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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 739 records · Page 41

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NASA NTRS1978

Solar Meter

The instrument pictured is an inexpensive solar meter which is finding wide acceptance among architects, engineers and others engaged in construction of solar energy facilities. It detects the amount of solar energy available at a building site, information necessary to design the most efficient type of solar system for a particular location. Incorporating technology developed by NASA's Lewis Research Center, the device is based upon the solar cell, which provides power for spacecraft by converting the sun's energy to electricity. The meter is produced by Dodge Products, Inc., Houston, Texas, a company formed to bring the technology to the commercial marketplace.

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NASA NTRS1987

Development of an integrated heat pipe-thermal storage system for a solar receiver

The Organic Rankine Cycle (ORC) Solar Dynamic Power System (SDPS) is one of the candidates for Space Station prime power application. In the low Earth orbit of the Space Station approximately 34 minutes of the 94-minute orbital period is spent in eclipse with no solar energy input to the power system. For this period the SDPS will use thermal energy storage (TES) material to provide a constant power output. An integrated heat-pipe thermal storage receiver system is being developed as part of the ORC-SDPS solar receiver. This system incorporates potassium heat pipe elements to absorb and transfer the solar energy within the receiver cavity. The heat pipes contain the TES canisters within the potassium vapor space with the toluene heater tube used as the condenser region of the heat pipe. During the insolation period of the Earth orbit, solar energy is delivered to the heat pipe in the ORC-SDPS receiver cavity. The heat pipe transforms the non-uniform solar flux incident in the heat pipe surface within the receiver cavity to an essentially uniform flux at the potassium vapor condensation interface in the heat pipe. During solar insolation, part of the thermal energy is delivered to the heater tube and the balance is stored in the TES units. During the eclipse period of the orbit, the balance stored in the TES units is transferred by the potassium vapor to the toluene heater tube.

Keddy, E. S.↗

DOE OSTI2020

Addressing the challenge of carbon-free energy

This century will witness a major transformation in how energy is acquired, stored, and utilized globally. The impetus for this change comes from the deep impacts that both developed and developing societies have had on our planet's environment during the past century, and the projections going forward of what will happen if we do not act transformativelywithin the next 2 decades. This paper describes the basis for a meeting held in October 2018 on the need for decarbonization in our energy landscape, and specifically the status and challenges of the science that provides the foundation for such technology. Within the realm of decarbonization in energy generation lies the science of solar energy conversion using new or improved photovoltaic materials and artificial photosynthesis for water splitting and other energy-storing reactions. The intimately related issue of renewable energy storage is being addressed with new strategies, materials, and approaches under current investigation and development. The need to improve the interactions between scientists working on these connected but separately considered challenges and on the transition of scientific achievement to practical application was also addressed, with specific efforts enumerated.

climate change↗

NASA NTRS2000

Satellite Measured Solar Protons from 1963-1993 and Their Influence on Ozone in a Changing Stratosphere

The fluxes of solar protons have been measured by a series of Interplanetary Monitoring Platform (IMP) satellites since 1963. Eight IMP satellites have been launched since 1963 providing excellent coverage of solar protons with energies from a few MeV to several hundred MeV. IMP 8, launched in October 1973, continues to provide proton measurements, twenty-six and a half (26 1/2) years after launch. These high energy solar protons rain down on the earth's polar atmosphere sporadically, primarily during solar proton events (SPEs) which typically last a few days. Solar protons with energies of 30 MeV or greater are capable of reaching the stratosphere and causing increases in odd nitrogen (NO(y)) constituents at polar latitudes ($>$ 60 degrees geomagnetic) which last for several months to years past the events. These enhanced NO(y) species can lead to significant upper stratospheric ozone depletions $ greater than $10\% during the gigantic SPEs that occurred in August 1972 and October 1989. We studied the effects of SPEs on the stratosphere from 1963 to the mid 1990s. During this time period, the stratospheric chlorine levels changed from relatively small in 1963 ($\sim$ 1 ppbv) to fairly substantial amounts in the mid-1990s ($\sim$ 3.3 ppbv). Our recently improved two-dimensional chemistry and transport atmospheric model was used to compute the effects of SPEs in this changing stratosphere. The long-lived SPE-produced NO(y) constituents were transported to lower stratospheric levels during winter after the events and caused impacts in the middle and lower stratosphere. Generally, the SPEs resulted in a decrease in ozone. However, during periods of high halogen loading these impacts resulted in interference with the chlorine and bromine loss cycles for ozone destruction. This interference actually led to a predicted total ozone increase that was especially notable in the time period 1992-4, a few years after the October 1989 SPE.

