3D-printed evaporator has a high solar steam efficiency of 85.6% under 1 sun illumination (1 kW m -2 ), which is among the best compared with other reported evaporators. The all-in-one structure design using the advanced 3D printing fabrication technique offers a new approach to solar energy harvesting for high-efficiency steam generation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Measurement of Skin Permeation/Penetration of Nanoparticles for Their Safety Evaluation

OpenAIRE

木村, 恵理子; 河野, 雄一郎; 藤堂, 浩明; 五十嵐, 良明; 杉林, 堅次

2012-01-01

The aim of the present study was to quantitatively evaluate the skin permeation/penetration of nanomaterials and to consider their penetration pathway through skin. Firstly, penetration/permeation of a model fluorescent nanoparticle, Fluoresbrite?, was determined through intact rat skin and several damaged skins. Fluoresbrite? permeated through only needle-punctured skin. The permeation profiles of soluble high molecular compounds, fluorescein isothiocyanate-dextrans (FITC-dextrans, FDs), wit...

Advances in High-Efficiency III-V Multijunction Solar Cells

Directory of Open Access Journals (Sweden)

Richard R. King

2007-01-01

Full Text Available The high efficiency of multijunction concentrator cells has the potential to revolutionize the cost structure of photovoltaic electricity generation. Advances in the design of metamorphic subcells to reduce carrier recombination and increase voltage, wide-band-gap tunnel junctions capable of operating at high concentration, metamorphic buffers to transition from the substrate lattice constant to that of the epitaxial subcells, concentrator cell AR coating and grid design, and integration into 3-junction cells with current-matched subcells under the terrestrial spectrum have resulted in new heights in solar cell performance. A metamorphic Ga0.44In0.56P/Ga0.92In0.08As/ Ge 3-junction solar cell from this research has reached a record 40.7% efficiency at 240 suns, under the standard reporting spectrum for terrestrial concentrator cells (AM1.5 direct, low-AOD, 24.0 W/cm2, 25∘C, and experimental lattice-matched 3-junction cells have now also achieved over 40% efficiency, with 40.1% measured at 135 suns. This metamorphic 3-junction device is the first solar cell to reach over 40% in efficiency, and has the highest solar conversion efficiency for any type of photovoltaic cell developed to date. Solar cells with more junctions offer the potential for still higher efficiencies to be reached. Four-junction cells limited by radiative recombination can reach over 58% in principle, and practical 4-junction cell efficiencies over 46% are possible with the right combination of band gaps, taking into account series resistance and gridline shadowing. Many of the optimum band gaps for maximum energy conversion can be accessed with metamorphic semiconductor materials. The lower current in cells with 4 or more junctions, resulting in lower I2R resistive power loss, is a particularly significant advantage in concentrator PV systems. Prototype 4-junction terrestrial concentrator cells have been grown by metal-organic vapor-phase epitaxy, with preliminary measured

Deep ocean model penetrator experiments

International Nuclear Information System (INIS)

Freeman, T.J.; Burdett, J.R.F.

1986-01-01

Preliminary trials of experimental model penetrators in the deep ocean have been conducted as an international collaborative exercise by participating members (national bodies and the CEC) of the Engineering Studies Task Group of the Nuclear Energy Agency's Seabed Working Group. This report describes and gives the results of these experiments, which were conducted at two deep ocean study areas in the Atlantic: Great Meteor East and the Nares Abyssal Plain. Velocity profiles of penetrators of differing dimensions and weights have been determined as they free-fell through the water column and impacted the sediment. These velocity profiles are used to determine the final embedment depth of the penetrators and the resistance to penetration offered by the sediment. The results are compared with predictions of embedment depth derived from elementary models of a penetrator impacting with a sediment. It is tentatively concluded that once the resistance to penetration offered by a sediment at a particular site has been determined, this quantity can be used to sucessfully predict the embedment that penetrators of differing sizes and weights would achieve at the same site

Tracking strategy for photovoltaic solar systems in high latitudes

International Nuclear Information System (INIS)

Quesada, Guillermo; Guillon, Laura; Rousse, Daniel R.; Mehrtash, Mostafa; Dutil, Yvan; Paradis, Pierre-Luc

2015-01-01

Highlights: • In cloudy conditions tracking the sun is ineffective. • A methodology to estimate a theoretical threshold for solar tracking was developed. • A tracking strategy to maximize electricity production was proposed. - Abstract: Several studies show that from about 20% to 50% more solar energy can be recovered by using photovoltaic systems that track the sun rather than systems set at a fixed angle. For overcast or cloudy days, recent studies propose the use of a set position in which each photovoltaic panel faces toward the zenith (horizontal position). Compared to a panel that follows the sun’s path, this approach claims that a horizontal panel increases the amount of solar radiation captured and subsequently the quantity of electricity produced. The present work assesses a solar tracking photovoltaic panel hourly and seasonally in high latitudes. A theoretical method based on an isotropic sky model was formulated, implemented, and used in a case study analysis of a grid-connected photovoltaic system in Montreal, Canada. The results obtained, based on the definition of a critical hourly global solar radiation, were validated numerically and experimentally. The study confirmed that a zenith-set sun tracking strategy for overcast or mostly cloudy days in summer is not advantageous

High efficient plastic solar cells fabricated with a high-throughput gravure printing method

Energy Technology Data Exchange (ETDEWEB)

Kopola, P.; Jin, H.; Tuomikoski, M.; Maaninen, A.; Hast, J. [VTT, Kaitovaeylae 1, FIN-90571 Oulu (Finland); Aernouts, T. [IMEC, Organic PhotoVoltaics, Polymer and Molecular Electronics, Kapeldreef 75, B-3001 Leuven (Belgium); Guillerez, S. [CEA-INES RDI, 50 Avenue Du Lac Leman, 73370 Le Bourget Du Lac (France)

