Effectiveness of solar radiation shields for thermal control of space vehicles subjected to large changes in solar energy
Solar radiation shield for thermal control of spacecraft subjected to large changes in solar energy
TEMPERATURE CONTROL↗
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The Potential for Electrons to Molecules Using Solar Energy
Solar photovoltaics (PV) do and will continue to play an important role in the electric power sector and can potentially support other sectors that are in need of decarbonized energy sources. Chemicals such as hydrogen, ammonia, and hydrocarbons including ethylene are currently produced from natural gas and crude oil. Thus, processes to produce them emit carbon dioxide and other greenhouse gases both directly and in upstream feedstock recovery processes. Electrons-to-molecules (E2M) technologies are being developed to convert carbon dioxide, water, and atmospheric nitrogen to desired chemical products and they are large electricity loads. Thus, they are emerging as a potential applications for PV. In its essence, they can act as electrochemical energy storage, thereby providing a means to further utilize the energy generated from PV and store it in molecular form. E2M systems offer an array of potential products and system designs that can be tailored to different end-uses and applications. It involves electrochemical conversion which uses electricity to break molecular bonds and produce new molecules. Various electrochemical conversion technologies split water into hydrogen and oxygen, reduce carbon dioxide into other hydrocarbon molecules, and several other possible combinations. While this Chapter does not attempt to provide an exhaustive summary or analysis of the potential products from E2M systems, it does provide an initial overview of the potential opportunities and challenges for PV and E2M systems in this space. This Chapter considers the potential for E2M to produce key chemicals and fuels that currently rely on hydrocarbons for production, either as a reactant or a source of high-grade heat.
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Solar Energy Technologies Office Fact Sheet
The U.S. Department of Energy Solar Energy Technologies Office (SETO) supports early-stage research and development to improve the affordability, reliability, and performance of solar technologies on the grid. The office invests in innovative research efforts that securely integrate more solar energy into the grid, enhance the use and storage of solar energy, and lower solar electricity costs.
Solar Energy Technologies Office Fact Sheet, SunSh↗
Best Practices Handbook for the Collection and Use of Solar Resource Data for Solar Energy Applications: Second Edition
As the world looks for low-carbon sources of energy, solar power stands out as the single most abundant energy resource on Earth. Harnessing this energy is the challenge for this century. Photovoltaics, solar heating and cooling, and concentrating solar power (CSP) are primary forms of energy applications using sunlight. These solar energy systems use different technologies, collect different fractions of the solar resource, and have different siting requirements and production capabilities. Reliable information about the solar resource is required for every solar energy application. This holds true for small installations on a rooftop as well as for large solar power plants; however, solar resource information is of particular interest for large installations, because they require substantial investment, sometimes exceeding 1 billion dollars in construction costs. Before such a project is undertaken, the best possible information about the quality and reliability of the fuel source must be made available. That is, project developers need reliable data about the solar resource available at specific locations, including historic trends with seasonal, daily, hourly, and (preferably) subhourly variability to predict the daily and annual performance of a proposed power plant. Without this data, an accurate financial analysis is not possible. Additionally, with the deployment of large amounts of distributed photovoltaics, there is an urgent need to integrate this source of generation to ensure the reliability and stability of the grid. Forecasting generation from the various sources will allow for larger penetrations of these generation sources because utilities and system operators can then ensure stable grid operations. Developed by the foremost experts in the field who have come together under the umbrella of the International Energy Agency's Solar Heating and Cooling Task 46, this handbook summarizes state-of-the-art information about all the above topics.
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Best Practices Handbook for the Collection and Use of Solar Resource Data for Solar Energy Applications: Third Edition
As the world looks for low-carbon sources of energy, solar power stands out as the single most abundant energy resource on Earth. Harnessing this energy is the challenge for this century. Photovoltaics, solar heating and cooling, and concentrating solar power (CSP) are primary forms of energy applications using sunlight. These solar energy systems use different technologies, collect different fractions of the solar resource, and have different siting requirements and production capabilities. Reliable information about the solar resource is required for every solar energy application. This holds true for small installations on a rooftop as well as for large solar power plants; however, solar resource information is of particular interest for large installations because they require substantial investment, sometimes exceeding 1 billion dollars in construction costs. Before such a project is undertaken, the best possible information about the quality and reliability of the fuel source must be made available. That is, project developers need reliable data about the solar resource available at specific locations, including historic trends with seasonal, daily, hourly, and (preferably) subhourly variability to predict the daily and annual performance of a proposed power plant. Without these data, an accurate financial analysis is not possible. Additionally, with the deployment of large amounts of distributed photovoltaics, there is an urgent need to integrate this source of generation to ensure the reliability and stability of the grid. Forecasting generation from the various sources will allow for larger penetrations of these generation sources because utilities and system operators can then ensure stable grid operations. Developed by the foremost experts in the field who have come together under the umbrella of the International Energy Agency’s Solar Heating and Cooling Task 46, this handbook summarizes state-of-the-art information about all these topics.
14 SOLAR ENERGY↗
Ultrafast probes at the interfaces of solar energy conversion materials
Ultrafast carrier dynamics at interfaces plays a major role in governing solar energy conversion efficiency in solar conversion systems, especially in solar cells and photoelectrochemical devices. Here, we discuss recent advances in ultrafast spectroscopic probes to understand the dynamics at such interfaces. Transient reflectance (TR) enables monitoring of the surface carriers that are within ~10 nm of the surface or interface of interest. Crucial parameters such as surface recombination velocity and carrier diffusion can be determined. When a strong surface or interfacial field is present the reflectance spectrum will exhibit Franz–Kelydesh oscillations. Monitoring the transient formation or decay of such oscillations informs about the interfacial field and is referred to as transient photoreflectance (TPR). Such fields are helpful in designing systems in order to move carriers away from surfaces where photocorrosion can occur and towards catalytic surfaces. Finally, we discuss transient infrared attenuated total reflection (TATR) to probe the ultrafast reaction intermediates in a photo-driven chemical reaction.
