Science.gov

Sample records for abundant solar energy

  1. Solar Photoelectrochemical Energy Conversion using Earth-Abundant Nanomaterials

    NASA Astrophysics Data System (ADS)

    Lukowski, Mark A.

    Although the vast majority of energy consumed worldwide is derived from fossil fuels, the growing interest in making cleaner alternative energies more economically viable has motivated recent research efforts aimed to improve photovoltaic, wind, and biomass power generation. Clean power generation also requires clean burning fuels, such as H2 and O2, so that energy can still be provided on demand at all times, despite the intermittent nature inherent to solar or wind power. My research has focused on the rational approach to synthesizing earth-abundant nanomaterials with applications in the generation of clean alternative fuels and understanding the structure-property relationships which directly influence their performance. Herein, we describe the development of low-cost, earth-abundant layered metal chalcogenides as high-performance electrocatalysts for hydrogen evolution, and hematite photoanodes for photoelectrochemical oxygen evolution. This work has revealed a particularly interesting concept where catalytic performance can be enhanced by controlling the phase behavior of the material and taking advantage of previously unexploited properties to overcome the challenges traditionally limiting the performance of these layered materials for hydrogen evolution catalysis.

  2. Solar abundance of platinum

    PubMed Central

    Burger, Harry; Aller, Lawrence H.

    1975-01-01

    Three lines of neutral platinum, located at λ 2997.98 Å, λ 3064.71 Å, and λ 3301.86 Å have been used to determine the solar platinum abundance by the method of spectral synthesis. On the scale, log A(H) = 12.00, the thus-derived solar platinum abundance is 1.75 ± 0.10, in fair accord with Cameron's value of log A(Pt) = 1.69 derived by Mason from carbonaceous chondrites and calculated on the assumption that log A(Si) = 7.55 in the sun. PMID:16592278

  3. Solar abundance of iridium

    PubMed Central

    Drake, Stephen; Aller, Lawrence H.

    1976-01-01

    By a method of spectrum synthesis, which yields log gfA, where g is the statistical weight of the lower level, f is the oscillator strength, and A is the abundance, an attempt is made to deduce the solar iridium abundance from one relatively unblended, but fairly weak IrI line, λ 3220.78 Å. If the Corliss-Bozman f-value for this line is adopted, we find log A(Ir) = 0.82 on the scale log A(H) = 12.00. The discordance with the value found from carbonaceous chondrites may arise from faulty f-values or from difficulties arising from line blending in this far ultraviolet domain of the solar spectrum. PMID:16578735

  4. Solar abundance of osmium

    PubMed Central

    Jacoby, George; Aller, Lawrence H.

    1976-01-01

    The abundance parameter, log gfA, where g is the statistical weight of the lower level, f is the oscillator strength, and A is the abundance (by numbers of atoms with respect to hydrogen), has been derived for three lines of osmium by a method of spectrum synthesis. An apparent discordance of the derived abundance with that found from the carbonaceous chondrites is probably to be attributed primarily to errors in the f-values, and blending with unknown contributors. PMID:16592314

  5. SOLAR MODELS WITH REVISED ABUNDANCE

    SciTech Connect

    Bi, S. L.; Li, T. D.; Yang, W. M.; Li, L. H.

    2011-04-20

    We present new solar models in which we use the latest low abundances and further include the effects of rotation, magnetic fields, and extra-mixing processes. We assume that the extra-element mixing can be treated as a diffusion process, with the diffusion coefficient depending mainly on the solar internal configuration of rotation and magnetic fields. We find that such models can well reproduce the observed solar rotation profile in the radiative region. Furthermore, the proposed models can match the seismic constraints better than the standard solar models, also when these include the latest abundances, but neglect the effects of rotation and magnetic fields.

  6. The solar abundance of beryllium

    NASA Technical Reports Server (NTRS)

    Ross, J. E.; Aller, L. H.

    1974-01-01

    The solar abundance of beryllium is deduced from high-resolution Kitt Peak observations of the 3130.43- and 3131.08-A lines of Be II interpreted by the method of spectrum synthesis. The results are in good agreement with those previously obtained by Grevesse (1968) and by Hauge and Engvold (1968) and indicate that in the photospheric layers, beryllium is depleted below the chondritic value by a factor of about two. It is found that the beryllium abundance is equal to logN(Be)/N(H) + 12 = 1.08 plus or minus 0.05.

  7. The solar abundance of Oxygen

    NASA Astrophysics Data System (ADS)

    Grevesse, N.

    2009-07-01

    With Martin Asplund (Max Planck Institute of Astrophysics, Garching) and Jacques Sauval (Observatoire Royal de Belgique, Brussels) I recently published detailed reviews on the solar chemical composition ({Asplund et al. 2005}, {Grevesse et al. 2007}). A new one, with Pat Scott (Stockholm University) as additional co-author, will appear in Annual Review of Astronomy and Astrophysics ({Asplund et al. 2009}). Here we briefly analyze recent works on the solar abundance of Oxygen and recommend a value of 8.70 in the usual astronomical scale.

  8. The solar abundance of thulium

    NASA Technical Reports Server (NTRS)

    Ross, J. E.; Aller, L. H.

    1974-01-01

    Consideration of one relatively unblended line of the solar spectrum, namely, the 3131.258-A line of Tm II, which yields a thulium abundance of 0.80 plus or minus 0.10 with the Corliss and Bozman (1962) f-value. The uncertainty of this figure is discussed in conjunction with the contradictory findings of some other investigators. The need for further detailed study of the lanthanides by the method of spectrum synthesis is pointed out.

  9. THE SOLAR FLARE IRON ABUNDANCE

    SciTech Connect

    Phillips, K. J. H.; Dennis, B. R. E-mail: Brian.R.Dennis@nasa.gov

    2012-03-20

    The abundance of iron is measured from emission line complexes at 6.65 keV (Fe line) and 8 keV (Fe/Ni line) in RHESSI X-ray spectra during solar flares. Spectra during long-duration flares with steady declines were selected, with an isothermal assumption and improved data analysis methods over previous work. Two spectral fitting models give comparable results, viz., an iron abundance that is lower than previous coronal values but higher than photospheric values. In the preferred method, the estimated Fe abundance is A(Fe) = 7.91 {+-} 0.10 (on a logarithmic scale, with A(H) = 12) or 2.6 {+-} 0.6 times the photospheric Fe abundance. Our estimate is based on a detailed analysis of 1898 spectra taken during 20 flares. No variation from flare to flare is indicated. This argues for a fractionation mechanism similar to quiet-Sun plasma. The new value of A(Fe) has important implications for radiation loss curves, which are estimated.

  10. Solar Energy.

    ERIC Educational Resources Information Center

    Eaton, William W.

    Presented is the utilization of solar radiation as an energy resource principally for the production of electricity. Included are discussions of solar thermal conversion, photovoltic conversion, wind energy, and energy from ocean temperature differences. Future solar energy plans, the role of solar energy in plant and fossil fuel production, and…

  11. Solar energy

    NASA Technical Reports Server (NTRS)

    Rapp, D.

    1981-01-01

    The book opens with a review of the patterns of energy use and resources in the United States, and an exploration of the potential of solar energy to supply some of this energy in the future. This is followed by background material on solar geometry, solar intensities, flat plate collectors, and economics. Detailed attention is then given to a variety of solar units and systems, including domestic hot water systems, space heating systems, solar-assisted heat pumps, intermediate temperature collectors, space heating/cooling systems, concentrating collectors for high temperatures, storage systems, and solar total energy systems. Finally, rights to solar access are discussed.

  12. Solar energy

    NASA Astrophysics Data System (ADS)

    Rapp, D.

    The book opens with a review of the patterns of energy use and resources in the United States, and an exploration of the potential of solar energy to supply some of this energy in the future. This is followed by background material on solar geometry, solar intensities, flat plate collectors, and economics. Detailed attention is then given to a variety of solar units and systems, including domestic hot water systems, space heating systems, solar-assisted heat pumps, intermediate temperature collectors, space heating/cooling systems, concentrating collectors for high temperatures, storage systems, and solar total energy systems. Finally, rights to solar access are discussed.

  13. Solar and stellar photospheric abundances

    NASA Astrophysics Data System (ADS)

    Allende Prieto, Carlos

    2016-07-01

    The determination of photospheric abundances in late-type stars from spectroscopic observations is a well-established field, built on solid theoretical foundations. Improving those foundations to refine the accuracy of the inferred abundances has proven challenging, but progress has been made. In parallel, developments on instrumentation, chiefly regarding multi-object spectroscopy, have been spectacular, and a number of projects are collecting large numbers of observations for stars across the Milky Way and nearby galaxies, promising important advances in our understanding of galaxy formation and evolution. After providing a brief description of the basic physics and input data involved in the analysis of stellar spectra, a review is made of the analysis steps, and the available tools to cope with large observational efforts. The paper closes with a quick overview of relevant ongoing and planned spectroscopic surveys, and highlights of recent research on photospheric abundances.

  14. Element Abundances in the Sun and Solar Wind Along the Solar Cycle

    NASA Astrophysics Data System (ADS)

    Landi, Enrico

    2015-04-01

    Element abundances are a critical parameter in almost every aspect of solar physics, from regulating the energy flow and the structure of the solar interior, to shaping the energy losses of the solar atmosphere, ruling the radiative output of the UV, EUV and X-rays solar radiation which impacts the Earth's upper atmosphere, and determining the composition of the solar wind.In this work we study the evolution of the element abundances in the solar corona and in the solar wind from 1996 to date using data from SoHO, Hinode, Ulysses and ACE satellites, in order to determine their variability along the solar cycle, and the relationship between solar abundance variations in the solar wind and in its source regions in the solar atmosphere. We study all the most abundant elements, with a special emphasis on Ne and O. We discuss our results in light of the source region of the solar wind, and of the radiative output of the solar corona.

  15. Solar coronal and photospheric abundances from solar energetic particle measurements

    NASA Technical Reports Server (NTRS)

    Breneman, H. H.; Stone, E. C.

    1985-01-01

    Solar energetic particle (SEP) elemental abundance data from the cosmic ray subsystem (CRS) aboard the Voyager 1 and 2 spacecraft are used to derive unfractionated coronal and photospheric abundances for elements with Z = 6-30. It is found that the ionic charge-to-mass ratio (Q/M) is the principal organizing parameter for the fractionation of SEPs by acceleration and propagation processes and for flare-to-flare variability, making possible a single-parameter Q/M-dependent correction to the average SEP abundances to obtain unfractionated coronal abundances. A further correction based on first ionization potential allows the determination of unfractionated photospheric abundances.

  16. Solar Coronal and photospheric abundances from solar energetic particle measurements

    NASA Technical Reports Server (NTRS)

    Breneman, H.; Stone, E. C.

    1985-01-01

    Solar energetic particle (SEP) elemental abundance data from the cosmic ray subsystem (CRS) aboard the Voyager 1 and 2 spacecraft are used to derive unfractionated coronal and photospheric abundances for elements with 3 Z or = 30. It is found that the ionic charge-to-mass ratio (Q/M) is the principal organizing parameter for the fractionation of SEPs by acceleration and propagation processes and for flare-to-flare variability, making possible a single-parameter Q/M-dependent correction to the average SEP abundances to obtain unfractionated coronal abundances. A further correction based on first ionization potential allows the determination of unfractionated photospheric abundances.

  17. Solar coronal and photospheric abundances from solar energetic particle measurements

    NASA Technical Reports Server (NTRS)

    Breneman, H.; Stone, E. C.

    1985-01-01

    Solar energetic particle (SEP) elemental abundance data from the Cosmic Ray Subsystem (CRS) aboard the Voyager 1 and 2 spacecraft are used to derive unfractionated coronal and photospheric abundances for elements with 3 = or Z or = 30. The ionic charge-to-mass ratio (Q/M) is the principal organizing parameter for the fractionation of SEPs by acceleration and propagation processes and for flare-to-flare variability, making possible a single-parameter Q/M-dependent correction to the average SEP abundances to obtain unfractionated coronal abundances. A further correction based on first ionization potential allows the determination of unfractionated photospheric abundances.

  18. Solar abundances as derived from solar energetic particles

    NASA Technical Reports Server (NTRS)

    Stone, E. C.

    1989-01-01

    Recent studies have shown that there are well defined average abundances of heavy (Z above 2) solar energetic particles (SEPs), with variations in the acceleration and propagation producing a systematic flare-to-flare fractionation that depends on the charge per unit mass of the ion. Correcting the average SEP abundances for this fractionation yields SEP-derived coronal abundances for 20 elements. High-resolution SEP studies have also provided isotopic abundances for five elements. SEP-derived abundances indicate that elements with high first ionization potentials (greater than 10 eV) are depleted in the corona relative to the photosphere and provide new information on the solar abundance of C and Ne-22.

  19. Solar Energy

    ERIC Educational Resources Information Center

    Building Design and Construction, 1977

    1977-01-01

    Describes 21 completed projects now using solar energy for heating, cooling, or electricity. Included are elementary schools in Atlanta and San Diego, a technical school in Detroit, and Trinity University in San Antonio, Texas. (MLF)

  20. Elemental abundances of solar sibling candidates

    SciTech Connect

    Ramírez, I.; Lambert, D. L.; Endl, M.; Cochran, W. D.; MacQueen, P. J.; Bajkova, A. T.; Bobylev, V. V.; Wittenmyer, R. A.

    2014-06-01

    Dynamical information along with survey data on metallicity and in some cases age have been used recently by some authors to search for candidates of stars that were born in the cluster where the Sun formed. We have acquired high-resolution, high signal-to-noise ratio spectra for 30 of these objects to determine, using detailed elemental abundance analysis, if they could be true solar siblings. Only two of the candidates are found to have solar chemical composition. Updated modeling of the stars' past orbits in a realistic Galactic potential reveals that one of them, HD 162826, satisfies both chemical and dynamical conditions for being a sibling of the Sun. Measurements of rare-element abundances for this star further confirm its solar composition, with the only possible exception of Sm. Analysis of long-term high-precision radial velocity data rules out the presence of hot Jupiters and confirms that this star is not in a binary system. We find that chemical tagging does not necessarily benefit from studying as many elements as possible but instead from identifying and carefully measuring the abundances of those elements that show large star-to-star scatter at a given metallicity. Future searches employing data products from ongoing massive astrometric and spectroscopic surveys can be optimized by acknowledging this fact.

  1. Abundance variations in the solar wind

    NASA Astrophysics Data System (ADS)

    von Steiger, R.; Schweingruber, R. F. Wimmer; Geiss, J.; Gloeckler, G.

    1995-07-01

    The solar wind (SW) allows us to probe the solar material in situ, particularly its composition, without the need to fly a spacecraft to inhospitably small heliocentric distances. However, it turns out that this plasma source is biased with respect to the photosphere. Elements with a low first ionization potential (FIP) are overabundant by a factor of 3-5 relative to high-FIP elements in the slow SW, but only by a factor of 1.5-2 in the fast streams emanating from coronal holes. It is thus important to have a good understanding of this FIP fractionation effect, which operates between the photosphere and the corona. Such a theory may improve on our understanding of the solar atmosphere and SW acceleration. We present SW measurements, concentrating on results of the SWICS mass spectrometer on Ulysses, which is currently sampling the SW on a highly inclined orbit. IN 1992/93, Ulysses was traversing a recurrent high-speed stream once per solar rotation, alternating with slow SW, providing a unique opportunity to compare these two SW types. We find a strongly positive correlation for low- to high-FIP element ratios (such as Mg/O) with coronal temperature, which in turn is anticorrelated with the SW speed. The correlation of these three parameters -- one chromospheric, one coronal, and one from the SW -- points at a common cause for their variations, and provides a challenge to theorists to model these three domains in an unified approach. Further, abundance variations found in the SW from coronal streamers and in coronal mass ejections are presented and discussed. Finally, we address the question of abundance variations within the fast streams, looking for abundance gradients with heliographic latitude.

  2. Ionic and electronic behaviors of earth-abundant semiconductor materials and their applications toward solar energy harvesting

    NASA Astrophysics Data System (ADS)

    Mayer, Matthew T.

    Semiconductor devices offer promise for efficient conversion of sunlight into other useful forms of energy, in either photovoltaic or photoelectrochemical cell configurations to produce electrical power or chemical energy, respectively. This dissertation examines ionic and electronic phenomena in some candidate semiconductors and seeks to understand their implications toward solar energy conversion applications. First, copper sulfide (Cu2S) was examined as a candidate photovoltaic material. It was discovered that its unique property of cation diffusion allows the room-temperature synthesis of vertically-aligned nanowire arrays, a morphology which facilitates study of the diffusion processes. This diffusivity was found to induce hysteresis in the electronic behavior, leading to the phenomena of resistive switching and negative differential resistance. The Cu2S were then demonstrated as morphological templates for solid-state conversion into different types of heterostructures, including segmented and rod-in-tube morphologies. Near-complete conversion to ZnS, enabled by the out-diffusion of Cu back into the substrate, was also achieved. While the ion diffusion property likely hinders the reliability of Cu 2S in photovoltaic applications, it was shown to enable useful electronic and ionic behaviors. Secondly, iron oxide (Fe2O3, hematite) was examined as a photoanode for photoelectrochemical water splitting. Its energetic limitations toward the water electrolysis reactions were addressed using two approaches aimed at achieving greater photovoltages and thereby improved water splitting efficiencies. In the first, a built-in n-p junction produced an internal field to drive charge separation and generate photovoltage. In the second, Fe 2O3 was deposited onto a smaller band gap material, silicon, to form a device capable of producing enhanced total photovoltage by a dual-absorber Z-scheme mechanism. Both approaches resulted in a cathodic shift of the photocurrent onset

  3. Solar abundances with the SPICE spectral imager on Solar Orbiter

    NASA Astrophysics Data System (ADS)

    Giunta, Alessandra; Haberreiter, Margit; Peter, Hardi; Vial, Jean-Claude; Harrison, Richard; Parenti, Susanna; Innes, Davina; Schmutz, Werner; Buchlin, Eric; Chamberlin, Phillip; Thompson, William; Bocchialini, Karine; Gabriel, Alan; Morris, Nigel; Caldwell, Martin; Auchere, Frederic; Curdt, Werner; Teriaca, Luca; Hassler, Donald M.; DeForest, Craig; Hansteen, Viggo; Carlsson, Mats; Philippon, Anne; Janvier, Miho; Wimmer-Schweingruber, Robert; Griffin, Douglas; Baudin, Frederic; Davila, Joseph; Fludra, Andrzej; Waltham, Nick; Eccleston, Paul; Gottwald, Alexander; Klein, Roman; Hanley, John; Walls, Buddy; Howe, Chris; Schuehle, Udo; Gyo, Manfred; Pfiffner, Dany

    2016-07-01

    Elemental composition of the solar atmosphere and in particular abundance bias of low and high First Ionization Potential (FIP) elements are a key tracer of the source regions of the solar wind. These abundances and their spatio-temporal variations, as well as the other plasma parameters , will be derived by the SPICE (Spectral Imaging of the Coronal Environment) EUV spectral imager on the upcoming Solar Orbiter mission. SPICE is designed to provide spectroheliograms (spectral images) using a core set of emission lines arising from ions of both low-FIP and high-FIP elements. These lines are formed over a wide range of temperatures, enabling the analysis of the different layers of the solar atmosphere. SPICE will use these spectroheliograms to produce dynamic composition maps of the solar atmosphere to be compared to in-situ measurements of the solar wind composition of the same elements (i.e. O, Ne, Mg, Fe). This will provide a tool to study the connectivity between the spacecraft (the Heliosphere) and the Sun. We will discuss the SPICE capabilities for such composition measurements.

  4. MEASUREMENTS OF ABSOLUTE ABUNDANCES IN SOLAR FLARES

    SciTech Connect

    Warren, Harry P.

    2014-05-01

    We present measurements of elemental abundances in solar flares with the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory. EVE observes both high temperature Fe emission lines (Fe XV-Fe XXIV) and continuum emission from thermal bremsstrahlung that is proportional to the abundance of H. By comparing the relative intensities of line and continuum emission it is possible to determine the enrichment of the flare plasma relative to the composition of the photosphere. This is the first ionization potential or FIP bias (f). Since thermal bremsstrahlung at EUV wavelengths is relatively insensitive to the electron temperature, it is important to account for the distribution of electron temperatures in the emitting plasma. We accomplish this by using the observed spectra to infer the differential emission measure distribution and FIP bias simultaneously. In each of the 21 flares that we analyze we find that the observed composition is close to photospheric. The mean FIP bias in our sample is f = 1.17 ± 0.22. This analysis suggests that the bulk of the plasma evaporated during a flare comes from deep in the chromosphere, below the region where elemental fractionation occurs.

  5. Solar Energy: Solar System Economics.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on solar system economics is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies.…

  6. Abundant Solar Nebula Solids in Comets

    NASA Technical Reports Server (NTRS)

    Messenger, S.; Keller, L. P.; Nakamura-Messenger, K.; Nguyen, A. N.; Clemett, S.

    2016-01-01

    Comets have been proposed to consist of unprocessed interstellar materials together with a variable amount of thermally annealed interstellar grains. Recent studies of cometary solids in the laboratory have shown that comets instead consist of a wide range of materials from across the protoplanetary disk, in addition to a minor complement of interstellar materials. These advances were made possible by the return of direct samples of comet 81P/Wild 2 coma dust by the NASA Stardust mission and recent advances in microscale analytical techniques. Isotopic studies of 'cometary' chondritic porous interplanetary dust particles (CP-IDPs) and comet 81P/Wild 2 Stardust samples show that preserved interstellar materials are more abundant in comets than in any class of meteorite. Identified interstellar materials include sub-micron-sized presolar silicates, oxides, and SiC dust grains and some fraction of the organic material that binds the samples together. Presolar grain abundances reach 1 weight percentage in the most stardust-rich CP-IDPs, 50 times greater than in meteorites. Yet, order of magnitude variations in presolar grain abundances among CP-IDPs suggest cometary solids experienced significant variations in the degree of processing in the solar nebula. Comets contain a surprisingly high abundance of nebular solids formed or altered at high temperatures. Comet 81P/Wild 2 samples include 10-40 micron-sized, refractory Ca- Al-rich inclusion (CAI)-, chondrule-, and ameboid olivine aggregate (AOA)-like materials. The O isotopic compositions of these refractory materials are remarkably similar to their meteoritic counterparts, ranging from 5 percent enrichments in (sup 16) O to near-terrestrial values. Comet 81P/Wild 2 and CP-IDPs also contain abundant Mg-Fe crystalline and amorphous silicates whose O isotopic compositions are also consistent with Solar System origins. Unlike meteorites, that are dominated by locally-produced materials, comets appear to be composed of

  7. Collecting Solar Energy. Solar Energy Education Project.

    ERIC Educational Resources Information Center

    O'Brien, Alexander

    This solar energy learning module for use with junior high school students offers a list of activities, a pre-post test, job titles, basic solar energy vocabulary, and diagrams of solar energy collectors and installations. The purpose is to familiarize students with applications of solar energy and titles of jobs where this knowledge could be…

  8. Solar energy collector

    DOEpatents

    Brin, Raymond L.; Pace, Thomas L.

    1978-01-01

    The invention relates to a solar energy collector comprising solar energy absorbing material within chamber having a transparent wall, solar energy being transmitted through the transparent wall, and efficiently absorbed by the absorbing material, for transfer to a heat transfer fluid. The solar energy absorbing material, of generally foraminous nature, absorbs and transmits the solar energy with improved efficiency.

  9. Solar Energy and You.

    ERIC Educational Resources Information Center

    Conservation and Renewable Energy Inquiry and Referral Service (DOE), Silver Spring, MD.

    This booklet provides an introduction to solar energy by discussing: (1) how a home is heated; (2) how solar energy can help in the heating process; (3) the characteristics of passive solar houses; (4) the characteristics of active solar houses; (5) how solar heat is stored; and (6) other uses of solar energy. Also provided are 10 questions to…

  10. Earth-Abundant Materials for Solar Hydrogen Generation

    NASA Astrophysics Data System (ADS)

    McKone, James Robert

    A critical challenge for the 21st century is shifting from the predominant use of fossil fuels to renewables for energy. Among many options, sunlight is the only single renewable resource with sufficient abundance to replace most or all of our current fossil energy use. However, existing photovoltaic and solar thermal technologies cannot be scaled infinitely due to the temporal and geographic intermittency of sunlight. Therefore efficient and inexpensive methods for storage of solar energy in a dense medium are needed in order to greatly increase utilization of the sun as a primary resource. For this purpose we have proposed an artificial photosynthetic system consisting of semiconductors, electrocatalysts, and polymer membranes to carry out photoelectrochemical water splitting as a method for solar fuel generation. This dissertation describes efforts over the last five years to develop critical semiconductor and catalyst components for efficient and scalable photoelectrochemical hydrogen evolution, one of the half reactions for water splitting. We identified and developed Ni--Mo alloy and Ni2P nanoparticles as promising earth-abundant electrocatalysts for hydrogen evolution. We thoroughly characterized Ni-Mo alloys alongside Ni and Pt catalysts deposited onto planar and structured Si light absorbers for solar hydrogen generation. We sought to address several key challenges that emerged in the use of non-noble catalysts for solar fuels generation, resulting in the synthesis and characterization of Ni--Mo nanopowder for use in a new photocathode device architecture. To address the mismatch in stability between non-noble metal alloys and Si absorbers, we also synthesized and characterized p-type WSe2 as a candidate light absorber alternative to Si that is stable under acidic and alkaline conditions.

  11. Elemental Abundance Variations in the Solar Atmosphere

    NASA Astrophysics Data System (ADS)

    Sheeley, N. R., Jr.

    1996-09-01

    Skylab solar images in the transition region lines of neon, magnesium, and calcium have been used to trace elemental abundance variations in sunspots and the quiet Sun. Sunspots are invariably accompanied by spikelike features, enriched in elements of low first ionization potential (FIP) such as magnesium and calcium, and extending outward from the penumbras. Material with the normal, unenriched, photospheric-like composition is sometimes seen over the umbra, but it is only seen in the presence of very bright chromospheric emission associated with flares or emerging flux. The salt-and-pepper fields of the quiet Sun give rise to small-scale structures, enhanced in the lines of both helium and neon, and having the "photospheric" composition. However, enrichments of low-Fl P elements are sometimes found at unipolar flux concentrations in coronal holes, and occasionally they have very large enrichment factors. These observations suggest that the composition depends on whether the plasma is coronal or not and that the fractionation process is somehow related to the production of coronal material.

  12. Initial Time Dependence of Abundances in Solar Energetic Particle Events

    NASA Technical Reports Server (NTRS)

    Reames, Donald V.; Ny, C. K.; Tylka, A. J.

    1999-01-01

    We compare the initial behavior of Fe/O and He/H abundance ratios and their relationship to the evolution of the proton energy spectra in "small" and "large" gradual solar energetic particle (SEP) events. The results are qualitatively consistent with the behavior predicted by the theory of Ng et al. (1999a, b). He/H ratios that initially rise with time are a signature of scattering by non-Kolmogorov Alfven wave spectra generated by intense beams of shock-accelerated protons streaming outward in large gradual SEP events.

  13. Solar energy conversion.

    SciTech Connect

    Crabtree, G. W.; Lewis, N. S.

    2008-03-01

    If solar energy is to become a practical alternative to fossil fuels, we must have efficient ways to convert photons into electricity, fuel, and heat. The need for better conversion technologies is a driving force behind many recent developments in biology, materials, and especially nanoscience. The Sun has the enormous untapped potential to supply our growing energy needs. The barrier to greater use of the solar resource is its high cost relative to the cost of fossil fuels, although the disparity will decrease with the rising prices of fossil fuels and the rising costs of mitigating their impact on the environment and climate. The cost of solar energy is directly related to the low conversion efficiency, the modest energy density of solar radiation, and the costly materials currently required. The development of materials and methods to improve solar energy conversion is primarily a scientific challenge: Breakthroughs in fundamental understanding ought to enable marked progress. There is plenty of room for improvement, since photovoltaic conversion efficiencies for inexpensive organic and dye-sensitized solar cells are currently about 10% or less, the conversion efficiency of photosynthesis is less than 1%, and the best solar thermal efficiency is 30%. The theoretical limits suggest that we can do much better. Solar conversion is a young science. Its major growth began in the 1970s, spurred by the oil crisis that highlighted the pervasive importance of energy to our personal, social, economic, and political lives. In contrast, fossil-fuel science has developed over more than 250 years, stimulated by the Industrial Revolution and the promise of abundant fossil fuels. The science of thermodynamics, for example, is intimately intertwined with the development of the steam engine. The Carnot cycle, the mechanical equivalent of heat, and entropy all played starring roles in the development of thermodynamics and the technology of heat engines. Solar-energy science faces

  14. Heavy-Element Abundances in Solar Energetic Particle Events

    NASA Technical Reports Server (NTRS)

    Reames, D. V.; Ng, C. K.

    2004-01-01

    We survey the relative abundances of elements with 1 < or equal to Z < or equal to 82 in solar energetic particle (SEP) events observed at 2-10 MeV/amu during nearly 9 years aboard the Wind spacecraft, with special emphasis on enhanced abundances of elements with Z > or equal to 34. Abundances of Fe/O again show a bimodal distribution with distinct contributions from impulsive and gradual SEP events as seen in earlier solar cycles. Periods with greatly enhanced abundances of (50 < or equal to Z < or equal to 56)/O, like those with enhanced (3)He/(4)He, fall prominently in the Fe-rich population of the impulsive SEP events. In a sample of the 39 largest impulsive events, 25 have measurable enhancements in (50 < or equal to z < or equal to 56)/O and (76 < or equal to Z < or equal to 82)/O, relative to coronal values, ranging from approx. 100 to 10,000. By contrast, in a sample of 45 large gradual events the corresponding enhancements vary from approx. 0.2 to 20. However, the magnitude of the heavy-element enhancements in impulsive events is less striking than their strong correlation with the Fe spectral index and flare size, with the largest enhancements occurring in flares with the steepest Fe spectra, the smallest Fe fluence, and the lowest X-ray intensity, as reported here for the first time. Thus it seems that small events with low energy input can produce only steep spectra of the dominant species but accelerate rare heavy elements with great efficiency, probably by selective absorption of resonant waves in the flare plasma. With increased energy input, enhancements diminish, as heavy ions are depleted, and spectra of the dominant species harden.

  15. OH Column Abundance Apparent Response to Solar Cycle 23

    NASA Astrophysics Data System (ADS)

    Burnett, C. R.; Minschwaner, K. R.

    2009-12-01

    The 33-year series of high spectral resolution measurements of absorption of sunlight by OH at 308 nm has exhibited temporary decreases of column abundances in 1986, 1997, and 2008 near the times of minimum solar activity. These observations and analyses are of significance as they encompass three complete solar cycles for comparison. During solar cycle 23, the annual average abundances increased approximately 20% from the minimum abundance in 1997 to high-sun enhanced values in 2000-2006, then dropped approximately 15% in 2008. The abundances exhibited a pronounced reduction at solar minimum in August-October 2008, similar to that seen in fall 1986 and fall 1997. The average morning abundances on those occasions were 13% smaller than the 1980-88 corresponding average, about 0.9 x 1013 cm-2, with minimum values broadly consistent with model results. In contrast, high-sun OH abundances observed during periods of solar maximum are approximately 33% larger than modeled abundances. This discrepancy cannot be explained by reasonable adjustments of reaction rates or modeled constituent concentrations in the stratosphere or mesosphere. However, the observed responses to a tropopause fold event in 1988 and to the Pinatubo aerosol in 1991 do suggest an important contribution to the total OH column from the lower stratosphere. In addition to the apparent variations with solar activity, this OH column database contains a number of other effects such as diurnal and seasonal patterns, and geographic differences between observations from Colorado, Florida, Alaska, Micronesia, New Zealand, and New Mexico.

  16. Conversion of solar energy

    NASA Astrophysics Data System (ADS)

    Semenov, N. N.; Shilov, A. E.

    The papers presented in this volume provide an overview of current theoretical and experimental research related to the conversion and practical utilization of solar energy. Topics discussed include semiconductor photovoltaic cells, orbital solar power stations, chemical and biological methods of solar energy conversion, and solar energy applications. Papers are included on new theoretical models of solar cells and prospects for increasing their efficiency, metrology and optical studies of solar cells, and some problems related to the thermally induced deformations of large space structures.

  17. Solar Energy Systems

    NASA Technical Reports Server (NTRS)

    1984-01-01

    Calibrated in kilowatt hours per square meter, the solar counter produced by Dodge Products, Inc. provides a numerical count of the solar energy that has accumulated on a surface. Solar energy sensing, measuring and recording devices in corporate solar cell technology developed by Lewis Research Center. Customers for their various devices include architects, engineers and others engaged in construction and operation of solar energy facilities; manufacturers of solar systems or solar related products, such as glare reducing windows; and solar energy planners in federal and state government agencies.

  18. A Solar Energy Bibliography.

    ERIC Educational Resources Information Center

    Guthrie, David L.; Riley, Robert A.

    This document contains 5,000 references to literature through 1976 dealing with various aspects of solar energy. Categories are established according to area of solar research. These categories include: (1) overview; (2) measurement; (3) low-range solar energy collection (below 120 degrees C); (4) intermediate-range solar energy collection (120…

  19. Solar-system abundances and processes of nucleosynthesis

    NASA Technical Reports Server (NTRS)

    Woolum, Dorothy S.

    1988-01-01

    The origin of the elements is studied. The average elemental composition of the solar system is examined and used to infer the primordial solar system abundances of the individual nuclides. Patterns in these nuclide abundances are used as clues to their origin. The possible cosmic significance of the patterns are considered. The astrophysical settings for nucleosynthesis and the chemical evolution of the Galaxy and information based on observed isotopic anomalies in meteorites are taken into account.

  20. The Origin of Element Abundance Variations in Solar Energetic Particles

    NASA Astrophysics Data System (ADS)

    Reames, Donald V.

    2016-08-01

    Abundance enhancements, during acceleration and transport in both gradual and impulsive solar energetic particle (SEP) events, vary approximately as power laws in the mass-to-charge ratio [A/Q] of the ions. Since the Q-values depend upon the electron temperature of the source plasma, this has allowed a determination of this temperature from the pattern of element-abundance enhancements and a verification of the expected inverse-time dependence of the power of A/Q for diffusive transport of ions from the SEP events, with scattering mean free paths found to be between 0.2 and 1 AU. SEP events derived from plasma of different temperatures map into different regions in typical cross-plots of abundances, spreading the distributions. In comparisons of SEP events with temperatures above 2 MK, impulsive events show much broader non-thermal variation of abundances than do gradual events. The extensive shock waves accelerating ions in gradual events may average over much of an active region where numerous but smaller magnetic reconnections, "nanojets", produce suprathermal seed ions, thus averaging over varying abundances, while an impulsive SEP event only samples one local region of abundance variations. Evidence for a reference He/O-abundance ratio of 91, rather than 57, is also found for the hotter plasma. However, while this is similar to the solar-wind abundance of He/O, the solar-wind abundances otherwise provide an unacceptably poor reference for the SEP-abundance enhancements, generating extremely large errors.

  1. NREL Explores Earth-Abundant Materials for Future Solar Cells (Fact Sheet)

    SciTech Connect

    Not Available

    2012-10-01

    Researchers at the National Renewable Energy Laboratory (NREL) are using a theory-driven technique - sequential cation mutation - to understand the nature and limitations of promising solar cell materials that can replace today's technologies. Finding new materials that use Earth-abundant elements and are easily manufactured is important for large-scale solar electricity deployment.

  2. Temporal Variability of Ion Acceleration and Abundances in Solar Flares

    NASA Technical Reports Server (NTRS)

    Shih, Albert

    2011-01-01

    Solar flares accelerate both ions and electrons to high energies, and their X-ray and gamma-ray signatures not only probe the relationship between their respective acceleration, but also allow for the measurement of accelerated and ambient abundances. RHESSI observations have shown a striking close linear correlation of gamma-ray line fluence from accelerated ions greater than approximately 20 MeV and bremsstrahlung emission from relativistic accelerated electrons greater than 300 keV, when integrated over complete flares, suggesting a common acceleration mechanism. SMM/GRS observations, however, show a weaker correlation, and this discrepancy might be associated with previously observed electron-rich episodes within flares and/or temporal variability of gamma-ray line fluxes over the course of flares. We use the latest RHESSI gamma-ray analysis techniques to study the temporal behavior of the RHESSI flares, and determine what changes can be attributed to an evolving acceleration mechanism or to evolving abundances. We also discuss possible explanations for changing abundances.

  3. Temporal Variability of Ion Acceleration and Abundances in Solar Flares

    NASA Technical Reports Server (NTRS)

    Shih, Albert Y.

    2012-01-01

    solar flares accelerate both ions and electrons to high energies, and their x-ray and gamma-ray signatures not only probe the relationship between their respective acceleration, but also allow for the measurement of accelerated and ambient abundances. RHESSI observations have shown a striking close linear correlation of gamma-ray line fluence from accelerated ions > approx 20 MeV and bremsstrahlung emission from relativistic accelerated electrons >300 kev, when integrated over complete flares, suggesting a common acceleration mechanism. SMM/GRS observations, however, show a weaker correlation, and this discrepancy might be associated with previously observed electron-rich episodes within flares and/or temporal variability of gamma-ray line fluxes over the course of flares. We use the latest RHESSI gamma-ray analysis techniques to study the temporal behavior of the RHESSI flares, and determine what changes can be attributed to an evolving acceleration mechanism or to evolving abundances. We also discuss possible explanations for changing abundances.

  4. Alternatives in solar energy

    NASA Technical Reports Server (NTRS)

    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.

  5. THE OXYGEN ABUNDANCE IN THE SOLAR NEIGHBORHOOD

    SciTech Connect

    RodrIguez, Monica; Delgado-Inglada, Gloria E-mail: gloria@inaoep.mx

    2011-06-01

    We present a homogeneous analysis of the oxygen abundance in five H II regions and eight planetary nebulae (PNe) located at distances lower than 2 kpc and with available spectra of high quality. We find that both the collisionally excited lines (CELs) and recombination lines imply that the PNe are overabundant in oxygen by about 0.2 dex. An explanation that reconciles the oxygen abundances derived with CELs for H II regions and PNe with the values found for B stars, the Sun, and the diffuse interstellar medium (ISM) requires the presence in H II regions of an organic refractory dust component that is not present in PNe. This dust component has already been invoked to explain the depletion of oxygen in molecular clouds and in the diffuse ISM.

  6. Stellar abundances in the solar neighborhood: The Hypatia Catalog

    SciTech Connect

    Hinkel, Natalie R.; Timmes, F.X.; Young, Patrick A.; Pagano, Michael D.; Turnbull, Margaret C.

    2014-09-01

    We compile spectroscopic abundance data from 84 literature sources for 50 elements across 3058 stars in the solar neighborhood, within 150 pc of the Sun, to produce the Hypatia Catalog. We evaluate the variability of the spread in abundance measurements reported for the same star by different surveys. We also explore the likely association of the star within the Galactic disk, the corresponding observation and abundance determination methods for all catalogs in Hypatia, the influence of specific catalogs on the overall abundance trends, and the effect of normalizing all abundances to the same solar scale. The resulting stellar abundance determinations in the Hypatia Catalog are analyzed only for thin-disk stars with observations that are consistent between literature sources. As a result of our large data set, we find that the stars in the solar neighborhood may reveal an asymmetric abundance distribution, such that a [Fe/H]-rich group near the midplane is deficient in Mg, Si, S, Ca, Sc II, Cr II, and Ni as compared to stars farther from the plane. The Hypatia Catalog has a wide number of applications, including exoplanet hosts, thick- and thin-disk stars, and stars with different kinematic properties.

  7. Neon and Oxygen Abundances and Abundance Ratio in the Solar Corona

    NASA Astrophysics Data System (ADS)

    Landi, E.; Testa, P.