Jackman, Charles H.↗

NASA NTRS1978

Public policy issues. A Southern California Gas Company project SAGE report

The use of solar energy to stretch our supplies of fossil fuels was investigated. Project SAGE (semi-automated ground environment) addresses itself to one application of this goal, solar assistance in central water heating systems for multifamily projects. Public policy issues that affect the rate of adoption of solar energy systems were investigated and policy actions were offered to accelerate the adoption of SAGE and other solar energy systems.

Barbieri, R. H.↗

DOE OSTI2023

Solar PV on U.S. Houses of Worship: Overview of Market Activity and Trends [Slides]

Rooftop solar photovoltaic systems on houses of worship can provide unique community benefits and can raise local awareness and acceptance of solar energy. Recognizing that potential, a stakeholder team selected under DOE’s Solar Energy Innovation Network is working to develop a scalable model for recruiting and installing solar PV on houses of worship in underserved communities. Berkeley Lab is providing analytical support to this stakeholder team through several work products, including this report, which provides a data-oriented overview of market activity and trends related to solar PV installations on U.S. houses of worship (HoW). Drawing on Berkeley Lab’s project-level dataset of U.S. solar PV installations, the report describes: -market size and growth trends for PV on HoW -demographic characteristics of the communities in which HoW with PV are located, including income, race and ethnicity, and educational levels -key characteristics of the PV systems installed on HoW, including system size, installed costs, prevalence of third-party ownership, and pairing with storage -characteristics of the installer network servicing PV installations on HoW The purpose of the market overview is to inform business development and policy-making efforts aimed at supporting solar adoption by HoW.

14 SOLAR ENERGY↗

DOE OSTI2021

Deployment of Community Scale Solar Photovoltaic Energy Systems in Forest County Potawatomi Community

FCPC is a federally recognized tribe with a membership of more than 1400. The Tribe has a reservation in Forest County, Wisconsin, and tribal trust lands in Milwaukee County, Wisconsin, with significant governmental and business operations in both areas. Until relatively recently, FCPC was one of the poorest tribes in the Midwest. Due to its successful gaming operations, it now has improved its financial situation and is using its resources to benefit both its members and the general public through environmental and other community efforts, many of which are long-delayed because of the extended period of abject poverty. The Tribe has developed the long-term goal of becoming energy independent using renewable resources. In order to meet this goal, the Tribe has taken several important steps. As an interim step, FCPC is purchasing nearly 55 million kilowatt hours of renewable energy certificates (“RECs”) annually from certified renewable energy facilities in the United States. These RECs offset more than 100% of the present electricity use at all of the Tribe’s facilities. The Tribe is currently ranked number 11 on the Environmental Protection Agency’s (EPA) Top 20 Local Government list of green power purchasers and is a member of the EPA’s Green Power Partnership. The original project suggested small scale installations on tribal homes and certain government buildings. The Tribe suggested that the project would result in 730 kw installed. By revising the project, the Tribe was able to install 938 kw and owns the largest installation in Northern Wisconsin with the 800 kW installation at the Potawatomi Carter Casino Hotel (“PCCH”). The PCCH installation, in summer months, can provide near 90% of the use during daylight hours. Although tracking was not immediately available FCPC has since confirmed significant production with certain quarterly savings nearing $210,000. These installations provide a reduction in facility costs providing more revenue for Tribal services including cultural, health, sustainable food sources, environmental preservation and other Tribal initiatives. Further, the installations have resulted in positive steps towards the Tribe’s goals of energy sovereignty and the use of 100% renewable clean energy. Finally, the PCCH project, specifically, has had the additional benefit of providing a likely area for a microgrid. The size of the installation and offset achieved have pushed the Tribe toward planning for storage and a microgrid system that would both further the Tribe’s energy goals and provide a safe haven for the Community during times of need.