2010-10-15

We report on polymer-based solar cells prepared by the high-throughput roll-to-roll gravure printing method. The engravings of the printing plate, along with process parameters like printing speed and ink properties, are studied to optimise the printability of the photoactive as well as the hole transport layer. For the hole transport layer, the focus is on testing different formulations to produce thorough wetting of the indium-tin-oxide (ITO) substrate. The challenge for the photoactive layer is to form a uniform layer with optimal nanomorphology in the poly-3-hexylthiophene (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) blend. This results in a power conversion efficiency of 2.8% under simulated AM1.5G solar illumination for a solar cell device with gravure-printed hole transport and a photoactive layer. (author)

Analysis of the economics of typical business applications of solar energy

Science.gov (United States)

1981-11-01

An economic analysis is provided of flat plate collector systems in industrial, commercial, and agricultural business applications in a variety of locations. A key element of the analysis is the federal solar investment tax credit. The SOLCOST Solar Energy Design Program is used for the study. The differences between industrial agricultural and commercial applications are considered, as are finance and tax data and fuel data. The rate of return and payback are the criteria used to compare the economic viability of systems. Market penetration estimates for process steam were derived for seven southwestern states where direct solar radiation is highest.

Transmission components of solar radiation in pine stands in relation to climatic and stand variables

Science.gov (United States)

Robert A. Muller

1971-01-01

In a new approach, transmission was studied by relating to stand biomass the ratio of incoming solar radiation beneath tree crowns to that within the atmosphere. Several assumptions were used to estimate analytically the various ways in which solar radiation penetrates through crowns of three pine species in northern California. Sunflecks accounted for much of the...

High-energy and high-fluence proton irradiation effects in silicon solar cells

International Nuclear Information System (INIS)

Yamaguchi, M.; Taylor, S.J.; Yang, M.; Matsuda, S.; Kawasaki, O.; Hisamatsu, T.

1996-01-01

We have examined proton irradiation damage in high-energy (1 endash 10 MeV) and high-fluence (approx-gt 10 13 cm -2 ) Si n + -p-p + structure space solar cells. Radiation testing has revealed an anomalous increase in short-circuit current I sc followed by an abrupt decrease and cell failure, induced by high-fluence proton irradiation. We propose a model to explain these phenomena by expressing the change in carrier concentration p of the base region as a function of the proton fluence in addition to the well-known model where the short-circuit current is decreased by minority-carrier lifetime reduction after irradiation. The reduction in carrier concentration due to majority-carrier trapping by radiation-induced defects has two effects. First, broadening of the depletion layer increases both the generation endash recombination current and also the contribution of the photocurrent generated in this region to the total photocurrent. Second, the resistivity of the base layer is increased, resulting in the abrupt decrease in the short circuit current and failure of the solar cells. copyright 1996 American Institute of Physics

Energy management strategy for solar-powered high-altitude long-endurance aircraft

International Nuclear Information System (INIS)

Gao, Xian-Zhong; Hou, Zhong-Xi; Guo, Zheng; Liu, Jian-Xia; Chen, Xiao-Qian

2013-01-01

Highlights: ► A new Energy Management Strategy (EMS) for high-altitude solar-powered aircraft is purposed. ► The simulations show that the aircraft can always keep the altitude above 16 km with the proposed EMS. ► The proposed EMS is capable to alleviate the power consumed for aircraft during night. ► The main technologies to improve the flight performance of aircraft are analyzed. - Abstract: Development of solar-powered High-Altitude Long-Endurance (HALE) aircraft has a great impact on both military and civil aviation industries since its features in high-altitude and energy source can be considered inexhaustible. Owing to the development constraints of rechargeable batteries, the solar-powered HALE aircraft must take amount of rechargeable batteries to fulfill the energy requirement in night, which greatly limits the operation altitude of aircraft. In order to solve this problem, a new Energy Management Strategy (EMS) is proposed based on the idea that the solar energy can be partly stored in gravitational potential in daytime. The flight path of HALE aircraft is divided into three stages. During the stage 1, the solar energy is stored in both lithium–sulfur battery and gravitational potential. The gravitational potential is released in stage 2 by gravitational gliding and the required power in stage 3 is supplied by lithium–sulfur battery. Correspondingly, the EMS is designed for each stage. The simulation results show that the aircraft can always keep the altitude above 16 km with the proposed EMS, and the power consumed during night can be also alleviated. Comparing with the current EMS, about 23.5% energy is remained in batteries with the proposed EMS during one day–night cycle. The sensitivities of the improvement of crucial technologies to the performance of aircraft are also analyzed. The results show that the enhancement of control and structural system, lithium–sulfur battery, and solar cell are ranked in descending order for the

Mixed-Penetrant Sorption in Ultrathin Films of Polymer of Intrinsic Microporosity PIM-1.

Science.gov (United States)

Ogieglo, Wojciech; Furchner, Andreas; Ghanem, Bader; Ma, Xiaohua; Pinnau, Ingo; Wessling, Matthias

2017-11-02

Mixed-penetrant sorption into ultrathin films of a superglassy polymer of intrinsic microporosity (PIM-1) was studied for the first time by using interference-enhanced in situ spectroscopic ellipsometry. PIM-1 swelling and the concurrent changes in its refractive index were determined in ultrathin (12-14 nm) films exposed to pure and mixed penetrants. The penetrants included water, n-hexane, and ethanol and were chosen on the basis of their significantly different penetrant-penetrant and penetrant-polymer affinities. This allowed studying microporous polymer responses at diverse ternary compositions and revealed effects such as competition for the sorption sites (for water/n-hexane or ethanol/n-hexane) or enhancement in sorption of typically weakly sorbing water in the presence of more highly sorbing ethanol. The results reveal details of the mutual sorption effects which often complicate comprehension of glassy polymers' behavior in applications such as high-performance membranes, adsorbents, or catalysts. Mixed-penetrant effects are typically very challenging to study directly, and their understanding is necessary owing to a broadly recognized inadequacy of simple extrapolations from measurements in a pure component environment.