    2015-02-01

    In this work we determine the Ne/O abundance ratio from Solar and Heliospheric Observatory (SOHO)/Solar Ultraviolet Measurement of Emitted Radiation (SUMER) off-disk observations of quiescent streamers over the 1996-2008 period. We find that the Ne/O ratio is approximately constant over solar cycle 23 from 1996 to 2005, at a value of 0.099 ± 0.017 this value is lower than the transition region determinations from the quiet Sun used to infer the neon photospheric abundance from the oxygen photospheric abundance. Also, the Ne/O ratio we determined from SUMER is in excellent agreement with in situ determinations from ACE/SWICS. In 2005-2008, the Ne/O abundance ratio increased with time and reached 0.25 ± 0.05, following the same trend found in the slowest wind analyzed by ACE/SWICS. Further, we measure the absolute abundance in the corona for both oxygen and neon from the data set of 1996 November 22, obtaining A o = 8.99 ± 0.04 and A Ne = 7.92 ± 0.03, and we find that both elements are affected by the first ionization potential (FIP) effect, with oxygen being enhanced by a factor of 1.4-2.1 over its photospheric abundance, and neon being changed by a factor of 0.75-1.20. We conclude that the Ne/O ratio is not constant in the solar atmosphere, both in time and at different heights, and that it cannot be reliably used to infer the neon abundance in the photosphere. Also, we argue that the FIP effect was less effective during the minimum of solar cycle 24, and that the Ne/O = 0.25 ± 0.05 value measured at that time is closer to the true photospheric value, leading to a neon photospheric abundance larger than assumed by ≈40%. We discuss the implications of these results for the solar abundance problem, for the FIP effect, and for the identification of the source regions of the solar wind.

  8. Solar Energy Technician/Installer

    ERIC Educational Resources Information Center

    Moore, Pam

    2007-01-01

    Solar power (also known as solar energy) is solar radiation emitted from the sun. Large panels that absorb the sun's energy as the sun beats down on them gather solar power. The energy in the rays can be used for heat (solar thermal energy) or converted to electricity (photovoltaic energy). Each solar energy project, from conception to…

  9. Nucleosynthesis: Stellar and Solar Abundances and Atomic Data

    NASA Technical Reports Server (NTRS)

    Cowan, John J.; Lawler, James E.; Sneden, Christopher; DenHartog, E. A.; Collier, Jason; Dodge, Homer L.

    2006-01-01

    Abundance observations indicate the presence of often surprisingly large amounts of neutron capture (i.e., s- and r-process) elements in old Galactic halo and globular cluster stars. These observations provide insight into the nature of the earliest generations of stars in the Galaxy the progenitors of the halo stars responsible for neutron-capture synthesis. Comparisons of abundance trends can be used to understand the chemical evolution of the Galaxy and the nature of heavy element nucleosynthesis. In addition age determinations, based upon long-lived radioactive nuclei abundances, can now be obtained. These stellar abundance determinations depend critically upon atomic data. Improved laboratory transition probabilities have been recently obtained for a number of elements. These new gf values have been used to greatly refine the abundances of neutron-capture elemental abundances in the solar photosphere and in very metal-poor Galactic halo stars. The newly determined stellar abundances are surprisingly consistent with a (relative) Solar System r-process pattern, and are also consistent with abundance predictions expected from such neutron-capture nucleosynthesis.

  10. Solar energy emplacement developer

    NASA Technical Reports Server (NTRS)

    Mortensen, Michael; Sauls, Bob

    1991-01-01

    A preliminary design was developed for a Lunar Power System (LPS) composed of photovoltaic arrays and microwave reflectors fabricated from lunar materials. The LPS will collect solar energy on the surface of the Moon, transform it into microwave energy, and beam it back to Earth where it will be converted into usable energy. The Solar Energy Emplacement Developer (SEED) proposed will use a similar sort of solar energy collection and dispersement to power the systems that will construct the LPS.

  11. Helium abundance variations in the solar wind: Observations from Ulysses

    SciTech Connect

    Barraclough, B.L.; Gosling, J.T.; Mccomas, D.J.; Goldstein, B.E.

    1995-06-01

    The abundance of helium in the solar wind averages approximately 4% but has been observed to vary by more than two orders of magnitude from 0.1 to 30%. Physical processes responsible for this variability are still not clearly understood. Previous work has shown a correlation between low He abundance and coronal streamer plasma and between high He abundance and coronal mass ejections (CMEs). The authors now have out-of-ecliptic data on helium in the solar wind from the plasma experiment aboard Ulysses. Tentative results show that the average high-latitude helium concentration is comparable to the in-ecliptic value for the present phase of the solar cycle, that excursions of the hour-averaged abundance very seldom fall outside the range 2.5 to 6.5%, and that there seems to be very little abundance enhancement associated with CMEs encountered at latitudes greater than 30 deg as opposed to the situation commonly encountered with in-ecliptic CMEs. In addition, preliminary observations of a single CME by both ISEE (in-ecliptic) and Ulysses (out-of-ecliptic) show a considerable He enhancement at ISEE with little or no perturbation of the average value at Ulysses` location. This paper will first present new results from the Ulysses mission up to the time of the meeting on the average abundance of helium in the solar wind as a function of spacecraft position, and will then focus on the out-of-ecliptic results including latitudinal abundance variations and observations of abundance enhancements (or lack thereof) in high-latitude CMEs.

  12. Experimenting with Solar Energy

    ERIC Educational Resources Information Center

    Roman, Harry T.

    2004-01-01

    Over the past 25 years, the author has had the opportunity to study the subject of solar energy and to get involved with the installation, operation, and testing of solar energy systems. His work has taken him all over the United States and put him in contact with solar experts from around the world. He has also had the good fortune of seeing some…

  13. Solar energy modulator

    NASA Technical Reports Server (NTRS)

    Hale, R. R. (Inventor); Mcdougal, A. R.

    1984-01-01

    A module is described with a receiver having a solar energy acceptance opening and supported by a mounting ring along the optic axis of a parabolic mirror in coaxial alignment for receiving solar energy from the mirror, and a solar flux modulator plate for varying the quantity of solar energy flux received by the acceptance opening of the module. The modulator plate is characterized by an annular, plate-like body, the internal diameter of which is equal to or slightly greater than the diameter of the solar energy acceptance opening of the receiver. Slave cylinders are connected to the modulator plate for supporting the plate for axial displacement along the axis of the mirror, therby shading the opening with respect to solar energy flux reflected from the surface of the mirror to the solar energy acceptance opening.

  14. Solar Energy: Heat Transfer.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on heat transfer is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies. The…

  15. Solar Energy: Heat Storage.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on heat storage is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies. The module…

  16. Solar Energy: Home Heating.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on home heating is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies. The module…

  17. Measurements of the Fe-group abundance in energetic solar particles

    NASA Technical Reports Server (NTRS)

    Bertsch, D. L.; Fichtel, C. E.; Pellerin, C. J.; Reames, D. V.

    1972-01-01

    The abundance of Fe-group nuclei in the energetic solar particles was measured twice in the 24 January 1971 event and once in the 2 September 1971 event. Including earlier results from the 2 September 1966 event, the Fe-group abundance was found to be in the range from 3% to 6% of the oxygen nuclei in the energy interval from 21 to 50 MeV/nucleon, in those events where the Fe-group abundance could be measured. Fe-nuclei have a different charge-to-mass ratio from that of the C, N, O nuclei, so small variations in the Fe abundance in solar particles are expected. In the three exposures where the statistics were adequate to construct an energy spectrum, the Fe-group nuclei were seen to have an energy/nucleon spectrum similar to that of the C, N, O nuclei; however, the energy/nucleon range was limited. The abundance for the Fe-group nuclei is consistent with the present solar spectroscopic abundance estimates.

  18. Solar System Abundances of the Elements

    NASA Astrophysics Data System (ADS)

    Palme, H.; Jones, A.

    2003-12-01

    This chapter is devoted to the discussion of the evolution of metabolism, with a particular focus towards redox metabolism and the utilization of redox energy by life. We will deal with various aspects of metabolism that involve direct interaction with, and the extraction of energy from, the environment (catabolic metabolism) and will talk briefly of the reactions that affect mineral formation and dissolution. However, we will de-emphasize the aspects related to the formation of complex molecules and organisms. To some, it will be refreshingly brief; to others, somewhat superficial. This is unavoidable, as our knowledge of the details of the evolution of metabolism is at best slim. However, by piecing together aspects of the properties and history of the Earth and coupling these with what we know of today's metabolism, it is possible to at least frame several different hypotheses that, with time, should be possible to test and modify so that the next writing of this chapter might contain some intellectual entrees and not just the appetizers. Any discussion of metabolic evolution must occur in concert with a consideration of the Earth - the understanding of the forces that drove the co-evolution of life and Earth can be achieved only by considering them together. This theme will pervade this chapter, and any real understanding of the evolution of metabolism must be inexorably coupled to, and consistent with, the geological record of the Earth.The first aspect of evolution concerns the metabolic participants as we know them now (i.e., a definition of metabolic diversity), and the second concerns the sequence of events that have led to this remarkable metabolic diversity. The first part is fairly straightforward: a discussion of the domains of life, and the metabolic achievements that are expressed in the various domains, and relating metabolism to biogeochemical processes whenever possible. The second part is much more problematic. While it is possible to make up

  19. Solar Energy Development Progresses

    ERIC Educational Resources Information Center

    Chemical and Engineering News, 1975

    1975-01-01

    Discusses an engineering conference at which participants agreed that solar energy is a feasible energy source, although costs of such technology are presently very high. Also describes recent developments in solar energy research, and estimates the costs of this technology. (MLH)

  20. Vibration-rotation bands of CH in the solar infrared spectrum and the solar carbon abundance

    NASA Technical Reports Server (NTRS)

    Grevesse, N.; Lambert, D. L.; Sauval, A. J.; Van Dishoek, E. F.; Farmer, C. B.; Norton, R. H.

    1991-01-01

    High resolution solar spectra obtained from the ATMOS Fourier Transform Spectrometer (Spacelab 3 flight on April 29-May 6, 1985) have made it possible to identify and measure a large number of lines of the vibration-rotation fundamental bands of the X2 Pi state of CH. From about 100 lines of the 1-0, 2-1, and 3-2 bands and adopting theoretical transition probabilities, a solar carbon abundance of 8.60 + or - 0.05 is derived. This value is compared with new results inferred from other carbon abundance indicators. The final recommended solar abundance of carbon is 8.60 + or - 0.05.

  1. He abundance variations in the solar wind: Observations from Ulysses

    SciTech Connect

    Barraclough, B.L.; Gosling, J.T.; Phillips, J.L.; McComas, D.J.; Feldman, W.C.; Goldstein, B.E.

    1995-09-01

    The Ulysses mission is providing the first opportunity to observe variations in solar wind plasma parameters at heliographic latitudes far removed from the ecliptic plane. We present an overview of the solar wind speed and the variability in helium abundance, [He] data on [He] in six high latitude coronal mass ejections (CMEs), and a superposed epoch analysis of [He] variations at the seven heliospheric current sheet (HCS) crossings made during the rapid-latitude-scan portion of the mission. The differences in the variability of the solar wind speed and [He] in high latitude and equatorial regions are quite striking. Solar wind speed is generally low but highly variable near the solar equator, while at higher latitudes the average speed is quite high with little variability. [He] can vary over nearly two decades at low solar latitudes, while at high latitudes it varies only slightly. In contrast to the high [He] that is commonly associated with CMEs observed in the ecliptic, none of the six high-speed CMEs encountered at high southern heliographic latitudes showed any significant variation in helium content. A superposed epoch analysis of the [He] during all seven HCS crossings made as Ulysses passed from the southern to northern solar hemisphere shows the expected [He] minimum near the crossing and a broad region of low [He] around the crossing time. We discuss how our solar wind [He] observations may provide an accurate measure of the helium composition for the entire convective zone of the Sun.

  2. Solar ADEPT: Efficient Solar Energy Systems

    SciTech Connect

    2011-01-01

    Solar ADEPT Project: The 7 projects that make up ARPA-E's Solar ADEPT program, short for 'Solar Agile Delivery of Electrical Power Technology,' aim to improve the performance of photovoltaic (PV) solar energy systems, which convert the sun's rays into electricity. Solar ADEPT projects are integrating advanced electrical components into PV systems to make the process of converting solar energy to electricity more efficient.

  3. Solar photospheric and coronal abundances from solar energetic particle measurements. Ph.D. Thesis

    NASA Technical Reports Server (NTRS)

    Breneman, H.

    1985-01-01

    Observations of solar energetic particles (SEP) from 22 solar flares in the 1977 to 1982 time period are reported. SEP abundances were obtained for all elements with 3 approximately less than Z approximately less than 30 except Li, Be, B, F, Sc, v, Co and Cu for which upper limits were obtained. Statistically meaningful abundances of several rare elements (P, Cl, K, Ti, and Mn) were determined for the first time, and the average abundance of the more abundant elements were determined with improved precision.

  4. Photochemical conversion of solar energy.

    PubMed

    Balzani, Vincenzo; Credi, Alberto; Venturi, Margherita

    2008-01-01

    Energy is the most important issue of the 21st century. About 85% of our energy comes from fossil fuels, a finite resource unevenly distributed beneath the Earth's surface. Reserves of fossil fuels are progressively decreasing, and their continued use produces harmful effects such as pollution that threatens human health and greenhouse gases associated with global warming. Prompt global action to solve the energy crisis is therefore needed. To pursue such an action, we are urged to save energy and to use energy in more efficient ways, but we are also forced to find alternative energy sources, the most convenient of which is solar energy for several reasons. The sun continuously provides the Earth with a huge amount of energy, fairly distributed all over the world. Its enormous potential as a clean, abundant, and economical energy source, however, cannot be exploited unless it is converted into useful forms of energy. This Review starts with a brief description of the mechanism at the basis of the natural photosynthesis and, then, reports the results obtained so far in the field of photochemical conversion of solar energy. The "grand challenge" for chemists is to find a convenient means for artificial conversion of solar energy into fuels. If chemists succeed to create an artificial photosynthetic process, "... life and civilization will continue as long as the sun shines!", as the Italian scientist Giacomo Ciamician forecast almost one hundred years ago.

  5. Solar Energy: Solar and the Weather.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on solar and the weather is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy technologies.…

  6. Correlation between lithium abundances and ages of solar twin stars

    NASA Astrophysics Data System (ADS)

    Carlos, Marília; Nissen, Poul E.; Meléndez, Jorge

    2016-03-01

    Aims: We want to determine the lithium abundances of solar twin stars as a function of stellar age to provide constraints for stellar evolutions models and to investigate whether there is a connection between low Li abundance and the occurrence of planets. Methods: For a sample of 21 solar twins observed with the HARPS spectrograph at high spectral resolution (R ≃ 115.000) and very high signal-to-noise ratio (600 ≤ S/N ≤ 2400), precise lithium abundances were obtained by spectral synthesis of the Li i 6707.8 Å line and compared to stellar ages, masses, and metallicities determined from a spectroscopic analysis of the same set of HARPS spectra. Results: We show that for the large majority of the solar twins there is a strong correlation between lithium abundance and stellar age. As the age increases from 1 to 9 Gyr, the Li abundance decreases by a factor of ~50. The relation agrees fairly well with predictions from non-standard stellar evolution models of Li destruction at the bottom of the upper convection zone. Two stars deviate from the relation by having Li abundances enhanced by a factor of ~10, which may be due to planet engulfment. On the other hand, we find no indication of a link between planet hosting stars and enhanced lithium depletion. Based on data products from observations made with ESO Telescopes at the La Silla Paranal Observatory, (observing programs 072.C-0488, 183.C-0972, 188.C-0265, and 0.88.C-0323).

  7. THE SOLAR ABUNDANCE PROBLEM: THE EFFECT OF THE TURBULENT KINETIC FLUX ON THE SOLAR ENVELOPE MODEL

    SciTech Connect

    Zhang, Q. S.

    2014-06-01

    Recent three-dimensional (3D) simulations have shown that the turbulent kinetic flux (TKF) is significant. We discuss the effects of TKF on the size of the convection zone and find that the TKF may help solve the solar abundance problem. The solar abundance problem is that, with new abundances, the solar convection zone depth, the sound speed in the radiative interior, the helium abundance, and the density in the convective envelope are not in agreement with helioseismic inversions. We have performed Monte Carlo simulations on solar convective envelope models with different profiles of TKF to test its effects. The solar abundance problem is revealed in the standard solar convective envelope model with AGSS09 composition, which shows significant differences (∼10)) in density from the helioseismic inversions, but the differences in the model with the old composition GN93 is small (∼0.5)). In the testing models with a different TKF imposed, it is found that the density profile is sensitive to the value of TKF at the base of the convective envelope and insensitive to the structure of TKF in the convection zone. The required value of turbulent kinetic luminosity at the base is about –13% to – 19% L {sub ☉}. Comparing with the 3D simulations, this value is plausible. This study is for the solar convective envelope only. Evolutionary solar models with TKF are required to investigat the effects of TKF on the solar interior structure below the convection zone and the whole solar abundance problem, but the profile of the TKF in the overshoot region is necessary.

  8. Solar energy collection system

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K. (Inventor)

    1977-01-01

    An improved solar energy collection system, having enhanced energy collection and conversion capabilities, is delineated. The system is characterized by a plurality of receivers suspended above a heliostat field comprising a multiplicity of reflector surfaces, each being adapted to direct a concentrated beam of solar energy to illuminate a target surface for a given receiver. A magnitude of efficiency, suitable for effectively competing with systems employed in collecting and converting energy extracted from fossil fuels, is indicated.

  9. Radio Bursts as Diagnostics of Relative Abundances in Solar Particles

    NASA Astrophysics Data System (ADS)

    Cane, H. V.; Richardson, I. G.; von Rosenvinge, T. T.

    2008-05-01

    Based solely on the presence of associated low frequency type III radio bursts with specific characteristics, Cane et al. (2002) suggested that large solar energetic particle events are likely to include contributions from particles accelerated in the associated flares. Studies using ACE/SIS observations of O and Fe intensity-time profiles have supported this suggestion. Nevertheless, some researchers have argued that particles cannot be flare accelerated if the relative abundances differ from those in the small particle events that are widely accepted to be composed of flare particles. However, based on the radio data, the flare particles in large events are not released at the time of the flare soft X-ray onset but are delayed, either because they are accelerated later or released later. These changed conditions are expected to alter the relative abundances (electrons to protons, heavy to light ions) compared to those associated with small flares. From a comprehensive analysis of the characteristics of the coronal mass ejections (CMEs), flares and radio bursts (at metric and longer wavelengths) associated with the ~340 proton events at >25 MeV that occurred during solar cycle 23, we confirm earlier results (Cane et al. 1986) that the timing of the type III bursts is a reasonable discriminator for the relative abundances at the start of solar particle events. In contrast, the speeds of the associated CMEs do not discriminate events, nor does the presence of meter wavelength type II bursts. Cane, H. V., R. E. McGuire, and T. T. von Rosenvinge (1986), Two classes of solar energetic particle events associated with impulsive and long-duration soft X-ray flares, Astrophys. J., 301, 448. Cane, H. V., W. C. Erickson, and N. P. Prestage (2002), Solar flares, type III radio bursts, coronal mass ejections, and energetic particles, J. Geophys. Res., 107(A10), 1315, doi:10.1029/2001JA000320.

  10. Solar Renewable Energy. Teaching Unit.

    ERIC Educational Resources Information Center

    Buchanan, Marion; And Others

    This unit develops the concept of solar energy as a renewable resource. It includes: (1) an introductory section (developing understandings of photosynthesis and impact of solar energy); (2) information on solar energy use (including applications and geographic limitations of solar energy use); and (3) future considerations of solar energy…

  11. Solar Energy: Solar System Design Fundamentals.

    ERIC Educational Resources Information Center

    Knapp, Henry H., III

    This module on solar system design fundamentals is one of six in a series intended for use as supplements to currently available materials on solar energy and energy conservation. Together with the recommended texts and references (sources are identified), these modules provide an effective introduction to energy conservation and solar energy…

  12. Generating potassium abundance variations in the Solar Nebula

    NASA Astrophysics Data System (ADS)

    Hubbard, Alexander

    2016-08-01

    An intriguing aspect of chondritic meteorites is that they are complementary: while their separate components have wildly varying abundances, bulk chondrites have nearly solar composition. This implies that the nearly solar reservoirs in which chondrites were born were in turn assembled from sub-reservoirs of differing compositions that birthed the different components. We focus on explaining the potassium abundance variations between chondrules even within a single chondrite, while maintaining the observed CI 41K to 39K ratios. This requires physically separating potassium and chondrules while the temperature is high enough for K to be in the gas phase. We examine several mechanisms which could drive the dust through gas and show that to do so locally would have required long (sub-orbital to many orbits) time scales; with shortest potassium depletion time-scales occurring in a scenario where chondrules formed high above the mid-plane and settled out of the evaporated potassium. While orbital time-scales are at odds with laboratory chondrule cooling rate estimates, any other model for the origin for the potassium abundance variation has to wrestle with the severe logistical difficulty of generating a plethora of correlated reservoirs which varied strongly in their potassium abundances, but not in their potassium isotope ratios.

  13. Elemental and isotopic abundances in the solar wind

    NASA Technical Reports Server (NTRS)

    Geiss, J.

    1972-01-01

    The use of collecting foils and lunar material to assay the isotopic composition of the solar wind is reviewed. Arguments are given to show that lunar surface correlated gases are likely to be most useful in studying the history of the solar wind, though the isotopic abundances are thought to give a good approximation to the solar wind composition. The results of the analysis of Surveyor material are also given. The conditions leading to a significant component of the interstellar gas entering the inner solar system are reviewed and suggestions made for experimental searches for this fraction. A critical discussion is given of the different ways in which the basic solar composition could be modified by fractionation taking place between the sun's surface and points of observation such as on the Moon or in interplanetary space. An extended review is made of the relation of isotopic and elemental composition of the interplanetary gas to the dynamic behavior of the solar corona, especially processes leading to fractionation. Lastly, connection is made between the subject of composition, nucleosynthesis and the convective zone of the sun, and processes leading to modification of initial accretion of certain gases on the Earth and Moon.

  14. Studies of chemical abundances in the outer solar system

    NASA Technical Reports Server (NTRS)

    Owen, T.

    1977-01-01

    Ground-based observations and the Pioneer 10 mission have led to new discoveries and revisions of previous ideas about the outer solar system. Among these are the discovery of atmospheres on lo and Ganymede, emission from sodium and hydrogen in a cloud around lo, and the presence of acetylene, ethane, and phosphine in the atmosphere of Jupiter. Titan, the largest satellite of Saturn, continues to be an extremely interesting and baffling object, clearly very different in composition from the bodies we are familiar with in the inner solar system; this is also true of Ganymede and Callisto. New data on the abundances of methane and hydrogen in the atmospheres of Uranus and Neptune suggest that the values of C/H in these atmospheres may be much lower than had been previously thought. This result reinforces the apparent compositional differences between these two planets and Jupiter and Saturn, whose atmospheres exhibit a near-solar value for this ratio.

  15. Studies of chemical abundances in the outer solar system

    NASA Technical Reports Server (NTRS)

    Owen, T.

    1974-01-01

    Ground-based observations and the Pioneer 10 mission have led to new discoveries and revisions of previous ideas about the outer solar system. Among these are the discovery of atmospheres on Io and Ganymede, emission from sodium and hydrogen in a cloud around Io, and the presence of acetylene, ethane, and phosphine in the atmosphere of Jupiter. Titan, the largest satellite of Saturn, continues to be an extremely interesting and baffling object, clearly very different in composition from the bodies familiar with in the inner solar system - which is also true of Ganymede and Callisto. New data on the abundances of methane and hydrogen in the atmospheres of Uranus and Neptune suggest that the values of C/H in these atmospheres may be much lower than had been previously thought. This result reinforces the apparent compositional difference between these two planets and Jupiter and Saturn, whose atmospheres exhibit a near-solar value for this ratio.

  16. Element Abundances in High-temperature Solar Flare Plasma from MESSENGER SAX Observations

    NASA Astrophysics Data System (ADS)

    Dennis, Brian R.; Nittler, Larry R.; Phillips, Kenneth; Schwartz, Richard A.; Starr, Richard D.; Tolbert, Anne K

    2014-06-01

    X-ray spectral measurements of many solar flares made with the MESSENGER SAX instrument have been used to determine the abundances of Fe, Ca, Ar, S, and Si in the high temperature plasma. All available data from launch in 2004 to date have been used to obtain spectral fits to the SAX data from 2.3 to 8.5 keV for all time intervals with a detectable count rate in the Fe-line complex at 6.7 keV. For each time interval, OSPEX, our object-oriented IDL spectral analysis program, is used to obtain values of the emission measure, temperature distribution, and abundances that give the best-fit of the corresponding CHIANTI photon spectrum folded through the instrument response matrix to the measured count-rate spectrum above background. Distributions will be presented of element abundances for each flare and for all flares detected during each year of observations. Variations in measured abundances will be discussed as to whether they reflect real differences from the mean or differences due to statistical and/or systematic uncertainties. Comparisons will be made with abundance measurements made from other data sets, in particular by Phillips and Dennis (2012) using data from the Ramaty High Energy Solar Spectroscopic Imager (RHESSI), and by Warren et al. (2013) using data from the EUV Variability Experiment (EVE) on the Solar Dynamics Observatory (SDO).Phillips, K. J. H. and Dennis, B. R., “The Solar Flare Iron Abundance,” 2012, ApJ, 748, 52.Warren, H. “Measurements of Absolute Abundances in Solar Flares,” 2013, arXiv, 2013arXiv1310.4765W

  17. He abundance variations in the solar wind: Observations from Ulysses

    SciTech Connect

    Barraclough, B.L.; Feldman, W.C.; Gosling, J.T.; McComas, D.J.; Phillips, J.L.; Goldstein, B.E.

    1996-07-01

    The Ulysses mission is providing the first opportunity to observe variations in solar wind plasma parameters at heliographic latitudes far removed from the ecliptic plane. We present here an overview of the solar wind speed and the variability in helium abundance, [He], for the entire mission to date, data on [He] in six high-latitude coronal mass ejections (CMEs), and a superposed epoch analysis of [He] variations at the seven heliospheric current sheet (HCS) crossings made during the rapid-latitude-scan portion of the mission. The differences in the variability of the solar wind speed and [He] in high-latitude and equatorial regions are quite striking. Solar wind speed is generally low but highly variable near the solar equator, while at higher latitudes the average speed is quite high (average speed around 760 km/s) with little variability. [He] can vary over nearly two decades at low solar latitudes, while at high latitudes it varies only slightly around an average value of {approximately}4.3{percent}. In contrast to the high [He] that is often associated with CMEs observed near the ecliptic, none of the six high-speed CMEs encountered at high southern heliographic latitudes showed any significant variation in helium content from average values. Reasons for this difference between high and low latitude CME observations are not yet understood. A superposed epoch analysis of the [He] during all seven HCS crossings made as Ulysses passed from the southern to northern solar hemisphere shows the expected [He] minimum near the crossing and a broad ({plus_minus}3day) period of low [He] around the crossing time. We briefly discuss how our solar wind [He] observations may provide an accurate measure of the helium composition for all regions of the sun lying above the helium ionization zone. {copyright} {ital 1996 American Institute of Physics.}

  18. Solar energy collection system

    NASA Technical Reports Server (NTRS)

    Miller, C. G.; Stephens, J. B. (Inventor)

    1979-01-01

    A fixed, linear, ground-based primary reflector having an extended curved sawtooth-contoured surface covered with a metalized polymeric reflecting material, reflects solar energy to a movably supported collector that is kept at the concentrated line focus reflector primary. The primary reflector may be constructed by a process utilizing well known freeway paving machinery. The solar energy absorber is preferably a fluid transporting pipe. Efficient utilization leading to high temperatures from the reflected solar energy is obtained by cylindrical shaped secondary reflectors that direct off-angle energy to the absorber pipe. A seriatim arrangement of cylindrical secondary reflector stages and spot-forming reflector stages produces a high temperature solar energy collection system of greater efficiency.

  19. Nitrogen isotope abundances in the recent solar wind.

    PubMed

    Kim, J S; Kim, Y; Marti, K; Kerridge, J F

    1995-06-01

    Although lunar crystalline rocks are essentially devoid of nitrogen, the same is not true of the lunar regolith. The nitrogen contents of individual regolith samples (which can be as high as 0.012% by mass) correlate strongly with abundances of noble gases known to be implanted in the lunar surface by solar radiation, indicating that lunar regolith nitrogen is also predominantly of solar origin. The large variability in 15N/14N ratios measured in different regolith samples may thus reflect long-term changes in the isotopic composition of the solar radiation. But attempts to explain these variations have been hampered by the lack of any firm constraint on 15N/14N in the present solar wind. Here we report measurements of nitrogen isotopes from two lunar samples that have had simple (and relatively recent) exposure histories. We find that nitrogen implanted in the lunar surface during the past 10(5) to 5 x 10(7) years has a 15N/14N ratio approximately 40% higher than that in the terrestrial atmosphere, which is substantially lower than most previous estimates. This isotopic signature probably represents the best measure of 15N/14N in the present-day solar wind.

  20. The Solar Energy Notebook.

    ERIC Educational Resources Information Center

    Rankins, William H., III; Wilson, David A.

    This publication is a handbook for the do-it-yourselfer or anyone else interested in solar space and water heating. Described are methods for calculating sun angles, available energy, heating requirements, and solar heat storage. Also described are collector and system designs with mention of some design problems to avoid. Climatological data for…

  1. Curriculum Reviews: Solar Energy.

    ERIC Educational Resources Information Center

    Riley, Joseph P.

    1982-01-01

    Reviews Solar Energy Education Project (SEEP), a set of 10 curriculum guides emphasizing process skills as well as content for grades K-9. Solar concepts are taught almost exclusively through process activities and, although developed in Australia, the curriculum is easily adaptable to American classrooms. (Author/JN)

  2. Solar Energy Project: Text.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    The text is a compilation of background information which should be useful to teachers wishing to obtain some technical information on solar technology. Twenty sections are included which deal with topics ranging from discussion of the sun's composition to the legal implications of using solar energy. The text is intended to provide useful…

  3. Solar Energy Project: Reader.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This document is designed to give both teachers and students the opportunity to review a variety of representative articles on solar energy. Consideration is given to the sun's role in man's past, present, and future. The present state of solar technology is examined theoretically, economically, and comparatively in light of growing need for…

  4. Solar Energy Systems

    NASA Technical Reports Server (NTRS)

    1981-01-01

    A waste water treatment plant in Wilton, Maine, where sludge is converted to methane gas, and Monsanto Company's Environmental Health Laboratory in St. Louis Missouri, where more than 200 solar collectors provide preheating of boiler feed water for laboratory use are representative of Grumman's Sunstream line of solar energy equipment. This equipment was developed with technology from NASA's Apollo lunar module program.

  5. Empirical Solar Abundance Scaling Laws of Supernova {gamma} Process Isotopes

    SciTech Connect

    Hayakawa, Takehito; Iwamoto, Nobuyuki; Kajino, Toshitaka; Shizum, Toshiyuki; Umeda, Hideyuki; Nomoto, Ken'Ichi

    2008-11-11

    Analyzing the solar system abundances, we have found two empirical abundance scaling laws concerning the p- and s-nuclei with the same atomic number. They are evidence that the 27 p-nuclei are synthesized by the supernova {gamma}-process. The scalings lead to a novel concept of 'universality of {gamma}-process' that the s/p and p/p ratios of nuclei produced by individual {gamma}-processes are almost constant, respectively. We have calculated the ratios of materials produced by the {gamma}-process based on core-collapse supernova explosion models under various astrophysical conditions and found that the scalings hold for individual {gamma}-processes independent of the conditions assumed. The results further suggest an extended universality that the s/p ratios in the {gamma}-process layers are not only constant but also centered on a specific value of 3. With this specific value and the scaling of the s/p ratios, we estimate that the ratios of the s-process abundance contributions from the AGB stars to the massive stars are almost 6.7 for the s-nuclei of A>90 in the solar system.

  6. Solar thermal energy receiver

    NASA Technical Reports Server (NTRS)

    Baker, Karl W. (Inventor); Dustin, Miles O. (Inventor)

    1992-01-01

    A plurality of heat pipes in a shell receive concentrated solar energy and transfer the energy to a heat activated system. To provide for even distribution of the energy despite uneven impingement of solar energy on the heat pipes, absence of solar energy at times, or failure of one or more of the heat pipes, energy storage means are disposed on the heat pipes which extend through a heat pipe thermal coupling means into the heat activated device. To enhance energy transfer to the heat activated device, the heat pipe coupling cavity means may be provided with extensions into the device. For use with a Stirling engine having passages for working gas, heat transfer members may be positioned to contact the gas and the heat pipes. The shell may be divided into sections by transverse walls. To prevent cavity working fluid from collecting in the extensions, a porous body is positioned in the cavity.

  7. Energy 101: Solar PV

    SciTech Connect

    2011-01-01

    Solar photovoltaic (PV) systems can generate clean, cost-effective power anywhere the sun shines. This video shows how a PV panel converts the energy of the sun into renewable electricity to power homes and businesses.

  8. Energy 101: Solar PV

    ScienceCinema

    None

    2016-07-12

    Solar photovoltaic (PV) systems can generate clean, cost-effective power anywhere the sun shines. This video shows how a PV panel converts the energy of the sun into renewable electricity to power homes and businesses.

  9. Development of Earth-Abundant and Non-Toxic Thin-Film Solar Cells

    NASA Astrophysics Data System (ADS)

    Park, Helen Hejin

    Although solar energy is the most abundant energy resource available, photovoltaic solar cells must consist of sufficiently abundant and environmentally friendly elements, for scalable low-cost production to provide a major amount of the world's energy supply. However, scalability is limited in current thin-film solar cell technologies based on Cu(In,Ga)(S,Se)2 and CdTe due to scarce, expensive, and toxic elements. Thin-film solar cells consisting of earth-abundant and non-toxic materials were made from pulsed chemical vapor deposition (pulsed-CVD) of SnS as the p-type absorber layer and atomic layer deposition (ALD) of Zn(O,S) as the n-type buffer layer. Solar cells with a structure of Mo/SnS/Zn(O,S)/ZnO/ITO were studied by varying the synthesis conditions of the SnS and Zn(O,S) layers. Annealing SnS in hydrogen sulfide increased the mobility by more than one order of magnitude, and improved the power conversion efficiency of the solar cell devices. Solar cell performance can be further optimized by adjusting the stoichiometry of Zn(O,S), and by tuning the electrical properties of Zn(O,S) through various in situ or post-annealing treatments. Zn(O,S) can be post-annealed in oxygen atmosphere or doped with nitrogen, by ammonium hydroxide or ammonia gas, during the ALD growth to reduce the carrier concentration, which can be critical for reducing interface recombination at the p-n junction. High carrier concentration buffer layers can be critical for reducing contact resistance with the ITO layer. Zn(O,S) can also be incorporated with aluminum by trimethylaluminum (TMA) doses to either increase or decrease the carrier concentration based on the stoichiometry of Zn(O,S).

  10. Solar Energy Reporting

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Last year the people of Cleveland, Ohio were troubled by natural gas shortages during one of the coldest winters on record. The severe winter generated a great deal of interest in solar energy as an alternative source of heat. Home owners, home builders and civic officials wanted to know just how much solar energy is available in Cleveland. Now they get a daily report through the city's news media, from information supplied as a community service by NASA's Lewis Research Center. Lewis routinely makes daily measurements of solar energy as part of its continuing research in behalf of the Department of Energy. The measuring device is a sun sensor called a pyranometer (upper photo) located atop a building at the NASA Center. To make the information conveniently available to news media, Lewis developed a Voice Output Integrating Insolometer, an automated system that acquires information from the sun sensor and translates it into a recorded telephone message. The Lewis pyranometer collects sun data for 15 hours daily and measures the total solar energy yield. For reporting to the public, the information is electronically converted to a specific reading. A media representative calling in gets a voice-synthesized announcement of a two or three digit number; the number corresponds to the kilowatt-hours of solar energy that would be available to a typical 500-square-foot solar collector system. Response in Cleveland has been favorable and interest is developing in other parts of the country.

  11. Coronal Abundance Anomalies in Solar-Like Stars

    NASA Astrophysics Data System (ADS)

    Laming, John

    We propose to model the trend of coronal abundance anomalies observed in a sample of solar-like stars by Wood & Linsky (2010). Dwarf stars of similar spectral type to the Sun show what has become known as a FIP (First Ionization Potential) Effect, where elements with first ionization potential below about 10 eV are enhanced in abundance in the corona by a factor of about 3 - 4. Stars of later spectral type show a diminished FIP effect, with the anomaly disappearing at about K5 spectral type. Beyond this, M dwarf stars show an inverse FIP effect, with the low FIP ions becoming depleted in the stellar corona, by factors of order 2.5 - 3. The solar case of positive FIP effect has been successfully interpreted as being due to the action of the ponderomotive force associated with chromospheric Alfven waves. In conditions in which upgoing Alfven waves are transmitted into coronal loops, or in which coronally generated waves reflect at loop footpoints, the ponderomotive force is directed upwards, and accelerates chromospheric ions (the low FIP elements) into the corona. Neutral atoms are not affected. The inverse FIP effect can arise when upward propagating chromospheric Alfven waves are reflected back down again at coronal loop footpoints, due to a mismatch between the wave frequency and the loop resonance. We propose to study stars for which parameters like asteroseismic oscillation frequencies, coronal abundance anomalies, and chromospheric structure are known. As well as constraining coronal magnetic fields and loop resonances in these stars, we expect important insights into the nature of stellar dynamos since the M dwarfs in the sample (with inverse FIP effect) are at or near the fully convective limit. Finally, we will be able to assess potential fractionation in the O/Ne abundance ratio. Drake & Testa (2005) argued that Ne is depleted in the solar corona relative to O, but not in the coronae of more active stars. Our FIP models provide some support for this in the

  12. The abundance of titanium in the solar photosphere

    NASA Astrophysics Data System (ADS)

    Gurtovenko, E. A.; Fedorchenko, G. L.; Sheminova, V. A.

    The abundance of titanium in the solar photosphere is determined from equivalent widths of 38 weak Fraunhofer lines of TiI. The oscillator strengths scale of Kurucz and Peytremann (1975) is used to obtain log(NTi/NH), + 12 = 4.95 + or - 0.05. The results are compared to other recent investigations, from which it is concluded that the oscillator strength system of Kurucz and Peytremann presents significant systematic errors, and must therefore be studied in detail, using a large number of lines for a wide range of equivalent widths.

  13. Bright Idea: Solar Energy Primer.

    ERIC Educational Resources Information Center

    Missouri State Dept. of Natural Resources, Jefferson City.

    This booklet is intended to address questions most frequently asked about solar energy. It provides basic information and a starting point for prospective solar energy users. Information includes discussion of solar space heating, solar water heating, and solar greenhouses. (Author/RE)

  14. Early solar mass loss, opacity uncertainties, and the solar abundance problem

    SciTech Connect

    Guzik, Joyce Ann; Keady, John; Kilcrease, David

    2009-01-01

    Solar models calibrated with the new element abundance mixture of Asplund et al. published in 2005 no longer produce good agreement with the sound speed, convection zone depth, and convection zone helium abundance inferred from solar oscillation data. Attempts to modify the input physics of the standard model, for example, by including enhanced diffusion, increased opacities, accretion, convective overshoot, or gravity waves have not restored the good agreement attained with the prior abundances. Here we present new models including early mass loss via a stronger solar wind. Early mass loss has been investigated prior to the solar abundance problem to deplete lithium and resolve the 'faint early sun problem'. We find that mass loss modifies the core structure and deepens the convection zone, and so improves agreement with oscillation data using the new abundances: however the amount of mass loss must be small to avoid destroying all of the surface lithium, and agreement is not fully restored. We also considered the prospects for increasing solar interior opacities. In order to increase mixture opacities by the 30% required to mitigate the abundance problem, the opacities of individual elements (e.g., O, N, C, and Fe) must be revised by a factor of two to three for solar interior conditions: we are investigating the possibility of broader calculated line wings for bound-bound transitions at the relevant temperatures to enhance opacity. We find that including all of the elements in the AGS05 opacity mixture (through uranium at atomic number Z=92) instead of only the 17 elements in the OPAL opacity mixture increases opacities by a negligible 0.2%.

  15. The Energy Crisis and Solar Energy

    ERIC Educational Resources Information Center

    Bockris, J. O'M.