14 SOLAR ENERGY↗

DOE OSTI2022

The WRF-Solar Ensemble Prediction System: Development, Test, and Validation

Providing reliable probabilistic solar radiation information is needed to improve management of the uncertainty and variability of solar generation. Thus, guidance on how to develop skillful and accurate ensemble forecasts is essential and it will ultimately contribute to integration of high amounts of solar energy on the grid. A team from the National Renewable Energy Laboratory and the National Center for Atmospheric Research had been collaborating to develop the WRF-Solar ensemble prediction system (WRF-Solar EPS) in the past three years to produce probabilistic solar irradiance forecasts and better predict solar energy by quantifying forecast uncertainty. The WRF-Solar EPS basically generates ensemble members for solar irradiance based on stochastic perturbations to provide intraday and day-ahead probabilistic forecasts. This study will present main research steps in developing the WRF-Solar EPS including: (a) tangent linear analysis for identifying key input variables of six WRF-Solar modules significantly related to predicting of cloud and solar irradiance, (b) combining stochastic perturbation technique with the WRF-Solar model, and (c) ensemble calibration method to decrease error and uncertainty of ensemble-based solar forecasts. The capability of WRF-Solar EPS is now updated to the most recent version of standard WRF model. This presentation will summarize comprehensive results from the evaluation of forecasts against the National Solar Radiation Data Base as well as ground-measured observations. Moreover, we will introduce the user's guide for WRF-Solar EPS (e.g., parameters to configure stochastic perturbations) and future extension of this research.

day-ahead forecast↗

NASA NTRS1980

Solar space heating for the Visitors Center, Stephens College, Columbia, Missouri

The solar energy system located at the Visitors' Center on the Stephens College Campus, Columbia, Missouri is discussed. The system is installed in a four-story, 15,000 square foot building. The solar energy system is an integral design of the building and utilizes 176 hydronic flat plate collectors which use a 50 percent water ethylene blycol solution and water-to-water heat exchanger. Solar heated water is stored in a 5,000 gallon water storage tank located in the basement equipment room. A natural gas fired hot water boiler supplies hot water when the solar energy heat supply fails to meet the demand. The designed solar contribution is 71 percent of the heating load.

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NASA NTRS2000

A High-Efficiency Refractive Secondary Solar Concentrator for High Temperature Solar Thermal Applications

A refractive secondary solar concentrator is a non-imaging optical device that accepts focused solar energy from a primary concentrator and redirects that light, by means of refraction and total internal reflection (TIR) into a cavity where the solar energy is used for power and/or propulsion applications. This concept offers a variety of advantages compared to typical reflective secondary concentrators (or the use of no secondary at all): higher optical efficiency, minimal secondary cooling requirements, a smaller cavity aperture, a reduction of outgassing from the cavity and flux tailoring of the solar energy within the heat receiver. During the past 2 years, NASA Lewis has been aggressively developing this concept in support of the NASA Marshall Shooting Star Flight Experiment. This paper provides a brief overview of the advantages and technical challenges associated with the development of a refractive secondary concentrator and the fabrication of a working unit in support of the flight demonstration program.

Piszczor, Michael F., Jr.↗

DOE OSTI2020

NREL Solar Data, Analysis, & Tools: FY19 Research Dissemination Statistics

This report summarizes the key Fiscal Year 2019 (FY19) outreach metrics for the NREL Solar Data, Analysis, and Tools (DAT) portfolio. All metrics herein reflect the reporting period of Oct. 1, 2018, through Sept. 30, 2019. These projects are all supported by the U.S. Department of Energy Solar Energy Technologies Office Soft Costs program.

14 SOLAR ENERGY↗

DOE OSTI2021

Why Plan for Utility-Scale Solar?

The Solar@Scale project is a DOE Solar Energy Technologies Office-funded collaboration between the American Planning Association and International City/County Management Association (ICMA) to provide best practices and guidance for local communities in planning for large-scale PV development. As a member of the Solar@Scale advisory committee, I have been asked to present on trends and land use projections for large-scale solar to demonstrate why local governments will likely see growing demand for solar energy development. These slides represent an introduction to projections from NREL's Standard Scenarios, Cambium, LBNL's Utility-Scale Solar report, and other data sources on the level of solar energy development that can be expected across the country.

