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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 37 records · Page 2

Solar Energy Technologies Office Workforce Request for Information and Convenings (Summary)

On May 4, 2021, the U.S. Department of Energy (DOE) Solar Energy Technologies Office (SETO) published a Request for Information (RFI) on programs that support the development of a diverse and skilled clean energy workforce. The purpose of the RFI was to solicit feedback from industry, academia, government agencies, worker organizations (including unions), and other stakeholders on issues related to the employment needs of the solar industry, and the perceived value of different workforce development programs, training strategies, and tools. To supplement the RFI, SETO hosted four virtual convenings that brought together the utility-scale solar industry, the distributed generation solar industry, and labor and other workforce training organizations to hear direct feedback on the questions in the RFI. In addition, SETO held listening sessions with about a dozen other organizations and staff who could not participate in the virtual convenings. Altogether, SETO received 45 responses from the RFI and heard directly from 80-100 other stakeholders via the convenings and listening sessions. This document summarizes the stakeholder feedback that SETO received as a result of this process. While both the RFI and convening series were focused on solar deployment and solar industry members, much of this information is relevant across clean energy technologies and programs. It is important to recognize that DOE is intentionally reviewing our workforce development programming and support to focus on clean energy careers more holistically.

14 SOLAR ENERGY↗

The Spectrophotometric Method of Determining the Transmission of Solar Energy in Salt Gradient Solar Ponds

In order to predict the thermal efficiency of a solar pond it is necessary to know total average solar energy reaching the storage layer. One method for determining this energy for water containing dissolved colored species is based upon spectral transmission measurements using a laboratory spectrophotometer. This method is examined and some of the theoretical ground work needed to discuss the measurement of transmission of light water. Results of in situ irradiance measurements from oceanography research are presented and the difficulties inherent in extrapolating laboratory data obtained with ten centimeter cells to real three dimensional pond situations is discussed. Particular emphasis is put on the need to account for molecular and particulate scattering in measurements done on low absorbing solutions. Despite these considerations it is expected that attenuation calculations based upon careful measurements using a dual beam spectrophotometer technique combined with known attenuation coefficients will be useful in solar pond modeling and monitoring for color buildup. Preliminary results using the CSM method are presented.

Giulianelli, J.↗

Roadmap for Solar Photovoltaic (PV) Cybersecurity: A vision for improving cyber maturity of distributed and utility-scale solar energy installations

As the solar energy sector continues to expand, its integration into the broader energy infrastructure presents both unprecedented opportunities and new risks. The increasing reliance on digital technologies and interconnected systems in solar energy creates an expanded attack surface for motivated cyber adversaries. Cyberattacks have the potential to cause disruptions in energy production, damage to equipment, financial losses, and compromises in national security. Therefore, ensuring robust cybersecurity measures is paramount to protect the integrity, availability, confidentiality, and access control of solar energy systems. However, there are still key gaps and challenges to be addressed in industry and research, which stakeholders must race to address as they combat a growing number of real-world cyber incidents that affect solar energy systems and a growing number of vulnerabilities discovered and disclosed in key types of equipment. This roadmap explore the current state of solar PV cybersecurity and the gaps and challenges still to be addressed.

14 - SOLAR ENERGY↗

Economic Evaluation of Townhouse Solar Energy System

Solar-energy site in Columbia, South Carolina, is comprised of four townhouse apartments. Report summarizes economic evaluation of solar--energy system and projected performance of similar systems in four other selected cities. System is designed to supply 65 percent of heating and 75 percent of hot water.

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Indoor test and long-term weathering effects on the thermal performance of the solar energy system (liquid) solar collector

The procedures used and the results obtained during the evaluation test program on a liquid solar collector are presented. The narrow flat plate collector with reflective concentrating mirrors uses water as the working fluid. The double-covered collector weighs 137 pounds and has overall dimensions of about 35" by 77" by 6.75". The test program was conducted to obtain the following information: thermal performance data under simulated conditions, structural behavior under static load, and the effects of long term exposure to natural weathering.

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Best Practices Handbook for the Collection and Use of Solar Resource Data for Solar Energy Applications: Fourth Edition

As the world increasingly seeks low-carbon energy solutions, solar power emerges as the most abundant resource on our planet. However, the challenge of effectively harnessing this energy is crucial in the coming years. Solar energy applications such as photovoltaics, solar heating and cooling, and concentrating solar power use different technologies to capitalize on sunlight. Each system has unique capabilities and requirements, underscoring the need for reliable information about solar resources across diverse installations, from residential rooftops to large-scale power plants. This is especially important for substantial projects, often exceeding $1 billion in construction costs. Before embarking on such ventures, it is imperative to obtain accurate data concerning solar resource quality and reliability at specific sites. Developers require detailed historical information, including seasonal, daily, hourly, and, ideally, subhourly variability to effectively predict a power plant's annual performance. Without these vital data, financial analyses fall short. Moreover, with the growing adoption of distributed photovoltaics, integrating these generation sources becomes critical to maintaining grid reliability and stability. By accurately forecasting generation patterns, utilities and system operators can facilitate greater integration of solar energy, thus ensuring the operational stability of the grid. The complexity and importance of these issues have prompted the foremost experts in the field to collaborate under the auspices of the International Energy Agency's (IEA's) Photovoltaic Power Systems Programme (PVPS) Task 16 to publish this handbook, which summarizes state-of-the-art information about all these topics. The efforts focus on providing reliable data and insights that can help shape our investments in solar energy and drive a sustainable future.

14 SOLAR ENERGY↗

Non-tracking solar energy collector system

A solar energy collector system is described characterized by an improved concentrator for directing incident rays of solar energy on parallel strip-like segments of a flatplate receiver. Individually mounted reflector modules of a common asymmetrical triangular cross-sectional configuration supported for independent orientation are asymmetric included with vee-trough concentrators for deflecting incident solar energy toward the receiver.