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Alternatives in solar energy
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.
Schueler, D. G.↗
Senior Housing Complex Energy Efficiency and Solar Energy Project
As part of a longer-term energy efficiency and solar development program on the Coeur d'Alene reservation, the Coeur d'Alene Tribe completed energy efficiency measures and deployed a solar photovoltaic system at its Senior Housing Complex. The project generated nearly 68,000 kWh of solar energy in its first year, and reduced energy used at the senior housing complex by 95,192 kWh, saving $7,144.56 in energy costs, and saving 48.1 metric tons of carbon dioxide.
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Solar energy to meet the nation's energy needs
Solar energy, being a non-depleting clean source of energy, is shown to be capable of providing energy in all the forms in which it is used today. It can be used to generate electricity, for heating and cooling buildings, and for producing clean renewable gaseous, liquid and solid fuel. There is little question of the technical feasibility for utilizing solar energy. The chief problem is rapidly providing innovative solutions that are economically competititive with other systems.
Rom, F. E.↗
Reducing the Costs of Paying for Consumed Electric Energy by Utilizing Solar Energy
The use of a low-power solar network and standalone power plants is the most promising for the needs of the housing and utilities sector, small industrial enterprises, social and public health facilities, recreation areas, remote objects, and agricultural industries; this will make it possible to reduce the load on the energy system at peak moments, as well as to decrease losses when transporting electric energy in its elements. It is assumed that the minimum value of the unit cost of generated electric energy is used as the criterion for configuring and selecting the parameters of solar power equipment, which will make it possible to set up an economically feasible additional power supply to the consumer, since it excludes the use of storage devices and rearrangement of the power supply system.
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Propagation of low energy solar electrons
Two events are reported in which 2-10 keV electrons of solar energy have undergone significant adiabatic mirroring and pitch angle scattering in large scale magnetic structures in the interplanetary medium within a distance of about 0.5 AU from the earth. Electrons of 3 keV, typical of the energies measured, have a speed of about one-tenth of the speed of light, so that their travel time from the sun at 0 deg pitch angle would be about 100 minutes. Their cyclotron radius is about 20 km for a pitch angle of 30 deg, and a field of magnitude of 5 nT, and the cyclotron period is about 7.1 milliseconds. The electrons are scattered by spatial variations in the interplanetary magnetic field. When the spatial variations are convected past a stationary spacecraft by a 500 km/sec solar wind, they are seen as temporal fluctuations at a frequency of about 3 Hz.
Anderson, K. A.↗
High energy solar beam testing in the JPL 25-ft space simulator
Modifications to the individual components in the solar simulation system to improve performance and reduce costs are described. The improvements include: an increase in lamp power from 20 KW to 30 KW; a family of solar beams from 8 to 18.5 feet in diameter at intensities related to beam size with a maximum intensity of 12 solar constants over a 9 ft. diameter; and up to 1.1 megawatts of simulated solar energy in the lamp array.
Harrell, J. W.↗
Solar Energy Innovation Network 2017-2024: Abbreviated Final Technical Report
This material is based upon work supported by the U.S. Department of Energy's (DOE) Office of Energy Efficiency and Renewable Energy (EERE) Solar Energy Technologies Office under the Agreement/Award Number 32954 for Solar Energy Innovation Network (SEIN) Project, 2017-2024. SEIN is a dynamic program that assembles diverse teams of stakeholders to research solutions to real-world challenges associated with solar energy adoption. In conjunction with its partner organizations, NREL implemented the program by providing research, analysis, and technical expertise directly to project teams and groups of teams (cohorts), by facilitating networked learning through cohorts and peer exchange, and by facilitating dissemination and replication of solutions and lessons learned among stakeholders across the U.S. with similar challenges.
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Building application of solar energy. Study no. 2: Representative buildings for solar energy performance analysis and market penetration
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.
Hirshberg, A. S.↗
Solar Energy Demonstrations
Solar energy furnishes all of the heating and hot water needs, plus 80 percent of the air conditioning, for the two-story Reedy Creek building. A unique feature of this installation is that the 16 semi-cylindrical solar collectors (center photo on opposite page with closeup of a single collector below it) are not mounted atop the roof as is customary, they actually are the roof. This arrangement eliminates the usual trusses, corrugated decking and insulating concrete in roof construction; that, in turn, reduces overall building costs and makes the solar installation more attractive economically. The Reedy Creek collectors were designed and manufactured by AAI Corporation of Baltimore, Maryland.
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Cone and column solar energy concentrator
Solar energy concentrator consists of a reflective membrane cone and a stepped parabolic column located along the optical axis of the cone. The membrane cone can be folded for packaging and is supported by an expandable ring at the rim of the cone when erected. The stepped parabolic column can be telescoped for packaging.
Mc Cusker, T. J.↗
Building application of solar energy. Study no. 4: Scenarios for the utilization of solar energy in southern California buildings, change 1
Plausible future market scenarios for solar heating and cooling systems into buildings in the area served by the Southern California Edison Company. A range of plausible estimates for the number of solar systems which might be installed and the electrical energy which might be displaced by energy from these systems are provided. The effect on peak electrical load was not explicitly calculated but preliminary conclusions concerning peak load can be inferred from the estimates presented. Two markets are investigated: the single family market and the large power commercial market.
Davis, E. S.↗