48 EE - Weatherization and Intergovernmental Progr↗

NASA NTRS1984

Solar Total Energy Project (STEP) Performance Analysis of High Temperature Energy Storage Subsystem

The 1982 milestones and lessons learned; performance in 1983; a typical day's operation; collector field performance and thermal losses; and formal testing are highlighted. An initial test that involves characterizing the high temperature storage (hts) subsystem is emphasized. The primary element is on 11,000 gallon storage tank that provides energy to the steam generator during transient solar conditions or extends operating time. Overnight, thermal losses were analyzed. The length of time the system is operated at various levels of cogeneration using stored energy is reviewed.

Moore, D. M.↗

NASA NTRS1977

Novel silicon crystals and method for their preparation

Plate shaped silicon crystals and their preparation by pouring a silicon melt into a suitable mold and then allowing it to solidify in a temperature gradient were investigated. The production of energy by direct conversion of solar energy into electrical energy by means of solar cells takes on increasing importance. While this type of energy production is already the prevailing form today in the realm of satellite technology, its terrestrial application has thus far encountered strict limitations owing to the high price of such solar cells. Of the greatest interest in this connection are silicon cells. A substantial reduction in the semiconductor material costs and the costs involved in the further processing to make solar cells are prerequisites for a rational market growth for solar energy.

Authier, B.↗

DOE OSTI2022

Molecular-Modified Photocathodes for Applications in Artificial Photosynthesis and Solar-to-Fuel Technologies

Nature offers inspiration for developing technologies that integrate the capture, conversion, and storage of solar energy. In this review article, we highlight principles of natural photosynthesis and artificial photosynthesis, drawing comparisons between solar energy transduction in biology and emerging solar-to-fuel technologies. Key features of the biological approach include use of earth-abundant elements and molecular interfaces for driving photoinduced charge separation reactions that power chemical transformations at global scales. Finally, for the artificial systems described in this review, emphasis is placed on advancements involving hybrid photocathodes that power fuel-forming reactions using molecular catalysts interfaced with visible-light-absorbing semiconductors.

14 SOLAR ENERGY↗

DOE OSTI2022

A Reliable, Cost-Effective Transformerless Medium-Voltage Inverter for Grid Integration of Combined Solar and Energy Storage

The goal of this project is to utilize an innovative holistic power electronic inverter design approach, which can leverage best-in-class silicon carbide (SiC) power modules, novel multi-level power electronic circuits, high frequency transformers, switching sequence based control and co-designed electro-thermal management methods, to realize a 300 kW transformerless medium-voltage (MV) inverter system. The system cost of the inverter is considered as a primary design objective alongside high power density, efficiency, low electromagnetic interference (EMI) and long lifespan. This design-oriented research activity, especially the proposed multi-objective optimization approach, will have broad impacts in holistic power electronic system design methods and in technologies that can be commercialized into a wide variety of wide bandgap power electronic applications.

14 SOLAR ENERGY↗

DOE OSTI2020

Spectral Radiative Properties of Ceramic Particles for Concentrated Solar Thermal Energy Storage Applications

This work investigates the spectral radiative properties of ceramic particles using a monochromator and a Fourier-transform infrared spectrometer (FTIR) with integrating spheres at wavelengths from 0.38 μm to 15 μm. Particles are encased between two transparent windows to obtain the directional-hemispherical reflectance of the particle bed. Two types of commercially available particles with three different sizes are examined. Integration over the solar spectrum reveals that the solar absorptance of the particle beds is between 0.940 and 0.957. The total emittance at 1000 K is also estimated by assuming the spectral emittance is independent of temperature. The optical constants of particles are modeled with effective medium approaches, considering the optical properties of individual constituent materials. The absorptance of the particle is estimated using the effective optical constants and compared with that of the particle bed from the measurement. Finally, this work facilitates the characterization of radiative properties of particles with a windowed method and provides a modeling scheme for approximating the radiative properties of composite ceramic materials.

14 SOLAR ENERGY↗

DOE OSTI2023

Expanding Solar Access: State Community Solar Landscape (2022)

This report supports the NCSP 2025 goal by documenting existing state-level community solar policies and programs. Although the purpose of this report is to present the existing market and policy status for community solar, with increasing attention on expanding access to solar energy for LMI customers, we also discuss key considerations for incorporating energy justice into community solar policies.

14 SOLAR ENERGY↗