    1974-01-01

    Examines the status of the energy crisis in Australia. Outlines energy alternatives for the 1990's and describes the present status of solar energy research and the economics of solar energy systems. (GS)

  16. Solar Energy Project, Activities: General Solar Topics.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of activities which introduce students to concepts and issues relating to solar energy. Lessons frequently presented in the context of solar energy as it relates to contemporary energy problems. Each unit presents an introduction; objectives; necessary skills and knowledge; materials; method;…

  17. Solar Flare Abundances of Potassium, Argon, and Sulphur

    NASA Technical Reports Server (NTRS)

    Oegerle, William (Technical Monitor); Phillips, K. J. H.; Sylwester, J.; Sylwester, B.; Landi, E.

    2003-01-01

    The absolute coronal abundances of potassium has been determined for the first time from X-ray solar flare line and continuous spectra together with absolute and relative abundances of Ar and S. Potassium is of importance in the continuing debate concerning the nature of the coronal/photospheric element abundance ratios which are widely considered to depend on first ionization potential since it has the lowest FIP of any common element in the Sun. The measurements were obtained with the RESIK crystal spectrometer on the Coronas-F spacecraft. A differential emission measure DEM = const. x exp (-(beta)T(sub e) was found to be the most consistent with the data out of three models considered. We find that the coronal ratio [K/H] = 3.7 x 10(exp - 7), a factor 3 times photospheric, in agreement with other observations using line-to-line ratios. Our measured value for the coronal ratio [Ar/H] = 1.5 x 10(exp -6) is significantly less than photospheric, indicating that there is a slight depletion of this high-FIP element in the corona. For S (an intermediate-FIP element) we obtained [S/H] = 2.2 x 10(exp - 5), approximately the same as in previous work.

  18. Elemental abundances of flaring solar plasma - Enhanced neon and sulfur

    NASA Technical Reports Server (NTRS)

    Schmelz, J. T.

    1993-01-01

    Elemental abundances of two flares observed with the SMM Flat Crystal Spectrometer are compared and contrasted. The first had a gradual rise and a slow decay, while the second was much more impulsive. Simultaneous spectra of seven bright soft X-ray resonance lines provide information over a broad temperature range and are available throughout both flares, making these events unique in the SMM data base. For the first flare, the plasma seemed to be characterized by coronal abundances but, for the second, the plasma composition could not be coronal, photospheric, or a linear combination of both. A good differential emission measure fit required enhanced neon such that Ne/O = 0.32 +/- 0.02, a value which is inconsistent with the current models of coronal abundances based on the elemental first-ionization potential. Similar values of enhanced neon are found for flaring plasma observed by the SMM gamma-ray spectrometer, in (He-3)-rich solar energetic particle events, and in the decay phase of several long duration soft X-ray events. Sulfur is also enhanced in the impulsive flare, but not as dramatically as neon. These events are compared with two models which attempt to explain the enhanced values of neon and sulfur.

  19. Solar Energy Demonstrations

    NASA Technical Reports Server (NTRS)

    1979-01-01

    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.

  20. Energy from solar balloons

    SciTech Connect

    Grena, Roberto

    2010-04-15

    Solar balloons are hot air balloons in which the air is heated directly by the sun, by means of a black absorber. The lift force of a tethered solar balloon can be used to produce energy by activating a generator during the ascending motion of the balloon. The hot air is then discharged when the balloon reaches a predefined maximum height. A preliminary study is presented, along with an efficiency estimation and some considerations on possible realistic configurations. (author)

  1. Activities for Teaching Solar Energy.

    ERIC Educational Resources Information Center

    Mason, Jack Lee; Cantrell, Joseph S.

    1980-01-01

    Plans and activities are suggested for teaching elementary children about solar energy. Directions are included for constructing a flat plate collector and a solar oven. Activities for a solar field day are given. (SA)

  2. Classic papers in Solar Energy: Solar distillation

    SciTech Connect

    Howe, E.D.

    1990-06-01

    The following Classic Paper was presented by Professor Howe at the first international Conference on Solar Energy at Tucson, Arizona, USA in 1955. That conference was sponsored by the Association of Applied solar Energy (AFASE), the precursor of ISES. Although this paper does not represent the many developments in solar distillation later applied by Professor Howe in the South Pacific, it is a classic paper because it presents Professor Howe's pioneering work in setting up the Seawater Conversion Laboratory in Richmond for the University of California at Berkeley, US. The research of Professor Howe and his colleagues at the Seawater Conversion Laboratory formed the foundation of contemporary solar energy desalination and distillation systems.

  3. SOLAR CYCLE ABUNDANCE VARIATIONS IN COROTATING INTERACTION REGIONS: EVIDENCE FOR A SUPRATHERMAL ION SEED POPULATION

    SciTech Connect

    Mason, G. M.; Desai, M. I.; Li, G.

    2012-04-01

    We have surveyed the heavy ion composition of corotating interaction regions (CIRs) over the recent solar minimum and combined this with our earlier survey to cover the 1998-2011 period encompassing a full solar cycle and onset of the new cycle. We find that the solar minimum CIR intensities and spectral forms are similar to those in active periods, indicating that the basic acceleration mechanism does not vary with solar activity for energies below a few MeV nucleon{sup -1}. However, the heavy ion abundances show a clear correlation with sunspot number, where heavy ions are more enhanced during active periods. Over the mass range He-Fe, the enhancement is organized by a power law in Q/M with exponent -1.9, with Fe/O varying by a factor of {approx}6. During solar minimum CIR Fe/O was {approx}0.05, well below the corresponding solar wind ratio. Previous studies have shown that rare ions (He{sup +}, {sup 3}He) enhanced in CIRs come from the suprathermal ion pool. The observations presented here extend this evidence, indicating that in addition to rare He{sup +} and {sup 3}He the CIR major heavy ion species are accelerated out of the suprathermal ion pool, not the bulk solar wind.

  4. Solar Energy Now.

    ERIC Educational Resources Information Center

    Rose, Harvey, Ed.

    Twenty articles addressing different aspects of solar energy are compiled in this book. They represent the views of different governmental and non-governmental organizations, members of congress, and other individuals including, for example, Barry Commoner and Amory Lovins. Topics discussed include the need for federal support, passive solar…

  5. Solar Photovoltaic Energy.

    ERIC Educational Resources Information Center

    Ehrenreich, Henry; Martin, John H.

    1979-01-01

    The goals of solar photovoltaic technology in contributing to America's future energy needs are presented in this study conducted by the American Physical Society. Although the time needed for photovoltaics to become popular is several decades away, according to the author, short-range applications are given. (Author/SA)

  6. Solar energy research and utilization

    NASA Technical Reports Server (NTRS)

    Cherry, W. R.

    1974-01-01

    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.

  7. Purdue Solar Energy Utilization Laboratory

    SciTech Connect

    Agrawal, Rakesh

    2014-01-21

    The objective of this project is to establish and set-up a laboratory that will facilitate research and development of new low-cost and high-efficiency solar energy utilization technologies at Purdue University. The outcome will help spur the creation of solar energy start-up companies and eventually a solar energy industry in Indiana that can help fulfill the growing national demand for solar energy.

  8. Central solar energy receiver

    DOEpatents

    Drost, M. Kevin

    1983-01-01

    An improved tower-mounted central solar energy receiver for heating air drawn through the receiver by an induced draft fan. A number of vertically oriented, energy absorbing, fin-shaped slats are radially arranged in a number of concentric cylindrical arrays on top of the tower coaxially surrounding a pipe having air holes through which the fan draws air which is heated by the slats which receive the solar radiation from a heliostat field. A number of vertically oriented and wedge-shaped columns are radially arranged in a number of concentric cylindrical clusters surrounding the slat arrays. The columns have two mirror-reflecting sides to reflect radiation into the slat arrays and one energy absorbing side to reduce reradiation and reflection from the slat arrays.

  9. Catalysis in solar energy

    NASA Astrophysics Data System (ADS)

    Maugh, T. H., II

    1983-09-01

    The progress of technologies to convert solar energy into useful work is reviewed, with particular attention given to the functional principles of solar cells and photoelectrochemical cells. The current in a solar cell is completely electronic, while in a photoelectric cell (PC) the current is partially ionic, i.e., the electrical contact between electrodes is accomplished chemically. The PC can be activated by photons to perform photoassisted electrolysis in the presence of an external potential, thus producing hydrogen fuel. Various materials are under study as photoanodes, with layered metal dichalcogenide semiconductors the best performers so far. The chalcogenides include MoS2, WS2, MoSe2, and WSe2, which could be applied to photochemical synthesis of redox products. Employment of Pt or Rh on the electrode surface has increased H2 production efficiency to 13.3 percent.

  10. Solar energy applications in the tropics

    SciTech Connect

    Lim, B.B.

    1983-01-01

    This book presents the papers given at a seminar on the use of solar energy in tropical regions. Topics considered at the seminar included solar decision making, solar radiation measurement, solar air conditioning, solar refrigeration, solar collectors, solar water heaters, photovoltaics, solar architecture, solar heating systems, research programs, solar drying, and performance testing.

  11. The Solar Photospheric Oxygen Abundance and the Role of 3D Model Atmospheres

    NASA Astrophysics Data System (ADS)

    Caffau, E.; Steffen, M.; Ludwig, H.-G.

    2008-09-01

    The solar oxygen abundance has undergone a major downward revision in the last decade, reputedly as a result of employing 3D hydrodynamical simulations to model the inhomogeneous structure of the solar photosphere. The very low oxygen abundance advocated by Asplund et al. 2004, A(O)=8.66, together with the downward revision of the abundances of other key elements, has created serious problems for solar models to explain the helioseismic measurements. In an effort to contribute to the dispute of whether the Sun has "solar" or "sub-solar" abundances, we have re-derived its photospheric abundance of oxygen, nitrogen, and other elements, independently of previous analyses. We applied a state-of-the art 3D (CO5BOLD) hydrodynamical simulation of the solar granulation as well as different 1D model atmospheres for the line by line spectroscopic abundance determinations. The analysis is based on both standard disk-center and full-disk spectral atlases; for oxygen we acquired in addition spectra at different heliocentric angles. The derived abundances are the result of equivalent width and/or line profile fitting of the available atomic lines. Our recommended oxygen abundance is A(O)=8.76+- 0.07, 0.1 dex higher than the value of Asplund et al. (2004). Our current estimate of the overall solar metallicity is 0.014< Z<0.016. Questions we discuss include: (i) Is the general downward revision of the solar abundances a 3D effect? (ii) How large are the abundance corrections due to horizontal inhomogeneities? (iii) What is the main reason for the differences between the abundances obtained in our study and those derived by Apslund and coworkers? (iv) How large are the uncertainties in the observed solar spectra? (v) What is the reason why the two forbidden oxygen lines, [OI] lambda 630 nm and [OI] lambda 636.3 nm, give significantly different answers for the solar oxygen abundance?

  12. A mechanism for the abundance enhancements of heavy nuclei in solar flare particle events

    NASA Technical Reports Server (NTRS)

    Cartwright, B. G.; Mogro-Campero, A.

    1973-01-01

    A mechanism is proposed to account for the recently reported abundance enhancements of heavy nuclei in solar flares. The mechanism requires two acceleration stages for its operation: First, fully stripped ions are accelerated to suprathermal energies, and subsequently, a fraction of these ions are Fermi accelerated to higher energies. It is shown that because injection into Fermi acceleration is rigidity dependent and the ions may pick up electrons during transport to the Fermi acceleration region, an enhancement of the abundances of heavy nuclei can occur. The degree of the enhancement depends on a number of factors particular to each flare, so that the degree of enhancement may be variable from flare to flare, or may be a function of time within a given flare. In some flares, conditions may be such that no enhancement would be expected.

  13. Solar eclipse monitoring for solar energy applications

    NASA Astrophysics Data System (ADS)

    Reda, Ibrahim

    2015-04-01

    In recent years, the interest in using solar energy as a major contributor to renewable energy applications has increased, and the focus to optimize the use of electrical energy based on demand and resources from different locations has strengthened. This article includes a procedure for implementing an algorithm to calculate the Moon's zenith angle with uncertainty of ±0.001° and azimuth angle with uncertainty of ±0.003°. In conjunction with Solar Position Algorithm, the angular distance between the Sun and the Moon is used to develop a method to instantaneously monitor the partial or total solar eclipse occurrence for solar energy applications. This method can be used in many other applications for observers of the Sun and the Moon positions for applications limited to the stated uncertainty.

  14. SOLARES - A new hope for solar energy

    NASA Technical Reports Server (NTRS)

    Billman, K. W.; Gilbreath, W. P.; Bowen, S. W.

    1978-01-01

    A system of orbiting reflectors, SOLARES, has been studied as a possible means of reducing the diurnal variation and enhancing the average intensity of sunlight with a space system of minimum mass and complexity. The key impact that such a system makes on the economic viability of solar farming and other solar applications is demonstrated. The system is compatible with incremental implementation and continual expansion to meet the world's power needs. Key technology, environmental, and economic issues and payoffs are identified. SOLARES appears to be economically superior to other advanced, and even competitive with conventional, energy systems and could be scaled to completely abate our fossil fuel usage for power generation. Development of the terrestrial solar conversion technique, optimized for this new artificial source of solar radiation, yet remains.

  15. Cylindrical solar energy collector

    SciTech Connect

    Kelton, W.G.

    1981-10-27

    A solar energy collector for utilizing the energy of the sun to heat a working fluid is described. The collector comprises a core conduit having a working fluid inlet end and a closure fit across the other end. A single return conduit is spirally wound upon the exterior surface of the core conduit, wherein the windings are in close lateral juxtaposition but with the return conduit and the core conduit both exposed to direct impingement of solar rays. A transparent tube coaxially surrounds the core conduit. Annular members are positioned at each end of the transparent tube to maintain the spatial relationship of the members and form an annular air insulation zone around the core conduit and return conduit.

  16. Solar energy: Technology and applications

    NASA Technical Reports Server (NTRS)

    Williams, J. R.

    1974-01-01

    It is pointed out that in 1970 the total energy consumed in the U.S. was equal to the energy of sunlight received by only 0.15% of the land area of the continental U.S. The utilization of solar energy might, therefore, provide an approach for solving the energy crisis produced by the consumption of irreplaceable fossil fuels at a steadily increasing rate. Questions regarding the availability of solar energy are discussed along with the design of solar energy collectors and various approaches for heating houses and buildings by utilizing solar radiation. Other subjects considered are related to the heating of water partly or entirely with solar energy, the design of air conditioning systems based on the use of solar energy, electric power generation by a solar thermal and a photovoltaic approach, solar total energy systems, industrial and agricultural applications of solar energy, solar stills, the utilization of ocean thermal power, power systems based on the use of wind, and solar-energy power systems making use of geosynchronous power plants.

  17. A COMPARISON OF ELEMENTAL ABUNDANCE RATIOS IN SEP EVENTS IN FAST AND SLOW SOLAR WIND REGIONS

    SciTech Connect

    Kahler, S. W.; Tylka, A. J.; Reames, D. V.

    2009-08-10

    The solar energetic (E > 1 MeV nucleon{sup -1}) particles (SEPs) observed in gradual events at 1 AU are assumed to be accelerated by coronal/interplanetary shocks from ambient thermal or suprathermal seed particles. If so, then the elemental abundances of SEPs produced in different solar wind (SW) stream types (transient, fast, and slow) might be systematically distinguished from each other. We look for these differences in SEP energy spectra and in elemental abundance ratios (including Mg/Ne and Fe/C, which compare low/high first ionization potential elements), in a large number of SEP time intervals over the past solar cycle. The SW regions are characterized by the three-component stream classification of Richardson et al. Our survey shows no significant compositional or energy spectral differences in the 5-10 MeV nucleon{sup -1} range for SEP events of different SW stream types. This result extends the earlier finding that SEP events are observed frequently in fast SW streams, although their higher Alfven and SW flow speeds should constrain SEP production by coronal mass ejection-driven shocks in those regions. We discuss the implications of our results for shock seed populations and cross-field propagation.

  18. The abundances of hydrogen, helium, oxygen, and iron accelerated in large solar particle events

    NASA Technical Reports Server (NTRS)

    Mazur, J. E.; Mason, G. M.; Klecker, B.; Mcguire, R. E.

    1993-01-01

    Energy spectra measured in 10 large flares with the University of Maryland/Max-Planck-Institut sensors on ISEE I and Goddard Space Flight Center sensors on IMP 8 allowed us to determine the average H, He, O, and Fe abundances as functions of energy in the range of about 0.3-80 MeV/nucleon. Model fits to the spectra of individual events using the predictions of a steady state stochastic acceleration model with rigidity-dependent diffusion provided a means of interpolating small portions of the energy spectra not measured with the instrumentation. Particles with larger mass-to-charge ratios were relatively less abundant at higher energies in the flare-averaged composition. The Fe/O enhancement at low SEP energies was less than the Fe/O ratios observed in He-3-rich flares. Unlike the SEP composition averaged above 5 MeV/nucleon, the average SEP abundances above 0.3 MeV/nucleon were similar to the average solar wind.

  19. Abundances and charge states in quiet-time low-energy ion fluxes at 1 AU

    NASA Astrophysics Data System (ADS)

    Kecskemety, Karoly; Zeldovich, Mariya; Klecker, Berndt; Logachev, Yurii

    Abundances of C and Fe ions with energies 0.04-1.28 MeV/nuc in the 23rd solar activity cycle are examined in the quiet-time fluxes using ACE, SOHO and STEREO data. They are com-bined with charge state measurement data from SEPICA (ACE, 0.18-0.43 MeV/nuc). Quiet periods of solar activity were selected using the criteria a) Jp < 2x10-4 protons/(cm2 s sr MeV) for 4-8 MeV protons (from EPHIN/SOHO) and b) the ratio H/He < 10 at these energies. The values of C/O and Fe/O were determined over the solar cycle and the following was found. In about 50% of the time intervals during high activity they both were near the average values observed in the solar corona, whereas at solar minimum in more than 90% of the periods the ratios were around the solar wind values. Most of the quiet time periods around maximum, which have sufficient statistics show high average Fe charge states (>15), consistent with im-pulsive solar event origin. During the SC minima the abundances in almost all cases correspond to solar wind values. The results obtained suggest that the active structures on the Sun arising at low solar activity are mostly responsible for background particle fluxes at these energies. There may be microflares, disappearing of ribbons, soft X-ray bright points etc.

  20. Solar Wind C, N, and O Abundances and the Solar Metallicity

    NASA Astrophysics Data System (ADS)

    von Steiger, R.; Zurbuchen, T.; Shearer, P.; Gilbert, J. A.

    2014-12-01

    ., ApJ, 2014) contribute 96% of the solar metallicity, we find that the solar wind metallicity is significantly higher than the recent compilation of spectroscopic abundances (Asplund et al., ARAA, 2009). It is more in line with earlier spectroscopic results and, more importantly, not incompatible with helioseismology results of the solar interior.

  1. Energy 101: Concentrating Solar Power

    ScienceCinema

    None

    2016-07-12

    From towers to dishes to linear mirrors to troughs, concentrating solar power (CSP) technologies reflect and collect solar heat to generate electricity. A single CSP plant can generate enough power for about 90,000 homes. This video explains what CSP is, how it works, and how systems like parabolic troughs produce renewable power. For more information on the Office of Energy Efficiency and Renewable Energy's CSP research, see the Solar Energy Technology Program's Concentrating Solar Power Web page at http://www1.eere.energy.gov/solar/csp_program.html.

  2. Energy 101: Concentrating Solar Power

    SciTech Connect

    2010-01-01

    From towers to dishes to linear mirrors to troughs, concentrating solar power (CSP) technologies reflect and collect solar heat to generate electricity. A single CSP plant can generate enough power for about 90,000 homes. This video explains what CSP is, how it works, and how systems like parabolic troughs produce renewable power. For more information on the Office of Energy Efficiency and Renewable Energy's CSP research, see the Solar Energy Technology Program's Concentrating Solar Power Web page at http://www1.eere.energy.gov/solar/csp_program.html.

  3. Quiet-Time Spectra and Abundances of Energetic Particles During the 1996 Solar Minimum

    NASA Technical Reports Server (NTRS)

    Reames, Donald V.

    1999-01-01

    We report the energy spectra and abundances of ions with atomic number, Z, in the interval Z is greater than or equal to 2 and Z is less than or equal to 36 and energies approximately 3-20 MeV/amu for solar and interplanetary quiet periods between 1994 November and 1998 April as measured by the large-geometry Low Energy Matrix Telescope (LEMT) telescope on the Wind spacecraft near Earth. The energy spectra show the presence of galactic (GCR) and "anomalous" cosmic ray (ACR) components, depending on the element. ACR components are reported for Mg and Si for the first time at 1 AU and the previous observation of S and Ar is confirmed. However, only GCR components are clearly apparent for the elements Ca, Ti, Cr, Fe, as well as for C. New limits are placed on a possible ACR contribution for other elements, including Kr.

  4. Solar Cells from Earth-Abundant Semiconductors with Plasmon-Enhanced Light Absorption

    SciTech Connect

    Atwater, Harry

    2012-04-30

    Progress is reported in these areas: Plasmonic Light Trapping in Thin Film a-Si Solar Cells; Plasmonic Light Trapping in Thin InGaN Quantum Well Solar Cells; and Earth Abundant Cu{sub 2}O and Zn{sub 3}P{sub 2} Solar Cells.

  5. Solar energy receiver

    DOEpatents

    Schwartz, Jacob

    1978-01-01

    An improved long-life design for solar energy receivers provides for greatly reduced thermally induced stress and permits the utilization of less expensive heat exchanger materials while maintaining receiver efficiencies in excess of 85% without undue expenditure of energy to circulate the working fluid. In one embodiment, the flow index for the receiver is first set as close as practical to a value such that the Graetz number yields the optimal heat transfer coefficient per unit of pumping energy, in this case, 6. The convective index for the receiver is then set as closely as practical to two times the flow index so as to obtain optimal efficiency per unit mass of material.

  6. ELEMENTAL ABUNDANCES IN THE FAST SOLAR WIND EMANATING FROM CHROMOSPHERIC FUNNELS

    SciTech Connect

    Pucci, Stefano; Lie-Svendsen, Oeystein; Esser, Ruth E-mail: Oystein.Lie-Svendsen@ffi.n

    2010-02-01

    We carry out a model study to determine whether a funnel-type flow geometry in the solar wind source region leads to sufficiently fast hydrogen flow to offset heavy element gravitational settling and can thus explain why solar wind abundances are not much smaller than photospheric abundances. We find that high first ionization potential (FIP) elements are more susceptible to gravitational settling than low-FIP elements, which are pulled up by Coulomb drag from protons, and hence the settling is more sensitive to the charge state of the elements than to their mass. Abundances at the top of the chromosphere, and hence solar wind abundances, can change by many orders of magnitude when the funnel areal expansion factor is changed by a small amount. The observed solar wind neon abundance provides the most severe constraint on the expansion, requiring a total flux tube expansion factor of at least 30-40.

  7. THE HELIUM ABUNDANCE IN POLAR CORONAL HOLES AND THE FAST SOLAR WIND

    SciTech Connect

    Byhring, H. S.

    2011-09-10

    I have studied the helium abundance in polar coronal holes and the fast solar wind using a time-dependent numerical model for the hydrogen-helium solar wind that spans the mid-to-upper chromosphere, transition region, corona, and solar wind. The model calculates the particle density, flow velocity, parallel and perpendicular temperature, and heat flux for all particle species simultaneously. The focus is on (1) the coronal/solar wind helium abundance as a function of the total magnetic field expansion and (2) the coronal abundance enhancements resulting from low helium heating rates. It is shown that the magnetic field expansion factor may be important in the determination of the solar wind helium abundance and that this can be understood in terms of gravitational settling in the chromosphere. I find that a total magnetic field expansion factor of about 20 is consistent with the observed helium abundance in the solar wind. Furthermore, it is demonstrated that existing observations, both spectroscopic observations of the corona and in situ observations in the solar wind, are compatible with helium abundance enhancements in the corona. For proton-electron plasma properties in accordance with observations, the coronal helium abundance enhancements occur in the region 1.2-2 R{sub sun}.

  8. Building interest in solar energy

    SciTech Connect

    1996-12-31

    Today`s solar technology and growing availability of energy-efficient mortgages offer advantages to home builders around the country. This article describes the different types of solar technology as well as the financing incentives that reward buyers of energy-efficient homes. Inset information includes consumer survey results about consumer interest in buying homes with solar features, current extra expense, and future savings, established home energy rating programs, and individual state financial incentives.

  9. Solar energy for the hospital?

    PubMed

    1981-01-01

    You can't scrap your boiler and expect solar panels to provide steam for process and heating, but solar systems are cost-effective now for domestic hot water generation, according to a leading solar energy engineering/design/build firm.

  10. Support for solar energy collectors

    DOEpatents

    Cole, Corey; Ardell-Smith, Zachary; Ciasulli, John; Jensen, Soren

    2016-11-01

    A solar energy collection system can include support devices configured to accommodate misalignment of components during assembly. For example, the system can include piles fixed to the earth and an adjustable bearing assembly at the upper end of the pile. The adjustable bearing assembly can include at least one of a vertical adjustment device, a lateral adjustment device and an angular adjustment device. The solar energy collection system can also include a plurality of solar energy collection device pre-wired together and mounted to a support member so as to form modular units. The system can also include enhanced supports for wire trays extending between rows of solar energy collection devices.

  11. Quiet-Time Spectra and Abundances of Energetic Particles During the 1996 Solar Minimum

    NASA Technical Reports Server (NTRS)

    Reames, Donald V.

    1998-01-01

    This report concerns the energy spectra and abundances of ions with atomic number, Z, in the interval 2 greater than or equal to Z and Z less than or equal to 36 and energies approximately 3-20 MeV/amu for solar and interplanetary quiet periods between November 1994 and April 1998 as measured by the large-geometry LEMT telescope on the Wind spacecraft near Earth. The energy spectra show the presence of galactic (GCR) and 'anomalous' cosmic ray (ACR) components, depending on the element. ACR components are reported for Mg and Si for the first time at 1 AU and the previous observation of S and Ar is confirmed. However, only GCR components are clearly apparent for the elements Ca, Ti, Cr, Fe, as well as for C. New limits are placed on a possible ACR contribution for other elements, including Kr.

  12. Terrestrial solar thermionic energy conversion systems concept

    NASA Technical Reports Server (NTRS)

    Shimada, K.; Swerdling, M.

    1975-01-01

    Results obtained from studies of a (1) solar concentrator, (2) solar energy receiver - thermionic converter system, and (3) solar thermionic topping system are described. Peripheral subsystems, which are required for any solar energy conversion system, are also discussed.

  13. Solar Energy and the Western Asian Countries

    NASA Astrophysics Data System (ADS)

    De Morais Mendonca Teles, Antonio

    2016-07-01

    The Western Asian countries receive the most abundant solar radiation of the world. They also have enormous reserves of oil and natural gas. But the world reserves of those fuels will certainly diminish greatly as the worldwide demand for energy will increase steadily in the coming decades. And the suppliers of energy will have to contend with public concerns about the polluting effects of those fuels and the possible dangers of nuclear energy. Clearly a power source based on an non exhaustible and non-polluting fuel could be expected to find a role. It now appears that such a source is at hand in the solar energy. Here in this paper, under the principles in the United Nations' Agenda 21, we suggest to Western Asian countries, the study and own development of the following technologies based on solar energy; and comment about them: *photo-voltaic solar cell power plants - in the future, its cost per kilowatt-hour will probably be competitive as to other sources of electrical energy. A new technique, the solar non-imaging concentrator, with amorphous silicon-based thin films solar cells at the focus of the concentrators, can collect and intensify solar radiation far better than conventional concentrators do, thus reducing much more the cost; *bio-gas - using biological gas to produce energy and for heating/cooling purposes; *wind generation of electricity - it's nowadays, a non-expensive technique; *water pump for irrigation and human consuming, driving their power from photovoltaic cells; *and the study and own development of solar lasers for peaceful scientific studies. In this new kind of laser, the external necessary pumping energy comes from the high intensity of sunlight, produced with non-imaging concentrators. Solar lasers can give unexpected new great uses for mankind. Those achievements will require international cooperation and transfer of information, sustained research and development work, and some initial subsides by independent governments. Solar

  14. Hydrogen production from solar energy

    NASA Technical Reports Server (NTRS)

    Eisenstadt, M. M.; Cox, K. E.

    1975-01-01

    Three alternatives for hydrogen production from solar energy have been analyzed on both efficiency and economic grounds. The analysis shows that the alternative using solar energy followed by thermochemical decomposition of water to produce hydrogen is the optimum one. The other schemes considered were the direct conversion of solar energy to electricity by silicon cells and water electrolysis, and the use of solar energy to power a vapor cycle followed by electrical generation and electrolysis. The capital cost of hydrogen via the thermochemical alternative was estimated at $575/kW of hydrogen output or $3.15/million Btu. Although this cost appears high when compared with hydrogen from other primary energy sources or from fossil fuel, environmental and social costs which favor solar energy may prove this scheme feasible in the future.

  15. Creating abundance: America's least-cost energy strategy

    SciTech Connect

    Sant, R.W.; Bakker, D.W.; Naill, R.F.

    1984-01-01

    This book is a lengthy essay describing the American accomplishments in taming the energy problem, although still untapped opportunities are noted. Contents: The concept of energy services. Lowering the energy cost in industry. Alternatives to traditional fuels. Two abundant energy futures. Some myths about energy. Index.

  16. The isotopic and elemental abundances of neon nuclei accelerated in solar flares

    NASA Technical Reports Server (NTRS)

    Dietrich, W. F.; Simpson, J. A.

    1979-01-01

    The relative isotopic abundances of Ne-20 and Ne-22 in seven solar flares were determined from measurements of the satellite IMP 8, yielding the ratio Ne-20/Ne-22 = 7.7 (+2.3, -1.5) for solar chromospheric matter. This value is in agreement with the ratio for the component neon-A (the 'primordial' component) found in carbonaceous chondrites. An elemental abundance ratio Ne/O = 0.14 + or - 0.01 also has been obtained which agrees closely with earlier reported measurements. It is shown that the effects of preferential acceleration relative to solar-system abundances with increasing charge number observed for some solar flares - though biasing the elemental ratio - does not appear to influence the neon isotopic abundances.

  17. Solar Energy Project: Teacher's Guide.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This collection of materials supports the teaching of solar energy concepts in the context of secondary school science. Included in this collection are a basic teacher's guide to activities involved in the curriculum; a discussion of multi-disciplinary extensions of solar energy education by subject area; a section on hardware needed for the…

  18. Solar energy trap

    NASA Technical Reports Server (NTRS)

    Brantley, L. W., Jr. (Inventor)

    1976-01-01

    An apparatus is described for trapping solar energy for heating a fluid that could be subsequently used in turbines and similar devices. The apparatus includes an elongated vertical light pipe having an open end through which the visible spectrum of electromagnetic radiation from the sun passes to strike a tubular absorber. The light pipe has a coated interior surface of a low absorptivity and a high reflectivity at the visible wavelengths and a high absorptivity/emissivity ratio at infrared wavelengths. The tubular absorber has a coating on the surface for absorbing visible wavelengths to heat the fluid passing through. Infrared wave lengths are radiated from the tubular absorber back into the light pipe for heating fluid passing through a tubular coil wound around it.

  19. National Energy Act statutes and solar energy

    SciTech Connect

    Howard, J.

    1980-02-01

    The National Energy Act of 1978 contains many provisions that will significantly affect solar technology commercialization and solar energy users. Four of the five statutes that comprise the National Energy Act deserve close attention. The National Energy Conservation Policy Act will promote residential solar installations. The Energy Tax Act will accelerate both residential and commercial solar system applications. The Public Utilities Regulatory Policies Act promotes efficient use of utility resources as well as decentralized power production. And, the Power Plan and Industrial Fuel Use Act places severe restrictions on future burning of petroleum and natural gas, which should lead some operators to build or convert to solar energy systems. Each of the preceding acts are considered in separate sections of this report. Federal regulations issued pursuant to the various provisions are also identified and discussed, and some of the problems with the provisions and regulations are noted.

  20. Barium disilicides (BaSi2) a low-cost, earth-abundant material for thin-film solar cells

    NASA Astrophysics Data System (ADS)

    Kumar, Mukesh; Umezawa, Naoto; Imai, Motoharu

    2015-03-01

    In order to meet the clean energy requirement, materials consisting of abundant, eco-friendly, and low-cost elements are of great interest. Therefore in this study, we discussed the importance of BaSi2 and other similar semiconducting compounds which contain inexpensive and earth abundant elements, for solar cell applications. Employing first-principles modeling within the density function theory, we analyze the structural, electronic and optical properties and find that these compounds have fundamental indirect band gaps and the gap energies are in the region of 0.9-1.3 eV, which is suitable for solar cell applications. Furthermore, a lower energy dispersion of the conduction band (CB), which results in a flat shape of the CB minimum, implies a large optical absorption. In fact, our calculations reveal that the photoabsorption of these compounds is stronger than other common PV materials like Si and Cu(Ga,In)Se2.

  1. Chemical abundances of solar-type dwarfs in open clusters

    NASA Astrophysics Data System (ADS)

    Schuler, Simon C.

    Open clusters have proven continuously to be invaluable tools to the studies of stellar physics and Galactic evolution. Until recently, however, the chemical abundances of the populous and astrophysically important late-F, G, and K open cluster dwarfs have gone largely unanalyzed. In this thesis I report on the study of the chemical abundances derived from high-resolution, moderate-to-high signal-to-noise echelle spectra obtained with the 10-m Keck I, 9.2-m Hobby- Eberly, 8.2-m VLT, 4.0-m KPNO, 2.7-m Harlan J. Smith, and the 2.1-m Otto Struve telescopes of cool dwarfs in the Pleiades, Hyades, and M34 open clusters. The main result of the study is the identification of excitation-related abundance trends found among cool open cluster dwarfs ( T eff <= 5500 K), as well as an overionization of Fe- abundances derived from singly ionized lines are greater than those derived from neutral lines- among the cool Hyades dwarfs; the trends are such that abundances derived from high-excitation (h >= 4.0 eV) spectral lines and using atmospheric models assuming local thermodynamic equilibrium (LTE) increase with decreasing T eff . Particular attention is given to the high-excitation (h = 9.15 eV) near-IR ll7774 O I triplet, a line used often in the derivation of stellar O abundances and known to be susceptible to non-LTE (NLTE) effects. The O I triplet-based abundances show a dramatic increase with decreasing T eff in all three clusters, behavior that is in stark contrast to expectations from canonical NLTE calculations. Other elements with lines of various excitation potentials are also analyzed and are found to exhibit abundance trends that are qualitatively similar to those of the O I triplet. Possible explanations for the observed cool open cluster dwarf abundance anomalies are investigated, and photospheric surface temperature inhomogeneities possibly due to spots, faculae, and/or plages are found to be a plausible culprit. Indeed, multi-component LTE model atmospheres are

  2. Three energy variables predict ant abundance at a geographical scale.

    PubMed

    Kaspari, M; Alonso, L; O'Donnell, S

    2000-03-01

    Energy theory posits three processes that link local abundance of ectotherms to geographical gradients in temperature. A survey of 49 New World habitats found a two order of magnitude span in the abundance (nests m(-2)) of ground nesting ants (Formicidae). Abundance increased with net primary productivity (r2=0.55), a measure of the baseline supply of harvestable energy. Abundance further increased with mean temperature (r2=0.056), a constraint on foraging activity for this thermophilic taxon. Finally for a given mean temperature, ants were more abundant in seasonal sites with longer, colder winters (r2 = 0.082) that help ectotherm taxa sequester harvested energy in non-productive months. All three variables are currently changing on a global scale. All should be useful in predicting biotic responses to climate change.

  3. Li abundance in the stars with solar-type activity

    NASA Astrophysics Data System (ADS)

    Mishenina, T. V.; Soubiran, C.; Kovtyukh, V. V.; Katsova, M. M.; Livshits, M. A.

    Li abundances, atmospheric parameters and rotational velocities for 150 dwarfs have been determined from the high resolution, high signal to noise echelle spectra, obtained with the ELODIE spectrograph at the OHP (France). Among them, there are 101 stars with a determined level of activity, a large part of them being of the BY Dra type. The level of chromospheric and coronal activity of the targets has been evaluated through the logR'_HK index and X-ray flux. We examined the Li abundance behavior with T_eff, vsini and level of the activity. Some correlations between the Li abundances, level of the chromospheric activity and rotational velocities vsini are confirmed. The correlation between the Li abundances and index of the chromospheric activity logR'_HK was found, especially for dwarfs with 5700>T_eff> 5200 K. Those correlations mainly demonstrate that measurable values of the lithium content (higher than the upper limit) refer to the stars with large spot areas in their photospheres. Considering the wider set of stars with high activity levels one can affirm that such a conclusion is valid also for the cooler, earlier K dwarfs. Our results confirm that basic factors of formation of detectable Li abundance and high activity are determined principally by smaller age and fast axial rotation, respectively; and apparently by the depth of the convective zone.

  4. The relative abundances of the elements silicon through nickel in the low energy galactic cosmic rays

    NASA Technical Reports Server (NTRS)

    Garcia-Munoz, M.; Mason, G. M.; Simpson, J. A.

    1978-01-01

    Measurements of the relative abundances of the elements Si through Ni in galactic cosmic rays in the energy interval 72 to 450 MeV/nucleon are reported based on data collected by a cosmic-ray telescope on the IMP 8 satellite. The measured abundances are compared with propagation calculations using various distributions of path lengths. It is found that the measurements favor an exponential distribution of path lengths truncated at short path lengths. The source abundances of Si, Ca, Fe, and Ni derived by extrapolating the measured abundances back to the source are shown to be comparable to the solar-system abundances. The relevance of the measurements of Sc through Mn to the Mn-54 radioactive decay is examined.

  5. Oscillator strengths for Y I and Y II and the solar abundance of yttrium

    SciTech Connect

    Hannaford, P.; Lowe, R.M.; Grevesse, N.; Biemont, E.; Whaling, W.

    1982-10-15

    Oscillator strengths have been determined from measurements of radiative lifetimes and branching ratios for 154 lines of Y I and 66 lines of Y II. These data are used, together with equivalent widths measured on the Jungfraujoch solar atlas, to perform a new determination of the solar abundance of yttrium: A/sub Y/ = 2.24 +- 0.03.

  6. On krypton isotopic abundances in the sun and in the solar wind

    NASA Technical Reports Server (NTRS)

    Marti, K.

    1980-01-01

    The Kr isotopic systematics in the meteorite Pesyanoe which is known to contain solar-type gases, are reported. Discrepancies in the isotopic data of fractions released at stepwise increasing temperatures cannot be reconciled with spallation Kr components, although spallation effects are significant. Fractionation mechanisms on the parent body and in the solar wind source region are considered and the implications for solar abundances discussed.

  7. On the differences in element abundances of energetic ions from corotating events and from large solar events

    NASA Technical Reports Server (NTRS)

    Reames, D. V.; Richardson, I. G.; Barbier, L. M.

    1991-01-01

    The abundances of energetic ions accelerated from high-speed solar wind streams by shock waves formed at corotating interaction regions (CIRs) where high-speed streams overtake the lower-speed solar wind are examined. The observed element abundances appear to represent those of the high-speed solar wind, unmodified by the shock acceleration. These abundances, relative to those in the solar photosphere, are organized by the first ionization potential (FIP) of the ions in a way that is different from the FIP effect commonly used to describe differences between abundances in the solar photosphere and those in the solar corona, solar energetic particles (SEPs), and the low-speed solar wind. In contrast, the FIP effect of the ion abundances in the CIR events is characterized by a smaller amplitude of the differences between high-FIP and low-FIP ions and by elevated abundances of He, C, and S.

  8. The elemental abundances of hydrogen through nickel in the low energy cosmic rays

    NASA Technical Reports Server (NTRS)

    Garcia-Munoz, M.; Simpson, J. A.

    1980-01-01

    The relative abundances of the elements H through Ni in the galactic cosmic rays have been measured in the energy range 70-280 MeV/nucleon with the University of Chicago cosmic ray telescope on board the satellite IMP-8 from January 1973 to September 1978. Cosmic ray source abundances have been derived by extrapolating the measured composition back to the source. A key factor in the propagation calculation is the use of a pathlength distribution and a solar modulation level shown to be consistent with the secondary to primary ratios and their energy dependence below about 1 GeV/n.

  9. Assessment of solar and wind energy resources in Ethiopia. I. Solar energy

    SciTech Connect

    Drake, F.; Mulugetta, Y.