Production price of hydrogen from grid connected electrolysis in a power market with high wind penetration

International Nuclear Information System (INIS)

Joergensen, Claus; Ropenus, Stephanie

2008-01-01

In liberalized power markets, there are significant power price fluctuations due to independently varying changes in demand and supply, the latter being substantial in systems with high wind power penetration. In such systems, hydrogen production by grid connected electrolysis can be cost optimized by operating an electrolyzer part time. This paper presents a study on the minimization of the hydrogen production price and its dependence on estimated power price fluctuations. The calculation of power price fluctuations is based on a parameterization of existing data on wind power production, power consumption and power price evolution in the West Danish power market area. The price for hydrogen is derived as a function of the optimal electrolyzer operation hours per year for four different wind penetration scenarios. It is found to amount to 0.41-0.45 EUR/Nm 3 . The study further discusses the hydrogen price sensitivity towards investment costs and the contribution from non-wind power sources. (author)

Production price of hydrogen from grid connected electrolysis in a power market with high wind penetration

Energy Technology Data Exchange (ETDEWEB)

Joergensen, Claus [Materials Research Department, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Ropenus, Stephanie [Systems Analysis Department, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

2008-10-15

In liberalized power markets, there are significant power price fluctuations due to independently varying changes in demand and supply, the latter being substantial in systems with high wind power penetration. In such systems, hydrogen production by grid connected electrolysis can be cost optimized by operating an electrolyzer part time. This paper presents a study on the minimization of the hydrogen production price and its dependence on estimated power price fluctuations. The calculation of power price fluctuations is based on a parameterization of existing data on wind power production, power consumption and power price evolution in the West Danish power market area. The price for hydrogen is derived as a function of the optimal electrolyzer operation hours per year for four different wind penetration scenarios. It is found to amount to 0.41-0.45 EUR/Nm{sup 3}. The study further discusses the hydrogen price sensitivity towards investment costs and the contribution from non-wind power sources. (author)

Production price of hydrogen from grid connected electrolysis in a power market with high wind penetration.

Energy Technology Data Exchange (ETDEWEB)

Joergensen, Claus [Materials Research Department, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, Frederiksborgvej 399, DK-4000 Roskilde (Denmark); Ropenus, Stephanie [Systems Analysis Department, Risoe National Laboratory for Sustainable Energy, Technical University of Denmark, P.O. Box 49, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

2008-10-15

In liberalized power markets, there are significant power price fluctuations due to independently varying changes in demand and supply, the latter being substantial in systems with high wind power penetration. In such systems, hydrogen production by grid connected electrolysis can be cost optimized by operating an electrolyzer part time. This paper presents a study on the minimization of the hydrogen production price and its dependence on estimated power price fluctuations. The calculation of power price fluctuations is based on a parameterization of existing data on wind power production, power consumption and power price evolution in the West Danish power market area. The price for hydrogen is derived as a function of the optimal electrolyzer operation hours per year for four different wind penetration scenarios. It is found to amount to 0.41-0.45 EUR/Nm{sup 3}. The study further discusses the hydrogen price sensitivity towards investment costs and the contribution from non-wind power sources. (author)

A Review of Hybrid Solar PV and Wind Energy System

Directory of Open Access Journals (Sweden)

Rashid Al Badwawi

2015-07-01

Full Text Available Due to the fact that solar and wind power is intermittent and unpredictable in nature, higher penetration of their types in existing power system could cause and create high technical challenges especially to weak grids or stand-alone systems without proper and enough storage capacity. By integrating the two renewable resources into an optimum combination, the impact of the variable nature of solar and wind resources can be partially resolved and the overall system becomes more reliable and economical to run. This paper provides a review of challenges and opportunities / solutions of hybrid solar PV and wind energy integration systems. Voltage and frequency fluctuation, and harmonics are major power quality issues for both grid-connected and stand-alone systems with bigger impact in case of weak grid. This can be resolved to a large extent by having proper design, advanced fast response control facilities, and good optimization of the hybrid systems. The paper gives a review of the main research work reported in the literature with regard to optimal sizing design, power electronics topologies and control. The paper presents a review of the state of the art of both grid-connected and stand-alone hybrid solar and wind systems.

Performance characterization of the SERI High-Flux Solar Furnace

Energy Technology Data Exchange (ETDEWEB)

Lewandowski, A.; Bingham, C. (Solar Energy Research Inst., Golden, CO (United States)); O' Gallagher, J.; Winston, R.; Sagie, D. (Univ. of Chicago, IL (United States))

1991-12-01

This paper describes a unique, new solar furnace at the Solar Energy Research Institute (SERI) that can generate a wide range of flux concentrations to support research in areas including materials processing, high-temperature detoxification and high-flux optics. The furnace is unique in that it uses a flat, tracking heliostat along with a long focal length-to-diameter (f/D) primary concentrator in an off-axis configuration. The experiments are located inside a building completely outside the beam between the heliostat and primary concentrator. The long f/D ratio of the primary concentrator was designed to take advantage of a nonimaging secondary concentrator to significantly increase the flux concentration capabilities of the system. Results are reported for both the single-stage and two-stage configurations. (orig.).

Horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications.

Science.gov (United States)

Ma, Hongcai; Wu, Lin

2015-07-10

We present the design of a horizontally staggered lightguide solar concentrator with lateral displacement tracking for high concentration applications. This solar concentrator consists of an array of telecentric primary concentrators, a horizontally staggered lightguide layer, and a vertically tapered lightguide layer. The primary concentrator is realized by two plano-aspheric lenses with lateral movement and maintains a high F-number over an angle range of ±23.5°. The results of the simulations show that the solar concentrator achieves a high concentration ratio of 500× with ±0.5° of acceptance angle by a single-axis tracker and dual lateral translation stages.