Selcuk, M. K.↗

Conclusions and recommendations of the United States Solar Energy Panel

The United States Solar Energy Panel was charged with assessing the potential of solar energy as a national energy resource. Three areas evolved where solar energy could supply significant amounts of the U.S. future energy needs: (1) energy for heating and cooling of buildings, (2) the production of fuels, and (3) the generation of electrical power. It was concluded that with adequate R&D support over the next 30 years, solar energy could provide at least 35 percent of the heating and cooling of future buildings, greater than 30 percent of the methane and hydrogen needed in the U.S. for gaseous fuels, and greater than 20 percent of the electrical power needs of the U.S. All of this could be done with a minimal effect on the environment and a substantial savings of nonrenewable fuels.

Cherry, W. R.↗

Nanostructured Solar Irradiation Control Materials for Solar Energy Conversion

Tailoring the solar absorptivity (alpha(sub s)) and thermal emissivity (epsilon(sub T)) of materials constitutes an innovative approach to solar energy control and energy conversion. Numerous ceramic and metallic materials are currently available for solar absorbance/thermal emittance control. However, conventional metal oxides and dielectric/metal/dielectric multi-coatings have limited utility due to residual shear stresses resulting from the different coefficient of thermal expansion of the layered materials. This research presents an alternate approach based on nanoparticle-filled polymers to afford mechanically durable solar-absorptive and thermally-emissive polymer nanocomposites. The alpha(sub s) and epsilon(sub T) were measured with various nano inclusions, such as carbon nanophase particles (CNPs), at different concentrations. Research has shown that adding only 5 wt% CNPs increased the alpha(sub s) and epsilon(sub T) by a factor of about 47 and 2, respectively, compared to the pristine polymer. The effect of solar irradiation control of the nanocomposite on solar energy conversion was studied. The solar irradiation control coatings increased the power generation of solar thermoelectric cells by more than 380% compared to that of a control power cell without solar irradiation control coatings.

Kang, Jinho↗

Solar energy control system

A solar energy control system for a hot air type solar energy heating system wherein thermocouples are arranged to sense the temperature of a solar collector, a space to be heated, and a top and bottom of a heat storage unit is disclosed. Pertinent thermocouples are differentially connected together, and these are employed to effect the operation of dampers, a fan, and an auxiliary heat source. In accomplishing this, the differential outputs from the thermocouples are amplified by a single amplifier by multiplexing techniques. Additionally, the amplifier is corrected as to offset by including as one multiplex channel a common reference signal.

Currie, J. R.↗

Development of low-cost silicon crystal growth techniques for terrestrial photovoltaic solar energy conversion

Because of the growing need for new sources of electrical energy, photovoltaic solar energy conversion is being developed. Photovoltaic devices are now being produced mainly from silicon wafers obtained from the slicing and polishing of cylindrically shaped single crystal ingots. Inherently high-cost processes now being used must either be eliminated or modified to provide low-cost crystalline silicon. Basic to this pursuit is the development of new or modified methods of crystal growth and, if necessary, crystal cutting. If silicon could be grown in a form requiring no cutting, a significant cost saving would potentially be realized. Therefore, several techniques for growth in the form of ribbons or sheets are being explored. In addition, novel techniques for low-cost ingot growth and cutting are under investigation.

Zoutendyk, J. A.↗

Non-tracking solar energy collector system

A solar energy collector system characterized by an improved concentrator for directing incident rays of solar energy on parallel vacuum-jacketed receivers or absorbers is described. Numerous individually mounted reflector modules of a common asymmetrical triangular cross-sectional configuration are supported for independent reorientation. Asymmetric vee-trough concentrators are defined.

Selcuk, M. K.↗

Solar energy research and utilization

The role of solar energy is visualized in the heating and cooling of buildings, in the production of renewable gaseous, liquid and solid fuels, and in the production of electric power over the next 45 years. Potential impacts of solar energy on various energy markets, and estimated costs of such solar energy systems are discussed. Some typical solar energy utilization processes are described in detail. It is expected that at least 20% of the U.S. total energy requirements by 2020 will be delivered from solar energy.

Cherry, W. R.↗

The Land Sparing, Water Surface Use Efficiency, and Water Surface Transformation of Floating Photovoltaic Solar Energy Installations

Floating photovoltaic solar energy installations (FPVs) represent a new type of water surface use, potentially sparing land needed for agriculture and conservation. However, standardized metrics for the land sparing and resource use efficiencies of FPVs are absent. These metrics are critical to understanding the environmental and ecological impacts that FPVs may potentially exhibit. Here, we compared techno-hydrological and spatial attributes of four FPVs spanning different climatic regimes. Next, we defined and quantified the land sparing and water surface use efficiency (WSUE) of each FPV. Lastly, we coined and calculated the water surface transformation (WST) using generation data at the world’s first FPV (Far Niente Winery, California). The four FPVs spare 59,555 m2 of land and have a mean land sparing ratio of 2.7:1 m2 compared to ground-mounted PVs. Mean direct and total capacity-based WSUE is 94.5 ± 20.1 SD Wm−2 and 35.2 ± 27.4 SD Wm−2, respectively. Direct and total generation-based WST at Far Niente is 9.3 and 13.4 m2 MWh−1 yr−1, respectively; 2.3 times less area than ground-mounted utility-scale PVs. Our results reveal diverse techno-hydrological and spatial attributes of FPVs, the capacity of FPVs to spare land, and the utility of WSUE and WST metrics.

14 SOLAR ENERGY↗