    1996-09-01

    This paper describes how data from a variety of sources are merged to present new countrywide maps of the solar energy distribution over Ethiopia. The spatial coverage of stations with radiation data was found to be unsatisfactory for the purpose of a countrywide solar energy assessment exercise. Therefore, radiation had to be predicted from sunshine hours by employing empirical models. Using data from seven stations in Ethiopia, linear and quadratic correlation relationships between monthly mean daily solar radiation and sunshine hours per day have been developed. These regional models show a distinct improvement over previously employed countrywide models. To produce a national solar-energy distribution profile, a spatial extension of the radiation/sunshine relationships had to be carried out. To do this, the intercepts(a) and slopes(b) of each of the seven linear regression equations and another six from previous studies, completed in neighbouring Sudan, Kenya and Yemen, were used to interpolate the corresponding values to areas between them. Subsequent to these procedures, 142 stations providing only sunshine data were assigned their `appropriate` a and b values to estimate the amount of solar radiation received, which was then used to produce annual and monthly solar radiation distribution maps for Ethiopia. The results show that in all regions solar energy is an abundant resource. 19 refs., 11 figs., 4 tabs.

  10. High flux solar energy transformation

    DOEpatents

    Winston, R.; Gleckman, P.L.; O'Gallagher, J.J.

    1991-04-09

    Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes. 7 figures.

  11. High flux solar energy transformation

    DOEpatents

    Winston, Roland; Gleckman, Philip L.; O'Gallagher, Joseph J.

    1991-04-09

    Disclosed are multi-stage systems for high flux transformation of solar energy allowing for uniform solar intensification by a factor of 60,000 suns or more. Preferred systems employ a focusing mirror as a primary concentrative device and a non-imaging concentrator as a secondary concentrative device with concentrative capacities of primary and secondary stages selected to provide for net solar flux intensification of greater than 2000 over 95 percent of the concentration area. Systems of the invention are readily applied as energy sources for laser pumping and in other photothermal energy utilization processes.

  12. The Geography of Solar Energy.

    ERIC Educational Resources Information Center

    LaHart, David E.; Allen, Rodney F.

    1984-01-01

    After learning about two promising techniques for generating electricity--photovoltaic cells and wind energy conversion systems--secondary students analyze two maps of the United States showing solar radiation and available wind power to determine which U.S. regions have potential for these solar electric systems. (RM)

  13. The Energy Impacts of Solar Heating.

    ERIC Educational Resources Information Center

    Whipple, Chris

    1980-01-01

    The energy required to build and install solar space- and water-heating equipment is compared to the energy saved under two solar growth paths corresponding to high and low rates of solar technology implementation. (Author/RE)

  14. Variations in Abundance Enhancements in Impulsive Solar Energetic-Particle Events and Related CMEs and Flares

    NASA Astrophysics Data System (ADS)

    Reames, Donald V.; Cliver, Edward W.; Kahler, Stephen W.

    2014-12-01

    We study event-to-event variations in the abundance enhancements of the elements He through Pb for Fe-rich impulsive solar energetic-particle (SEP) events, and their relationship with properties of associated coronal mass ejections (CMEs) and solar flares. Using a least-squares procedure we fit the power-law enhancement of element abundances as a function of their mass-to-charge ratio A/ Q to determine both the power and the coronal temperature (which determines Q) in each of 111 impulsive SEP events identified previously. Individual SEP events with the steepest element enhancements, e.g. ˜ ( A/ Q)6, tend to be smaller, lower-fluence events with steeper energy spectra that are associated with B- and C-class X-ray flares, with cooler (˜ 2.5 MK) coronal plasma, and with narrow (< 100∘), slower (< 700 km s-1) CMEs. On the other hand, higher-fluence SEP events have flatter energy spectra, less-dramatic heavy-element enhancements, e.g. ˜ ( A/ Q)3, and come from somewhat hotter coronal plasma (˜ 3.2 MK) associated with C-, M-, and even X-class X-ray flares and with wider CMEs. Enhancements in 3He/4He are uncorrelated with those in heavy elements. However, events with 3He/4He≥0.1 are even more strongly associated with narrow, slow CMEs, with cooler coronal plasma, and with B- and C-class X-ray flares than are other Fe-rich impulsive SEP events with smaller enhancements of 3He.

  15. Solar '80s: A Teacher's Handbook for Solar Energy Education.

    ERIC Educational Resources Information Center

    LaHart, David E.

    This guide is intended to assist the teacher in exploring energy issues and the technology of solar energy conversion and associated technologies. Sections of the guide include: (1) Rationale; (2) Technology Overview; (3) Sun Day Suggestions for School; (4) Backyard Solar Water Heater; (5) Solar Tea; (6) Biogas; (7) Solar Cells; (8) Economics; (9)…

  16. Solar energy: principles and possibilities.

    PubMed

    Rhodes, Christopher J

    2010-01-01

    As the world faces an impending dearth of fossil fuels, most immediately oil, alternative sources of energy must be found. 174 PW worth of energy falls onto the top of the Earth's atmosphere in the form of sunlight which is almost 10,000 times the total amount of energy used by humans on Earth, as taken from all sources, oil, coal, natural gas, nuclear and hydroelectric power combined. If even a fraction of this could be harvested efficiently, the energy crunch could in principle be averted. Various means for garnering energy from the Sun are presented, including photovoltaics (PV), thin film solar cells, quantum dot cells, concentrating PV and thermal solar power stations, which are more efficient in practical terms. Finally the prospects of space based (satellite) solar power are considered. The caveat is that even if the entire world electricity budget could be met using solar energy, the remaining 80% of energy which is not used as electricity but thermal power (heat) still needs to be found in the absence of fossil fuels. Most pressingly, the decline of cheap plentiful crude oil (peak oil) will not find a substitution via solar unless a mainly electrified transportation system is devised and it is debatable that there is sufficient time and conventional energy remaining to accomplish this. The inevitable contraction of transportation will default a deconstruction of the globalised world economy into that of a system of localised communities.

  17. MODELING IRON ABUNDANCE ENHANCEMENTS IN THE SLOW SOLAR WIND

    SciTech Connect

    Byhring, H. S.; Esser, R.; Cranmer, S. R.; Lie-Svendsen, Oe.; Habbal, S. R.

    2011-05-10

    We have studied the behavior of Fe ions in the slow solar wind, using a fluid model extending from the chromosphere to 1 AU. Emphasis is on elemental 'pileup' in the corona, i.e., a region where the Fe density increases and has a local maximum. We study the behavior of individual Fe ions relative to each other in the pileup region, where Fe{sup +10} and Fe{sup +12} have been used as examples. We find that elemental pileups can occur for a variety of densities and temperatures in the corona. We also calculate the ion fractions and obtain estimates for the freezing-in distance of Fe in the slow solar wind. We find that the freezing-in distance for iron is high, between 3 and 11 R{sub sun}, and that a high outflow velocity, of order 50-100 km s{sup -1}, in the region above the temperature maximum is needed to obtain ion fractions for Fe{sup +10} and Fe{sup +12} that are consistent with observations.

  18. Science Activities in Energy: Solar Energy II.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Included in this science activities energy package are 14 activities related to solar energy for secondary students. Each activity is outlined on a single card and is introduced by a question such as: (1) how much solar heat comes from the sun? or (2) how many times do you have to run water through a flat-plate collector to get a 10 degree rise in…

  19. Science Activities in Energy: Solar Energy.

    ERIC Educational Resources Information Center

    Oak Ridge Associated Universities, TN.

    Presented is a science activities in energy package which includes 12 activities relating to solar energy. Activities are simple, concrete experiments for fourth, fifth, and sixth grades, which illustrate principles and problems relating to energy. Each activity is outlined on a single card which is introduced by a question. A teacher's supplement…

  20. Chemistry of Personalized Solar Energy

    PubMed Central

    Nocera, Daniel G.

    2012-01-01

    Personalized energy (PE) is a transformative idea that provides a new modality for the planet’s energy future. By providing solar energy to the individual, an energy supply becomes secure and available to people of both legacy and non-legacy worlds, and minimally contributes to increasing the anthropogenic level of carbon dioxide. Because PE will be possible only if solar energy is available 24 hours a day, 7 day a week, the key enabler for solar PE is an inexpensive storage mechanism. HX (X = halide or OH−) splitting is a fuel-forming reaction of sufficient energy density for large scale solar storage but the reaction relies on chemical transformations that are not understood at the most basic science level. Critical among these are multielectron transfers that are proton-coupled and involve the activation of bonds in energy poor substrates. The chemistry of these three italicized areas is developed, and from this platform, discovery paths leading to new HX and H2O splitting catalysts are delineated. For the case of the water splitting catalyst, it captures many of the functional elements of photosynthesis. In doing so, a highly manufacturable and inexpensive method has been discovered for solar PE storage. PMID:19775081

  1. A comparison of solar wind and estimated solar system xenon abundances - A test for solid/gas fractionation in the solar nebula

    NASA Technical Reports Server (NTRS)

    Wiens, Roger C.; Burnett, D. S.; Neugebauer, M.; Pepin, R. O.

    1992-01-01

    The solar Xe elemental abundance is determined here using solar wind measurements from lunar ilmenites which are normalized to Si by spacecraft data. The results are compared with estimated abundances assuming no fractionation. When corrected for solar wind/photospheric fractionation, the Xe-130 abundance given by surface layer oxidation of ilmenite from solid 71501 exposed within the last 200 m.y. is 0.24 +/- 0.09 normalized to Si = 10 exp 6. This is indistinguishable from estimates made assuming no solid/gas fractionation. Results from breccia 79035 ilmenite exposed at least 1 Gyr ago indicate that the solar wind Xe flux may have been significantly higher relative to other noble gases, perhaps due to more efficient Xe ionization. If this is true, fluxes of C and S, which have first ionization potentials similar to Xe, should also be higher in the ancient solar wind from the same time period.

  2. Asteroseismic estimate of helium abundance of a solar analog binary system

    SciTech Connect

    Verma, Kuldeep; Antia, H. M.; Faria, João P.; Monteiro, Mário J. P. F. G.; Basu, Sarbani; Mazumdar, Anwesh; Appourchaux, Thierry; Chaplin, William J.; García, Rafael A.

    2014-08-01

    16 Cyg A and B are among the brightest stars observed by Kepler. What makes these stars more interesting is that they are solar analogs. 16 Cyg A and B exhibit solar-like oscillations. In this work we use oscillation frequencies obtained using 2.5 yr of Kepler data to determine the current helium abundance of these stars. For this we use the fact that the helium ionization zone leaves a signature on the oscillation frequencies and that this signature can be calibrated to determine the helium abundance of that layer. By calibrating the signature of the helium ionization zone against models of known helium abundance, the helium abundance in the envelope of 16 Cyg A is found to lie in the range of 0.231 to 0.251 and that of 16 Cyg B lies in the range of 0.218 to 0.266.

  3. LITHIUM ABUNDANCE AS A PREDICTOR OF MASS AND AGE IN SOLAR-ANALOG STARS

    SciTech Connect

    Li, T. D.; Bi, S. L.; Liu, K.; Tian, Z. J.; Ge, Z. S.; Chen, Y. Q.

    2012-02-20

    In order to estimate the mass and age of stars, we construct a grid of stellar models for eight solar-analog stars including diffusion and rotation-induced mixing for the given ranges of stellar mass, metallicity, and rotational rate. By combining stellar models with observational data including lithium abundance, we obtain more accurate estimations of mass and age for solar-analog stars. The results indicate that stars HIP 56948, HIP 73815, and HIP 78399 are three possible solar twins. Furthermore, we find that lithium depletion due to extra-mixing in solar analogs strongly depends on mass, metallicity, and rotational history. Therefore, lithium abundance can be used as a good constraint in stellar modeling.

  4. Surface meteorology and Solar Energy

    NASA Technical Reports Server (NTRS)

    Stackhouse, Paul W. (Principal Investigator)

    The Release 5.1 Surface meteorology and Solar Energy (SSE) data contains parameters formulated for assessing and designing renewable energy systems. Parameters fall under 11 categories including: Solar cooking, solar thermal applications, solar geometry, tilted solar panels, energy storage systems, surplus product storage systems, cloud information, temperature, wind, other meteorological factors, and supporting information. This latest release contains new parameters based on recommendations by the renewable energy industry and it is more accurate than previous releases. On-line plotting capabilities allow quick evaluation of potential renewable energy projects for any region of the world. The SSE data set is formulated from NASA satellite- and reanalysis-derived insolation and meteorological data for the 10-year period July 1983 through June 1993. Results are provided for 1 degree latitude by 1 degree longitude grid cells over the globe. Average daily and monthly measurements for 1195 World Radiation Data Centre ground sites are also available. [Mission Objectives] The SSE project contains insolation and meteorology data intended to aid in the development of renewable energy systems. Collaboration between SSE and technology industries such as the Hybrid Optimization Model for Electric Renewables ( HOMER ) may aid in designing electric power systems that employ some combination of wind turbines, photovoltaic panels, or diesel generators to produce electricity. [Temporal_Coverage: Start_Date=1983-07-01; Stop_Date=1993-06-30] [Spatial_Coverage: Southernmost_Latitude=-90; Northernmost_Latitude=90; Westernmost_Longitude=-180; Easternmost_Longitude=180].

  5. Solar energy power station

    SciTech Connect

    Assaf, G.; Bronicki, L.Y.

    1983-03-22

    A solar power station has a heat source in the form of the heat storage layer of a solar pond, a heat sink in the form of the wind-mixed layer of the pond covering the halocline interposed between the heat storage layer and the wind-mixed layer, and a power plant associated therewith. The power plant includes a boiler responsive to water from the heat storage layer for vaporizing a working fluid, a prime mover for producing work by extracting heat from vaporized working fluid, and a condenser cooled by water from a cooling pond connected to the solar pond such that only water in the wind-mixed layer is exchanged with the cooling pond. The wind-mixed layer serves to dissipate heat from the condenser and the volume of water in the cooling pond increase the heat absorption capacity of the heat sink.

  6. Solar neon abundances from gamma-ray spectroscopy and He-3-rich particle events

    NASA Technical Reports Server (NTRS)

    Reames, D. V.; Ramaty, R.; Von Rosenvinge, T. T.

    1988-01-01

    Ambient solar atmospheric abundances derived from gamma-ray spectroscopy are compared with observations of solar energetic particles. Agreement is found between the gamma-ray-derived Ne/O ratio and the corresponding mean ratio for He-3-rich flares. Both of these values are significantly higher than inferred coronal Ne/O ratios. It is suggested that the mean Ne/O ratio in He-3-rich flares reflects the composition of the flare plasma rather than the acceleration process.

  7. Silicon to iron abundances in solar cosmic rays and in the sun

    NASA Technical Reports Server (NTRS)

    Vahia, M. N.; Biswas, S.; Durgaprasad, N.

    1985-01-01

    Differential spectra of even charged nuclei between Si and Fe in the August 4, 1972 event were made in the energy region of 10 to 40 MeV/n-1 using rocket borne plastic detectors. The resulting relative abundances of elements and low energy enhancements are obtained and compared with spectroscopically determined photospheric abundances. The implications of the relative abundances on the acceleration mechanisms is discussed.

  8. Solar energy research and utilization

    NASA Technical Reports Server (NTRS)

    Cherry, W. R.

    1974-01-01

    The role is described that solar energy will play in the heating and cooling of buildings, the production of renewable gaseous, liquid and solid fuels, and the production of electric power over the next 45 years. Potential impacts on the various energy markets and estimated costs of such systems are discussed along with illustrations of some of the processes to accomplish the goals. The conclusions of the NSF/NASA Solar Energy Panel (1972) are given along with the estimated costs to accomplish the 15 year recommended program and also the recent and near future budget appropriations and recommendations are included.

  9. Integrated solar energy system optimization

    NASA Astrophysics Data System (ADS)

    Young, S. K.

    1982-11-01

    The computer program SYSOPT, intended as a tool for optimizing the subsystem sizing, performance, and economics of integrated wind and solar energy systems, is presented. The modular structure of the methodology additionally allows simulations when the solar subsystems are combined with conventional technologies, e.g., a utility grid. Hourly energy/mass flow balances are computed for interconnection points, yielding optimized sizing and time-dependent operation of various subsystems. The program requires meteorological data, such as insolation, diurnal and seasonal variations, and wind speed at the hub height of a wind turbine, all of which can be taken from simulations like the TRNSYS program. Examples are provided for optimization of a solar-powered (wind turbine and parabolic trough-Rankine generator) desalinization plant, and a design analysis for a solar powered greenhouse.

  10. Solar Energy - Solution or Pipedream?

    ERIC Educational Resources Information Center

    Polk, Joyce

    This series of lessons and class activities is designed for presentation in a sequence of nine class days. The collection is intended to provide the student in advanced science classes with awareness of the possibilities and limitations of solar energy as a potential solution to the energy crisis. Included are discussion of the following: (1)…

  11. Generating potassium abundance variations in the Solar Nebula

    NASA Astrophysics Data System (ADS)

    Hubbard, Alexander

    2016-01-01

    In a steadily growing wave from Spitzer through ALMA, observations of protoplanetary disks have shed ever greater light on the environment of planet formation. Nonetheless, the only source of information for the dynamics on the small, turbulent scales which control the accretion flow comes from the history of our own Solar System. The meteoritical record includes chondrites, mixtures of thermally unprocessed matrix and glassy, melted matrix. It is still unknown what mechanism heated to chondrule precursors to the 1700K temperature required to make chondrules. However, their size and composition tells us a lot about the environment in which chondrules formed, and chondrites were assembled. In particular, we show that the volatile depletion commonly (but not universally) seen in chondrules argues that they must have spent a prolonged, orbital-scale period at elevated temperatures around 1000K. This is in significant tension with chondrule cooling estimates of hours to days from laboratory studies, although those studies probe a different temperature scale. Intriguingly, the 1000K temperature scale would allow for sufficient thermal ionization of alkali metals to allow the magneto-rotational instability to act. This argues for a magnetic heating mechanism for chondrule formation. Further, the matrix was not processed at 1000K, which argues for a spatial separation between the chondrule forming, and the chondrite assembly regions.

  12. Thin film solar energy collector

    DOEpatents

    Aykan, Kamran; Farrauto, Robert J.; Jefferson, Clinton F.; Lanam, Richard D.

    1983-11-22

    A multi-layer solar energy collector of improved stability comprising: (1) a substrate of quartz, silicate glass, stainless steel or aluminum-containing ferritic alloy; (2) a solar absorptive layer comprising silver, copper oxide, rhodium/rhodium oxide and 0-15% by weight of platinum; (3) an interlayer comprising silver or silver/platinum; and (4) an optional external anti-reflective coating, plus a method for preparing a thermally stable multi-layered solar collector, in which the absorptive layer is undercoated with a thin film of silver or silver/platinum to obtain an improved conductor-dielectric tandem.

  13. Solar Energy-An Everyday Occurrence

    ERIC Educational Resources Information Center

    Keister, Carole; Cornell, Lu Beth

    1978-01-01

    Describes a solar energy research project sponsored by the Energy Research and Development Administration and conducted at Timonium School in Maryland. Elementary student involvement in solar energy studies resulting from the project is noted. (MDR)

  14. Solar energy, its conversion and utilization

    NASA Technical Reports Server (NTRS)

    Farber, E. A.

    1972-01-01

    The work being carried out at the University of Florida Solar Energy and Energy Conversion Laboratory in converting solar energy, our only income, into other needed and useful forms of energy is described. A treatment such as this demonstrates, in proper perspective, how solar energy can benefit mankind with its many problems of shortages and pollution. Descriptions were given of the conversion processes, equipment, and performance. The testing of materials, solar water heating, space heating, cooking and baking, solar distillation, refrigeration and air-conditioning, work with the solar furnace, conversion to mechanical power, hot air engines, solar-heated sewage digestion, conversion to electricity, and other devices will be discussed.

  15. Influence of gravity waves on the internal rotation and Li abundance of solar-type stars.

    PubMed

    Charbonnel, Corinne; Talon, Suzanne

    2005-09-30

    The Sun's rotation profile and lithium content have been difficult to understand in the context of conventional models of stellar evolution. Classical hydrodynamic models predict that the solar interior must rotate highly differentially, in disagreement with observations. It has recently been shown that internal waves produced by convection in solar-type stars produce an asymmetric, shear layer oscillation, similar to Earth's quasi-biennial oscillation, that leads to efficient angular momentum redistribution from the core to the envelope. We present results of a model that successfully reproduces both the rotation profile and the surface abundance of lithium in solar-type stars of various ages.

  16. Can industry afford solar energy

    NASA Astrophysics Data System (ADS)

    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.

  17. The solar wind neon abundance observed with ACE/SWICS and ULYSSES/SWICS

    SciTech Connect

    Shearer, Paul; Raines, Jim M.; Lepri, Susan T.; Thomas, Jonathan W.; Gilbert, Jason A.; Landi, Enrico; Zurbuchen, Thomas H.; Von Steiger, Rudolf

    2014-07-01

    Using in situ ion spectrometry data from ACE/SWICS, we determine the solar wind Ne/O elemental abundance ratio and examine its dependence on wind speed and evolution with the solar cycle. We find that Ne/O is inversely correlated with wind speed, is nearly constant in the fast wind, and correlates strongly with solar activity in the slow wind. In fast wind streams with speeds above 600 km s{sup –1}, we find Ne/O = 0.10 ± 0.02, in good agreement with the extensive polar observations by Ulysses/SWICS. In slow wind streams with speeds below 400 km s{sup –1}, Ne/O ranges from a low of 0.12 ± 0.02 at solar maximum to a high of 0.17 ± 0.03 at solar minimum. These measurements place new and significant empirical constraints on the fractionation mechanisms governing solar wind composition and have implications for the coronal and photospheric abundances of neon and oxygen. The results are made possible by a new data analysis method that robustly identifies rare elements in the measured ion spectra. The method is also applied to Ulysses/SWICS data, which confirms the ACE observations and extends our view of solar wind neon into the three-dimensional heliosphere.

  18. Short review on solar energy systems

    NASA Astrophysics Data System (ADS)

    Herez, Amal; Ramadan, Mohamad; Abdulhay, Bakri; Khaled, Mahmoud

    2016-07-01

    Solar energy can be utilized mainly in heat generation and electricity production. International energy agency (IEA) shows, in a comparative study on the world energy consumption that in 2050 solar arrays installation will provide about 45% of world energy demand. Solar energy is one of the most important renewable energy source which plays a great role in providing energy solutions. As known there is wide variety of types of collectors and applications of solar energy. This paper aimed to make a short review on solar energy systems, according to types of collectors and applications used.

  19. Institutionalizing solar energy education

    SciTech Connect

    Arwood, J.W.

    1997-12-31

    As America entered the final decade of the 20th century, millions of people turned out to celebrate Earth Day`s 20th anniversary. Environmental awareness was on an upswing, and as a result, environmental education became a priority across the country. Environmental education was making significant headway into the public school system, and recycling emerged as the vanguard of this movement. At first the exclusive province of school children, recycling soon became a household habit. As children collected cans for cash, they also taught their parents to recycle. In its movement from classroom to curbside, recycling rode the school bus to Main Street and, within a few short years, became institutionalized. In this paper, the author demonstrates how the Solar Information and Education Program has evolved to the point where it has become an institutionalized, lasting part of the school experience for thousands of Arizona students. It is hoped that the solar experience for the state`s young people will duplicate the recycling experience of a decade ago, this time taking solar technology from chalkboard to rooftop.

  20. Solar Program Assessment: Environmental Factors - Solar Total Energy Systems.

    ERIC Educational Resources Information Center

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    The purpose of this report is to present and prioritize the major environmental, safety, and social/institutional issues associated with the further development of Solar Total Energy Systems (STES). Solar total energy systems represent a specific application of the Federally-funded solar technologies. To provide a background for this analysis, the…

  1. Neon Lights up a Controversy: The Solar Ne/O Abundance

    NASA Astrophysics Data System (ADS)

    Schmelz, J. T.; Nasraoui, K.; Roames, J. K.; Lippner, L. A.; Garst, J. W.

    2005-12-01

    The standard solar model was so reliable that it could predict the existence of the massive neutrino. Helioseismology measurements were so precise that they could determine the depth of the convection zone. This agreement between theory and observation was the envy of all astrophysics-until recently, when sophisticated three-dimensional hydrodynamic calculations of the solar atmosphere reduced the metal content by a factor of almost 2. Antia & Basu suggested that a higher value of the solar neon abundance, ANe/AO=0.52, would resolve this controversy. Drake & Testa presented evidence in favor of this idea from a sample of 21 Chandra stars with enhanced values of the neon abundance, ANe/AO=0.41. In this Letter, we have analyzed solar active region spectra from the archive of the Flat Crystal Spectrometer on the Solar Maximum Mission, a NASA mission from the 1980s, as well as full-Sun spectra from the pioneering days of X-ray astronomy in the 1960s. These data are consistent with the standard neon-to-oxygen abundance value, ANe/AO=0.15 (Grevesse & Sauval). We conclude, therefore, that the enhanced-neon hypothesis will not resolve the current controversy.

  2. The solar flare iron line to continuum ratio and the coronal abundances of iron and helium

    NASA Technical Reports Server (NTRS)

    Mckenzie, D. L.

    1975-01-01

    Narrow band Ross filter measurements of the Fe 25 line flux around 0.185 nm and simultaneous broadband measurements during a solar flare were used to determine the relationship between the solar coronal abundances of iron and helium. The Fe 25 ion population was also determined as a function of time. The proportional counter and the Ross filter on OSO-7 were utilized. The data were analyzed under the separate assumptions that (1) the electron density was high enough that a single temperature could characterize the continuum spectrum and the ionization equilibrium, and that (2) the electron density was low so that the ion populations trailed the electron temperature in time. It was found that the density was at least 5x10 to the 9th power, and that the high density assumption was valid. It was also found that the iron abundance is 0.000011 for a helium abundance of 0.2, relative to hydrogen.

  3. Solar Energy for Rural Egypt

    NASA Astrophysics Data System (ADS)

    Abdelsalam, Tarek I.; Darwish, Ziad; Hatem, Tarek M.

    Egypt is currently experiencing the symptoms of an energy crisis, such as electricity outage and high deficit, due to increasing rates of fossil fuels consumption. Conversely, Egypt has a high solar availability of more than 18.5 MJ daily. Additionally, Egypt has large uninhabited deserts on both sides of the Nile valley and Sinai Peninsula, which both represent more than 96.5 % of the nation's total land area. Therefore, solar energy is one of the promising solutions for the energy shortage in Egypt. Furthermore, these vast lands are advantageous for commissioning large-scaled solar power projects, not only in terms of space availability, but also of availability of high quality silicon (sand) required for manufacturing silicon wafers used in photovoltaic (PV) modules. Also, rural Egypt is considered market a gap for investors, due to low local competition, and numerous remote areas that are not connected to the national electricity grid. Nevertheless, there are some obstacles that hinder the progress of solar energy in Egypt; for instance, the lack of local manufacturing capabilities, security, and turbulent market in addition to other challenges. This paper exhibits an experience of the authors designing and installing decentralized PV solar systems, with a total rated power of about 11 kW, installed at two rural villages in at the suburbs of Fayoum city, in addition to a conceptual design of a utility scale, 2 MW, PV power plant to be installed in Kuraymat. The outcomes of this experience asserted that solar PV systems can be a more technically and economically feasible solution for the energy problem in rural villages.

  4. Theoretical Evaluation of Cu-Sn-S and Cu-Sb-S Based Solar Absorbers for Earth-Abundant Thin-Film Solar Cells

    NASA Astrophysics Data System (ADS)

    Zawadzki, Pawel; Peng, Haowei; Zakutayev, Andriy; Lany, Stephan

    2013-03-01

    Current thin-film solar absorbers such as Cu(In/Ga)Se2 or CdTe, although remarkably efficient, incorporate limited-supply elements like indium or tellurium. Meeting the cost competiveness criterion necessary for a large-scale deployment of thin-film PV technologies requires development of new earth-abundant solar absorbers. In an effort to accelerate such development we combine first principles theory and high throughput experiments to explore In-free ternary copper chalcogenides. As part of the theoretical evaluation, we study the Cu2SnS3, Cu4SnS4, CuSbS2 and Cu3SbS3 based compounds formed by isovalent alloying on Sn, Sb, and S sites. For this set of materials we predict band-structures and optical absorption coefficients and demonstrate the feasibility of achieving the optimal band gap of 1.3 eV for a single junction cell and a high optical absorption of ~104 cm-1 at Eg+0.2 eV. We additionally perform defect studies to elucidate the doping trends within this class of materials. The project ``Rapid Development of Earth-abundant Thin Film Solar Cells'' is supported as a part of the SunShot initiative by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy under Contract No. DE-AC36-08GO28308 to NREL.

  5. Wireless Solar Water Splitting Using Silicon-Based Semiconductors and Earth-Abundant Catalysts

    SciTech Connect

    Reece, SY; Hamel, JA; Sung, K; Jarvi, TD; Esswein, AJ; Pijpers, JJH; Nocera, DG

    2011-11-03

    We describe the development of solar water-splitting cells comprising earth-abundant elements that operate in near-neutral pH conditions, both with and without connecting wires. The cells consist of a triple junction, amorphous silicon photovoltaic interfaced to hydrogen- and oxygen-evolving catalysts made from an alloy of earth-abundant metals and a cobalt|borate catalyst, respectively. The devices described here carry out the solar-driven water-splitting reaction at efficiencies of 4.7% for a wired configuration and 2.5% for a wireless configuration when illuminated with 1 sun (100 milliwatts per square centimeter) of air mass 1.5 simulated sunlight. Fuel-forming catalysts interfaced with light-harvesting semiconductors afford a pathway to direct solar-to-fuels conversion that captures many of the basic functional elements of a leaf.

  6. Two distinct halo populations in the solar neighborhood: evidence from stellar abundance of beryllium

    NASA Astrophysics Data System (ADS)

    Tan, Kefeng; Zhao, Gang

    2014-01-01

    It is now generally believed that the Galaxy was formed through hierarchical merging, which means that different components of the Galaxy may have experienced different chemical evolution histories. Since alpha elements are mainly produced by core collapse supernovae, they are closely associated with the star formation history of the Galaxy. In this regard, Galactic components with different alpha elemental abundance patterns may show different behaviors in beryllium abundances since the production of beryllium is correlated with the cosmic rays and thus the supernovae. A recent study by Nissen & Schuster (2010) has revealed the existence of two distinct halo populations in the solar neighborhood based on the alpha elemental abundances and kinematics of 94 dwarf stars. We determined beryllium abundances for some of these stars and find systematic differences in beryllium abundances between these two halo populations. Our results consolidate the conclusion of two distinct halo populations in the solar neighborhood. Our results also show that beryllium abundance is a very good indicator of star formation rate, and could be used to trace the substructures of the Galactic halo.

  7. Solar energy and substainable development

    NASA Astrophysics Data System (ADS)

    Roux, Maria Carmen; Nalin, Olivier

    2010-05-01

    At the dawn of the 21st century, the world population doesn't stop rising. More than ever, energy and environment problems remain at the heart of our society concerns. What will we leave to the future generations ? Therefore, a twenty pupil class of 4e (13 and 14 year old pupils) has made a specific work about this topic, called "solar power and sustainable development". Initially, the pupils participated to the settlement of a meteorological station on the school grounds. This station, which provides readings about temperature, relative humidity, rainfall, sun radiations, wind power and wind heading is fed by photovoltaic cells and thus works independently. The pupils have then come to realize the ecological and practical interests of such a functioning (e.g. : for the latter : neither batteries nor electrical wires are needed). These past few years, in Provence (a highly sunny region), many solar panel installations have been created and many private house roofs have been equipped with photovoltaic cells. Indeed, this energy presents some significant assets : it is free, clean and will never run out. The village of Vinon sur Verdon, where stands our college, is partly fed by a solar panel park, located a few kilometers away. Strongly sensitive to the assets of this energy source, the pupils have made a poster asserting the benefits of solar power. Another side of solar energy has been asserted : the output of hot sanitary water. They have built a miniature on this topic. In order to be thorough, some elements remain in shadow, such as environment impacts done by the making, the transport and the recycling of solar panels that will be brought up in a collaboration with research establishments.

  8. Solar energy and the aeronautics industry

    NASA Astrophysics Data System (ADS)

    Benedek, L.

    1985-11-01

    An introduction to the physical aspects of solar energy, incidental energy and variations in solar flux is presented, along with an explanation of the physical principles of obtaining solar energy. The history of the application of solar energy to aeronautics, including the Gossamer Penguin and the Solar Challenger is given. Finally, an analysis of the possibilities of using a reaction motor with hybrid propulsion combining solar energy with traditional fuels as well as calculations of the proposed cycle and its mode of operation are given.

  9. Solar energy and the aeronautics industry. Thesis

    NASA Technical Reports Server (NTRS)

    Benedek, L.

    1985-01-01

    An introduction to the physical aspects of solar energy, incidental energy and variations in solar flux is presented, along with an explanation of the physical principles of obtaining solar energy. The history of the application of solar energy to aeronautics, including the Gossamer Penguin and the Solar Challenger is given. Finally, an analysis of the possibilities of using a reaction motor with hybrid propulsion combining solar energy with traditional fuels as well as calculations of the proposed cycle and its mode of operation are given.

  10. Solar Energy. Instructional Materials.

    ERIC Educational Resources Information Center

    Jordan, Kenneth; Thessing, Dan

    This document is one of five learning packets on alternative energy developed as part of a descriptive curriculum research project in Arkansas (see note). The overall objectives of the learning packets are to improve the level of instruction in the alternative energies by vocational exploration teachers, and to facilitate the integration of new…

  11. Solar Energy Education Bibliography.

    ERIC Educational Resources Information Center

    Center for Renewable Resources, Washington, DC.

    This annotated bibliography lists publications and audiovisual materials devoted to renewable energy sources: sun, wind, water and biomass. A few general texts are included that present concepts fundamental to all energy sources. Materials were selected to be adaptable to classroom, workshops, and training sessions. Also, many do-it-yourself…

  12. Solar Energy Project, Activities: Biology.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of biology experiments. Each unit presents an introduction; objectives; skills and knowledge needed; materials; methods; questions; recommendations for further work; and a teacher information sheet. The teacher information…

  13. Warming up to solar energy

    SciTech Connect

    Biondo, B.

    1996-07-01

    Increasingly alarmed by threats to their financial security posed by an escalating number of weather-related catastrophes, major insurance companaies, particularly those in Europe and Asia, are starting to support a variety of measures that would slowe the production of grenhouse gases worlwide. As the insurance and banking industries turn their attention to global warming, investments in solar energy take on growing appeal.

  14. Food dehydration by solar energy.

    PubMed

    Bolin, H R; Salunkhe, D K

    1982-01-01

    Solar driers that are currently being investigated for drying of agricultural products can be divided into two major divisions, depending upon how they transfer the incident solar energy to the product to be dried. These two divisions are direct and indirect drying, with some work also being done on combination drying procedures. In direct solar driers, the product to be dried is usually either inside a tent, greenhouse, or a glass-topped box, where the product to be dried is heated by the direct rays from the sun and the moist air is removed by ambient wind movement. These dryers do accelerate moisture loss rate and the product is usually safe from inclement weather. These dryers usually do not require fans for forced air circulation. With indirect drying, the opposite is true, where most require powered fans for forced air circulation. With this type of dryer, both flatplate and inflated tube solar heat absorbers are used, with each offering certain advantages. Also, combination dryers have been built that utilize both direct and indirect principles. Product evaluation of solar dried foods indicate that in most cases the physical properties, flavor, and vitamin A and C retention were as good as, or better than, conventional dried foods. The economics of the solar systems indicate that most drying procedures are economically feasible for use in small-scale operations only, with the exception of grain drying.

  15. Food dehydration by solar energy.

    PubMed

    Bolin, H R; Salunkhe, D K

    1982-01-01

    Solar driers that are currently being investigated for drying of agricultural products can be divided into two major divisions, depending upon how they transfer the incident solar energy to the product to be dried. These two divisions are direct and indirect drying, with some work also being done on combination drying procedures. In direct solar driers, the product to be dried is usually either inside a tent, greenhouse, or a glass-topped box, where the product to be dried is heated by the direct rays from the sun and the moist air is removed by ambient wind movement. These dryers do accelerate moisture loss rate and the product is usually safe from inclement weather. These dryers usually do not require fans for forced air circulation. With indirect drying, the opposite is true, where most require powered fans for forced air circulation. With this type of dryer, both flatplate and inflated tube solar heat absorbers are used, with each offering certain advantages. Also, combination dryers have been built that utilize both direct and indirect principles. Product evaluation of solar dried foods indicate that in most cases the physical properties, flavor, and vitamin A and C retention were as good as, or better than, conventional dried foods. The economics of the solar systems indicate that most drying procedures are economically feasible for use in small-scale operations only, with the exception of grain drying. PMID:7047079

  16. Solar-assisted low energy dwellings

    SciTech Connect

    Esbensen, T V

    1980-02-01

    The Zero Energy House Group was formed as a subproject of the CCMS Solar Energy Pilot Study in 1974 by seven participating countries experimenting with solar-assisted low-energy dwellings for temperate and northern European climatic conditions. A Zero Energy House is one in which solar energy is used to meet the reduced energy needs of buildings incorporating various thermal energy conservation features. This final report of the Zero Energy House Group includes brief descriptions of 13 major low-energy dwellings in the participating CCMS countries. An overall assessment of the state-of-the-art in solar-assisted low-energy dwellings is also included.

  17. Solar Wind Helium Abundance as a Function of Speed and Heliographic Latitude: Variation through a Solar Cycle

    NASA Technical Reports Server (NTRS)

    Kasper, J. C.; Stenens, M. L.; Stevens, M. L.; Lazarus, A. J.; Steinberg, J. T.; Ogilvie, Keith W.

    2006-01-01

    We present a study of the variation of the relative abundance of helium to hydrogen in the solar wind as a function of solar wind speed and heliographic latitude over the previous solar cycle. The average values of A(sub He), the ratio of helium to hydrogen number densities, are calculated in 25 speed intervals over 27-day Carrington rotations using Faraday Cup observations from the Wind spacecraft between 1995 and 2005. The higher speed and time resolution of this study compared to an earlier work with the Wind observations has led to the discovery of three new aspects of A(sub He), modulation during solar minimum from mid-1995 to mid-1997. First, we find that for solar wind speeds between 350 and 415 km/s, A(sub He), varies with a clear six-month periodicity, with a minimum value at the heliographic equatorial plane and a typical gradient of 0.01 per degree in latitude. For the slow wind this is a 30% effect. We suggest that the latitudinal gradient may be due to an additional dependence of coronal proton flux on coronal field strength or the stability of coronal loops. Second, once the gradient is subtracted, we find that A(sub He), is a remarkably linear function of solar wind speed. Finally, we identify a vanishing speed, at which A(sub He), is zero, is 259 km/s and note that this speed corresponds to the minimum solar wind speed observed at one AU. The vanishing speed may be related to previous theoretical work in which enhancements of coronal helium lead to stagnation of the escaping proton flux. During solar maximum the A(sub He), dependences on speed and latitude disappear, and we interpret this as evidence of two source regions for slow solar wind in the ecliptic plane, one being the solar minimum streamer belt and the other likely being active regions.

  18. Solar Spicules Generate Energy

    NASA Video Gallery

    Looking almost like seaweed waving in the water, these giant jets shooting off the sun's surface may hold enough energy to heat the sun's atmosphere, the corona, to well over a million degrees Fahr...

  19. Solar energy conversion.

    SciTech Connect

    Crabtree, G. W.; Lewis, N. S.; Materials Science Division; Cal Tech

    2007-03-01

    The Sun provides Earth with a staggering amount of energy - enough to power the great oceanic and atmospheric currents, the cycle of evaporation and condensation that brings fresh water inland and drives river flow, and the typhoons, hurricanes, and tornadoes that so easily destroy the natural and built landscape. The San Francisco earthquake of 1906, with magnitude 7.8, released an estimated 10{sup 17} joules of energy, the amount the Sun delivers to Earth in one second. Earth's ultimate recoverable resource of oil, estimated at 3 trillion barrels, contains 1.7 x 10{sup 22} joules of energy, which the Sun supplies to Earth in 1.5 days. The amount of energy humans use annually, about 4.6 x 10{sup 20} joules, is delivered to Earth by the Sun in one hour. The enormous power that the Sun continuously delivers to Earth, 1.2 x 10{sup 5} terawatts, dwarfs every other energy source, renewable or nonrenewable. It dramatically exceeds the rate at which human civilization produces and uses energy, currently about 13 TW.