A high absorbance material for solar collectors' applications

International Nuclear Information System (INIS)

Oliva, A I; Maldonado, R D; Díaz, E A; Montalvo, A I

2013-01-01

In this work, we proposed a low cost material to be used as an excellent absorber for solar collectors, to increase its thermal efficiency by the high capacity to absorb solar radiation. The material, known as 'smoke black' (soot) can be obtained by the incomplete combustion of organic materials, such as the oxygen-acetylene, paraffin, or candles. A comparative analysis between the optical properties (reflectance, absorbance, and emissivity) measured on three covered copper surfaces (without paint, with a commercial matte black paint, and with smoke black) shows amazing optical results for the smoke black. Reflectance values of the smoke black applied over copper surfaces improves 56 times the values obtained from commercial black paints. High values of emissivity (E=0.9988) were measured on the surface covered with smoke black by spectrophotometry in the UV-VIS range, which represents about 7% of increment as compared with the value obtained for commercial black paints (E=0.938). The proposed high absorbance material can be easily applied on any kind of surfaces at low cost.

A high-performance stand-alone solar PV power system for LED lighting

KAUST Repository

Huang, B. J.; Hsu, P. C.; Wu, M. S.; Chen, K.Y.

2010-01-01

The present study developed a high-performance solar PV power technology for the LED lighting of a solar home system. The nMPPO (near-Maximum-Power- Point- Operation) design is employed in system design to eliminate MPPT. A feedback control system

Clay-brick firing in a high-temperature solar furnace

Energy Technology Data Exchange (ETDEWEB)

Villeda-Munoz, G. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico)]. E-mail: gvilledam@ipn.mx; Castaneda-Miranda, A. [Computation & amp; Mechatronic Studies Division, Universidad Politecnica de Queretaro, Queretaro (Mexico)]. E-mail: acastaneda@upq.edu.mx; Pless, R.C. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico)]. E-mail: rpless@ipn.mx; Vega-Duran, J.T. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico); Pineda-Pinon, J. [Centro de Investigacion en Ciencia Aplicada y Tecnologia Avanzada, Instituto Politecnico Nacional, Unidad Queretaro, Queretaro (Mexico)]. E-mail: jpinedap@ipn.mx

2011-10-15

The firing process for clay-brick production in traditional kilns generates atmospheric pollution when industrial and domestic scrap is used as fuel. An alternative is presented here, using the solar energy for clay-brick firing. We are developing a system for clay-brick firing to reach temperatures between 900 degrees Celsius and 1050 degrees Celsius; these temperatures are sufficiently high to fire bricks or similar ceramic products. The present paper describes the design and characterization of the components of a solar furnace for clay-brick firing with inner chamber dimensions of 0.48 * 0.61 * 0.64 m. To convey the sunlight to the firing chamber, a heliostat with nine 1 * 1 m mirrors is used to send the rays of the sun to an off-axis parabolic concentrator that focuses the light on the entrance of the firing chamber. The heliostat has a solar-tracking system which makes primary and secondary adjustments to assure that the reflected solar radiation always arrives at the concentrator. The firing chamber contains a prismatic cavity that absorbs the solar radiation to generate the heat which is needed for baking the bricks inside the firing chamber. [Spanish] El proceso de coccion para la produccion de tabiques de arcilla en hornos tradicionales genera contaminacion atmosferica cuando los desechos industriales y domesticos se usan como combustibles. Aqui se presenta una alternativa, utilizando la energia solar para la coccion de tabiques de arcilla. Estamos desarrollando un sistema para la coccion de tabiques de arcilla para alcanzar temperaturas entre 900 grados centigradosy 1050 grados centigrados; estas temperaturas son suficientemente altas para cocer tabiques o productos ceramicos similares. El presente articulo describe el diseno y caracterizacion de los componentes de un horno solar para la coccion de tabiques de arcilla con una camara con dimensiones internas de 0.48 * 0.61 *× 0.64 m. Para dirigir los rayos solares a la camara de coccion, un heliostato

Current Understanding of Physicochemical Mechanisms for Cell Membrane Penetration of Arginine-rich Cell Penetrating Peptides: Role of Glycosaminoglycan Interactions.

Science.gov (United States)

Takechi-Haraya, Yuki; Saito, Hiroyuki

2018-01-01

Arginine-rich cell penetrating peptides (CPPs) are very promising drug carriers to deliver membrane-impermeable pharmaceuticals, such as siRNA, bioactive peptides and proteins. CPPs directly penetrate into cells across cell membranes via a spontaneous energy-independent process, in which CPPs appear to interact with acidic lipids in the outer leaflet of the cell membrane. However, acidic lipids represent only 10 to 20% of the total membrane lipid content and in mammalian cell membranes they are predominantly located in the inner leaflet. Alternatively, CPPs favorably bind in a charge density- dependent manner to negatively charged, sulfated glycosaminoglycans (GAGs), such as heparan sulfate and chondroitin sulfate, which are abundant on the cell surface and are involved in many biological functions. We have recently demonstrated that the interaction of CPPs with sulfated GAGs plays a critical role in their direct cell membrane penetration: the favorable enthalpy contribution drives the high-affinity binding of arginine-rich CPPs to sulfated GAGs, initiating an efficient cell membrane penetration. The favorable enthalpy gain is presumably mainly derived from a unique property of the guanidino group of arginine residues forming multidentate hydrogen bonding with sulfate and carboxylate groups in GAGs. Such interactions can be accompanied with charge neutralization of arginine-rich CPPs, promoting their partition into cell membranes. This review summarizes the current understanding of the physicochemical mechanism for lipid membrane penetration of CPPs, and discusses the role of the GAG interactions on the cell membrane penetration of CPPs. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Potential high efficiency solar cells: Applications from space photovoltaic research

Science.gov (United States)

Flood, D. J.

1986-01-01

NASA involvement in photovoltaic energy conversion research development and applications spans over two decades of continuous progress. Solar cell research and development programs conducted by the Lewis Research Center's Photovoltaic Branch have produced a sound technology base not only for the space program, but for terrestrial applications as well. The fundamental goals which have guided the NASA photovoltaic program are to improve the efficiency and lifetime, and to reduce the mass and cost of photovoltaic energy conversion devices and arrays for use in space. The major efforts in the current Lewis program are on high efficiency, single crystal GaAs planar and concentrator cells, radiation hard InP cells, and superlattice solar cells. A brief historical perspective of accomplishments in high efficiency space solar cells will be given, and current work in all of the above categories will be described. The applicability of space cell research and technology to terrestrial photovoltaics will be discussed.