  20. Fast variations of helium abundance in the solar wind and their consequences

    NASA Astrophysics Data System (ADS)

    Durovcova, Tereza; Zastenker, Georgy; Nemecek, Zdenek; Safrankova, Jana; Cagas, Petr

    2016-07-01

    The relative abundance of helium in the solar wind results from the physical processes ongoing at the Sun surface and this fact leads to the generally accepted interpretation of He density jumps observed on large (minutes to hours) scales as remnants of the structure of solar wind coronal sources. However, an analysis of the data from the BMSW instrument (the Spektr-R spacecraft) shows that the He content can rapidly vary over short time scales. Comparing measurements of several spacecraft operating the interplanetary space (Themis and Spektr-R around the Earth, and Wind in the L1 point), we present a study of fast variations of the He abundance under different solar wind conditions that supports the idea that a majority of these variations on short timescales (3-30 s) are generated by in-transit turbulence that is probably driven by the speed difference between the ion species. This turbulence contributes to the solar wind heating and leads to a positive correlation of the proton temperature with the He abundance.

  1. THE SOLAR FLARE CHLORINE ABUNDANCE FROM RESIK X-RAY SPECTRA

    SciTech Connect

    Sylwester, B.; Sylwester, J.; Phillips, K. J. H.; Kuznetsov, V. D. E-mail: js@cbk.pan.wroc.pl E-mail: kvd@izmiran.ru

    2011-09-01

    The abundance of chlorine is determined from X-ray spectra obtained with the RESIK instrument on CORONAS-F during solar flares between 2002 and 2003. Using weak lines of He-like Cl, Cl XVI, between 4.44 and 4.50 A, and with temperatures and emission measures from GOES on an isothermal assumption, we obtained A(Cl) = 5.75 {+-} 0.26 on a scale A(H) = 12. The uncertainty reflects an approximately a factor of two scatter in measured line fluxes. Nevertheless, our value represents what is probably the best solar determination yet obtained. It is higher by factors of 1.8 and 2.7 than Cl abundance estimates from an infrared sunspot spectrum and nearby H II regions. The constancy of the RESIK abundance values over a large range of flares (GOES class from below C1 to X1) argues for any fractionation that may be present in the low solar atmosphere to be independent of the degree of solar activity.

  2. Renewable Energy: Solar Fuels GRC and GRS

    SciTech Connect

    Nathan Lewis Nancy Ryan Gray

    2010-02-26

    from a carbon-neutral source. Sunlight is by far the most abundant global carbon-neutral energy resource. More solar energy strikes the surface of the earth in one hour than is obtained from all of the fossil fuels consumed globally in a year. Sunlight may be used to power the planet. However, it is intermittent, and therefore it must be converted to electricity or stored chemical fuel to be used on a large scale. The 'grand challenge' of using the sun as a future energy source faces daunting challenges - large expanses of fundamental science and technology await discovery. A viable solar energy conversion scheme must result in a 10-50 fold decrease in the cost-to-efficiency ratio for the production of stored fuels, and must be stable and robust for a 20-30 year period. To reduce the cost of installed solar energy conversion systems to $0.20/peak watt of solar radiation, a cost level that would make them economically attractive in today's energy market, will require revolutionary technologies. This GRC seeks to present a forum for the underlying science needed to permit future generations to use the sun as a renewable and sustainable primary energy source. Speakers will discuss recent advances in homoogeneous and heterogeneous catalysis of multi-electron transfer processes of importance to solar fuel production, such as water oxidation and reduction, and carbon dioxide reduction. Speakers will also discuss advances in scaleably manufacturable systems for the capture and conversion of sunlight into electrical charges that can be readily coupled into, and utilized for, fuel production in an integrated system.

  3. Comparative evaluation of solar, fission, fusion, and fossil energy resources. Part 1: Solar energy

    NASA Technical Reports Server (NTRS)

    Williams, J. R.

    1974-01-01

    The utilization of solar energy to meet the energy needs of the U.S. is discussed. Topics discussed include: availability of solar energy, solar energy collectors, heating for houses and buildings, solar water heater, electric power generation, and ocean thermal power.

  4. Solar Energy in the Home. Revised.

    ERIC Educational Resources Information Center

    Roeder, Allen A.; Woodland, James A.

    Recommended for grades 10-12 physical, earth, or general science classes, this 5-7 day unit is designed to give students a general understanding of solar energy and its use as a viable alternative to present energy sources. Along with this technology, students examine several factors of solar energy which influence the choice of solar home site…

  5. Solar Energy - An Option for Future Energy Production

    ERIC Educational Resources Information Center

    Glaser, Peter E.

    1972-01-01

    Discusses the exponential growth of energy consumption and future consequences. Possible methods of converting solar energy to power such as direct energy conversion, focusing collectors, selective rediation absorbers, ocean thermal gradient, and space solar power are considered. (DF)

  6. Central solar-energy receiver

    DOEpatents

    Not Available

    1981-10-27

    An improved tower-mounted central solar energy receiver for heating air drawn through the receiver by an induced draft fan is described. A number of vertically oriented, energy absorbing, fin-shaped slats are radially arranged in a number of concentric cylindrical arrays on top of the tower coaxially surrounding a pipe having air holes through which the fan draws air which is heated by the slats which receive the solar radiation from a heliostat field. A number of vertically oriented and wedge-shaped columns are radially arranged in a number of concentric cylindrical clusters surrounding the slat arrays. The columns have two mirror-reflecting sides to reflect radiation into the slat arrays and one energy absorbing side to reduce reradiation and reflection from the slat arrays.

  7. Fluid absorption solar energy receiver

    NASA Technical Reports Server (NTRS)

    Bair, Edward J.

    1993-01-01

    A conventional solar dynamic system transmits solar energy to the flowing fluid of a thermodynamic cycle through structures which contain the gas and thermal energy storage material. Such a heat transfer mechanism dictates that the structure operate at a higher temperature than the fluid. This investigation reports on a fluid absorption receiver where only a part of the solar energy is transmitted to the structure. The other part is absorbed directly by the fluid. By proportioning these two heat transfer paths the energy to the structure can preheat the fluid, while the energy absorbed directly by the fluid raises the fluid to its final working temperature. The surface temperatures need not exceed the output temperature of the fluid. This makes the output temperature of the gas the maximum temperature in the system. The gas can have local maximum temperatures higher than the output working temperature. However local high temperatures are quickly equilibrated, and since the gas does not emit radiation, local high temperatures do not result in a radiative heat loss. Thermal radiation, thermal conductivity, and heat exchange with the gas all help equilibrate the surface temperature.

  8. Feasibility study of solar energy in residential electricity generation

    NASA Astrophysics Data System (ADS)

    Solanki, Divyangsinh G.

    With the increasing demand for energy and the concerns about the global environment, along with the steady progress in the field of renewable energy technologies, new opportunities and possibilities are opening up for an efficient utilization of renewable energy sources. Solar energy is undoubtedly the most clean, inexhaustible and abundant source of renewable energy. Photovoltaic (PV) technology is one of the most efficient mean to utilize solar power. The focus of this study was to establish economics of a residential photovoltaic system for a typical home in south Texas. The PV system serves the needs of a typical mid-size home inhibited by a typical family. Assumptions are made for the typical daily energy consumption, and the necessary equipments like solar arrays, batteries, inverter, etc. are sized and evaluated optimally so as to reduce the life cycle cost (LCC) of the system. Calculations are done taking into consideration the economic parameters concerned with the system.

  9. ON THE ORIGIN OF THE SLOW SPEED SOLAR WIND: HELIUM ABUNDANCE VARIATIONS

    SciTech Connect

    Rakowski, Cara E.; Laming, J. Martin

    2012-07-20

    The first ionization potential (FIP) effect is the by now well-known enhancement in abundance over photospheric values of Fe and other elements with FIP below about 10 eV observed in the solar corona and slow speed solar wind. In our model, this fractionation is achieved by means of the ponderomotive force, arising as Alfven waves propagate through or reflect from steep density gradients in the solar chromosphere. This is also the region where low FIP elements are ionized, and high FIP elements are largely neutral leading to the fractionation as ions interact with the waves but neutrals do not. Helium, the element with the highest FIP and consequently the last to remain neutral as one moves upward, can be depleted in such models. Here, we investigate this depletion for varying loop lengths and magnetic field strengths. Variations in this depletion arise as the concentration of the ponderomotive force at the top of the chromosphere varies in response to Alfven wave frequency with respect to the resonant frequency of the overlying coronal loop, the magnetic field, and possibly also the loop length. We find that stronger depletions of He are obtained for weaker magnetic field, at frequencies close to or just above the loop resonance. These results may have relevance to observed variations of the slow wind solar He abundance with wind speed, with slower slow speed solar wind having a stronger depletion of He.

  10. Universal solar energy desalination system

    NASA Astrophysics Data System (ADS)

    Fusco, V. S.

    Design considerations to allow site-dependent flexibility in the choice of solar/wind powered desalinization plant configurations are discussed. A prototype design was developed for construction of 6300 cu m per day brackish water treatment in Brownsville, TX. The water is treated to reduce the amount of suspended solids and prevent scaling. A reverse osmosis unit processes the treated liquid to recover water at a ratio of 90%. The power system comprises a parabolic trough solar thermal system with an organic Rankine cycle generator, rock-oil thermal storage, and 200 kW wind turbines. Analysis of the complementarity of the solar and wind subsystems indicates that at any site one system will supplement the other. Energy storage, e.g., battery banks, would increase system costs to unacceptable levels. Climatic conditions will significantly influence the sizing of each segment of the total power system.

  11. Solar energy for village development.

    PubMed

    Brown, N L; Howe, J W

    1978-02-10

    The National Academy of Sciences held a joint workshop with the Government of Tanzania last August on the potential of solar energy for the villages of that country. Costs of five solar technologies (mini-hydroelectric generators, wind, methane generation from organic wastes, photovoltaic cells, and flat-plate solar collectors) were compared with costs of diesel-generated electricity and with electricity from the national grid. Each of the five technologies is either now competitive with diesel or will be in a few years. Although the figures presented are not conclusive since they are derived from calculations rather than an actual test, the results are encouraging enough to warrant serious testing in Third World villages.

  12. Extinct radioactivities - A three-phase mixing model. [for early solar system abundances

    NASA Technical Reports Server (NTRS)

    Clayton, D. D.

    1983-01-01

    A new class of models is advanced for interpreting the relationship of radioactive abundances in the early solar system to their average concentration in the interstellar medium. The model assumes that fresh radioactivities are ejected from supernovae into the hot interstellar medium, and that the time scales for changes of phase into molecular clouds determine how much survives for formation therein of the solar system. A more realistic and physically motivated understanding of the low observed concentrations of I-129, Pu-244, and Pd-107 may result.

  13. Decentalized solar photovoltaic energy systems

    SciTech Connect

    Krupka, M. C.

    1980-09-01

    Environmental data for decentralized solar photovoltaic systems have been generated in support of the Technology Assessment of Solar Energy Systems program (TASE). Emphasis has been placed upon the selection and use of a model residential photovoltaic system to develop and quantify the necessary data. The model consists of a reference home located in Phoenix, AZ, utilizing a unique solar cell array-roof shingle combination. Silicon solar cells, rated at 13.5% efficiency at 28/sup 0/C and 100 mW/cm/sup 2/ (AMI) insolation are used to generate approx. 10 kW (peak). An all-electric home is considered with lead-acid battery storage, dc-ac inversion and utility backup. The reference home is compared to others in regions of different insolation. Major material requirements, scaled to quad levels of end-use energy include significant quantities of silicon, copper, lead, antimony, sulfuric acid and plastics. Operating residuals generated are negligible with the exception of those from the storage battery due to a short (10-year) lifetime. A brief general discussion of other environmental, health, and safety and resource availability impacts is presented. It is suggested that solar cell materials production and fabrication may have the major environmental impact when comparing all facets of photovoltaic system usage. Fabrication of the various types of solar cell systems involves the need, handling, and transportation of many toxic and hazardous chemicals with attendant health and safety impacts. Increases in production of such materials as lead, antimony, sulfuric acid, copper, plastics, cadmium and gallium will be required should large scale usage of photovoltaic systems be implemented.

  14. Solar energy meter

    NASA Technical Reports Server (NTRS)

    Masters, R. M.

    1977-01-01

    An instrument was developed to continually integrate the energy available in incident light on a specifically oriented surface. The unit was designed for outdoor use in remote locations and is capable of operation over a temperature range of -20 to +60 C with good accuracy. The unit is weather resistant, requires low power, has a high input impedance, is inexpensive, and has a visual readout and an analog output for recording.

  15. Metallic Abundances of 2002 Leonid Meteoroids in Two Dust Trails Formed in Different Epochs: No Evidence of Solar Heating Effect

    NASA Astrophysics Data System (ADS)

    Kasuga, T.; Watanabe, J.; Yamamoto, T.; Ebizuka, N.; Kawakita, H.

    2006-02-01

    High-definition TV spectra in the ultraviolet to visible region were obtained during the 2002 Leonid aircraft campaign. We analyzed 20 meteor spectra obtained from the 1767 (seven revolution) and 1866 (four revolution) trails on 2002 November 19 and identified neutral atoms, mainly Mg I, Fe I, Ca I, and Na I, in the observed wavelengths between 300 and 650 nm. The singly ionized atomic emissions, Ca II and Mg II lines, also appeared in the spectrum. The abundances of the metallic atoms, the electronic excitation temperature, and the electron density are obtained for each spectrum, assuming the Boltzmann distribution for the number at each energy level. The metallic abundances of Fe, Ca, and Na relative to Mg are slightly lower than solar abundances on average. We could not find any evidence of the solar heating effect on Leonid meteoroids between the 1767 and 1866 trails on orbit with their perihelion (q~1 AU). We can support the idea that silicate and carbon-mixed silicate are preserved in interplanetary space for at least several hundred years. Bands of CHON-related molecules, such as OH and CN, are not detected in this study.

  16. Ti-ii transition probabilities and radiative lifetimes in TI and the solar titanium abundance

    NASA Astrophysics Data System (ADS)

    Bizzarri, A.; Huber, M. C. E.; Noels, A.; Grevesse, N.; Bergeson, S. D.; Tsekeris, P.; Lawler, J. E.

    1993-06-01

    Transition probabilities of 100 Ti-II emission lines, originating from 7 different atomic levels, have been determined by combining branching fractions with radiative lifetimes. The branching fractions were measured using Fourier transform spectroscopy on a hollow cathode. The radiative lifetimes of these 7 - and 35 additional - levels were measured using time resolved laser-induced fluorescence on a slow Ti ion beam. The transition probabilities of 21 very weak lines have been used to derive a solar titanium abundance of αTi = log(NTi/NH) + 12=5.04±0.04 dex, which is insensitive to the solar model. This value is in disagreement with the meteoritic titanium abundance (4.93±0.02).

  17. The energy impacts of solar heating.

    PubMed

    Whipple, C

    1980-04-18

    The energy required to build and install solar space- and water-heating equipment is compared to the energy it saves under two solar growth paths corresponding to high and low rates of implementation projected by the Domestic Policy Review of Solar Energy. For the rapid growth case, the cumulative energy invested to the year 2000 is calculated to be (1/2) to 1(1/2) times the amount saved. An impact of rapid solar heating implementation is to shift energy demand from premium heating fuels (natural gas and oil) to coal and nuclear power use in the industries that provide materials for solar equipment.

  18. Meteoritic Constraints on Models of the Solar Nebula: The Abundances of Moderately Volatile Elements

    NASA Technical Reports Server (NTRS)

    Cassen, P.; Cuzzi, Jeffrey N. (Technical Monitor)

    1994-01-01

    The "moderately volatile" elements are those which condense (or evaporate) in the temperature range 650 - 1350 K, as a mix of material with solar abundances is cooled (or heated) under equilibrium conditions. Their relative abundances in chondritic meteorites are solar (or "cosmic", as defined by tile composition of CI meteorites) to within a factor of several, but vary within that range in a way that correlates remarkably well with condensation temperature, independent of chemical affinity. It has been argued that this correlation reflects a systematically selective process which favored the accretion of refractory material over volatile material from a cooling nebula. Wasson and Chou suggested that condensation and settling of solids contemporaneously with the cooling and removal of nebular gas could produce tile observed abundance patterns, but a quantitative model has been lacking. We show that the abundance patterns of the moderately volatile elements in chondritic meteorites can be produced, in some degree of quantitative detail, by models of the solar nebula that are designed to conform to observations of T Tauri stars and the global conservation laws. For example, even if the local surface density of the nebula is not decreasing, condensation and accretion of solids from radially inflowing gas in a cooling nebula can result in depletions of volatiles, relative to refractories, like those observed. The details of the calculated abundance patterns depend on (but are not especially sensitive to) model parameters, and can exhibit the variations that distinguish the meteorite classes. Thus it appears that nebula characteristics Such as cooling rates, radial flow velocities, and particle accumulation rates can be quantitatively constrained by demanding that they conform to meteoritic data; and the models, in turn, can produce testable hypotheses regarding the time and location of the formation of the chondrite parent bodies and the planets.

  19. Meteoritic Constraints on Models of the Solar Nebula: The Abundances of Moderately Volatile Elements

    NASA Technical Reports Server (NTRS)

    Cassen, Patrick; Cuzzi, Jeff (Technical Monitor)

    1994-01-01

    The "moderately volatile" elements are those which condense (or evaporate) in the temperature range 650 - 1350 K, as a mix of material with solar abundances is cooled (or heated) tinder equilibrium conditions. Their relative abundances in chondritic meteorites are solar (or "cosmic", as defined by the composition of Cl meteorites) to within a factor of several, but vary within that range in a way that correlates remarkably well with condensation temperature, independent of chemical affinity. It has been argued that this correlation reflects a systematically selective process which favored the accretion of refractory material over volatile material from a cooling nebula. Wasson and Chou (Meteoritics 9, 69-94, 1974, and Wasson and co-authors in subsequent papers) suggested that condensation and settling of solids contemporaneously with the cooling and removal of nebular gas could produce the observed abundance patterns, but a quantitative model has been lacking. We show that the abundance patterns of the moderately volatile elements in chondritic meteorites can be produced, in some degree of quantitative detail, by models of the solar nebula that are designed to conform to observations of T Tauri stars and the global conservation laws. For example, even if the local surface density of the nebula is not decreasing, condensation and accretion of solids from radially inflowing gas in a cooling nebula can result in depletions of volatiles, relative to refractories, like those observed, The details of the calculated abundance patterns depend on (but are not especially sensitive to) model parameters, and can exhibit the variations that distinguish the meteorite classes. Thus it appears that nebula characteristics such as cooling rates, radial flow velocities, and particle accumulation rates can be quantitatively constrained by demanding that they conform to meteoritic data; and the models, in turn, can produce testable hypotheses regarding the time and location of the

  20. Effects of Chemical Abundances on the Structure and Dynamics of the Solar Atmosphere

    NASA Astrophysics Data System (ADS)

    Demarque, Pierre; Basu, S.; Robinson, F.; Hunter, C.; Kallinger, T.

    2008-05-01

    This paper presents a comparison between two three-dimensional radiative hydrodynamical (3D RHD) simulations of the solar outer layers using the Grevesse & Sauval (1998; GS98) and the Asplund, Grevesse & Sauval (2005; AGS05) mixtures, respectively. The AGS05 mixture is a revision of the solar abundance mixture using a model atmosphere based on the stratification and dynamics of a solar 3D RHD simulation performed with the GS98 mixture, using the code of Stein & Nordlund (1989, 1998). Our simulations use the same code, and physically realistic treatment of radiative opacities and equation of state as Robinson et al. (2003). A comparison between our GS98 and AGS05 3D simulations shows differences both in the mean vertical temperature gradient and in the turbulent velocity field in the line forming region of the solar atmosphere. The whole superadiabatic layer (SAL) in the AGS05 simulation, including its peak, is shifted outward with respect to the GS98 SAL. Turbulent velocities, critical for absorption line profile calculations, are larger in the AGS05 simulation by about 10%. Since opacities for the AGS05 mixture are lower than those for the GS98 mixture, the T-τ relations derived from the two simulations are different. At 5000K, τ obtained from the GS98 simulation is about 30% larger than that obtained from the AGS05 simulation. These results show the importance of preserving self consistency in the chemical abundances between the model atmosphere and the 3D HRD simulation. When deriving the solar abundances, one must iterate the chemical composition in the model atmosphere, and hence in the 3D simulation on which the atmosphere is based. This research was supported in part by NASA/ATP grant NAG5-13299 (PD and FR) and NSF grant ATM 0348837 to SB.

  1. Earth--abundant water--splitting catalysts coupled to silicon solar cells for solar--to--fuels conversion

    NASA Astrophysics Data System (ADS)

    Cox, Casandra R.

    Direct solar--to--fuels conversion can be achieved by coupling semiconductors with water--splitting catalysts. A 10% or higher solar to fuels conversion is minimally necessary for the realization of a robust future technology. Many water--splitting devices have been proposed but due to expensive designs and/or materials, none have demonstrated the necessary efficiency at low--cost that is a requisite for large--scale implementation. In this thesis, a modular approach is used to couple water--splitting catalysts with crystalline silicon (c--Si) photovoltaics, with ultimate goal of demonstrating a stand--alone and direct solar-to-fuels water--splitting device comprising all non--precious, technology ready, materials. Since the oxygen evolution reaction is the key efficiency--limiting step for water--splitting, we first focus on directly interfacing oxygen evolution catalysts with c--Si photovoltaics. Due to the instability of silicon under oxidizing conditions, a protective interface between the PV and OER catalyst is required. This coupling of catalyst to Si semiconductor thus requires optimization of two interfaces: the silicon|protective layer interface; and, the protective layer|catalyst interface. A modular approach allows for the independent optimization and analysis of these two interfaces. A stand--alone water--splitting device based on c--Si is created by connecting multiple single junction c-Si solar cells in series. Steady--state equivalent circuit analysis allows for a targeted solar--to--fuels efficiency to be designed within a predictive framework for a series--connected c--Si solar cells and earth--abundant water--splitting catalysts operating at neutral pH. Guided by simulation and modeling, a completely modular, stand--alone water--splitting device possessing a 10% SFE is demonstrated. Importantly, the modular approach enables facile characterization and trouble--shooting for each component of the solar water--splitting device. Finally, as direct

  2. The Future of Using Earth-Abundant Elements in Counter Electrodes for Dye-Sensitized Solar Cells.

    PubMed

    Briscoe, Joe; Dunn, Steve

    2016-05-01

    With limited global resources for many of the elements that are found in some of the most common renewable energy technologies, there is a growing need to use "Earth-abundant" elements as a long-term solution to growing energy demands. The dye-sensitized solar cell has the potential to produce low-cost renewable energy, with inexpensive production and most components using Earth-abundant elements. However, the most commonly used material for the cell counter electrode (CE) is platinum, an extremely expensive and rare element. A selection of the materials investigated as alternative CEs are discussed, including metal sulfides, oxides, carbides, and nitrides and carbon-based materials such as carbon nanotubes, graphene, and conductive polymers. As well as having the potential for lower cost, these materials can also produce more-efficient devices due to their high surface area and catalytic activity. Therefore, once issues such as stability have been studied in more detail and scale-up of production methods are considered, there is a very promising future for the replacement of Pt in DSSCs with lower-cost, Earth-abundant alternatives.

  3. The Future of Using Earth-Abundant Elements in Counter Electrodes for Dye-Sensitized Solar Cells.

    PubMed

    Briscoe, Joe; Dunn, Steve

    2016-05-01

    With limited global resources for many of the elements that are found in some of the most common renewable energy technologies, there is a growing need to use "Earth-abundant" elements as a long-term solution to growing energy demands. The dye-sensitized solar cell has the potential to produce low-cost renewable energy, with inexpensive production and most components using Earth-abundant elements. However, the most commonly used material for the cell counter electrode (CE) is platinum, an extremely expensive and rare element. A selection of the materials investigated as alternative CEs are discussed, including metal sulfides, oxides, carbides, and nitrides and carbon-based materials such as carbon nanotubes, graphene, and conductive polymers. As well as having the potential for lower cost, these materials can also produce more-efficient devices due to their high surface area and catalytic activity. Therefore, once issues such as stability have been studied in more detail and scale-up of production methods are considered, there is a very promising future for the replacement of Pt in DSSCs with lower-cost, Earth-abundant alternatives. PMID:26727984

  4. VizieR Online Data Catalog: Chemical abundances of solar analogues (Adibekyan+, 2016)

    NASA Astrophysics Data System (ADS)

    Adibekyan, V.; Delgado-Mena, E.; Figueira, P.; Sousa, S. G.; Santos, N. C.; Gonzalez Hernandez, J. I.; Minchev, I.; Faria, J. P.; Israelian, G.; Harutyunyan, G.; Suarez-Andres, L.; Hakobyan, A. A.

    2016-06-01

    To understand if the abundance trend observed with the condensation temperature is a function of Galactocentric distances for a fixed age of stars, we selected about 40 stars with ages similar to that of the Sun but with different mean Galactocentric distances from the Geneva-Copenhagen Survey sample (GCS, Nordstroem et al., 2004A&A...418..989N, Cat. V/117): with the smallest (Rmean~6.5kpc), largest (Rmean~9kpc), and solar (Rmean~8kpc) Galactocentric Rmean values. High-resolution and high signal-to-noise (S/N) spectra for these stars were obtained by performing new observations with HARPS (22 stars) and UVES (six stars) ESO spectrographs, and by extracting spectra for 14 stars from the ESO archive. The file param.dat lists the stellar parameters of the stars. The file abund.dat lists the derived abundances of the elements for each star. (2 data files).

  5. Abundance and composition of solar KR in the H3-H6 chondrite ACFER111

    NASA Technical Reports Server (NTRS)

    Pedroni, A.

    1993-01-01

    He/Ne, Ne/Ar, and Ar/Kr abundance ratios of solar gases extracted by stepped heating, stepped oxidation, and stepped etching of lunar and meteoritic regoliths are significantly lower than ratios measured directly or predicted by model estimates. Of these, the differences in the He/Ne and Ne/Ar ratios are explained to be owing to diffusive fractionation losses from the host minerals. In contrast, it remains controversial if the Ar/Kr and Kr/Xe ratios were fractionated prior to or after the implantation of the gases into the minerals. In the H3-H6 chondritic regolith breccia ACFER 111, measured He/Ne and Ne/Ar ratios appear to be of nearly unfractionated solar composition. The Ar/Kr ratio of ACFER 111, might thus be also unfractionated. We examined by stepped etching a metal sample of ACFER 111 and obtained an average solar 36Ar/84Kr = 3150 plus or minus 300 which is in agreement with the model predictions. The isotopic composition of solar Kr was observed to change in the course of the etching in a way very similar to that report for lunar ilmenites by the Zurich group. This can be interpreted as a change of the mixing ratio of Solar Wind (SW) and Solar Energetic Particles (SEP). The isotopic composition of the SEP component obtained from our Kr data, however, is distinct from that reported by the Zurich group.

  6. Hydrogen, helium, and other solar-wind components in lunar soil - Abundances and predictions

    NASA Technical Reports Server (NTRS)

    Taylor, Lawrence A.

    1990-01-01

    The lack of a shielding atmosphere on the moon permits solar-wind particles to impinge upon the lunar soil and become implanted into the various phases which comprise the soil. Relatively large quantities of solar-wind implanted hydrogen (50-100 ppm) and helium (10-50 ppm) are present. The measured parameter of I(s)FeO, a direct indicator of maturity and exposure age, can be used as a first approximation to predict the abundances of many solar-wind components in the soils. However, because ilmenite acts as a 'sponge' for the retention of certain elements, the TiO2 content of the soil is a better indicator for hydrogen and helium contents.

  7. High Precision Abundances of the Old Solar Twin HIP 102152: Insights on Li Depletion from the Oldest Sun

    NASA Astrophysics Data System (ADS)

    Monroe, TalaWanda R.; Meléndez, Jorge; Ramírez, Iván; Yong, David; Bergemann, Maria; Asplund, Martin; Bedell, Megan; Tucci Maia, Marcelo; Bean, Jacob; Lind, Karin; Alves-Brito, Alan; Casagrande, Luca; Castro, Matthieu; do Nascimento, José-Dias; Bazot, Michael; Freitas, Fabrício C.

    2013-09-01

    We present the first detailed chemical abundance analysis of the old 8.2 Gyr solar twin, HIP 102152. We derive differential abundances of 21 elements relative to the Sun with precisions as high as 0.004 dex (lsim1%), using ultra high-resolution (R = 110,000), high S/N UVES spectra obtained on the 8.2 m Very Large Telescope. Our determined metallicity of HIP 102152 is [Fe/H] = -0.013 ± 0.004. The atmospheric parameters of the star were determined to be 54 K cooler than the Sun, 0.09 dex lower in surface gravity, and a microturbulence identical to our derived solar value. Elemental abundance ratios examined versus dust condensation temperature reveal a solar abundance pattern for this star, in contrast to most solar twins. The abundance pattern of HIP 102152 appears to be the most similar to solar of any known solar twin. Abundances of the younger, 2.9 Gyr solar twin, 18 Sco, were also determined from UVES spectra to serve as a comparison for HIP 102152. The solar chemical pattern of HIP 102152 makes it a potential candidate to host terrestrial planets, which is reinforced by the lack of giant planets in its terrestrial planet region. The following non-local thermodynamic equilibrium Li abundances were obtained for HIP 102152, 18 Sco, and the Sun: log epsilon (Li) = 0.48 ± 0.07, 1.62 ± 0.02, and 1.07 ± 0.02, respectively. The Li abundance of HIP 102152 is the lowest reported to date for a solar twin, and allows us to consider an emerging, tightly constrained Li-age trend for solar twin stars. Based on observations obtained at the European Southern Observatory (observing programs 083.D-0871 and 188.C-0265).

  8. HIGH PRECISION ABUNDANCES OF THE OLD SOLAR TWIN HIP 102152: INSIGHTS ON Li DEPLETION FROM THE OLDEST SUN

    SciTech Connect

    Monroe, TalaWanda R.; Melendez, Jorge; Tucci Maia, Marcelo; Freitas, Fabricio C.; Yong, David; Asplund, Martin; Alves-Brito, Alan; Casagrande, Luca; Bergemann, Maria; Bedell, Megan; Bean, Jacob; Lind, Karin; Castro, Matthieu; Do Nascimento, Jose-Dias; Bazot, Michael

    2013-09-10

    We present the first detailed chemical abundance analysis of the old 8.2 Gyr solar twin, HIP 102152. We derive differential abundances of 21 elements relative to the Sun with precisions as high as 0.004 dex ({approx}<1%), using ultra high-resolution (R = 110,000), high S/N UVES spectra obtained on the 8.2 m Very Large Telescope. Our determined metallicity of HIP 102152 is [Fe/H] = -0.013 {+-} 0.004. The atmospheric parameters of the star were determined to be 54 K cooler than the Sun, 0.09 dex lower in surface gravity, and a microturbulence identical to our derived solar value. Elemental abundance ratios examined versus dust condensation temperature reveal a solar abundance pattern for this star, in contrast to most solar twins. The abundance pattern of HIP 102152 appears to be the most similar to solar of any known solar twin. Abundances of the younger, 2.9 Gyr solar twin, 18 Sco, were also determined from UVES spectra to serve as a comparison for HIP 102152. The solar chemical pattern of HIP 102152 makes it a potential candidate to host terrestrial planets, which is reinforced by the lack of giant planets in its terrestrial planet region. The following non-local thermodynamic equilibrium Li abundances were obtained for HIP 102152, 18 Sco, and the Sun: log {epsilon} (Li) = 0.48 {+-} 0.07, 1.62 {+-} 0.02, and 1.07 {+-} 0.02, respectively. The Li abundance of HIP 102152 is the lowest reported to date for a solar twin, and allows us to consider an emerging, tightly constrained Li-age trend for solar twin stars.

  9. Hydrogen energy - An inexhaustible abundant clean energy system

    NASA Astrophysics Data System (ADS)

    Nayar, M. G.

    1981-04-01

    A review is presented of various hydrogen production processes from possible primary energy resources. The processes covered are nuclear coal gasification, thermochemical hydrogen production, and hydrogen production by electrolysis, which includes solid polymer electrolyte-based electrolyzers, high-temperature electrolyzers, and photoelectrochemical decomposition of water. Attention is given to hydrogen transport and storage (in metal hydride systems) and to its application as an automotive fuel. Hydrogen as a secondary energy source is also discussed, and its uses as an off-peak power storage medium and as an energy transmission medium are described. Costs, flow diagrams and chemical formulas are analyzed in detail.

  10. Solar energy applications in telecommunications

    NASA Astrophysics Data System (ADS)

    Girard, J.

    The results of a half-decade of a coupled wind-photovoltaic powered, remotely sited telecommunications installation called 'Aerosolec' are reported. A station is examined which was situated at 500 m altitude between Nice and Monaco and comprised a 4 module solar cell plant generating 180 W, a 300 W windpowered generator, and a battery bank. The batteries were linked by a diode, charged by the photovoltaics only when load was met, and provided voltage when the wind/solar cell configuration failed to produce enough power to meet demand. Output of the generators and meteorological parameters were recorded for two years. The station drew a nominal 180W, which was met by the power systems, and involved an actual extra discharge of excess energy. Other, similar stations are outlined, and the use of coupled wind/solar systems for telephone service in remote sites, for optic fiber repeaters, and for telephone relay station are recommended. Cost advantages are seen with the solar/wind systems over liquid hydrocarbon fueled generator systems for low power demand installations.

  11. Solar Fe abundance and magnetic fields. Towards a consistent reference metallicity

    NASA Astrophysics Data System (ADS)

    Fabbian, D.; Moreno-Insertis, F.; Khomenko, E.; Nordlund, Å.

    2012-12-01

    Aims: We investigate the impact on Fe abundance determination of including magnetic flux in series of 3D radiation-magnetohydrodynamics (MHD) simulations of solar convection, which we used to synthesize spectral intensity profiles corresponding to disc centre. Methods: A differential approach is used to quantify the changes in theoretical equivalent width of a set of 28 iron spectral lines spanning a wide range in wavelength, excitation potential, oscillator strength, Landé factor, and formation height. The lines were computed in local thermodynamic equilibrium (LTE) using the spectral synthesis code LILIA. We used input magnetoconvection snapshots covering 50 min of solar evolution and belonging to series having an average vertical magnetic flux density of ⟨ Bvert ⟩ = 0,50,100, and 200 G. For the relevant calculations we used the Copenhagen Stagger code. Results: The presence of magnetic fields causes both a direct (Zeeman-broadening) effect on spectral lines with non-zero Landé factor and an indirect effect on temperature-sensitive lines via a change in the photospheric T - τ stratification. The corresponding correction in the estimated atomic abundance ranges from a few hundredths of a dex up to |Δlog ɛ(Fe)⊙| ~ 0.15 dex, depending on the spectral line and on the amount of average magnetic flux within the range of values we considered. The Zeeman-broadening effect gains relatively more importance in the IR. The largest modification to previous solar abundance determinations based on visible spectral lines is instead due to the indirect effect, i.e., the line-weakening caused by a warmer stratification as seen on an optical depth scale. Our results indicate that the average solar iron abundance obtained when using magnetoconvection models can be ~ 0.03-0.11 dex higher than when using the simpler hydrodynamics (HD) convection approach. Conclusions: We demonstrate that accounting for magnetic flux is important in state-of-the-art solar photospheric

  12. Solar energy in buildings: Implications for California energy policy

    NASA Technical Reports Server (NTRS)

    Hirshberg, A. S.; Davis, E. S.

    1977-01-01

    An assessment of the potential of active solar energy systems for buildings in California is summarized. The technology used for solar heating, cooling, and water heating in buildings is discussed. The major California weather zones and the solar energy designs are described, as well as the sizing of solar energy systems and their performance. The cost of solar energy systems is given both at current prices and at prices consistent with optimistic estimates for the cost of collectors. The main institutional barriers to the wide spread use of solar energy are summarized.

  13. Analyzing Stellar Bio-Essential Element Abundances in the Solar Neighborhood

    NASA Astrophysics Data System (ADS)

    Hinkel, N. R.; Kane, S.

    2013-12-01

    We present results from a compilation of abundance data for stars found near to the Sun, within 150 pc, as part of the Hypatia Catalog (Hinkel et al. 2013, in review). Hypatia contains spectroscopic abundance data for 50 elements within 3069 stars from literature sources. Our focus has been on determining chemical trends specific to bio-essential elements -- namely: C, N, O, Mg, S, Ti, as well as many others. We have also carefully analyzed the abundances with respect to known exoplanets and their characteristics, in order to find possible Earthlike planets. The habitability of an exoplanet is strongly related to the physical properties of the host star. This is what determines the "habitable zone," or region surrounding a star at which a planet is able to reach and maintain a temperature conducive to life. The element abundances measured in the atmosphere of the host star also acts as a proxy for the abundances found within the planet. The composition of the planet is particularly important when determining if the planet is habitable because they provide the building blocks from which life may start. Therefore, we seek to find those patterns in our solar neighborhood that already possess bio-essential elements, such as C, N, O, Mg, S, Ti, in hopes of finding habitable, Earthlike exoplanets. By using Hypatia, we have confirmed the evidence that the [Fe/H] abundance ratio is related to the presence of planets. We have also examined the ratios of the bio-essential elements within the confirmed host-stars as compared to the non-host stars, for example, between Alpha Centauri A (non-host) and B (host) in Hinkel & Kane (2013), see figure. This comparison has lead us to conclude the possible existence of a yet undiscovered planet around Alpha Cen A. We have also found, more generally, that enriched bio-essential abundances are present in lower mass planets and are also seen in planets with orbital periods greater than 300 days. It is through the analysis of these bio

  14. Solar: A Clean Energy Source for Utilities

    SciTech Connect

    Solar Energy Technologies Program

    2010-09-28

    The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts with utilities to remove the technical, regulatory, and market challenges they face in deploying solar technologies.

  15. Variations of the relative abundances of He, (C,N,O) and Fe-group nuclei in solar cosmic rays and their relationship to solar particle acceleration

    NASA Technical Reports Server (NTRS)

    Bertsch, D. L.; Biswas, S.; Fichtel, C. E.; Pellerin, C. J.; Reames, D. V.

    1973-01-01

    Measurements of the flux of helium nuclei in the 24 January 1971 event and of helium and (C,N,O) nuclei in the 1 September 1971 event are combined with previous measurements to obtain the relative abundances of helium, (C,N,O), and Fe-group nuclei in these events. These data are then summarized together with previously reported results to show that, even when the same detector system using a dE/dx plus range technique is used, differences in the He/(C,N,O) value in the same energy/nucleon interval are observed in solar cosmic ray events. Further, when the He/(C,N,O) value is lower the He/(Fe-group nuclei) value is also systematically lower in these large events. When solar particle acceleration theory is analyzed, it is seen that the results suggest that, for large events, Coulomb energy loss probably does not play a major role in determining solar particle composition at higher energies (10 MeV). The variations in multicharged nuclei composition are more likely due to partial ionization during the acceleration phase.

  16. A Case for Solar Energy Education.

    ERIC Educational Resources Information Center

    Goodkind, Thomas

    1978-01-01

    Describing the need for energy alternatives in the U.S. which consumes 33 percent of the world's petroleum output, this article advocates educational leadership via solar energy education, maintaining that solar energy education can become the catalyst for energy education in our schools because it is fresh, visible, and challenging. (JC)

  17. Cocoon drying through solar energy

    SciTech Connect

    Kulunk, M.

    1983-12-01

    In this paper, silk cocoon drying operations through solar energy have been presented. Nearly no comprehensive work has been appeared in literature on this unusual application. General mechanism of solar drying methods are presented by some authors for instance, Roman and Jindal. This application seems vitally significant for silk cocoon producer countries like Turkey. The rate of production accelerates year by year and it is about 3000 tons per year presently in Turkey. In Turkey, by now and currently, a water vapour chamber is utilized in the killing process of silkworm. Vapour produced by burning of conventional fuels posses many drawbacks beside being very expensive and also non-renewable. Vapour effects the quality and quantity of silk thread negatively. For instance, the colour of silk cocoon tends to turn to pale instead of being gleamy. This is not tolerable. The length and mass of silk thread obtained per a typical cocoon sample is increased about 10.1 and 16.5 per cent respectively in the average by using solar energy.