Second Generation Novel High Temperature Commercial Receiver & Low Cost High Performance Mirror Collector for Parabolic Solar Trough

Energy Technology Data Exchange (ETDEWEB)

Stettenheim, Joel [Norwich Technologies, White River Junction, VT (United States)

2016-02-29

Norwich Technologies (NT) is developing a disruptively superior solar field for trough concentrating solar power (CSP). Troughs are the leading CSP technology (85% of installed capacity), being highly deployable and similar to photovoltaic (PV) systems for siting. NT has developed the SunTrap receiver, a disruptive alternative to vacuum-tube concentrating solar power (CSP) receivers, a market currently dominated by the Schott PTR-70. The SunTrap receiver will (1) operate at higher temperature (T) by using an insulated, recessed radiation-collection system to overcome the energy losses that plague vacuum-tube receivers at high T, (2) decrease acquisition costs via simpler structure, and (3) dramatically increase reliability by eliminating vacuum. It offers comparable optical efficiency with thermal loss reduction from ≥ 26% (at presently standard T) to ≥ 55% (at high T), lower acquisition costs, and near-zero O&M costs.

Role of solar influences on geomagnetosphere and upper atmosphere

Science.gov (United States)

Kumar Tripathi, Arvind

The Earth's magnetosphere and upper atmosphere can be greatly perturbed by variations in the solar luminosity caused by disturbances on the solar surface. The state of near-Earth space environment is governed by the Sun and is very dynamic on all spatial and temporal scale. The geomagnetic field which protects the Earth from solar wind and cosmic rays is also essential to the evolution of life; its variations can have either direct or indirect effect on human physiology and health state even if the magnitude of the disturbance is small. Geomagnetic disturbances are seen at the surface of the Earth as perturbations in the components of the geomagnetic field, caused by electric currents flowing in the magnetosphere and upper atmosphere. Ionospheric and thermospheric storms also result from the redistribution of particles and fields. Global thermospheric storm winds and composition changes are driven by energy injection at high latitudes. These storm effects may penetrate downwards to the lower thermosphere and may even perturb the mesosphere. Many of the ionospheric changes at mid-latitude can be understood as a response to thermospheric perturbations. The transient bursts of solar energetic particles, often associated with large solar transients, have been observed to have effects on the Earth's middle and lower atmosphere, including the large-scale destruction of polar stratospheric and tropospheric ozone. In the present, we have discussed effect of solar influences on earth's magnetosphere and upper atmosphere that are useful to space weather and global warming, on the basis of various latest studies.

Modular Ultra-High Power Solar Array Architecture, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Deployable Space Systems, Inc. (DSS) will focus the proposed SBIR program on the development of a new highly-modularized and extremely-scalable solar array that...

High Efficiency Quantum Well Waveguide Solar Cells, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The long-term objective of this program is to develop flexible, lightweight, single-junction solar cells using quantum structured designs that can achieve ultra-high...

Innovative architecture design for high performance organic and hybrid multi-junction solar cells

Science.gov (United States)

Li, Ning; Spyropoulos, George D.; Brabec, Christoph J.

2017-08-01

The multi-junction concept is especially attractive for the photovoltaic (PV) research community owing to its potential to overcome the Schockley-Queisser limit of single-junction solar cells. Tremendous research interests are now focused on the development of high-performance absorbers and novel device architectures for emerging PV technologies, such as organic and perovskite PVs. It has been predicted that the multi-junction concept is able to boost the organic and perovskite PV technologies approaching the 20% and 30% benchmarks, respectively, showing a bright future of commercialization of the emerging PV technologies. In this contribution, we will demonstrate innovative architecture design for solution-processed, highly functional organic and hybrid multi-junction solar cells. A simple but elegant approach to fabricating organic and hybrid multi-junction solar cells will be introduced. By laminating single organic/hybrid solar cells together through an intermediate layer, the manufacturing cost and complexity of large-scale multi-junction solar cells can be significantly reduced. This smart approach to balancing the photocurrents as well as open circuit voltages in multi-junction solar cells will be demonstrated and discussed in detail.

Unraveling the High Open Circuit Voltage and High Performance of Integrated Perovskite/Organic Bulk-Heterojunction Solar Cells.

Science.gov (United States)

Dong, Shiqi; Liu, Yongsheng; Hong, Ziruo; Yao, Enping; Sun, Pengyu; Meng, Lei; Lin, Yuze; Huang, Jinsong; Li, Gang; Yang, Yang

2017-08-09

We have demonstrated high-performance integrated perovskite/bulk-heterojunction (BHJ) solar cells due to the low carrier recombination velocity, high open circuit voltage (V OC ), and increased light absorption ability in near-infrared (NIR) region of integrated devices. In particular, we find that the V OC of the integrated devices is dominated by (or pinned to) the perovskite cells, not the organic photovoltaic cells. A Quasi-Fermi Level Pinning Model was proposed to understand the working mechanism and the origin of the V OC of the integrated perovskite/BHJ solar cell, which following that of the perovskite solar cell and is much higher than that of the low bandgap polymer based organic BHJ solar cell. Evidence for the model was enhanced by examining the charge carrier behavior and photovoltaic behavior of the integrated devices under illumination of monochromatic light-emitting diodes at different characteristic wavelength. This finding shall pave an interesting possibility for integrated photovoltaic devices to harvest low energy photons in NIR region and further improve the current density without sacrificing V OC , thus providing new opportunities and significant implications for future industry applications of this kind of integrated solar cells.

Probabilistic forecasting of the solar irradiance with recursive ARMA and GARCH models

DEFF Research Database (Denmark)

David, M.; Ramahatana, F.; Trombe, Pierre-Julien

2016-01-01

Forecasting of the solar irradiance is a key feature in order to increase the penetration rate of solar energy into the energy grids. Indeed, the anticipation of the fluctuations of the solar renewables allows a better management of the production means of electricity and a better operation...... sky index show some similarities with that of financial time series. The aim of this paper is to assess the performances of a commonly used combination of two linear models (ARMA and GARCH) in econometrics in order to provide probabilistic forecasts of solar irradiance. In addition, a recursive...... regarding the statistical distribution of the error, the reliability of the probabilistic forecasts stands in the same order of magnitude as other works done in the field of solar forecasting....

Penetrating chest injury: A miraculous life salvage

Directory of Open Access Journals (Sweden)

Santosh B Dalavi

2013-01-01

Full Text Available An unusual penetrating chest injury was caused by high velocity road traffic accident. An 18-year-old had a four wheeler accident and was brought in emergency department with a ′bamboo′ stick on the left side chest exiting through back. After the stabilization of vital parameters, an inter-costal tube drainage was done on the left side. Except the minor brochopleural fistula which healed by 10 th day, his recovery was uneventful. The outcome was consistent with current aggressive management of penetrating chest injuries. Management of penetrating chest injury involving pulmonary trauma is based on three principles. One is stabilization of hemodynamics of patient with proper clinical evaluation. Second, a mere intercostal tube drainage sufficient for majority of the cases. Third, post-operative active as well as passive physiotherapy is necessary for speedy recovery.

Cosmic ray nucleonic intensity in low-amplitude days during the passage of high-speed solar wind streams

International Nuclear Information System (INIS)

Agarwal, R.; Mishra, R.K.; Tiwari, S.; or rm_jbp@yahoo.co.in

2008-01-01

One of the most striking features of solar wind is its organization into high- and low- speed streams. It is now well established that the passage over the Earth of high-speed solar wind streams leads to geomagnetic disturbances. The high-speed plasma streams are thus a key element in the complex chain of events that link geomagnetic activity to the solar activity and are therefore of great interest to the solar terrestrial physics. Two types of high-speed solar wind streams - coronal-hole-associated (or corotating) and flare-generated - were studied based on magnetic field and solar wind plasma parameters. In the work, the dependence was obtained for cosmic ray (CR) depressions due to high-speed solar wind streams during low-amplitude days. The CR nucleonic intensity data were subjected to the superposed epoch analysis with respect to the start time of high-speed solar wind streams. It was found that streams of both types produce significant deviations in the CR intensity during low-amplitude anisotropic wave train events. At the onset of such streams the CR intensity reaches its minimum during low-amplitude events and then increases statistically. (Authors)

Measurement and modeling of the low-temperature penetration-depth anomaly in high-quality MgB{sub 2} thin films

Energy Technology Data Exchange (ETDEWEB)

Agassi, Y.D. [Naval Surface Warfare Center, Carderock Division, Bethesda, MD 20817 (United States); Oates, D.E., E-mail: OATES@LL.MIT.EDU [MIT-Lincoln Laboratory, Lexington, MA 02420 (United States); Moeckly, B.H. [STI, Inc. Santa Barbara, CA 93111 (United States)

2012-10-15

Based on our measurements of intermodulation distortion in MgB{sub 2}, we have previously proposed that the {pi} energy-gap in MgB{sub 2} entails six nodal lines [Y.D. Agassi, D.E. Oates, and B.H. Moeckly, Phys. Rev. B 80 (2009) 174522]. Here we report high-precision measurements in MgB{sub 2} stripline resonators that show an increase of the penetration depth as the temperature is decreased below 5 K. This increase is consistent with the Script-Small-L = 6 symmetry of the {pi} energy gap that we have proposed. We interpret the increase as a manifestation of Andreev surface-attached states that are associated with the nodal lines of the {pi} energy gap. Penetration-depth calculations are in good agreement with our data. To reconcile the present interpretation with existing literature, we review other penetration-depth data, magnetic-impurity and tunneling experiments, and data on the paramagnetic Meissner effect. We conclude that these data do not rule out the interpretation of our experimental data based on a nodal {pi} energy gap.

Highly crumpled solar reduced graphene oxide electrode for supercapacitor application

Science.gov (United States)

Mohanapriya, K.; Ahirrao, Dinesh J.; Jha, Neetu

2018-04-01

Highly crumpled solar reduced graphene oxide (CSRGO) was synthesized by simple and rapid method through freezing the solar reduced graphene oxide aqueous suspension using liquid nitrogen and used as electrode material for supercapacitor application. This electrode material was characterized by transmission electron microscope (TEM), X-Ray diffractometer (XRD) and Raman Spectroscopy techniques to understand the morphology and structure. The electrochemical performance was studied by cyclic voltammetry (CV), galvanostatic charge/discharge (CD) and electrochemical impedance spectroscopy (EIS) using 6M KOH electrolyte. The CSRGO exhibit high specifc capacitance of 210.1 F g-1 at the current density of 0.5 A g-1 and shows excellent rate capability. These features make the CSRGO material as promising electrode for high-performance supercapacitors.

Review of Congestion Management Methods for Distribution Networks with High Penetration of Distributed Energy Resources

DEFF Research Database (Denmark)

Huang, Shaojun; Wu, Qiuwei; Liu, Zhaoxi

2014-01-01

This paper reviews the existing congestion management methods for distribution networks with high penetration of DERs documented in the recent research literatures. The congestion management methods for distribution networks reviewed can be grouped into two categories – market methods and direct...... control methods. The market methods consist of dynamic tariff, distribution capacity market, shadow price and flexible service market. The direct control methods are comprised of network reconfiguration, reactive power control and active power control. Based on the review of the existing methods...

Meteoric ions in the corona and solar wind

International Nuclear Information System (INIS)

Lemaire, J.