  18. Abundance ratios of oxygen, neon, and magnesium in solar active regions and flares: The FIP effect

    NASA Technical Reports Server (NTRS)

    Widing, K. G.; Feldman, U.

    1995-01-01

    Relative abundances of oxygen, neon, and magnesium have been derived for a sample of nine solar active regions, flares, and an erupting prominance by combining plots of the ion differential emission measures. The observations were photographed in the 300-600 A range by the Naval Research Laboratory (NRL) spectroheliograph on Skylab. Methods for deriving the Mg/Ne abundance ratio-which measures the separation between the low- first ionization potential (FIP) and high-FIP abundnace plateaus-have been described in previous papers. In this paper we describe the spectroscopic methods for deriving the O/Ne abundance ratio, which gives the ratio between two high-FIP elements. The plot of the O/Ne ratio versus the Mg/Ne ratio in the sample of nine Skylab events is shown. The variation in the Mg/Ne ratio by a factor of 6 is associated with a much smaller range in the O/Ne ratio. This is broadly consistent with the presence of the standard FIP pattern of abundances in the outer atmosphere of the Sun. However, a real change in the relative abundances of oxygen and neon by a factor of 1.5 cannot be excluded.

  19. NON-WKB MODELS OF THE FIRST IONIZATION POTENTIAL EFFECT: IMPLICATIONS FOR SOLAR CORONAL HEATING AND THE CORONAL HELIUM AND NEON ABUNDANCES

    SciTech Connect

    Laming, J. Martin

    2009-04-20

    We revisit in more detail a model for element abundance fractionation in the solar chromosphere that gives rise to the 'first ionization potential (FIP) effect' in the solar corona and wind. Elements with first ionization potential below about 10 eV, i.e., those that are predominantly ionized in the chromosphere, are enriched in the corona by a factor of 3-4. We model the propagation of Alfven waves through the chromosphere using a non-WKB treatment, and evaluate the ponderomotive force associated with these waves. Under solar conditions, this is generally pointed upward in the chromosphere, and enhances the abundance of chromospheric ions in the corona. Our new approach captures the essentials of the solar coronal abundance anomalies, including the depletion of He relative to H, and also the putative depletion of Ne, recently discussed in the literature. We also argue that the FIP effect provides the strongest evidence to date for energy fluxes of Alfven waves sufficient to heat the corona. However, it appears that these waves must also be generated in the corona, in order to preserve the rather regular fractionation pattern without strong variations from loop to loop observed in the solar corona and slow-speed solar wind.

  20. A large detector for cosmic ray abundance and energy measurements

    NASA Astrophysics Data System (ADS)

    Alsop, C.

    A large aperture, balloon borne cosmic ray detector was designed to measure the energy spectra of individual cosmic ray species with Z greater than 8 in the energy range 0.3GeV/N to 400GeV/N. The energy dependence of the abundance spectrum extending up to such high energies will provide valuable data for determining the nature of the origin and propagation of cosmic rays in the Galaxy. The properties of cosmic ray nuclei and the interpretation of the energy dependence of the abundance spectrum are discussed. The design and response of the BUGS IV cosmic ray detector are described. The measurement techniques used are gas scintillation, gas proportional scintillation and Cerenkov radiation from both gases and solids. The light collection properties of the detector and several experimental investigations of the light collection efficiency of the drift chamber region are described. The expected signals from the gas scintillation and gas Cerenkov emissions are predicted and the choice of a suitable scintillating gas mixture for minimizing the uncertainty in the charge and energy measurements is considered. The theoretical aspects of electron drift and diffusion in gases and several experimental investigations on the electron drift in the BUGS IV drift chamber are given. Also some preliminary results from a uniform field drift chamber are included which demonstrate the sensitivity of the electron drift velocity in inert gas mixtures to water vapor contamination. The expected overall performance of BUGS IV and the results of an experimental simulation of the parachute landing of the detector are given.

  1. Energy Conversion: Nano Solar Cell

    NASA Astrophysics Data System (ADS)

    Yahaya, Muhammad; Yap, Chi Chin; Mat Salleh, Muhamad

    2009-09-01

    Problems of fossil-fuel-induced climate change have sparked a demand for sustainable energy supply for all sectors of economy. Most laboratories continue to search for new materials and new technique to generate clean energy at affordable cost. Nanotechnology can play a major role in solving the energy problem. The prospect for solar energy using Si-based technology is not encouraging. Si photovoltaics can produce electricity at 20-30 c//kWhr with about 25% efficiency. Nanoparticles have a strong capacity to absorb light and generate more electrons for current as discovered in the recent work of organic and dye-sensitized cell. Using cheap preparation technique such as screen-printing and self-assembly growth, organic cells shows a strong potential for commercialization. Thin Films research group at National University Malaysia has been actively involved in these areas, and in this seminar, we will present a review works on nanomaterials for solar cells and particularly on hybrid organic solar cell based on ZnO nanorod arrays. The organic layer consisting of poly[2-methoxy-5-(2-ethylhexyloxy)-1, 4-phenylenevinylene] (MEHPPV) and [6, 6]-phenyl C61-butyric acid 3-ethylthiophene ester (PCBE) was spin-coated on ZnO nanorod arrays. ZnO nanorod arrays were grown on FTO glass substrates which were pre-coated with ZnO nanoparticles using a low temperature chemical solution method. A gold electrode was used as the top contact. The device gave a short circuit current density of 2.49×10-4 mA/cm2 and an open circuit voltage of 0.45 V under illumination of a projector halogen light at 100 mW/cm2.

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

    NASA Technical Reports Server (NTRS)

    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.

  3. Solar Energy Education. Renewable energy activities for earth science

    SciTech Connect

    Not Available

    1980-01-01

    A teaching manual is provided to aid teachers in introducing renewable energy topics to earth science students. The main emphasis is placed on solar energy. Activities for the student include a study of the greenhouse effect, solar gain for home heating, measuring solar radiation, and the construction of a model solar still to obtain fresh water. Instructions for the construction of apparatus to demonstrate a solar still, the greenhouse effect and measurement of the altitude and azimuth of the sun are included. (BCS)

  4. Solar Energy Education. Renewable energy: a background text. [Includes glossary

    SciTech Connect

    Not Available

    1985-01-01

    Some of the most common forms of renewable energy are presented in this textbook for students. The topics include solar energy, wind power hydroelectric power, biomass ocean thermal energy, and tidal and geothermal energy. The main emphasis of the text is on the sun and the solar energy that it yields. Discussions on the sun's composition and the relationship between the earth, sun and atmosphere are provided. Insolation, active and passive solar systems, and solar collectors are the subtopics included under solar energy. (BCS)

  5. The initial abundance and distribution of 92Nb in the Solar System

    NASA Astrophysics Data System (ADS)

    Iizuka, Tsuyoshi; Lai, Yi-Jen; Akram, Waheed; Amelin, Yuri; Schönbächler, Maria

    2016-04-01

    Niobium-92 is an extinct proton-rich nuclide, which decays to 92Zr with a half-life of 37 Ma. This radionuclide potentially offers a unique opportunity to determine the timescales of early Solar System processes and the site(s) of nucleosynthesis for p-nuclei, once its initial abundance and distribution in the Solar System are well established. Here we present internal Nb-Zr isochrons for three basaltic achondrites with known U-Pb ages: the angrite NWA 4590, the eucrite Agoult, and the ungrouped achondrite Ibitira. Our results show that the relative Nb-Zr isochron ages of the three meteorites are consistent with the time intervals obtained from the Pb-Pb chronometer for pyroxene and plagioclase, indicating that 92Nb was homogeneously distributed among their source regions. The Nb-Zr and Pb-Pb data for NWA 4590 yield the most reliable and precise reference point for anchoring the Nb-Zr chronometer to the absolute timescale: an initial 92Nb/93Nb ratio of (1.4 ± 0.5) ×10-5 at 4557.93 ± 0.36 Ma, which corresponds to a 92Nb/93Nb ratio of (1.7 ± 0.6) ×10-5 at the time of the Solar System formation. On the basis of this new initial ratio, we demonstrate the capability of the Nb-Zr chronometer to date early Solar System objects including troilite and rutile, such as iron and stony-iron meteorites. Furthermore, we estimate a nucleosynthetic production ratio of 92Nb to the p-nucleus 92Mo between 0.0015 and 0.035. This production ratio, together with the solar abundances of other p-nuclei with similar masses, can be best explained if these light p-nuclei were primarily synthesized by photodisintegration reactions in Type Ia supernovae.

  6. More Efficient Solar Thermal-Energy Receiver

    NASA Technical Reports Server (NTRS)

    Dustin, M. O.

    1987-01-01

    Thermal stresses and reradiation reduced. Improved design for solar thermal-energy receiver overcomes three major deficiencies of solar dynamic receivers described in literature. Concentrator and receiver part of solar-thermal-energy system. Receiver divided into radiation section and storage section. Concentrated solar radiation falls on boiling ends of heat pipes, which transmit heat to thermal-energy-storage medium. Receiver used in number of applications to produce thermal energy directly for use or to store thermal energy for subsequent use in heat engine.

  7. Closed landfills to solar energy power plants: Estimating the solar potential of closed landfills in California

    NASA Astrophysics Data System (ADS)

    Munsell, Devon R.

    Solar radiation is a promising source of renewable energy because it is abundant and the technologies to harvest it are quickly improving. An ongoing challenge is to find suitable and effective areas to implement solar energy technologies without causing ecological harm. In this regard, one type of land use that has been largely overlooked for siting solar technologies is closed or soon to be closed landfills. Utilizing Geographic Information System (GIS) based solar modeling; this study makes an inventory of solar generation potential for such sites in the state of California. The study takes account of various site characteristics in relation to the siting needs of photovoltaic (PV) geomembrane and dish-Stirling technologies (e.g., size, topography, closing date, solar insolation, presence of landfill gas recovery projects, and proximity to transmission grids and roads). This study reaches the three principal conclusions. First, with an estimated annual solar electricity generation potential of 3.7 million megawatt hours (MWh), closed or soon to be closed landfill sites could provide an amount of power significantly larger than California's current solar electric generation. Secondly, the possibility of combining PV geomembrane, dish-Stirling, and landfill gas (LFG) to energy technologies at particular sites deserves further investigation. Lastly, there are many assumptions, challenges, and limitations in conducting inventory studies of solar potential for specific sites, including the difficulty in finding accurate data regarding the location and attributes of potential landfills to be analyzed in the study. Furthermore, solar modeling necessarily simplifies a complex phenomenon, namely incoming solar radiation. Additionally, site visits, while necessary for finding details of the site, are largely impractical for a large scale study.

  8. Solar wind iron abundance variations at solar wind speeds up to 600 km s sup -1, 1972 to 1976

    NASA Technical Reports Server (NTRS)

    Mitchell, D. G.; Roelof, E. C.; Bame, S. J.

    1982-01-01

    The Fe/H ratios in the peaks of high speed streams (HSS) were analyzed during the decline of Solar Cycle 20 and the following minimum (October 1972 to December 1976). The response of the 50 to 200 keV ion channel of the APL/JHU energetic particle experiment (EPE) on IMP-7 and 8 was utilized to solar wind iron ions at high solar wind speeds (V or = 600 km/sec). Fe measurements with solar wind H and He parameters were compared from the Los Alamos National Laboratory (LANL) instruments on the same spacecraft. In general, the Fe distribution parameters (bulk velocity, flow direction, temperature) are found to be similar to the LANL He parameters. Although the average Fe/H ration in many steady HSS peaks agrees within observational uncertainties with the nominal coronal ratio of 4.7 x 0.00001, abundance variations of a factor of up to 6 are obtained across a given coronal-hole associated HSS.

  9. Relative elemental abundance and heating constraints determined for the solar corona from SERTS measurements

    NASA Technical Reports Server (NTRS)

    Falconer, David A.

    1994-01-01

    Intensities of EUV spectral lines were measured as a function of radius off the solar limb by two flights of Goddard's Solar EUV Rocket Telescope and Spectrograph (SERTS) for three quiet sun regions. The density scale height, line-ratio densities, line-ratio temperatures, and emission measures were determined. The line-ratio temperature determined from the ionization balances of Arnaud and Rothenflug (1985) were more self-consistent than the line-ratio temperatures obtained from the values of Arnaud and Raymond (1992). Limits on the filling factor were determined from the emission measure and the line-ratio densities for all three regions. The relative abundances of silicon, aluminum, and chromium to iron were determined. Results did agree with standard coronal relative elemental abundances for one observation, but did not agree for another. Aluminum was overabundant while silicon was underabundant. Heating was required above 1.15 solar radii for all three regions studied. For two regions, local nonconductive heating is needed for any filling factor, and in all three regions for filling factor of 0.1.

  10. Improving Air Quality with Solar Energy

    DOE R&D Accomplishments Database

    2008-04-01

    This fact sheet series highlights how renewable energy and energy efficiency technologies can and are being used to reduce air emissions and meet environmental goals, showcasing case studies and technology-specific topics. This one focus on solar energy technologies.

  11. MULTIFUNCTIONAL SOLAR ENERGY SYSTEMS RESEARCH PROJECT

    SciTech Connect

    Byard Wood, Lance Seefeldt, Ronald Sims, Bradley Wahlen, and Dan Dye

    2012-06-29

    The solar energy available within the visible portion of the solar spectrum is about 300 W/m2 (43%) and that available in the UV and IR portion is about 400 W/m2 (57%). This provides opportunities for developing integrated energy systems that capture and use specific wavelengths of the solar spectrum for different purposes. For example: biofuels from photosynthetic microbes use only the visible light; solar cells use a narrow band of the solar spectrum that could be either mostly in the visible or in the IR regions of the solar spectrum, depending on the photovoltaic materials, e.g., gallium antimonide (GaSb) cells utilize predominately IR radiation; and finally, solar panels that heat water utilize a broad range of wavelengths (visible plus IR). The basic idea of this research is that sunlight has many possible end-use applications including both direct use and energy conversion schemes; it is technically feasible to develop multifunctional solar energy systems capable of addressing several end-use needs while increasing the overall solar energy utilization efficiency when compared to single-purpose solar technologies. Such a combination of technologies could lead to more cost-competitive ?multifunctional? systems that add value and broaden opportunities for integrated energy systems. The goal of this research is to increase the overall energy efficacy and cost competitiveness of solar systems. The specific objectives of this research were: 1) Evaluate the efficacy of a combined photobioreactor and electric power system; 2) Improve the reliability and cost effectiveness of hybrid solar lighting systems ? a technology in which sunlight is collected and distributed via optical fibers into the interior of a building; 3) Evaluate the efficacy of using filtered light to increase the production of biomass in photobioreactors and provide more solar energy for other uses; 4) Evaluates several concepts for wavelength shifting such that a greater percentage of the solar

  12. Nanostructured solar irradiation control materials for solar energy conversion

    NASA Astrophysics Data System (ADS)

    Kang, Jin Ho; Marshall, Iseley A.; Torrico, Mattew N.; Taylor, Chase R.; Ely, Jeffry; Henderson, Angel; Sauti, Godfrey; Gibbons, Luke J.; Kim, Jae-Woo; Park, Cheol; Lowther, Sharon E.; Lillehei, Peter T.; Bryant, Robert G.

    2012-10-01

    Tailoring the solar absorptivity (αs) and thermal emissivity (ɛT) 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 αs and ɛT 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 αs and μT 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.

  13. Nanostructured Solar Irradiation Control Materials for Solar Energy Conversion

    NASA Technical Reports Server (NTRS)

    Kang, Jinho; Marshall, I. A.; Torrico, M. N.; Taylor, C. R.; Ely, Jeffry; Henderson, Angel Z.; Kim, J.-W.; Sauti, G.; Gibbons, L. J.; Park, C.; Lowther, S. E.; Lillehei, P. T.; Bryant, R. G.

    2012-01-01

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

  14. Combined solar collector and energy storage system

    NASA Technical Reports Server (NTRS)

    Jensen, R. N. (Inventor)

    1980-01-01

    A combined solar energy collector, fluid chiller and energy storage system is disclosed. A movable interior insulated panel in a storage tank is positionable flush against the storage tank wall to insulate the tank for energy storage. The movable interior insulated panel is alternately positionable to form a solar collector or fluid chiller through which the fluid flows by natural circulation.

  15. Teaching Children to Value Solar Energy

    ERIC Educational Resources Information Center

    Hugerat, Muhamad; Saker, Salem; Odeh, Saeed; Agbaria, Adnan

    2011-01-01

    In this educational initiative, we suggest to build a real model of solar village inside the school, which uses only solar energy. These educational initiatives emphasize the importance of energy for a technological society and the advantage of alternative energy sources. In this scientific educational initiative, the pupils in three elementary…

  16. A Revision to the Solar System Abundance and Condensation Temperature of Boron from Uncontaminated Falls

    NASA Astrophysics Data System (ADS)

    Zhai, M.; Shaw, D. M.

    1993-07-01

    We requested from participating museum curators interior fragments of chosen falls, never touched by water or other possible sources of B contamination. Thirty six were obtained, crushed, and analyzed for B by PGNAA (prompt gamma- ray neutron activation analyses) at McMaster University and at The National Institute of Standards and Technology. Boron concentrations are close to the sensitivity limit in both laboratories. Results agree well, but with slight systematic differences attributable to blank and background correction factors. Our results (Table 1) are similar to previous measurements on falls [1], but lower than in Antarctic meteorites [2,3], some of which are altered. To calculate the solar system abundance of B, the four carbonaceous chondrite analyses (Table 1) were used as follows. Since CM and CV meteorites contain 48% and 42% matrix [4], if the B ratio of inclusions/matrix is 0.17 [3], then the matrix of the four carbonaceous chondrites averages 0.97 ppm B. Taking the average Si abundance in CI to be 10.64% [5], the calculated solar system abundances from the four carbonaceous chondrites are 23.51, 22.54, 16.95, and 34.20, with a geometric mean of 23.5 B atom/10^6 Si atoms. For comparison, of 18 analyses of interior samples of falls and Antarctic carbonaceous chondrites [1,2,3], 12 have normalized matrix B between 17.6 and 31.4. A composite chondrite atomic composition was calculated for Mg, Na, Li, B, Ga, S, and Zn using their average abundances in H, L, LL, E, and CC meteorites, weighted by their fall frequencies [7] and normalized to Si and the CI abundance [5]. The values show a systematic decrease (Table 2). If this trend is related to volatility [8], then the condensation temperature of B should be between the condensation temperature of Li and Ga, at about 1125 degrees K. If the relative abundances of these elements are similar in the Earth's mantle except for Na [8], then Na appears to show a lower condensation temperature, similar to B. This

  17. The isotopic abundances of neon, magnesium and silicon nuclei accelerated in solar flares

    NASA Technical Reports Server (NTRS)

    Dietrich, W. F.; Simpson, J. A.

    1980-01-01

    Direct measurements of the relative abundance of the isotopes Ne-20 and Ne-22 are reported along with a preliminary value for the Mg-26/Mg-24 ratio and an upper limit to the abundance of Si-30 in solar flare accelerated nuclei. A Ne-20/Ne-22 ratio of 7.7 plus 2.3 or minus 1.7 is in agreement with the ratio for the component Neon-A found in carbonaceous chondrites, while a preliminary value of 0.22 plus or minus 0.07 for Mg-26/Mg-24 is larger by approximately one standard deviation than the expected ratio of 0.14 given by Cameron (1973).

  18. Solar Abundances of Rock Forming Elements, Extreme Oxygen and Hydrogen in a Young Polluted White Dwarf

    NASA Astrophysics Data System (ADS)

    Farihi, J.; Koester, D.; Zuckerman, B.; Vican, L.; Gänsicke, B. T.; Smith, N.; Walth, G.; Breedt, E.

    2016-09-01

    The Teff = 20 800 K white dwarf WD 1536+520 is shown to have broadly solar abundances of the major rock forming elements O, Mg, Al, Si, Ca, and Fe, together with a strong relative depletion in the volatile elements C and S. In addition to the highest metal abundances observed to date, including log (O/He) =-3.4, the helium-dominated atmosphere has an exceptional hydrogen abundance at log (H/He) =-1.7. Within the uncertainties, the metal-to-metal ratios are consistent with the accretion of an H2O-rich and rocky parent body, an interpretation supported by the anomalously high trace hydrogen. The mixed atmosphere yields unusually short diffusion timescales for a helium atmosphere white dwarf, of no more than a few hundred yr, and equivalent to those in a much cooler, hydrogen-rich star. The overall heavy element abundances of the disrupted parent body deviate modestly from a bulk Earth pattern, and suggest the deposition of some core-like material. The total inferred accretion rate is 4.2 × 109 g s-1, and at least 4 times higher than any white dwarf with a comparable diffusion timescale. Notably, when accretion is exhausted in this system, both metals and hydrogen will become undetectable within roughly 300 Myr, thus supporting a scenario where the trace hydrogen is related to the ongoing accretion of planetary debris.

  19. Solar Energy for Pacific Northwest Buildings.

    ERIC Educational Resources Information Center

    Reynolds, John S.

    Data presented in this report indicate that solar space and water heating are possible in the Pacific Northwest. The first section of the report contains solar records from several stations in the region illustrating space heating needs that could be met, on an average daily basis, by solar energy. The data are summarized, and some preliminary…

  20. Battle Keeps Solar Energy in Receiver

    NASA Technical Reports Server (NTRS)

    Mcdougal, A. R.; Hale, R. R.

    1982-01-01

    Mirror structure in solar concentrator reduces heat loss by reflection and reradiation. Baffle reflects entering rays back and forth in solar-concentrator receiver until they reach heat exchanger. Similarly, infrared energy reradiated by heat exchanger is prevented from leaving receiver. Surfaces of baffle and inside wall of receiver are polished and highly reflective at solar and infrared wavelengths.

  1. The Solar Energy Timetable. Worldwatch Paper 19.

    ERIC Educational Resources Information Center

    Hayes, Denis

    This publication proposes a timetable for converting the world economy to solar energy. The contents include: (1) A solar-powered world by 2025; (2) Heating and cooling; (3) Renewable fuels; (4) Electricity; (5) Getting there from here; and (6) Notes. Numerous facts are presented within these sections. International solar research programs are…

  2. Adaptive, full-spectrum solar energy system

    DOEpatents

    Muhs, Jeffrey D.; Earl, Dennis D.

    2003-08-05

    An adaptive full spectrum solar energy system having at least one hybrid solar concentrator, at least one hybrid luminaire, at least one hybrid photobioreactor, and a light distribution system operably connected to each hybrid solar concentrator, each hybrid luminaire, and each hybrid photobioreactor. A lighting control system operates each component.

  3. The early solar system abundance of /sup 244/Pu as inferred from the St. Severin chondrite

    SciTech Connect

    Hudson, G.B.; Kennedy, B.M.; Podosek, F.A.; Hohenberg, C.M.

    1987-03-01

    We describe the analysis of Xe released in stepwise heating of neutron-irradiated samples of the St. Severin chondrite. This analysis indicates that at the time of formation of most chondritic meteorites, approximately 4.56 x 10/sup 9/ years ago, the atomic ratio of /sup 244/Pu//sup 238/U was 0.0068 +- 0.0010 in chondritic meteorites. We believe that this value is more reliable than that inferred from earlier analyses of St. Severin. We feel that this value is currently the best available estimate for the early solar system abundance of /sup 244/Pu. 42 refs., 2 tabs.

  4. Interannual variability of solar energy generation in Australia

    NASA Astrophysics Data System (ADS)

    Davy, R.; Troccoli, A.

    2012-04-01

    Australia has an abundant solar energy resource that is likely to be used for energy generation on a large scale. Variable sources of electricity generation require knowledge of the nature of their variability at all time scales. This study examines the effect that El Nino Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) have on solar radiation in Australia, in order to establish the role for seasonal forecasting of solar power. Calendar years are classified into their ENSO state using a sea surface temperature index. The ERA-Interim and NCEP reanalysis products are then used to estimate the effect of ENSO on global horizontal solar irradiance over the continent. A bootstrap technique is used to obtain confidence regions for the effect in both winter and summer. The main impact of ENSO occurs during winter over a large part of eastern Australia. Little impact was observed over the continent during summer. A similar analysis is conducted for the Indian Ocean Dipole (IOD) to ensure that the observed ENSO effect is not a manifestation of the IOD. This study indicates that the ENSO phenomenon may account for solar energy changes of more than 10% in some locations on a seasonal basis. We show that the solar radiation analysis is directly applicable to solar energy yield. Knowledge of this variability may influence the location of large solar generation plants. Also, there is a potential to predict solar energy a few months ahead by means of seasonal forecasting systems, which would help to assist with planning for electricity grid.

  5. Stellar coronal abundances. 3: The solar first ionization potential effect determined from full-disk observation

    NASA Technical Reports Server (NTRS)

    Laming, J. Martin; Drake, J. J.; Widing, Kenneth G.

    1995-01-01

    In this paper we reanalayze the full-disk quiet-sun spectrum of Mallinovsky & Heroux (1973) with modern atomic data. The purposes of this are to check our atomic data and methods in other investigations using data from nearby stars obtained with the NASA Extreme Ultraviolet Explorer (EUVE) satellite, and to confirm that the solar first ionization potential (FIP) effect investigated by previous authors studying discrete solar regions is the same as that found in full-disk spectra. We recover the usual solar FIP effect of a coronal abundance enhancement of elements with a low FIP of a factor approximately 3-4 for lines formed at temperatures greater than approximately 10(exp 6) K. For lower temperatures, the FIP effect seems to be substantially smaller, in qualitative agreement with other data. Comparing our full-disk result with those from discrete solar structures suggest that the FIP effect is a function of altitude, with the lower temperature full-disk emission being dominated by the super-granulation network. We also compare the recent ionization balance of Arnaud & Raymond (1992) with that of Arnaud & Rothenflug (1985).

  6. Simple Experiments on the Use of Solar Energy

    ERIC Educational Resources Information Center

    Vella, G. J.; Goldsmid, H. J.

    1976-01-01

    Describes 5 solar energy experiments that can be used in secondary school: flat-plate collector, solar thermoelectric generator, simple concentrators, solar cell, and natural storage of solar energy. (MLH)

  7. Biomimetic utilization of solar energy

    NASA Astrophysics Data System (ADS)

    Dzhabiev, T. S.; Shilov, Aleksandr E.

    2012-12-01

    The most interesting recent publications dealing with so-called artificial photosynthesis, i.e., the development of photocatalytic converters of solar energy to the chemical bond energy using the fundamental principles of natural oxygenic photosynthesis, are discussed. The key stages of photosynthesis that should be reproduced in the artificial converters include light harvesting and transport of the light quantum to reaction centres where photoinduced charge separation occurs to give elementary reducing agents and oxidants (electrons and holes). The dark catalytic reactions involving the elementary reducing agents and oxidants give stable end products, namely, dioxygen and carbohydrates in the natural photosynthesis or dioxygen and hydrogen in the artificial photosynthesis. The bibliography includes 99 references.

  8. Summary of solar energy technology characterizations

    SciTech Connect

    D'Alessio, Dr., Gregory J.; Blaunstein, Dr., Robert R.

    1980-09-01

    This report summarizes the design, operating, energy, environmental, and economic characteristics of 38 model solar systems used in the Technology Assessment of Solar Energy Systems Project including solar heating and cooling of buildings, agricultural and industrial process heat, solar electric conversion, and industrial biomass systems. The generic systems designs utilized in this report were based on systems studies and mission analyses performed by the DOE National Laboratories and the MITRE Corporation. The purpose of those studies were to formulate materials and engineering cost data and performance data of solar equipment once mass produced.

  9. Research opportunities to advance solar energy utilization.

    PubMed

    Lewis, Nathan S

    2016-01-22

    Major developments, as well as remaining challenges and the associated research opportunities, are evaluated for three technologically distinct approaches to solar energy utilization: solar electricity, solar thermal, and solar fuels technologies. Much progress has been made, but research opportunities are still present for all approaches. Both evolutionary and revolutionary technology development, involving foundational research, applied research, learning by doing, demonstration projects, and deployment at scale will be needed to continue this technology-innovation ecosystem. Most of the approaches still offer the potential to provide much higher efficiencies, much lower costs, improved scalability, and new functionality, relative to the embodiments of solar energy-conversion systems that have been developed to date.

  10. Development of solar energy in Peru

    NASA Astrophysics Data System (ADS)

    Pierson, H. O.; Nahui, A.

    1981-06-01

    Development of solar energy technology utilization in Peru is discussed. Peru receives a high degree of solar radiation (except for part of its coastal area) and has almost an ideal climate for the development of solar energy. The development of low temperature applications, including the design of passive solar heated buildings for the high Andes, the design and evaluation of various types of solar water heaters and crop dryers for both household and industrial uses (based on flat plate collectors), and the construction of a desalinization prototype plant are reported. Photovoltaic systems are investigated for suitable applications and have an excellent potential, especially in telecommunications.

  11. Environmental aspects of solar energy technologies

    SciTech Connect

    Strojan, C.L.

    1980-09-01

    Solar energy technologies have environmental effects, and these may be positive or negative compared with current ways of producing energy. In this respect, solar energy technologies are no different from other energy systems. Where solar energy technologies differ is that no unresolvable technological problems (e.g., CO/sub 2/ emissions) or sociopolitical barriers (e.g., waste disposal, catastrophic accidents) have been identified. This report reviews some of the environmental aspects of solar energy technologies and ongoing research designed to identify and resolve potential environmental concerns. It is important to continue research and assessment of environmental aspects of solar energy to ensure that unanticipated problems do not arise. It is also important that the knowledge gained through such environmental research be incorporated into technology development programs and policy initiatives.

  12. Solar Energy Systems for Ohioan Residential Homeowners

    NASA Astrophysics Data System (ADS)

    Luckett, Rickey D.

    Dwindling nonrenewable energy resources and rising energy costs have forced the United States to develop alternative renewable energy sources. The United States' solar energy industry has seen an upsurge in recent years, and photovoltaic holds considerable promise as a renewable energy technology. The purpose of this case study was to explore homeowner's awareness of the benefits of solar energy. Disruptive-innovation theory was used to explore marketing strategies for conveying information to homeowners about access to new solar energy products and services. Twenty residential homeowners were interviewed face-to-face to explore (a) perceived benefits of solar energy in their county in Ohio, and (b) perceptions on the rationale behind the marketing strategy of solar energy systems sold for residential use. The study findings used inductive analyses and coding interpretation to explore the participants' responses that revealed 3 themes: the existence of environmental benefits for using solar energy systems, the expensive cost of equipment associated with government incentives, and the lack of marketing information that is available for consumer use. The implications for positive social change include the potential to enable corporate leaders, small business owners, and entrepreneurs to develop marketing strategies for renewable energy systems. These strategies may promote use of solar energy systems as a clean, renewable, and affordable alternative electricity energy source for the 21st century.

  13. Solar applications analysis for energy storage

    NASA Technical Reports Server (NTRS)

    Blanchard, T.

    1980-01-01

    The role of energy storage as it relates to solar energy systems is considered. Storage technologies to support solar energy applications, the status of storage technologies, requirements and specifications for storage technologies, and the adequacy of the current storage research and development program to meet these requirements are among the factors discussed. Emphasis is placed on identification of where the greatest potential exists for energy storage in support of those solar energy systems which could have a significant impact on the U.S. energy mix.

  14. Advanced research in solar-energy storage

    SciTech Connect

    Luft, W.

    1983-01-01

    The Solar Energy Storage Program at the Solar Energy Research Institute is reviewed. The program provides research, systems analyses, and economic assessments of thermal and thermochemical energy storage and transport. Current activities include experimental research into very high temperature (above 800/sup 0/C) thermal energy storage and assessment of novel thermochemical energy storage and transport systems. The applications for such high-temperature storage are thermochemical processes, solar thermal-electric power generation, cogeneration of heat and electricity, industrial process heat, and thermally regenerative electrochemical systems. The research results for five high-temperature thermal energy storage technologies and two thermochemical systems are described.

  15. Solar Energy for Transportation Fuel (LBNL Science at the Theater)

    SciTech Connect

    Lewis, Nate

    2008-05-12

    Nate Lewis' talk looks at the challenge of capturing solar energy and storing it as an affordable transportation fuel - all on a scale necessary to reduce global warming. Overcoming this challenge will require developing new materials that can use abundant and inexpensive elements rather than costly and rare materials. He discusses the promise of new materials in the development of carbon-free alternatives to fossil fuel.

  16. Solar Energy for Transportation Fuel (LBNL Science at the Theater)

    ScienceCinema

    Lewis, Nate

    2016-07-12

    Nate Lewis' talk looks at the challenge of capturing solar energy and storing it as an affordable transportation fuel - all on a scale necessary to reduce global warming. Overcoming this challenge will require developing new materials that can use abundant and inexpensive elements rather than costly and rare materials. He discusses the promise of new materials in the development of carbon-free alternatives to fossil fuel.

  17. HDO abundance in the envelope of the solar-type protostar IRAS 16293-2422

    NASA Astrophysics Data System (ADS)

    Parise, B.; Caux, E.; Castets, A.; Ceccarelli, C.; Loinard, L.; Tielens, A. G. G. M.; Bacmann, A.; Cazaux, S.; Comito, C.; Helmich, F.; Kahane, C.; Schilke, P.; van Dishoeck, E.; Wakelam, V.; Walters, A.

    2005-02-01

    We present IRAM 30 m and JCMT observations of HDO lines towards the solar-type protostar IRAS 16293-2422. Five HDO transitions have been detected on-source, and two were unfruitfully searched for towards a bright spot of the outflow of IRAS 16293-2422. We interpret the data by means of the Ceccarelli et al. (\\cite{Ceccarelli1996}) model, and derive the HDO abundance in the warm inner and cold outer parts of the envelope. The emission is well explained by a jump model, with an inner abundance xHDO_in = 1×10-7 and an outer abundance xHDO_out ≤ 1×10-9 (3σ). This result is in favor of HDO enhancement due to ice evaporation from the grains in the inner envelope. The deuteration ratio HDO/H2O is found to be fin=3% and fout ≤0.2% (3σ) in the inner and outer envelope respectively and therefore, the fractionation also undergoes a jump in the inner part of the envelope. These results are consistent with the formation of water in the gas phase during the cold prestellar core phase and storage of the molecules on the grains, but do not explain why observations of H2O ices consistently derive a H2O ice abundance of several 10-5 to 10-4, some two orders of magnitude larger than the gas phase abundance of water in the hot core around IRAS 16293-2422. Based on observations with the IRAM 30 m telescope in Spain and with The James Clerk Maxwell Telescope, operated by The Joint Astronomy Centre on behalf of the Particle Physics and Astronomy Research Council of the United Kingdom, the Netherlands Organisation of Scientific Research, and the National Research Council of Canada.

  18. Non-solar noble gas abundances in the atmosphere of Jupiter

    NASA Technical Reports Server (NTRS)

    Lunine, Jonathan I.; Stevenson, David J.

    1986-01-01

    The thermodynamic stability of clathrate hydrate is calculated to predict the formation conditions corresponding to a range of solar system parameters. The calculations were performed using the statistical mechanical theory developed by van der Waals and Platteeuw (1959) and existing experimental data concerning clathrate hydrate and its components. Dissociation pressures and partition functions (Langmuir constants) are predicted at low pressure for CO clathrate (hydrate) using the properties of chemicals similar to CO. It is argued that nonsolar but well constrained noble gas abundances may be measurable by the Galileo spacecraft in the Jovian atmosphere if the observed carbon enhancement is due to bombardment of the atmosphere by clathrate-bearing planetesimals sometime after planetary formation. The noble gas abundances of the Jovian satellite Titan are predicted, assuming that most of the methane in Titan is accreted as clathrate. It is suggested that under thermodynamically appropriate conditions, complete clathration of water ice could have occurred in high-pressure nebulas around giant planets, but probably not in the outer solar nebula. The stability of clathrate in other pressure ranges is also discussed.

  19. Abundance of He-3 and other solar-wind-derived volatiles in lunar soil

    NASA Technical Reports Server (NTRS)

    Swindle, Timothy D.

    1992-01-01

    Volatiles implanted into the lunar regolith by the solar wind are potentially important lunar resources. Wittenberg et al. (1986) have proposed that lunar He-3 could be used as a fuel for terrestrial nuclear fusion reactors. They argue that a fusion scheme involving D and He-3 would be cleaner and more efficient than currently-proposed schemes involving D and T. However, since the terrestrial inventory of He-3 is so small, they suggest that the lunar regolith, with concentrations of the order of parts per billion (by mass) would be an economical source of He-3. Solar-wind implantation is also the primary source of H, C, and N in lunar soil. These elements could also be important, particularly for life support and for propellant production. In a SERC study of the feasibility of obtaining the necessary amount of He-3, Swindle et al. (1990) concluded that the available amount is sufficient for early reactors, at least, but that the mining problems, while not necessarily insurmountable, are prodigious. The volatiles H, C, and N, on the other hand, come in parts per million level abundances. The differences in abundances mean that (1) a comparable amount of H, C, and/or N could be extracted with orders of magnitude smaller operations than required for He-3, and (2) if He-3 extraction ever becomes important, huge quantities of H, C, and N will be produced as by-products.

  20. HAT-P-26b: A Neptune-mass Exoplanet with Primordial Solar Heavy Element Abundance

    NASA Astrophysics Data System (ADS)

    Wakeford, Hannah; Sing, David; Deming, Drake; Kataria, Tiffany; Lopez, Eric

    2016-10-01

    A trend in giant planet mass and atmospheric heavy elemental abundance was first noted last century from observations of planets in our own solar system. These four data points from Jupiter, Saturn, Uranus, and Neptune have served as a corner stone of planet formation theory. Here we add another point in the mass-metallicity trend from a detailed observational study of the extrasolar planet HAT-P-26b, which inhabits the critical mass regime near Neptune and Uranus. Neptune-sized worlds are among the most common planets in our galaxy and frequently exist in orbital periods very different from that of our own solar system ice giants. Atmospheric studies are the principal window into these worlds, and thereby into their formation and evolution, beyond those of our own solar system. Using the Hubble Space Telescope and Spitzer, from the optical to the infrared, we conducted a detailed atmospheric study of the Neptune-mass exoplanet HAT-P-26b over 0.5 to 4.5 μm. We detect prominent H2O absorption at 1.4 μm to 525 ppm in the atmospheric transmission spectrum. We determine that HAT-P-26b's atmosphere is not rich in heavy elements (≈1.8×solar), which goes distinctly against the solar system mass-metallicity trend. This likely indicates that HAT-P-26b's atmosphere is primordial and obtained its gaseous envelope late in its disk lifetime with little contamination from metal-rich planetesimals.

  1. What Are the Sources of Solar Energetic Particles? Element Abundances and Source Plasma Temperatures

    NASA Astrophysics Data System (ADS)

    Reames, Donald V.

    2015-11-01

    We have spent 50 years in heated discussion over which populations of solar energetic particles (SEPs) are accelerated at flares and which by shock waves driven out from the Sun by coronal mass ejections (CMEs). The association of the large "gradual" SEP events with shock acceleration is supported by the extensive spatial distribution of SEPs and by the delayed acceleration of the particles. Recent STEREO observations have begun to show that the particle onset times correspond to the observed time of arrival of the shock on the observer's magnetic flux tube and that the SEP intensities are related to the local shock speed. The relative abundances of the elements in these gradual events are a measure of those in the ambient solar corona, differing from those in the photosphere by a widely-observed function of the first ionization potential (FIP) of the elements. SEP events we call "impulsive", the traditional "3He-rich" events with enhanced heavy-element abundances, are associated with type III radio bursts, flares, and narrow CMEs; they selectively populate flux tubes that thread a localized source, and they are fit to new particle-in-cell models of magnetic reconnection on open field lines as found in solar jets. These models help explain the strong enhancements seen in heavy elements as a power (of 2-8) in the mass-to-charge ratio A/Q throughout the periodic table from He to Pb. A study of the temperature dependence of A/Q shows that the source plasma in impulsive SEP events must lie in the range of 2-4 MK to explain the pattern of abundances. This is much lower than the temperatures of >10 MK seen on closed loops in solar flares. Recent studies of A/Q-dependent enhancements or suppressions from scattering during transport show source plasma temperatures in gradual SEP events to be 0.8-1.6 MK in 69 % of the events, i.e. coronal plasma; 24 % of the events show reaccelerated impulsive-event material.