1990-01-01

The total mass of refractory material of interplanetary origin penetrating and evaporated in the meltosphere surrounding the sun has been inferred from observations of meteoroids and fireballs falling in earth's atmosphere. The amount of iron atoms deposited this way in the solar corona is of the order of 3000 t/s or larger. The measured flux of outflowing solar wind iron ions is equal to 2200 t/s. The close agreement of both fluxes is evidence that a significant fraction of iron ions observed in the solar wind and in the corona must be of meteoric origin. A similar accord is also obtained for silicon ions. The mean velocity of meteoroid ions formed in the solar corona is equal to the free-fall velocity: i.e., independent of their atomic mass as the thermal speed of heavy ion measured in low-density solar wind streams at 1 AU. Furthermore, the heavy ions of meteoric origin escape out of the corona with a larger bulk velocity than the protons which are mainly of solar origin. These differences of heavy ion and proton bulk velocities are also observed in the solar wind. 52 refs

All-Nonvacuum-Processed CIGS Solar Cells Using Scalable Ag NWs/AZO-Based Transparent Electrodes.

Science.gov (United States)

Wang, Mingqing; Choy, Kwang-Leong

2016-07-06

With record cell efficiency of 21.7%, CIGS solar cells have demonstrated to be a very promising photovoltaic (PV) technology. However, their market penetration has been limited due to the inherent high cost of the cells. In this work, to lower the cost of CIGS solar cells, all nonvacuum-processed CIGS solar cells were designed and developed. CIGS absorber was prepared by the annealing of electrodeposited metallic layers in a chalcogen atmosphere. Nonvacuum-deposited Ag nanowires (NWs)/AZO transparent electrodes (TEs) with good transmittance (92.0% at 550 nm) and high conductivity (sheet resistance of 20 Ω/□) were used to replace the vacuum-sputtered window layer. Additional thermal treatment after device preparation was conducted at 220 °C for a few of minutes to improve both the value and the uniformity of the efficiency of CIGS pixel cell on 5 × 5 cm substrate. The best performance of the all-nonvacuum-fabricated CIGS solar cells showed an efficiency of 14.05% with Jsc of 34.82 mA/cm(2), Voc of 0.58 V, and FF of 69.60%, respectively, which is comparable with the efficiency of 14.45% of a reference cell using a sputtered window layer.

Penetration portion shielding structure

International Nuclear Information System (INIS)

Hayashi, Katsumi; Narita, Hitoshi; Handa, Hiroyuki; Takeuchi, Jun; Tozuka, Fumio.

1994-01-01

Openings of a plurality of shieldings for penetration members are aligned to each other, and penetration members are inserted from the openings. Then, the openings of the plurality of shielding members are slightly displaced with each other to make the penetration portions into a helical configuration, so that leakage of radiation is reduced. Upon removal of the members, reverse operation is conducted. When a flowable shielding material is used, the penetration portions are constituted with two plates having previously formed openings and pipes for connecting the openings with each other and a vessel covering the entire of them. After passing the penetration members such as a cable, the relative position of the two plates is changed by twisting, to form a helical configuration which reduces radiation leakage. Since they are bent into the helical configuration, shielding performance is extremely improved compared with a case that radiation leakage is caused from an opening of a straight pipe. In addition, since they can be returned to straight pipes, attachment, detachment and maintenance can be conducted easily. (N.H.)

Efficiency of low versus high airline pressure in stunning cattle with a pneumatically powered penetrating captive bolt gun.

Science.gov (United States)

Oliveira, Steffan Edward Octávio; Gregory, Neville George; Dalla Costa, Filipe Antonio; Gibson, Troy John; Paranhos da Costa, Mateus José Rodrigues

2017-08-01

The efficiency of stunning cattle was assessed in 443 animals (304 pure Zebu and 139 crossbred cattle), being mainly mature bulls and cows. Cattle were stunned using a Jarvis pneumatically powered penetrating captive bolt gun operating with low (160-175psi, N=82) and high (190psi, N=363) airline pressure, which was within the manufactures specifications. Signs of brain function and the position of the shots on the heads were recorded after stunning. Velocity of the captive bolt and its physical parameters were calculated. Cattle shot with low pressures showed more rhythmic respiration (27 vs. 8%, P<0.001), less tongue protrusion (4 vs. 12%, P=0.03) and less masseter relaxation (22 vs. 48%, P<0.001). There was an increased frequency of shots in the ideal position when cattle were shot with the low compared to high airline pressures (15.3 vs. 3.1%). Bolt velocity and its physical parameters were significantly (P<0.01) higher when using high pressure. Airline pressures below 190psi are inappropriate when shooting adult Zebu beef cattle with pneumatically powered penetrating captive bolt guns. Copyright © 2017 Elsevier Ltd. All rights reserved.

The Effect and Mechanism of Transdermal Penetration Enhancement of Fu's Cupping Therapy: New Physical Penetration Technology for Transdermal Administration with Traditional Chinese Medicine (TCM) Characteristics.

Science.gov (United States)

Xie, Wei-Jie; Zhang, Yong-Ping; Xu, Jian; Sun, Xiao-Bo; Yang, Fang-Fang

2017-03-27

In this paper, a new type of physical penetration technology for transdermal administration with traditional Chinese medicine (TCM) characteristics is presented. Fu's cupping therapy (FCT), was established and studied using in vitro and in vivo experiments and the penetration effect and mechanism of FCT physical penetration technology was preliminarily discussed. With 1-(4-chlorobenzoyl)-5-methoxy-2-methylindole-3-ylacetic acid (indomethacin, IM) as a model drug, the establishment of high, medium, and low references was completed for the chemical permeation system via in vitro transdermal tests. Furthermore, using chemical penetration enhancers (CPEs) and iontophoresis as references, the percutaneous penetration effect of FCT for IM patches was evaluated using seven species of in vitro diffusion kinetics models and in vitro drug distribution; the IM quantitative analysis method in vivo was established using ultra-performance liquid chromatography-tandem mass spectrometry technology (UPLC-MS/MS), and pharmacokinetic parameters: area under the zero and first moment curves from 0 to last time t (AUC 0-t , AUMC 0-t ), area under the zero and first moment curves from 0 to infinity (AUC 0-∞ , AUMC 0-∞ ), maximum plasma concentration (C max ) and mean residence time (MRT), were used as indicators to evaluate the percutaneous penetration effect of FCT in vivo. Additionally, we used the 3 K factorial design to study the joint synergistic penetration effect on FCT and chemical penetration enhancers. Through scanning electron microscopy (SEM) and transmission electron microscope (TEM) imaging, micro- and ultrastructural changes on the surface of the stratum corneum (SC) were observed to explore the FCT penetration mechanism. In vitro and in vivo skin permeation experiments revealed that both the total cumulative percutaneous amount and in vivo percutaneous absorption amount of IM using FCT were greater than the amount using CPEs and iontophoresis. Firstly, compared with

Highly Efficient Flexible Quantum Dot Solar Cells with Improved Electron Extraction Using MgZnO Nanocrystals.

Science.gov (United States)

Zhang, Xiaoliang; Santra, Pralay Kanti; Tian, Lei; Johansson, Malin B; Rensmo, Håkan; Johansson, Erik M J

2017-08-22

Colloidal quantum dot (CQD) solar cells have high potential for realizing an efficient and lightweight energy supply for flexible or wearable electronic devices. To achieve highly efficient and flexible CQD solar cells, the electron transport layer (ETL), extracting electrons from the CQD solid layer, needs to be processed at a low-temperature and should also suppress interfacial recombination. Herein, a highly stable MgZnO nanocrystal (MZO-NC) layer is reported for efficient flexible PbS CQD solar cells. Solar cells fabricated with MZO-NC ETL give a high power conversion efficiency (PCE) of 10.4% and 9.4%, on glass and flexible plastic substrates, respectively. The reported flexible CQD solar cell has the record efficiency to date of flexible CQD solar cells. Detailed theoretical simulations and extensive characterizations reveal that the MZO-NCs significantly enhance charge extraction from CQD solids and diminish the charge accumulation at the ETL/CQD interface, suppressing charge interfacial recombination. These important results suggest that the low-temperature processed MZO-NCs are very promising for use in efficient flexible solar cells or other flexible optoelectronic devices.

Implementation of a subcanopy solar radiation model on a forested headwater basin in the Southern Appalachians to estimate riparian canopy density and stream insolation for stream temperature models

Science.gov (United States)

Belica, L.; Petras, V.; Iiames, J. S., Jr.; Caldwell, P.; Mitasova, H.; Nelson, S. A. C.

2016-12-01

Water temperature is a key aspect of water quality and understanding how the thermal regimes of forested headwater streams may change in response to climatic and land cover changes is increasingly important to scientists and resource managers. In recent years, the forested mountain watersheds of the Southeastern U.S. have experienced changing climatic patterns as well as the loss of a keystone riparian tree species and anticipated hydrologic responses include lower summer stream flows and decreased stream shading. Solar radiation is the main source of thermal energy to streams and a key parameter in heat-budget models of stream temperature; a decrease in flow volume combined with a reduction in stream shading during summer have the potential to increase stream temperatures. The high spatial variability of forest canopies and the high spatio-temporal variability in sky conditions make estimating the solar radiation reaching small forested headwater streams difficult. The Subcanopy Solar Radiation Model (SSR) (Bode et al. 2014) is a GIS model that generates high resolution, spatially explicit estimates of solar radiation by incorporating topographic and vegetative shading with a light penetration index derived from leaf-on airborne LIDAR data. To evaluate the potential of the SSR model to provide estimates of stream insolation to parameterize heat-budget models, it was applied to the Coweeta Basin in the Southern Appalachians using airborne LIDAR (NCALM 2009, 1m resolution). The LIDAR derived canopy characteristics were compared to current hyperspectral images of the canopy for changes and the SSR estimates of solar radiation were compared with pyranometer measurements of solar radiation at several subcanopy sites during the summer of 2016. Preliminary results indicate the SSR model was effective in identifying variations in canopy density and light penetration, especially in areas associated with road and stream corridors and tree mortality. Current LIDAR data and

Analysis of distribution systems with a high penetration of distributed generation

DEFF Research Database (Denmark)

Lund, Torsten

Since the mid eighties, a large number of wind turbines and distributed combined heat and power plants (CHPs) have been connected to the Danish power system. Especially in the Western part, comprising Jutland and Funen, the penetration is high compared to the load demand. In some periods the wind...... power alone can cover the entire load demand. The objective of the work is to investigate the influence of wind power and distributed combined heat and power production on the operation of the distribution systems. Where other projects have focused on the modeling and control of the generators and prime...... movers, the focus of this project is on the operation of an entire distribution system with several wind farms and CHPs. Firstly, the subject of allocation of power system losses in a distribution system with distributed generation is treated. A new approach to loss allocation based on current injections...

A case of an intrahepatic fish bone penetration

International Nuclear Information System (INIS)

Tsuboi, Kazuhiko; Nakajima, Yoshiro; Yamamoto, Shunji; Nagao, Masatoshi; Nishimura, Kazumasa.

1981-01-01

A 56-year-old man was admitted to our hospital because of epigastric discomfort, appetite loss and body weight loss. A gallstone, signs of chronic inflammation and CEA-Z: 12.5 ng/ml were found. Abdominal CT scan revealed an intrahepatic low density nodule and an intra-and-extrahepatic high-dense, needle-like foreign body. By laparotomy a fish bone penetrating into the left lateral segment of the liver from the anterior wall of the prepyloric region of the stomach was found. Cholecystectomy was performed. The penetrating fish bone was withdrawn from the liver easily. The Postoperative course was smooth. The possibility of the definitive preoperative diagnosis of the intestinal fish bone penetration by abdominal CT scan was suggested. (author)

A novel drug delivery gel of terbinafine hydrochloride with high penetration for external use.