  2. Magnetic tornadoes as energy channels into the solar corona.

    PubMed

    Wedemeyer-Böhm, Sven; Scullion, Eamon; Steiner, Oskar; van der Voort, Luc Rouppe; de la Cruz Rodriguez, Jaime; Fedun, Viktor; Erdélyi, Robert

    2012-06-28

    Heating the outer layers of the magnetically quiet solar atmosphere to more than one million kelvin and accelerating the solar wind requires an energy flux of approximately 100 to 300 watts per square metre, but how this energy is transferred and dissipated there is a puzzle and several alternative solutions have been proposed. Braiding and twisting of magnetic field structures, which is caused by the convective flows at the solar surface, was suggested as an efficient mechanism for atmospheric heating. Convectively driven vortex flows that harbour magnetic fields are observed to be abundant in the photosphere (the visible surface of the Sun). Recently, corresponding swirling motions have been discovered in the chromosphere, the atmospheric layer sandwiched between the photosphere and the corona. Here we report the imprints of these chromospheric swirls in the transition region and low corona, and identify them as observational signatures of rapidly rotating magnetic structures. These ubiquitous structures, which resemble super-tornadoes under solar conditions, reach from the convection zone into the upper solar atmosphere and provide an alternative mechanism for channelling energy from the lower into the upper solar atmosphere. PMID:22739314

  3. Magnetic tornadoes as energy channels into the solar corona.

    PubMed

    Wedemeyer-Böhm, Sven; Scullion, Eamon; Steiner, Oskar; van der Voort, Luc Rouppe; de la Cruz Rodriguez, Jaime; Fedun, Viktor; Erdélyi, Robert

    2012-06-27

    Heating the outer layers of the magnetically quiet solar atmosphere to more than one million kelvin and accelerating the solar wind requires an energy flux of approximately 100 to 300 watts per square metre, but how this energy is transferred and dissipated there is a puzzle and several alternative solutions have been proposed. Braiding and twisting of magnetic field structures, which is caused by the convective flows at the solar surface, was suggested as an efficient mechanism for atmospheric heating. Convectively driven vortex flows that harbour magnetic fields are observed to be abundant in the photosphere (the visible surface of the Sun). Recently, corresponding swirling motions have been discovered in the chromosphere, the atmospheric layer sandwiched between the photosphere and the corona. Here we report the imprints of these chromospheric swirls in the transition region and low corona, and identify them as observational signatures of rapidly rotating magnetic structures. These ubiquitous structures, which resemble super-tornadoes under solar conditions, reach from the convection zone into the upper solar atmosphere and provide an alternative mechanism for channelling energy from the lower into the upper solar atmosphere.

  4. Non-tracking solar energy collector system

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K. (Inventor)

    1978-01-01

    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.

  5. Projects in a Solar Energy Course.

    ERIC Educational Resources Information Center

    Lindsay, Richard H.

    1983-01-01

    Describes student projects on applications of solar energy optics to home design. Project criterion (requiring sketches and detailed calculations of time rate of energy flow/production) is that half the heat for the heating season be taken from the solar resource; calculations must be based on meteorological data for a specific location. (JM)

  6. Economic Evaluation of Townhouse Solar Energy System

    NASA Technical Reports Server (NTRS)

    1982-01-01

    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.

  7. Solar Energy for Space Heating & Hot Water.

    ERIC Educational Resources Information Center

    Energy Research and Development Administration, Washington, DC. Div. of Solar Energy.

    This pamphlet reviews the direct transfer of solar energy into heat, particularly for the purpose of providing space and hot water heating needs. Owners of buildings and homes are provided with a basic understanding of solar heating and hot water systems: what they are, how they perform, the energy savings possible, and the cost factors involved.…

  8. Solar energy for industrial process heat

    NASA Technical Reports Server (NTRS)

    Barbieri, R. H.; Pivirotto, D. L.

    1979-01-01

    Findings of study of potential use for solar energy utilization by California dairy industry, prove that applicable solar energy system furnish much of heat needed for milk processing with large savings in expenditures for oil and gas and ensurance of adequate readily available sources of process heat.

  9. The soft X-ray background as a supernova blast wave viewed from inside: Solar abundance models

    NASA Technical Reports Server (NTRS)

    Edgar, R. J.

    1984-01-01

    A model of the soft X-ray background is presented in which the Sun is assumed to be inside an active supernova blast wave. The blast wave evolves in a preexisting cavity. The broad band surface brightnesses is explained by such a blast wave with an explosion energy of E sub approx. 5 x 10 to the 50th power ergs and radius 80 to 100 pc, using solar abundances. An approach to treating the problem of large anisotropies in the ambient medium is also explored, accommodating the observed anticorrelation between the soft X-ray surface brightness and the 21 cm column density. It is found that only for post shock temperatures below 10 6 K a shock propagating into a density enhancement will be dimmer than a similar shock in a lower density region.

  10. The soft X-ray background as a supernova blast wave viewed from inside - Solar abundance models

    NASA Technical Reports Server (NTRS)

    Edgar, R. J.

    1986-01-01

    A model of the soft X-ray background is presented in which the sun is assumed to be inside an active supernova blast wave. The blast wave evolves in a preexisting cavity. The broad band surface brightnesses is explained by such a blast wave with an explosion energy of E sub approximately 5 x 10 to the 50th power ergs and radius 80 to 100 pc, using solar abundances. An approach to treating the problem of large anisotropies in the ambient medium is also explored, accommodating the observed anticorrelation between the soft X-ray surface brightness and the 21 cm column density. It is found that only for post shock temperatures below 10 to the 6 power K a shock propagating into a density enhancement will be dimmer than a similar shock in a lower density region.

  11. Material for conversion of solar energy

    SciTech Connect

    Taoda, H.; Asahina, T.; Hayakawa, K.; Kawase, K.; Kosaka, M.; Yumoto, T.

    1984-09-25

    A material comprising an organic compound capable of inducing its own photo-isomerization, a photosensitizer, and a side-reaction inhibitor exhibits an ability to convert solar energy into another form of energy and store it in such form.

  12. The SERI solar energy storage program

    NASA Technical Reports Server (NTRS)

    Copeland, R. J.; Wright, J. D.; Wyman, C. E.

    1980-01-01

    In support of the DOE thermal and chemical energy storage program, the solar energy storage program (SERI) provides research on advanced technologies, systems analyses, and assessments of thermal energy storage for solar applications in support of the Thermal and Chemical Energy Storage Program of the DOE Division of Energy Storage Systems. Currently, research is in progress on direct contact latent heat storage and thermochemical energy storage and transport. Systems analyses are being performed of thermal energy storage for solar thermal applications, and surveys and assessments are being prepared of thermal energy storage in solar applications. A ranking methodology for comparing thermal storage systems (performance and cost) is presented. Research in latent heat storage and thermochemical storage and transport is reported.

  13. The Effects of Magnetic Field Morphology on the Determination of Oxygen and Iron Abundances in the Solar Photosphere

    NASA Astrophysics Data System (ADS)

    Moore, Christopher S.; Uitenbroek, Han; Rempel, Matthias; Criscuoli, Serena; Rast, Mark

    2016-01-01

    The solar chemical abundance (or a scaled version of it) is implemented in numerous astrophysical analyses. Thus, an accurate and precise estimation of the solar elemental abundance is crucial in astrophysics.We have explored the impact of magnetic fields on the determination of the solar photospheric oxygen andiron abundances using 3D radiation-magnetohydrodynamic (MHD) simulations of convection. Specifically, weexamined differences in abundance deduced from three classes of atmospheres simulated with the MURaM code: apure hydrodynamic (HD) simulation, an MHD simulation with a local dynamo magnetic field that has saturated withan unsigned vertical field strength of 80 G at the optical depth unity surface, and an MHD simulation with an initially imposed vertical mean field of 80 G. We use differential equivalent width analysis for diagnosing abundances derived from five oxygen and four iron spectral lines of differing wavelength, oscillator strength, excitation potential, and Lande g-factor, and find that the morphology of the magnetic field is important to the outcome of abundance determinations. The largest deduced abundance differences are found in the vertical mean field simulations and small scale unresolved field resulting from the local dynamo has a smaller impact on abundance determinations.

  14. Magnetic energy flow in the solar wind.

    NASA Technical Reports Server (NTRS)

    Modisette, J. L.

    1972-01-01

    Discussion of the effect of rotation (tangential flow) of the solar wind on the conclusions of Whang (1971) suggesting an increase in the solar wind velocity due to the conversion of magnetic energy to kinetic energy. It is shown that the effect of the rotation of the sun on the magnetic energy flow results in most of the magnetic energy being transported by magnetic shear stress near the sun.

  15. MeV He3/He4 isotope abundances in solar energetic particle events: SOHO/COSTEP observations

    NASA Astrophysics Data System (ADS)

    Bothmer, V.:; Sierks, H.; Böhm, E.; Kunow, H.

    2001-08-01

    We present first results based on a systematic survey of 4-41 MeV/N 3He/4He isotope abundances with ratios >0.01 detected by the COmprehensive SupraThermal and Energetic Particle analyzer (COSTEP) onboard the SOHO (SOlar and Heliospheric Observatory) spacecraft. More than about 25% of the identified events showed 3He/4He ratios in the range 0.1-1. For events with sufficiently high detector count rates the atomic mass plots can be resolved up to a time resolution of about 1 hour. These events are most suitable for comparisons with in situ solar wind plasma and magnetic field measurements and SOHO's optical white-light and extreme ultraviolet (EUV) observations of the Sun. The correlations show an association with passages of shock associated coronal mass ejections (CMEs) in the solar wind that inhibit high He/H plasma overabundances. It is likely that the CMEs have been released in strong magnetic reconfiguration processes at the solar source sites. Here we present a brief overview of such an event detected on October 30, 2000. 1. Introduction The SOHO/COSTEP instrument measures solar energetic particles (SEPs) at MeV energies in the interplanetary medium. The solid state detectors are capable to detect 3 He/4 He-enrichments at these energies (Müller-Mellin et al., 1995). Usually, the 3 He/4 He-ratio in the solar wind is at the order of 10-4 , but occasionally ratios up to about values of ~1 or even above have been observed in SEP events (e.g., Mason et al., 1999). The origin of these isotope abundances has commonly been attributed to impulsive solar flares and wave-particle interaction mechanisms (Temerin and Roth, 1992). However, fully satisfying physical explanations are still lacking. Here we present first results of a systematic survey of the He-measurements taken by COSTEP since launch in 1995 until the end of the year 2000. 2. Data For this study we have analyzed SOHO/COSTEP measurements of 4.3-40.9 MeV/N helium particles as well as COSTEP data covering

  16. Primitive Solar System materials and Earth share a common initial 142Nd abundance

    NASA Astrophysics Data System (ADS)

    Bouvier, A.; Boyet, M.

    2016-09-01

    The early evolution of planetesimals and planets can be constrained using variations in the abundance of neodymium-142 (142Nd), which arise from the initial distribution of 142Nd within the protoplanetary disk and the radioactive decay of the short-lived samarium-146 isotope (146Sm). The apparent offset in 142Nd abundance found previously between chondritic meteorites and Earth has been interpreted either as a possible consequence of nucleosynthetic variations within the protoplanetary disk or as a function of the differentiation of Earth very early in its history. Here we report high-precision Sm and Nd stable and radiogenic isotopic compositions of four calcium-aluminium-rich refractory inclusions (CAIs) from three CV-type carbonaceous chondrites, and of three whole-rock samples of unequilibrated enstatite chondrites. The CAIs, which are the first solids formed by condensation from the nebular gas, provide the best constraints for the isotopic evolution of the early Solar System. Using the mineral isochron method for individual CAIs, we find that CAIs without isotopic anomalies in Nd compared to the terrestrial composition share a 146Sm/144Sm-142Nd/144Nd isotopic evolution with Earth. The average 142Nd/144Nd composition for pristine enstatite chondrites that we calculate coincides with that of the accessible silicate layers of Earth. This relationship between CAIs, enstatite chondrites and Earth can only be a result of Earth having inherited the same initial abundance of 142Nd and chondritic proportions of Sm and Nd. Consequently, 142Nd isotopic heterogeneities found in other CAIs and among chondrite groups may arise from extrasolar grains that were present in the disk and incorporated in different proportions into these planetary objects. Our finding supports a chondritic Sm/Nd ratio for the bulk silicate Earth and, as a consequence, chondritic abundances for other refractory elements. It also removes the need for a hidden reservoir or for collisional erosion

  17. Primitive Solar System materials and Earth share a common initial (142)Nd abundance.

    PubMed

    Bouvier, A; Boyet, M

    2016-01-01

    The early evolution of planetesimals and planets can be constrained using variations in the abundance of neodymium-142 ((142)Nd), which arise from the initial distribution of (142)Nd within the protoplanetary disk and the radioactive decay of the short-lived samarium-146 isotope ((146)Sm). The apparent offset in (142)Nd abundance found previously between chondritic meteorites and Earth has been interpreted either as a possible consequence of nucleosynthetic variations within the protoplanetary disk or as a function of the differentiation of Earth very early in its history. Here we report high-precision Sm and Nd stable and radiogenic isotopic compositions of four calcium-aluminium-rich refractory inclusions (CAIs) from three CV-type carbonaceous chondrites, and of three whole-rock samples of unequilibrated enstatite chondrites. The CAIs, which are the first solids formed by condensation from the nebular gas, provide the best constraints for the isotopic evolution of the early Solar System. Using the mineral isochron method for individual CAIs, we find that CAIs without isotopic anomalies in Nd compared to the terrestrial composition share a (146)Sm/(144)Sm-(142)Nd/(144)Nd isotopic evolution with Earth. The average (142)Nd/(144)Nd composition for pristine enstatite chondrites that we calculate coincides with that of the accessible silicate layers of Earth. This relationship between CAIs, enstatite chondrites and Earth can only be a result of Earth having inherited the same initial abundance of (142)Nd and chondritic proportions of Sm and Nd. Consequently, (142)Nd isotopic heterogeneities found in other CAIs and among chondrite groups may arise from extrasolar grains that were present in the disk and incorporated in different proportions into these planetary objects. Our finding supports a chondritic Sm/Nd ratio for the bulk silicate Earth and, as a consequence, chondritic abundances for other refractory elements. It also removes the need for a hidden reservoir or

  18. Primitive Solar System materials and Earth share a common initial (142)Nd abundance.

    PubMed

    Bouvier, A; Boyet, M

    2016-09-14

    The early evolution of planetesimals and planets can be constrained using variations in the abundance of neodymium-142 ((142)Nd), which arise from the initial distribution of (142)Nd within the protoplanetary disk and the radioactive decay of the short-lived samarium-146 isotope ((146)Sm). The apparent offset in (142)Nd abundance found previously between chondritic meteorites and Earth has been interpreted either as a possible consequence of nucleosynthetic variations within the protoplanetary disk or as a function of the differentiation of Earth very early in its history. Here we report high-precision Sm and Nd stable and radiogenic isotopic compositions of four calcium-aluminium-rich refractory inclusions (CAIs) from three CV-type carbonaceous chondrites, and of three whole-rock samples of unequilibrated enstatite chondrites. The CAIs, which are the first solids formed by condensation from the nebular gas, provide the best constraints for the isotopic evolution of the early Solar System. Using the mineral isochron method for individual CAIs, we find that CAIs without isotopic anomalies in Nd compared to the terrestrial composition share a (146)Sm/(144)Sm-(142)Nd/(144)Nd isotopic evolution with Earth. The average (142)Nd/(144)Nd composition for pristine enstatite chondrites that we calculate coincides with that of the accessible silicate layers of Earth. This relationship between CAIs, enstatite chondrites and Earth can only be a result of Earth having inherited the same initial abundance of (142)Nd and chondritic proportions of Sm and Nd. Consequently, (142)Nd isotopic heterogeneities found in other CAIs and among chondrite groups may arise from extrasolar grains that were present in the disk and incorporated in different proportions into these planetary objects. Our finding supports a chondritic Sm/Nd ratio for the bulk silicate Earth and, as a consequence, chondritic abundances for other refractory elements. It also removes the need for a hidden reservoir or

  19. Modular High-Energy Systems for Solar Power Satellites

    NASA Technical Reports Server (NTRS)

    Howell, Joe T.; Carrington, Connie K.; Marzwell, Neville I.; Mankins, John C.

    2006-01-01

    Modular High-Energy Systems are Stepping Stones to provide capabilities for energy-rich infrastructure located in space to support a variety of exploration scenarios as well as provide a supplemental source of energy during peak demands to ground grid systems. Abundant renewable energy at lunar or other locations could support propellant production and storage in refueling scenarios that enable affordable exploration. Renewable energy platforms in geosynchronous Earth orbits can collect and transmit power to satellites, or to Earth-surface locations. Energy-rich space technologies also enable the use of electric-powered propulsion systems that could efficiently deliver cargo and exploration facilities to remote locations. A first step to an energy-rich space infrastructure is a 100-kWe class solar-powered platform in Earth orbit. The platform would utilize advanced technologies in solar power collection and generation, power management and distribution, thermal management, electric propulsion, wireless avionics, autonomous in space rendezvous and docking, servicing, and robotic assembly. It would also provide an energy-rich free-flying platform to demonstrate in space a portfolio of technology flight experiments. This paper summary a preliminary design concept for a 100-kWe solar-powered satellite system to demonstrate in-flight a variety of advanced technologies, each as a separate payload. These technologies include, but are not limited to state-of-the-art solar concentrators, highly efficient multi-junction solar cells, integrated thermal management on the arrays, and innovative deployable structure design and packaging to enable the 100-kW satellite feasible to launch on one existing launch vehicle. Higher voltage arrays and power distribution systems (PDS) reduce or eliminate the need for massive power converters, and could enable direct-drive of high-voltage solar electric thrusters.

  20. Solar energy for electricity and fuels.

    PubMed

    Inganäs, Olle; Sundström, Villy

    2016-01-01

    Solar energy conversion into electricity by photovoltaic modules is now a mature technology. We discuss the need for materials and device developments using conventional silicon and other materials, pointing to the need to use scalable materials and to reduce the energy payback time. Storage of solar energy can be achieved using the energy of light to produce a fuel. We discuss how this can be achieved in a direct process mimicking the photosynthetic processes, using synthetic organic, inorganic, or hybrid materials for light collection and catalysis. We also briefly discuss challenges and needs for large-scale implementation of direct solar fuel technologies.

  1. Solar energy innovation and Silicon Valley

    NASA Astrophysics Data System (ADS)

    Kammen, Daniel M.

    2015-03-01

    The growth of the U. S. and global solar energy industry depends on a strong relationship between science and engineering innovation, manufacturing, and cycles of policy design and advancement. The mixture of the academic and industrial engine of innovation that is Silicon Valley, and the strong suite of environmental policies for which California is a leader work together to both drive the solar energy industry, and keep Silicon Valley competitive as China, Europe and other area of solar energy strength continue to build their clean energy sectors.

  2. Space solar power - An energy alternative

    NASA Technical Reports Server (NTRS)

    Johnson, R. W.

    1978-01-01

    The space solar power concept is concerned with the use of a Space Power Satellite (SPS) which orbits the earth at geostationary altitude. Two large symmetrical solar collectors convert solar energy directly to electricity using photovoltaic cells woven into blankets. The dc electricity is directed to microwave generators incorporated in a transmitting antenna located between the solar collectors. The antenna directs the microwave beam to a receiving antenna on earth where the microwave energy is efficiently converted back to dc electricity. The SPS design promises 30-year and beyond lifetimes. The SPS is relatively pollution free as it promises earth-equivalence of 80-85% efficient ground-based thermal power plant.

  3. The Mysterious Case of the Solar Argon Abundance Near Sunspots in Flares

    NASA Astrophysics Data System (ADS)

    Doschek, George A.; Warren, Harry

    2016-05-01

    Recently Doschek et al. (2015, ApJL, 808, L7) reported on an observation of an enhancement of the abundance of Ar XIV relative to Ca XIV of about a factor of 30 near a sunspot during a flare, observed in spectra recorded by the Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft. This enhancement yields an argon/calcium abundance ratio 7 times greater than expected from the photospheric abundances. Such a large abundance anomaly is unprecedented in the solar atmosphere. We interpreted this result as due to an inverse First Ionization Potential (FIP) effect. Argon is a high-FIP element and calcium is a low-FIP element. In the published work two lines of Ar XIV were observed and one line was tentatively identified as an Ar XI line. The number of argon lines was limited by the limitations of the flare study that was executed. In this paper we report observing a similar enhancement in a full-CCD EIS flare spectrum in argon lines with reasonable statistics and lack of blending that lie within the EIS wavelength ranges. The observed lines include two Ar XI lines, four Ar XIII lines, six Ar XIV lines, and one Ar XV line. The enhancement is far less than reported in Doschek et al. (2015) but exhibits similar morphology. The argon abundance is close to a photospheric abundance in the enhanced area, and is only marginally an inverse FIP effect. However, as for the published cases, this newly discovered enhancement occurs in association with a sunspot in a small area only a few arcsec in size and therefore we feel it is produced by the same physics that produced the strong inverse FIP case. There is no enhancement effect observed in the normally high-FIP sulfur and oxygen line ratios relative to lines of low-FIP elements available to EIS. Calculations of path lengths in the strongest enhanced area in Doschek et al. (2015) indicate that the argon/calcium enhancement is due to a depletion of low-FIP elements. This work is supported by a NASA Hinode grant.

  4. Solar Energy Education. Renewable energy activities for biology

    SciTech Connect

    Not Available

    1982-01-01

    An instructional aid for teachers is presented that will allow biology students the opportunity to learn about renewable energy sources. Some of the school activities include using leaves as collectors of solar energy, solar energy stored in wood, and a fuel value test for green and dry woods. A study of organic wastes as a source of fuel is included. (BCS)

  5. Solar energy education. Renewable energy activities for general science

    SciTech Connect

    Not Available

    1985-01-01

    Renewable energy topics are integrated with the study of general science. The literature is provided in the form of a teaching manual and includes such topics as passive solar homes, siting a home for solar energy, and wind power for the home. Other energy topics are explored through library research activities. (BCS)

  6. Advanced solar energy conversion. [solar pumped gas lasers

    NASA Technical Reports Server (NTRS)

    Lee, J. H.

    1981-01-01

    An atomic iodine laser, a candidate for the direct solar pumped lasers, was successfully excited with a 4 kW beam from a xenon arc solar simulator, thus proving the feasibility of the concept. The experimental set up and the laser output as functions of operating conditions are presented. The preliminary results of the iodine laser amplifier pumped with the HCP array to which a Q switch for giant pulse production was coupled are included. Two invention disclosures - a laser driven magnetohydrodynamic generator for conversion of laser energy to electricity and solar pumped gas lasers - are also included.

  7. How to Bring Solar Energy to Seven Billion People (LBNL Science at the Theater)

    ScienceCinema

    Wadia, Cyrus

    2016-07-12

    By exploiting the powers of nanotechnology and taking advantage of non-toxic, Earth-abundant materials, Berkeley Lab's Cyrus Wadia has fabricated new solar cell devices that have the potential to be several orders of magnitude less expensive than conventional solar cells. And by mastering the chemistry of these materials-and the economics of solar energy-he envisions bringing electricity to the 1.2 billion people now living without it.

  8. How to Bring Solar Energy to Seven Billion People (LBNL Science at the Theater)

    SciTech Connect

    Wadia, Cyrus

    2009-04-06

    By exploiting the powers of nanotechnology and taking advantage of non-toxic, Earth-abundant materials, Berkeley Lab's Cyrus Wadia has fabricated new solar cell devices that have the potential to be several orders of magnitude less expensive than conventional solar cells. And by mastering the chemistry of these materials-and the economics of solar energy-he envisions bringing electricity to the 1.2 billion people now living without it.

  9. Solar Energy: Its Technologies and Applications

    DOE R&D Accomplishments Database

    Auh, P. C.

    1978-06-01

    Solar heat, as a potential source of clean energy, is available to all of us. Extensive R and D efforts are being made to effectively utilize this renewable energy source. A variety of different technologies for utilizing solar energy have been proven to be technically feasible. Here, some of the most promising technologies and their applications are briefly described. These are: Solar Heating and Cooling of Buildings (SHACOB), Solar Thermal Energy Conversion (STC), Wind Energy Conversion (WECS), Bioconversion to Fuels (BCF), Ocean Thermal Energy Conversion (OTEC), and Photovoltaic Electric Power Systems (PEPS). Special emphasis is placed on the discussion of the SHACOB technologies, since the technologies are being expeditiously developed for the near commercialization.

  10. Low cost solar energy collection system

    NASA Technical Reports Server (NTRS)

    Miller, C. G.; Stephans, J. B. (Inventor)

    1977-01-01

    A fixed, linear, ground-based primary reflector having an extended, curved sawtooth contoured surface covered with a metallized polymeric reflecting material, reflected solar energy to a movably supported collector that was kept at the concentrated line focus of the reflector primary. Efficient utilization leading to high temperatures from the reflected solar energy was obtained by cylindrical shaped secondary reflectors that directed off-angle energy to the absorber pipe.

  11. The early solar system abundance of Pu-244 as inferred from the St. Severin chondrite

    NASA Technical Reports Server (NTRS)

    Hudson, G. B.; Kennedy, B. M.; Podosek, F. A.; Hohenberg, C. M.

    1989-01-01

    The isotopic composition of Xe released in stepwise heating of neutron-irradiated samples of the St. Severin chondrite was measured. This analysis shows that at the time of formation of most chondritic meteorites, approximately 4.56 x 10 to the 9th yr ago, the atomic ratio of Pu-244/U-238 was 0.0068 + or - 0.0010 in chondritic meteorites. This value is believed to be more reliable that inferred from earlier analyses of St. Severin and is the best estimate for the early solar system abundance of Pu-244. The comparison of Xe compositions between irradiated and unirradiated samples shows that the composition of trapped (ambient) Xe in St. Severin has a significantly lower value of Xe-136/Xe-130 than average carbonaceous chondrites.

  12. The HDO Abundance in the Solar-Type Protostar IRAS 16293-2422

    NASA Astrophysics Data System (ADS)

    Caux, E.; Parise, B.; Castets, A.; Ceccarelli, C.; Tielens, A.

    2005-12-01

    From JCMT (James Clerk Maxwell Telescope) and IRAM observations of five HDO lines towards the solar-type protostar IRAS 16293-2422, we derive the HDO abundance, x, and the deuteration ratio, f = HDO/H2O, in the warm inner part and in the cold outer part of the envelope. We find xHDO_in = 1×10-7, xHDO_out ≤ 1×10-9 (3σ), fin = 3% and fout ≤ 0.2% (3σ). This is consistent with the formation of water in the gas phase during the cold prestellar core stage and with the storage of molecules on dust grains. The HDO enhancement is due to ice evaporation from the grains in the inner envelope.

  13. Accurate fundamental parameters and detailed abundance patterns from spectroscopy of 93 solar-type Kepler targets

    NASA Astrophysics Data System (ADS)

    Bruntt, H.; Basu, S.; Smalley, B.; Chaplin, W. J.; Verner, G. A.; Bedding, T. R.; Catala, C.; Gazzano, J.-C.; Molenda-Żakowicz, J.; Thygesen, A. O.; Uytterhoeven, K.; Hekker, S.; Huber, D.; Karoff, C.; Mathur, S.; Mosser, B.; Appourchaux, T.; Campante, T. L.; Elsworth, Y.; García, R. A.; Handberg, R.; Metcalfe, T. S.; Quirion, P.-O.; Régulo, C.; Roxburgh, I. W.; Stello, D.; Christensen-Dalsgaard, J.; Kawaler, S. D.; Kjeldsen, H.; Morris, R. L.; Quintana, E. V.; Sanderfer, D. T.

    2012-06-01

    We present a detailed spectroscopic study of 93 solar-type stars that are targets of the NASA/Kepler mission and provide detailed chemical composition of each target. We find that the overall metallicity is well represented by Fe lines. Relative abundances of light elements (CNO) and α elements are generally higher for low-metallicity stars. Our spectroscopic analysis benefits from the accurately measured surface gravity from the asteroseismic analysis of the Kepler light curves. The accuracy on the log g parameter is better than 0.03 dex and is held fixed in the analysis. We compare our Teff determination with a recent colour calibration of VT-KS [TYCHO V magnitude minus Two Micron All Sky Survey (2MASS) KS magnitude] and find very good agreement and a scatter of only 80 K, showing that for other nearby Kepler targets, this index can be used. The asteroseismic log g values agree very well with the classical determination using Fe I-Fe II balance, although we find a small systematic offset of 0.08 dex (asteroseismic log g values are lower). The abundance patterns of metals, α elements and the light elements (CNO) show that a simple scaling by [Fe/H] is adequate to represent the metallicity of the stars, except for the stars with metallicity below -0.3, where α-enhancement becomes important. However, this is only important for a very small fraction of the Kepler sample. We therefore recommend that a simple scaling with [Fe/H] be employed in the asteroseismic analyses of large ensembles of solar-type stars.

  14. Antisoiling Coatings for Solar-Energy Devices

    NASA Technical Reports Server (NTRS)

    Cuddihy, E. F.; Willis, P.

    1986-01-01

    Fluorocarbons resist formation of adherent deposits. Promising coating materials reduce soiling of solar photovoltaic modules and possibly solar thermal collectors. Contaminating layers of various degrees of adherence form on surfaces of devices, partially blocking incident solar energy, reducing output power. Loose soil deposits during dry periods but washed off by rain. New coatings help prevent formation of more-adherent, chemically and physically bonded layers rain alone cannot wash away.

  15. Solar energy storage researchers information user study

    SciTech Connect

    Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

    1981-03-01

    The results of a series of telephone interviews with groups of users of information on solar energy storage are described. In the current study only high-priority groups were examined. Results from 2 groups of researchers are analyzed: DOE-Funded Researchers and Non-DOE-Funded Researchers. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

  16. Solar energy to meet the nation's energy needs

    NASA Technical Reports Server (NTRS)

    Rom, F. E.; Thomas, R. L.

    1973-01-01

    Discussion of the possibilities afforded by solar energy as one of the alternative energy sources capable to take the place of the dwindling oil and gas reserves. Solar energy, being a nondepleting clean source of energy, is shown to be capable of providing energy in all the forms in which it is used today. Steps taken toward providing innovative solutions that are economically competitive with other systems are briefly reviewed.

  17. The Helium Abundance at Quiescent Current Sheets and the Slow Solar Wind

    NASA Technical Reports Server (NTRS)

    Suess, Steven T.; Ko, Y.-K.; VonSteiger, R.

    2008-01-01

    Ulysses MAG data were used to identify current sheets during sunspot minimum years of 1994-1997 and 2004-2006. The purpose of limiting the dates was to focus attention on 'quiescent current sheets' with as little influence from ICMEs as possible. SWOOPS data were then used in a superposed epoch analysis to study Helium abundance in the vicinity of the current sheet, similar to the study done by Borrini et al. (1981). That earlier study found a narrow (ca. 2 day) minimum in He/H around the current sheet that is extremely variable from one year to the next in the period 1971-1978. A similar result is found here for data at all latitudes and distances in 2004-2006. Conversely, data from 1994-1997 produce a deep minimum several times wider (ca. 10 days). The reason for this is found to be that low He/H is more closely associated with slow wind than the current sheet per se. There are thus apparently at least two sources of slow wind, one associated with very low He/H of 0-0.02 and one associated with moderate abundance of 0.03-0.05. The large variability is a consequence of the relatively small number of current sheet encounters around solar minimum and the random distribution of low He/H intervals, lasting less than 1 day to more than 7 days, throughout slow wind.

  18. Dormitory Solar-Energy-System Economics

    NASA Technical Reports Server (NTRS)

    1982-01-01

    102-page report analyzes long-term economic performance of a prepackaged solar energy assembly system at a dormitory installation and extrapolates to four additional sites about the U.S. Method of evaluation is f-chart procedure for solar-heating and domestic hotwater systems.

  19. Heat-Energy Analysis for Solar Receivers

    NASA Technical Reports Server (NTRS)

    Lansing, F. L.

    1982-01-01

    Heat-energy analysis program (HEAP) solves general heat-transfer problems, with some specific features that are "custom made" for analyzing solar receivers. Can be utilized not only to predict receiver performance under varying solar flux, ambient temperature and local heat-transfer rates but also to detect locations of hotspots and metallurgical difficulties and to predict performance sensitivity of neighboring component parameters.

  20. Tower Power: Producing Fuels from Solar Energy

    ERIC Educational Resources Information Center

    Antal, M. J., Jr.

    1976-01-01

    This article examines the use of power tower technologies for the production of synthetic fuels. This process overcomes the limitations of other processes by using a solar furnace to drive endothermic fuel producing reactions and the resulting fuels serve as a medium for storing solar energy. (BT)

  1. Solar and laser energy conversion with Schottky barrier solar cells

    NASA Technical Reports Server (NTRS)

    Stirn, R. J.; Yeh, Y.-C. M.

    1974-01-01

    Photovoltaic devices have been fabricated for solar and short-wavelength laser energy conversion using the thin metal film-semiconductor (Schottky barrier) approach. Studies of the metal film optical characteristics and the voltage outputs were emphasized. Air mass zero efficiencies of 8 to 9% in GaAs and laser conversion efficiencies of 25% at 4880 A in GaAs(0.6)P(0.4) are presently measured, with projected efficiencies of 15 and 45%, respectively. The techniques, if applied successfully to semiconductor thin films, could have an impact in solar energy terrestrial application.

  2. Polymers in solar energy utilization

    NASA Technical Reports Server (NTRS)

    Liang, R. H.; Coulter, D. R.; Dao, C.; Gupta, A.

    1983-01-01

    A laser photoacoustic technique (LPAT) has been verified for performing accelerated life testing of outdoor photooxidation of polymeric materials used in solar energy applications. Samples of the material under test are placed in a chamber with a sensitive microphone, then exposed to chopped laser radiation. The sample absorbs the light and converts it to heat by a nonradiative deexcitation process, thereby reducing pressure fluctuations within the cell. The acoustic signal detected by the microphone is directly proportional to the amount of light absorbed by the specimen. Tests were performed with samples of ethylene/methylacrylate copolymer (EMA) reprecipitated from hot cyclohexane, compressed, and molded into thin (25-50 microns) films. The films were exposed outdoors and sampled by LPAT weekly. The linearity of the light absorbed with respect to the acoustic signal was verified.Correlations were established between the photoacoustic behavior of the materials aged outdoors and the same kinds of samples cooled and heated in a controlled environment reactor. The reactor tests were validated for predicting outdoor exosures up to 55 days.

  3. Solar Energy: Progress and Promise.

    ERIC Educational Resources Information Center

    Council on Environmental Quality, Washington, DC.

    This report discusses many of the economic and policy questions related to the widespread introduction of solar power, presents recent progress in developing solar technologies and advancing their economic feasibility, and reviews some recommendations that have been made for achieving the early introduction and sustained application of solar…

  4. Our prodigal sun. [solar energy technology

    NASA Technical Reports Server (NTRS)

    1974-01-01

    Characteristics of the sun are reported indicating it as a source of energy. Data from several space missions are discussed, and the solar activity cycle is presented. The corona, flares, prominences, spots, and wind of the sun are also discussed.

  5. Dark Energy and The Dark Matter Relic Abundance

    SciTech Connect

    Rosati, Francesca

    2004-11-17

    Two mechanisms by which the quintessence scalar could enhance the relic abundance of dark matter particles are discussed. These effects can have an impact on supersymmetric candidates for dark matter.

  6. Argonne Solar Energy Program annual report. Summary of solar program activities for fiscal year 1979

    SciTech Connect

    1980-06-01

    The R and D work done at Argonne National Laboratory on solar energy technologies during the period October 1, 1978 to September 30, 1979 is described. Technical areas included in the ANL solar program are solar energy collection, heating and cooling, thermal energy storage, ocean thermal energy conversion, photovoltaics, biomass conversion, satellite power systems, and solar liquid-metal MHD power systems.

  7. A New Solar Fluorine Abundance and a Fluorine Determination in the Two Open Clusters M67 and NGC 6404

    NASA Astrophysics Data System (ADS)

    Maiorca, E.; Uitenbroek, H.; Uttenthaler, S.; Randich, S.; Busso, M.; Magrini, L.

    2014-06-01

    We present a new determination of the solar fluorine abundance together with abundance measurements of fluorine in two Galactic open clusters. We analyzed a sunspot spectrum, observed by L. Wallace and W. Livingston with the Fourier Transform Spectrometer at the McMath/Pierce Solar Telescope situated on Kitt Peak, and spectra of four giants in the old cluster M67 (~4.5 Gyr) and three giants in the young cluster NGC 6404 (~0.5 Gyr), obtained with the CRIRES spectrograph at the Very Large Telescope. Fluorine was measured through the synthesis of the available HF lines. We adopted the recent set of experimental molecular parameters of HF delivered by the HITRAN database, and found a new solar fluorine abundance of A(F) = 4.40 ± 0.25, in good agreement with the M67 average fluorine abundance of A(F) = 4.49 ± 0.20. The new solar abundance is in a very good agreement with the meteoritic value. The modern spectrosynthesis tools used and the agreement with the meteoritic value and with the results in open cluster M67, known to be a solar analogue, make our solar determination very robust. At the same time, the fluorine measurement in the above-mentioned open clusters is the first step toward understanding its evolution during the last ~10 Gyr in the Galactic disk. In order to develop this project, a larger sample of open clusters is required, in order to allow us to trace the evolution of fluorine as a function of time and, in turn, to better understand its origin.

  8. A new solar fluorine abundance and a fluorine determination in the two open clusters M67 and NGC 6404

    SciTech Connect

    Maiorca, E.; Randich, S.; Magrini, L.; Uitenbroek, H.; Uttenthaler, S.; Busso, M.

    2014-06-20

    We present a new determination of the solar fluorine abundance together with abundance measurements of fluorine in two Galactic open clusters. We analyzed a sunspot spectrum, observed by L. Wallace and W. Livingston with the Fourier Transform Spectrometer at the McMath/Pierce Solar Telescope situated on Kitt Peak, and spectra of four giants in the old cluster M67 (∼4.5 Gyr) and three giants in the young cluster NGC 6404 (∼0.5 Gyr), obtained with the CRIRES spectrograph at the Very Large Telescope. Fluorine was measured through the synthesis of the available HF lines. We adopted the recent set of experimental molecular parameters of HF delivered by the HITRAN database, and found a new solar fluorine abundance of A(F) = 4.40 ± 0.25, in good agreement with the M67 average fluorine abundance of A(F) = 4.49 ± 0.20. The new solar abundance is in a very good agreement with the meteoritic value. The modern spectrosynthesis tools used and the agreement with the meteoritic value and with the results in open cluster M67, known to be a solar analogue, make our solar determination very robust. At the same time, the fluorine measurement in the above-mentioned open clusters is the first step toward understanding its evolution during the last ∼10 Gyr in the Galactic disk. In order to develop this project, a larger sample of open clusters is required, in order to allow us to trace the evolution of fluorine as a function of time and, in turn, to better understand its origin.

  9. Energy transfer processes in solar energy conversion

    SciTech Connect

    Fayer, M.D.

    1988-01-01

    The program involves the investigation of excitation transport and electron transfer in complex systems. In the area of electron transfer, we have been studying electron back transfer following donor-acceptor photoinduced electron transfer. We are addressing this problem both theoretically and experimentally. In the area of excitation transport, we have been examining transport in solid solutions, liquid solutions, and in clustered excitation transport systems. Again, we are pursuing both experimental and theoretical approaches. The problem of electron back transfer between photogenerated ions is of central importance in both artificial and biological solar energy conversion. Once an electron has been transferred from an optically excited donor to an acceptor, back transfer competes with the ability of the radical ions to go on to do useful chemistry. We are studying the back transfer process using picosecond transient grating experiments in conjunction with time resolved and steady state fluorescence quenching measurements. The transient grating experiments makes the back transfer process a direct experimental observable, while the fluorescence experiments allow the forward transfer to be examined. By combining the experiments, a complete picture emerges. 10 refs.

  10. Energy savings obtainable through passive solar techniques

    SciTech Connect

    Balcomb, J.D.

    1980-01-01

    A passive solar energy system is one in which the thermal energy flow is by natural means, that is by radiation, conduction, or natural convection. The purpose of the paper is to provide a survey of passive solar heating experience, especially in the US. Design approaches are reviewed and examples shown. Misconceptions are discussed. Advantages are listed. The Los Alamos program of performance simulation and evaluation is described and a simplified method of performance estimation is outlined.

  11. Solar energy to meet the nation's energy needs

    NASA Technical Reports Server (NTRS)

    Rom, F. E.; Thomas, R. L.

    1973-01-01

    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.

  12. Solar Spots - Activities to Introduce Solar Energy into the K-8 Curricula.

    ERIC Educational Resources Information Center

    Longe, Karen M.; McClelland, Michael J.

    Following an introduction to solar technology which reviews solar heating and cooling, passive solar systems (direct gain systems, thermal storage walls, sun spaces, roof ponds, and convection loops), active solar systems, solar electricity (photovoltaic and solar thermal conversion systems), wind energy, and biomass, activities to introduce solar…

  13. Solar energy control system. [temperature measurement

    NASA Technical Reports Server (NTRS)

    Currie, J. R. (Inventor)

    1981-01-01

    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.

  14. Solar energy receiver for a Stirling engine

    NASA Technical Reports Server (NTRS)

    Selcuk, M. K. (Inventor)

    1980-01-01

    A solar energy receiver includes a separable endless wall formed of a ceramic material in which a cavity of substantially cylindrical configuration is defined for entrapping solar flux. An acceptance aperture is adapted to admit to the cavity a concentrated beam of solar energy. The wall is characterized by at least one pair of contiguously related segments separated by lines of cleavage intercepting the aperture. At least one of the segments is supported for pivotal displacement. A thermal-responsive actuator is adapted to respond to excessive temperatures within the cavity for initiating pivoted displacement of one segment, whereby thermal flux is permitted to escape from the cavity.

  15. Solar energy thermalization and storage device

    DOEpatents

    McClelland, John F.

    1981-09-01

    A passive solar thermalization and thermal energy storage assembly which is visually transparent. The assembly consists of two substantial parallel, transparent wall members mounted in a rectangular support frame to form a liquid-tight chamber. A semitransparent thermalization plate is located in the chamber, substantially paralled to and about equidistant from the transparent wall members to thermalize solar radiation which is stored in a transparent thermal energy storage liquid which fills the chamber. A number of the devices, as modules, can be stacked together to construct a visually transparent, thermal storage wall for passive solar-heated buildings.

  16. Solar energy thermalization and storage device

    DOEpatents

    McClelland, J.F.

    A passive solar thermalization and thermal energy storage assembly which is visually transparent is described. The assembly consists of two substantial parallel, transparent wall members mounted in a rectangular support frame to form a liquid-tight chamber. A semitransparent thermalization plate is located in the chamber, substantially paralled to and about equidistant from the transparent wall members to thermalize solar radiation which is stored in a transparent thermal energy storage liquid which fills the chamber. A number of the devices, as modules, can be stacked together to construct a visually transparent, thermal storage wall for passive solar-heated buildings.

  17. The effects of mass flow on the temperature and abundance structure of the solar transition region

    NASA Technical Reports Server (NTRS)

    Woods, D. T.; Holzer, Thomas E.

    1991-01-01

    The density and temperature structure of a multicomponent plasma consisting of electrons, protons, ionized helium, and a trace minor ion species are computed. The equations of force and energy balance for this model are developed and solved. It is found that in the case of downflows the minor ion temperature can be significantly hotter than the electron temperature, and significant abundance enhancements are possible due to the slowdown of the minor species from the effect of the thermal force. A simple physical picture of the source of the thermal force is given.

  18. The Case for the Large Scale Development of Solar Energy

    ERIC Educational Resources Information Center

    O'Reilly, S. A.

    1977-01-01

    Traces the history of solar energy development. Discusses global effects (temperature, particle and other pollution) of burning fossil fuels. Provides energy balance equations for solar energy distribution and discusses flat plate collectors, solar cells, photochemical and photobiological conversion of solar energy, heat pumps. (CS)

  19. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 24 Housing and Urban Development 2 2014-04-01 2014-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any...

  20. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 24 Housing and Urban Development 2 2012-04-01 2012-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any...

  1. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 24 Housing and Urban Development 2 2013-04-01 2013-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by up... to the installation of a solar energy system. (b) Solar energy system is defined as any...

  2. The solar elemental abundances problem: Large enhancements in photoionization and bound-free opacity

    NASA Astrophysics Data System (ADS)

    Pradhan, A.; Nahar, S.

    2016-05-01

    Aimed at solving the outstanding problem of solar opacity and radiation transport, we report substantial photoabsorption in the high-energy regime due to atomic core photo-excitations not heretofore considered. In an extensive R-Matrix calculations of unprecedented complexity for an important iron ion Fe XVII, with a wave function expansion of 99 Fe XVIII core states from n <= 4 complexes (equivalent to 218 fine structure levels), we find: i) up to orders of magnitude enhancement in background photoionization cross sections, in addition to strongly peaked photo-excitation-of-core resonances not considered in current opacity models, and ii) demonstrate convergence with respect to successive core excitations. These findings may explain the ``higher-than-predicted'' monochromatic iron opacity measured recently at the Sandia Z-pinch fusion device at solar interior conditions. The findings will also impact the total atomic photoabsorption and radiation transport in laboratory and astrophysical plasmas, such as UV emission from host stars of extra-solar planets. Support: NSF, DOE, Ohio Supercomputer Center, Columbus, OH.

  3. Solar energy applications at Army ammunition plants

    NASA Astrophysics Data System (ADS)

    Lowry, A. P.; Moy, S. M.

    1982-06-01

    The Army Ammunition Plants use significant quantities of fossil fuels. To reduce dependence on these scarce, costly, and non-renewable fuels, a study was conducted to investigate potential solar energy applications at the AAPs. Solar energy is a low-level energy source which is best applied to low temperature applications. It can be used at the AAPs to preheat boiler feedwater, provide hot air for dry-houses, provide domestic hot water and heat for administration buildings, and provide hot water for manufacturing processes such as metal cleaning, phosphating, and X-ray film processing. Use of the flat plate collectors, evacuated tube collectors, or solar ponds with the possible addition of a heat pump, offers reasonably economical means of applying solar technology to AAP needs.

  4. The HESP (High Energy Solar Physics) project

    NASA Technical Reports Server (NTRS)

    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.

  5. Passive solar energy information user study

    SciTech Connect

    Belew, W.W.; Wood, B.L.; Marle, T.L.; Reinhardt, C.L.

    1980-11-01

    The results of a series of telephone interviews with groups of users of information on passive solar heating and cooling are described. These results, part of a larger study on many different solar technologies, identify types of information each group needed and the best ways to get information to each group. The overall study provides baseline data about information needs in the solar community. An earlier study identified the information user groups in the solar community and the priority (to accelerate solar energy commercialization) of getting information to each group. In the current study only high-priority groups were examined. Results from seven passive groups respondents are analyzed in this report: Federally Funded Researchers, Manufacturer Representatives, Architects, Builders, Educators, Cooperative Extension Service County Agents, and Homeowners. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

  6. Basic Research Needs for Solar Energy Utilization. Report of the Basic Energy Sciences Workshop on Solar Energy Utilization, April 18-21, 2005

    SciTech Connect

    Lewis, N. S.; Crabtree, G.; Nozik, A. J.; Wasielewski, M. R.; Alivisatos, P.; Kung, H.; Tsao, J.; Chandler, E.; Walukiewicz, W.; Spitler, M.; Ellingson, R.; Overend, R.; Mazer, J.; Gress, M.; Horwitz, J.; Ashton, C.; Herndon, B.; Shapard, L.; Nault, R. M.

    2005-04-21

    World demand for energy is projected to more than double by 2050 and to more than triple by the end of the century. Incremental improvements in existing energy networks will not be adequate to supply this demand in a sustainable way. Finding sufficient supplies of clean energy for the future is one of society?s most daunting challenges. Sunlight provides by far the largest of all carbon-neutral energy sources. More energy from sunlight strikes the Earth in one hour (4.3 ? 1020 J) than all the energy consumed on the planet in a year (4.1 ? 1020 J). We currently exploit this solar resource through solar electricity ? a $7.5 billion industry growing at a rate of 35?40% per annum ? and solar-derived fuel from biomass, which provides the primary energy source for over a billion people. Yet, in 2001, solar electricity provided less than 0.1% of the world's electricity, and solar fuel from modern (sustainable) biomass provided less than 1.5% of the world's energy. The huge gap between our present use of solar energy and its enormous undeveloped potential defines a grand challenge in energy research. Sunlight is a compelling solution to our need for clean, abundant sources of energy in the future. It is readily available, secure from geopolitical tension, and poses no threat to our environment through pollution or to our climate through greenhouse gases. This report of the Basic Energy Sciences Workshop on Solar Energy Utilization identifies the key scientific challenges and research directions that will enable efficient and economic use of the solar resource to provide a significant fraction of global primary energy by the mid 21st century. The report reflects the collective output of the workshop attendees, which included 200 scientists representing academia, national laboratories, and industry in the United States and abroad, and the U.S. Department of Energy?s Office of Basic Energy Sciences and Office of Energy Efficiency and Renewable Energy.

  7. Solar Energy Education. Home economics: student activities. Field test edition

    SciTech Connect

    Not Available

    1981-03-01

    A view of solar energy from the standpoint of home economics is taken in this book of activities. Students are provided information on solar energy resources while performing these classroom activities. Instructions for the construction of a solar food dryer and a solar cooker are provided. Topics for study include window treatments, clothing, the history of solar energy, vitamins from the sun, and how to choose the correct solar home. (BCS)

  8. On-farm applications of solar energy

    SciTech Connect

    Butler, J.L.

    1980-01-01

    The solar energy used by photosynthesis must be supplemented with additional energy in order to maintain a highly productive agriculture. Petroleum energy, which supplies most of the energy for production agriculture appears to be nearing depletion. Approximately half of the energy requirement is for stationary uses, such as environmental temperature and humidity control, crop drying, water heating, and irrigation. Energy for all these, especially the first three may be supplied by solar energy. Much of the technology is available to make the applications now, but economic feasibility may depend upon additional increase in the cost of fossil fuel energy. In most areas, additional research is needed to reduce the gap between present system costs and economic feasibility, especially for those uses which are highly seasonal in nature.

  9. Efficient solar water oxidation using photovoltaic devices functionalized with earth-abundant oxygen evolving catalysts.

    PubMed

    Cristino, Vito; Berardi, Serena; Caramori, Stefano; Argazzi, Roberto; Carli, Stefano; Meda, Laura; Tacca, Alessandra; Bignozzi, Carlo Alberto

    2013-08-21

    Indium tin oxide (ITO) surfaces of triple junction photovoltaic cells were functionalized with oxygen evolving catalysts (OECs) based on amorphous hydrous earth-abundant metal oxides (metal = Fe, Ni, Co), obtained by straightforward Successive Ionic Layer Adsorption and Reaction (SILAR) in an aqueous environment. Functionalization with Fe(iii) oxides gave the best results, leading to photoanodes capable of efficiently splitting water, with photocurrent densities up to 6 ± 1 mA cm(-2) at 0 V vs. the reversible hydrogen electrode (RHE) under AM 1.5 G simulated sunlight illumination. The resulting Solar To Hydrogen (STH) conversion efficiencies, measured in two electrodes configuration, were in the range 3.7-5%, depending on the counter electrode that was employed. Investigations on the stability showed that these photoanodes were able to sustain 120 minutes of continuous illumination with a < 10% photocurrent loss at 0 V vs. RHE. Pristine photoanodic response of the cells could be fully restored by an additional SILAR cycle, evidencing that the observed loss is due to the detachment of the more weakly surface bound catalyst.

  10. Dye-sensitized Solar Cells for Solar Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Roy, M. S.; Deol, Y. S.; Kumar, Manish; Prasad, Narottam; Janu, Yojana

    2011-10-01

    Dye-sensitized solar cells (DSSCs) also known as Gratzel cells, have attracted the interests of researchers to a great extent because of its cost effective and easy manufacturing process without involving highly sophisticated lithographic technique and high cost raw materials as usually seen in conventional solar cell. Based on simple photo-electrochemical process, it has got immense potential in converting solar energy to electrical power in remote and desert area where the supply of conventional power is not possible. The overall peak power-production efficiency of dye-sensitized solar cells has been reported around 11 percent, so they are best suited to low-density applications and the price-to-performance ratio obtained through these solar cells is superior to others. DSSCs have ability to absorb even diffused sunlight and therefore work in cloudy whether as well without much impact over the efficiency. The present communication deals with a review of our work on DSSCs wherein we have used cost effective natural dyes/pigments as a sensitizer of nc-TiO2 and discussed about various key factors affecting the conversion efficiency of DSSC.

  11. A survey of approximately 1 MeV/nucleon solar flare particle abundances, in the Z ? 1-26 range, during the 1973-1977 solar minimum period

    NASA Technical Reports Server (NTRS)

    Mason, G. M.; Gloeckler, G.; Fisk, L. A.; Hovestadt, D.

    1980-01-01

    The abundances of the major elements over the range H-Fe in solar flare energetic particles near 1 MeV/nucleon were surveyed for a large number of flares during the period 1973-1977; observations were carried out by the IMP 8 spacecraft in interplanetary space. The survey considered two types of solar flare events: (1) large events from which the average boundaries were deduced, and (2) events which have significant abundance differences from average. In addition, two He-3-rich events with abundance features that are different from previous examples are reported: one case with no enhancements of heavy ions, and a second case in which, compared to O, the heavy-ion enhancements are confined to the charge range Si-Fe rather than the usual case in which all elements Ne-Fe are enriched.

  12. Explore engineering with solar energy

    SciTech Connect

    Davidson, J.H.

    1995-11-01

    An outreach program was initiated at the University of Minnesota by faculty and student members of the Society of Women Engineers in the spring of 1994 to interest students in 3rd through 9th grade, particularly girls, in careers in engineering. Interaction with elementary and junior high students focuses on hands-on experiences with portable solar devices. This paper reports progress of the program including descriptions of the solar devices, their use in visits to local schools, day visits to the University, and week-long summer camps, and continuing education programs for elementary and secondary school teachers.

  13. MEASUREMENTS OF THE RELATIVE ABUNDANCES OF HIGH-ENERGY COSMIC-RAY NUCLEI IN THE TeV/NUCLEON REGION

    SciTech Connect

    Ahn, H. S.; Ganel, O.; Han, J. H.; Kim, K. C.; Lee, M. H.; Malinin, A.; Allison, P. S.; Beatty, J. J.; Brandt, T. J.; Bagliesi, M. G.; Bigongiari, G.; Maestro, P.; Marrocchesi, P. S.; Barbier, L.; Childers, J. T.; DuVernois, M. A.; Conklin, N. B.; Coutu, S.; Jeon, J. A.; Lee, J.

    2010-06-01

    We present measurements of the relative abundances of cosmic-ray nuclei in the energy range of 500-3980 GeV/nucleon from the second flight of the Cosmic Ray Energetics And Mass balloon-borne experiment. Particle energy was determined using a sampling tungsten/scintillating-fiber calorimeter, while particle charge was identified precisely with a dual-layer silicon charge detector installed for this flight. The resulting element ratios C/O, N/O, Ne/O, Mg/O, Si/O, and Fe/O at the top of atmosphere are 0.919 {+-} 0.123{sup stat} {+-} 0.030{sup syst}, 0.076 {+-} 0.019{sup stat} {+-} 0.013{sup syst}, 0.115 {+-} 0.031{sup stat} {+-} 0.004{sup syst}, 0.153 {+-} 0.039{sup stat} {+-} 0.005{sup syst}, 0.180 {+-} 0.045{sup stat} {+-} 0.006{sup syst}, and 0.139 {+-} 0.043{sup stat} {+-} 0.005{sup syst}, respectively, which agree with measurements at lower energies. The source abundance of N/O is found to be 0.054 {+-} 0.013{sup stat} {+-} 0.009{sup syst+0.010esc} {sub -0.017}. The cosmic-ray source abundances are compared to local Galactic (LG) abundances as a function of first ionization potential and as a function of condensation temperature. At high energies the trend that the cosmic-ray source abundances at large ionization potential or low condensation temperature are suppressed compared to their LG abundances continues. Therefore, the injection mechanism must be the same at TeV/nucleon energies as at the lower energies measured by HEAO-3, CRN, and TRACER. Furthermore, the cosmic-ray source abundances are compared to a mixture of 80% solar system abundances and 20% massive stellar outflow (MSO) as a function of atomic mass. The good agreement with TIGER measurements at lower energies confirms the existence of a substantial fraction of MSO material required in the {approx}TeV per nucleon region.

  14. General solar energy information user study

    NASA Astrophysics Data System (ADS)

    Belew, W. W.; Wood, B. L.; Marle, T. L.; Reinhardt, C. L.

    1981-03-01

    The results of a series of telephone interviews with groups of users of information on general solar energy are presented. These results identify types of information each group needed and the best ways to get information to each group. Results from 13 groups of respondents are analyzed: loan officers, real estate appraisers, tax assessors, insurers, lawyers, utility respresentatives, public interest group representatives, information and agricultural representatives, public interest group representatives, information and agricultural specialists at state cooperative extension service offices, and state energy office representatives. The data will be used as input to the determination of information products and services the Solar Energy Research Institute, the Solar Energy Information Data Bank Network, and the entire information outreach community should be preparing and disseminating.

  15. Port of Galveston Solar Energy Project

    SciTech Connect

    Falcioni, Diane; Cuclis, Alex; Freundlich, Alex

    2014-03-31

    This study on the performance characteristics of existing solar technologies in a maritime environment was funded by an award given to The Port of Galveston (POG) from the U.S. Department of Energy (DOE). The study includes research performed by The Center for Advanced Materials at the University of Houston (UH). The UH researchers examined how solar cell efficiencies and life spans can be improved by examining the performance of a variety of antireflective (AR) coatings mounted on the top of one of the POG’s Cruise Terminals. Supplemental supporting research was performed at the UH laboratories. An educational Kiosk was constructed with a 55” display screen providing information about solar energy, the research work UH performed at POG and real time data from the solar panels located on the roof of the Cruise Terminal. The Houston Advanced Research Center (HARC) managed the project.

  16. Energy Primer: Solar, Water, Wind, and Biofuels.

    ERIC Educational Resources Information Center

    Portola Inst., Inc., Menlo Park, CA.

    This is a comprehensive, fairly technical book about renewable forms of energy--solar, water, wind, and biofuels. The biofuels section covers biomass energy, agriculture, aquaculture, alcohol, methane, and wood. The focus is on small-scale systems which can be applied to the needs of the individual, small group, or community. More than one-fourth…

  17. The Status of Solar Energy as Fuel.

    ERIC Educational Resources Information Center

    Hall, D. O.

    1979-01-01

    Discused is the biological conversion of solar energy via photosynthesis into stored energy in the form of biomass. Detailed are the research and development programs on biomass of the United States, Canada, Australia, New Zealand, Europe, Brazil, Philippines, Sahel, India, and China. (BT)

  18. Using Solar Energy to Desalinate Water.

    ERIC Educational Resources Information Center

    Tabor, Harry Z.

    1978-01-01

    Material presented is adapted from Desalination with Solar Energy, a paper presented before the International Symposium on Energy Sources and Development, held in Spain in 1977. Desalination systems energized by the sun, conditions governing their efficiency, and their costs are discussed. (HM)

  19. Solar energy system with wind vane

    DOEpatents

    Grip, Robert E

    2015-11-03

    A solar energy system including a pedestal defining a longitudinal axis, a frame that is supported by the pedestal and that is rotateable relative to the pedestal about the longitudinal axis, the frame including at least one solar device, and a wind vane operatively connected to the frame to urge the frame relative to the pedestal about the longitudinal axis in response to wind acting on the wind vane.

  20. Reliability engineering in solar energy: workshop proceedings

    SciTech Connect

    Gross, G.

    1980-03-01

    A workshop to reveal the scope of reliability-related activities in solar energy conversion projects and in nonsolar segments of industry is described. Two reliability programs, one in heating and cooling and one in photovoltaics, are explicated. This document also presents general suggestions for the establishment of a unified program for reliability, durability, maintainability, and safety (RDM and S) in present and future solar projects.

  1. Decentralized solar photovoltaic energy systems

    NASA Astrophysics Data System (ADS)

    Krupka, M. C.

    1980-09-01

    Emphasis was placed upon the selection and use of a model residential photovoltaic system to develop and quantify the necessary data. The model consists of a reference home located in Phoenix, AZ utilizing a unique solar cell array roof shingle combination. Silicon solar cells, rated at 13.5 percent efficiency at 28 C and 100 mW/sq cm insolation are used to generate 10 kW (peak). An all electric home is considered with lead acid battery storage, DC AC inversion and utility backup. The reference home is compared to others in regions of different insolation. It is suggested that solar cell materials production and fabrication may have the major environmental impact when comparing all facets of photovoltaic system usage. Fabrication of the various types of solar cell systems involves the need, handling, and transportation of many toxic and hazardous chemicals with attendant health and safety impacts. Increases in production of such materials as lead, antimony, sulfuric acid, copper, plastics, cadmium and gallium will be required should large scale usage of photovoltaic systems be implemented.

  2. Desalting system utilizing solar energy

    SciTech Connect

    Iida, T.

    1985-06-25

    A heat-transfer medium is heated by a solar heat collector and then adiabatically compressed. The heat-transfer medium thus compressed exchanges heat with the seawater to heat it, and is then adiabatically expanded with the heated seawater being evaporated and the steam thus produced, upon heat exchange with the seawater, changed into fresh water.

  3. Solar Energy of the North

    SciTech Connect

    Davis St. Peter Director of Faclities Charles Bonin Vice President of Administration & Finance

    2012-01-12

    The concept of this project was to design a solar array that would not only provide electricity for the major classroom building of the campus but would also utilize that electricity to enhance the learning environment. It was also understood that the project would be a research and data gathering project.

  4. The Prospects of Solar Energy for Developing Nations.

    ERIC Educational Resources Information Center

    Ramachandran, A.; Gururaja, J.

    1979-01-01

    Discussed are the potential application of solar energy and its possible benefits to developing countries. Various energy needs, including domestic, agricultural, and household, that could be met by using solar energy are discussed. (BT)

  5. Solar wind-magnetosphere energy input functions

    SciTech Connect

    Bargatze, L.F.; McPherron, R.L.; Baker, D.N.

    1985-01-01

    A new formula for the solar wind-magnetosphere energy input parameter, P/sub i/, is sought by applying the constraints imposed by dimensional analysis. Applying these constraints yields a general equation for P/sub i/ which is equal to rho V/sup 3/l/sub CF//sup 2/F(M/sub A/,theta) where, rho V/sup 3/ is the solar wind kinetic energy density and l/sub CF//sup 2/ is the scale size of the magnetosphere's effective energy ''collection'' region. The function F which depends on M/sub A/, the Alfven Mach number, and on theta, the interplanetary magnetic field clock angle is included in the general equation for P/sub i/ in order to model the magnetohydrodynamic processes which are responsible for solar wind-magnetosphere energy transfer. By assuming the form of the function F, it is possible to further constrain the formula for P/sub i/. This is accomplished by using solar wind data, geomagnetic activity indices, and simple statistical methods. It is found that P/sub i/ is proportional to (rho V/sup 2/)/sup 1/6/VBG(theta) where, rho V/sup 2/ is the solar wind dynamic pressure and VBG(theta) is a rectified version of the solar wind motional electric field. Furthermore, it is found that G(theta), the gating function which modulates the energy input to the magnetosphere, is well represented by a ''leaky'' rectifier function such as sin/sup 4/(theta/2). This function allows for enhanced energy input when the interplanetary magnetic field is oriented southward. This function also allows for some energy input when the interplanetary magnetic field is oriented northward. 9 refs., 4 figs.

  6. Galactic chemical evolution and solar s-process abundances: Dependence on the {sup 13}C-pocket structure

    SciTech Connect

    Bisterzo, S.; Travaglio, C.; Gallino, R.; Wiescher, M.; Käppeler, F. E-mail: sarabisterzo@gmail.com

    2014-05-20

    We study the s-process abundances (A ≳ 90) at the epoch of the solar system formation. Asymptotic giant branch yields are computed with an updated neutron capture network and updated initial solar abundances. We confirm our previous results obtained with a Galactic chemical evolution (GCE) model: (1) as suggested by the s-process spread observed in disk stars and in presolar meteoritic SiC grains, a weighted average of s-process strengths is needed to reproduce the solar s distribution of isotopes with A > 130; and (2) an additional contribution (of about 25%) is required in order to represent the solar s-process abundances of isotopes from A = 90 to 130. Furthermore, we investigate the effect of different internal structures of the {sup 13}C pocket, which may affect the efficiency of the {sup 13}C(α, n){sup 16}O reaction, the major neutron source of the s process. First, keeping the same {sup 13}C profile adopted so far, we modify by a factor of two the mass involved in the pocket; second, we assume a flat {sup 13}C profile in the pocket, and we test again the effects of the variation of the mass of the pocket. We find that GCE s predictions at the epoch of the solar system formation marginally depend on the size and shape of the {sup 13}C pocket once a different weighted range of {sup 13}C-pocket strengths is assumed. We obtain that, independently of the internal structure of the {sup 13}C pocket, the missing solar system s-process contribution in the range from A = 90 to 130 remains essentially the same.

  7. Surface Plasmon-Assisted Solar Energy Conversion.

    PubMed

    Dodekatos, Georgios; Schünemann, Stefan; Tüysüz, Harun

    2016-01-01

    The utilization of localized surface plasmon resonance (LSPR) from plasmonic noble metals in combination with semiconductors promises great improvements for visible light-driven photocatalysis, in particular for energy conversion. This review summarizes the basic principles of plasmonic photocatalysis, giving a comprehensive overview about the proposed mechanisms for enhancing the performance of photocatalytically active semiconductors with plasmonic devices and their applications for surface plasmon-assisted solar energy conversion. The main focus is on gold and, to a lesser extent, silver nanoparticles in combination with titania as semiconductor and their usage as active plasmonic photocatalysts. Recent advances in water splitting, hydrogen generation with sacrificial organic compounds, and CO2 reduction to hydrocarbons for solar fuel production are highlighted. Finally, further improvements for plasmonic photocatalysts, regarding performance, stability, and economic feasibility, are discussed for surface plasmon-assisted solar energy conversion.

  8. An assessment of solar energy as a national energy resource

    NASA Technical Reports Server (NTRS)

    Donovan, P.; Woodward, W.; Cherry, W. E.; Morse, F. H.; Herwig, L. O.

    1972-01-01

    The applications are discussed of solar energy for thermal energy for buildings; chemical and biological conversion of organic materials to liquid, solid, and gaseous fuels; and the generation of electricity. It is concluded that if solar development programs are successful, building heating for public use is possible within 5 years, building cooling in 6 to 10 years, synthetic fuels from organic materials in 5 to 8 years, and electricity production in 10 to 15 years.

  9. Education: the key to the future of solar energy

    SciTech Connect

    Hamos, R.E.

    1982-01-01

    Industry-approved educational programs in solar technology (especially domestic hot water) can ensure the growth of the solar industry. Effective solar training should include a variety of training aids such as a student manual, solar trainer, actual equipment, overhead transparencies and 35 mm slides. Without such educational programs, misconceptions and misunderstandings may doom solar to be permanently branded as an alternate energy source.

  10. Solar absorption cooling: An innovative use of solar energy

    SciTech Connect

    Hewett, R.

    1995-12-31

    Solar thermal energy systems that generate hot water for applications in industry, commerce, and government have been available commercially in the US since the 1970s. Absorption chillers to provide space cooling for nonresidential facilities have been available for commercial use since the 1960s. This paper discusses the merging of the two technologies into one: solar absorption cooling. The author will describe the operating principles of small (up to about 200 tons) single- and double-effect solar-driven absorption cooling systems and specify the potential benefits of the technology. Then, the costs and technical and economic performances of two projects are discussed. One is a successfully operating system in a commercial building in Sacramento, CA; the other is a successfully operating system at the US Army`s Yuma Proving Ground in Arizona. While solar absorption cooling technology is available for commercial use, cost, performance, and economic barriers still block market acceptance and widespread use. These barriers are discussed as they relate to the two specific projects.

  11. Abundance, distribution, and origin of 60Fe in the solar protoplanetary disk

    NASA Astrophysics Data System (ADS)

    Tang, Haolan; Dauphas, Nicolas

    2012-12-01

    Meteorites contain relict decay products of short-lived radionuclides that were present in the protoplanetary disk when asteroids and planets formed. Several studies reported a high abundance of 60Fe (t1/2=2.62±0.04 Myr) in chondrites (60Fe/56Fe∼6×10-7), suggesting that planetary materials incorporated fresh products of stellar nucleosynthesis ejected by one or several massive stars that exploded in the vicinity of the newborn Sun. We measured 58Fe/54Fe and 60Ni/58Ni isotope ratios in whole rocks and constituents of differentiated achondrites (ureilites, aubrites, HEDs, and angrites), unequilibrated ordinary chondrites Semarkona (LL3.0) and NWA 5717 (ungrouped petrologic type 3.05), metal-rich carbonaceous chondrite Gujba (CBa), and several other meteorites (CV, EL H, LL chondrites; IIIAB, IVA, IVB iron meteorites). We derive from these measurements a much lower initial 60Fe/56Fe ratio of (11.5±2.6)×10-9 and conclude that 60Fe was homogeneously distributed among planetary bodies. This low ratio is consistent with derivation of 60Fe from galactic background (60Fe/56Fe≈2.8×10-7 in the interstellar medium from γ-ray observations) and can be reconciled with high 26Al/27Al∼5×10-5 in chondrites if solar material was contaminated through winds by outer layers of one or several massive stars (e.g., a Wolf-Rayet star) rich in 26Al and poor in 60Fe. We present the first chronological application of the 60Fe-60Ni decay system to establish the time of core formation on Vesta at 3.7-1.7+2.5 Myr after condensation of calcium-aluminum-rich inclusions (CAIs).

  12. Manufacture of silicon carbide using solar energy

    DOEpatents

    Glatzmaier, Gregory C.

    1992-01-01

    A method is described for producing silicon carbide particles using solar energy. The method is efficient and avoids the need for use of electrical energy to heat the reactants. Finely divided silica and carbon are admixed and placed in a solar-heated reaction chamber for a time sufficient to cause a reaction between the ingredients to form silicon carbide of very small particle size. No grinding of silicon carbide is required to obtain small particles. The method may be carried out as a batch process or as a continuous process.

  13. Electric utility solar energy activities: 1980 survey

    NASA Astrophysics Data System (ADS)

    Wentworth, M. C.

    1980-12-01

    Brief descriptions of 839 projects being conducted by 236 utility companies are given. Also included are an index of projects by category, a statistical summary, a list of participating utilities with information contacts and addresses, a list of utilities with projects designated by category, a list of utilities organized by state, a list of available reports on utility sponsored projects, and a list of projects having multiple utility participants. Project categories include solar heating and cooling of buildings, wind energy conversion, solar thermal electric power, photovoltaics, biomass conversion, process heat, and ocean energy conversion.

  14. Impacts of solar energy utilization

    NASA Technical Reports Server (NTRS)

    1973-01-01

    Various methods of conducting surveys and analyses to determine the attitude of the public toward the energy crisis are discussed. Models to determine the impact of the energy crisis and proposed alternative sources of energy on the social structure are analyzed. The various interest groups which are concerned with energy and the nature of their interest are identified. The government structure for controlling resource production and allocation is defined.

  15. Solar energy and job creation benefits of photovoltaics in times of high unemployment

    SciTech Connect

    Hohmeyer, O.H.

    1994-12-31

    Solar energy is normally discussed under the aspects of its medium to long term contribution to the global energy supply and its present cost. The situation is characterized by the benefits of an abundant renewable energy supply option o the one side and comparatively high internal energy production costs of solar energy on the other. Besides the environmental and health benefits of renewables not taken into account in cost comparisons, solar energy has a significantly higher job creation potential as conventional energy supply options. The paper gives an introduction into the basic methodological aspects of comparing job creation effects of different energy technologies and reports on the latest results of ongoing research on the specific effects of photovoltaics as compared to conventional electricity generation.

  16. Solar energy apparatus with apertured shield

    NASA Technical Reports Server (NTRS)

    Collings, Roger J. (Inventor); Bannon, David G. (Inventor)

    1989-01-01

    A protective apertured shield for use about an inlet to a solar apparatus which includesd a cavity receiver for absorbing concentrated solar energy. A rigid support truss assembly is fixed to the periphery of the inlet and projects radially inwardly therefrom to define a generally central aperture area through which solar radiation can pass into the cavity receiver. A non-structural, laminated blanket is spread over the rigid support truss in such a manner as to define an outer surface area and an inner surface area diverging radially outwardly from the central aperture area toward the periphery of the inlet. The outer surface area faces away from the inlet and the inner surface area faces toward the cavity receiver. The laminated blanket includes at least one layer of material, such as ceramic fiber fabric, having high infra-red emittance and low solar absorption properties, and another layer, such as metallic foil, of low infra-red emittance properties.

  17. Urban air pollution and solar energy

    NASA Technical Reports Server (NTRS)

    Gammon, R. B.; Huning, J. R.; Reid, M. S.; Smith, J. H.

    1981-01-01

    The design and performance of solar energy systems for many potential applications (industrial/residential heat, electricity generation by solar concentration and photovoltaics) will be critically affected by local insolation conditions. The effects of urban air pollution are considered and reviewed. A study of insolation data for Alhambra, California (9 km south of Pasadena) shows that, during a recent second-stage photochemical smog alert (greater than or equal to 0.35 ppm ozone), the direct-beam insolation at solar noon was reduced by 40%, and the total global by 15%, from clean air values. Similar effects have been observed in Pasadena, and are attributable primarily to air pollution. Effects due to advecting smog have been detected 200 km away, in the Mojave Desert. Preliminary performance and economic simulations of solar thermal and photovoltaic power systems indicate increasing nonlinear sensitivity of life cycle plant cost to reductions in insolation levels due to pollution.

  18. Optical waveguide solar energy system for lunar material processing

    SciTech Connect

    Nakamura, T.; Senior, C.L.; Shoji, J.M.; Waldron, R.D.

    1995-11-01

    This paper summarizes the study on the optical waveguide (OW) solar energy system for lunar material processing. In the OW solar energy system, solar radiation is collected by the concentrator which transfers the concentrated solar radiation to the OW transmission line consisting of low-loss optical fibers and related optical components. The OW line transmits the high intensity solar radiation to the thermal reactor of the lunar materials processing plant. Based on the results discussed in this paper the authors conclude that the OW solar energy system is a viable concept which can effectively utilize solar energy for lunar material processing.

  19. Incentives for solar energy in industry

    NASA Astrophysics Data System (ADS)

    Bergeron, K. D.

    1981-05-01

    Several issues are analyzed on the effects that government subsidies and other incentives have on the use of solar energy in industry, as well as on other capital-intensive alternative energy supplies. Discounted cash flow analysis is used to compare tax deductions for fuel expenses with tax credits for capital investments for energy. The result is a simple expression for tax equity. The effects that market penetration of solar energy has on conventional energy prices are analyzed with a free market model. It is shown that net costs of a subsidy program to the society can be significantly reduced by price. Several government loan guarantee concepts are evaluated as incentives that may not require direct outlays of government funds; their relative effectiveness in achieving loan leverage through project financing, and their cost and practicality, are discussed.

  20. Magnetospheric feedbacks in solar wind energy transfer

    NASA Astrophysics Data System (ADS)

    Palmroth, Minna; Pulkkinen, Tuija I.; Anekallu, Chandrasekhar R.; Honkonen, Ilja; Koskinen, Hannu E. J.; Lucek, Elizabeth A.; Dandouras, Iannis

    2010-05-01

    The solar wind kinetic energy, fueling all dynamical processes within the near-Earth space, is extracted by a dynamo process at the magnetopause converting kinetic energy into magnetic energy. We investigate the magnetopause energy transfer both in small and large scales; using Cluster observations as well as a three-dimensional global magnetohydrodynamic (MHD) simulation GUMICS-4. In the simulation, the spatial distribution of the energy transfer exhibits a dependence on the interplanetary magnetic field (IMF) orientation, which is shown to agree with observational local estimates from Cluster spacecraft recordings. In both sythetic runs with artificial solar wind input as well as in reproductions of the observed solar wind we observe a "hysteresis" effect, where the magnetopause energy input stays enhanced longer than the traditional energy transfer proxies (e.g., epsilon) indicate. Specifically we focus in the simulation of a substorm sequence on Feb 18, 2004, during which an exceptional agreement between the simulation results and spacecraft recordings was observed on several orbits within the near-Earth space. In this event, we again observe the hysteresis effect and investigate the processes causing it at the magnetopause. We argue that since GUMICS-4 reproduces the observed signatures of the substorm sequence in question, the simulation results represent physical processes within the magnetosphere. We conclude that as the simulation energy input exhibits delays already at the magnetopause, the delays in the classical substorm loading - unloading cycle may be interpreted in a new light.

  1. Solar Energy Education. Reader, Part II. Sun story. [Includes glossary

    SciTech Connect

    Not Available

    1981-05-01

    Magazine articles which focus on the subject of solar energy are presented. The booklet prepared is the second of a four part series of the Solar Energy Reader. Excerpts from the magazines include the history of solar energy, mythology and tales, and selected poetry on the sun. A glossary of energy related terms is included. (BCS)

  2. Plasmonic Enhancement Mechanisms in Solar Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Cushing, Scott K.

    Semiconductor photovoltaics (solar-to-electrical) and photocatalysis (solar-to-chemical) requires sunlight to be converted into excited charge carriers with sufficient lifetimes and mobility to drive a current or photoreaction. Thin semiconductor films are necessary to reduce the charge recombination and mobility losses, but thin films also limit light absorption, reducing the solar energy conversion efficiency. Further, in photocatalysis, the band edges of semiconductor must straddle the redox potentials of a photochemical reaction, reducing light absorption to half the solar spectrum in water splitting. Plasmonics transforms metal nanoparticles into antennas with resonances tuneable across the solar spectrum. If energy can be transferred from the plasmon to the semiconductor, light absorption in the semiconductor can be increased in thin films and occur at energies smaller than the band gap. This thesis investigates why, despite this potential, plasmonic solar energy harvesting techniques rarely appear in top performing solar architectures. To accomplish this goal, the possible plasmonic enhancement mechanisms for solar energy conversion were identified, isolated, and optimized by combining systematic sample design with transient absorption spectroscopy, photoelectrochemical and photocatalytic testing, and theoretical development. Specifically, metal semiconductor nanostructures were designed to modulate the plasmon's scattering, hot carrier, and near field interactions as well as remove heating and self-catalysis effects. Transient absorption spectroscopy then revealed how the structure design affected energy and charge carrier transfer between metal and semiconductor. Correlating this data with wavelength-dependent photoconversion efficiencies and theoretical developments regarding metal-semiconductor interactions identified the origin of the plasmonic enhancement. Using this methodology, it has first been proven that three plasmonic enhancement routes are

  3. Development of a Conceptual Structure for Architectural Solar Energy Systems.

    ERIC Educational Resources Information Center

    Ringel, Robert F.

    Solar subsystems and components were identified and conceptual structure was developed for architectural solar energy heating and cooling systems. Recent literature related to solar energy systems was reviewed and analyzed. Solar heating and cooling system, subsystem, and component data were compared for agreement and completeness. Significant…

  4. Solar Energy Employment and Requirements, 1978-1985.

    ERIC Educational Resources Information Center

    Levy, Girard W.; Field, Jennifer

    Based on data collected from a mailed survey of 2800 employers engaged in solar energy activities, a study identified the characteristics of establishments engaged in solar work and the number and occupational distribution of persons working in solar energy activities in 1978, and projected solar labor requirements through 1983. The scope of the…

  5. Solar Energy Education. Reader, Part IV. Sun schooling

    SciTech Connect

    Not Available

    1981-05-01

    A collection of magazine articles which focus on solar energy is presented. This is the final book of the four part series of the Solar Energy Reader. The articles include brief discussions on energy topics such as the sun, ocean energy, methane gas from cow manure, and solar homes. Instructions for constructing a sundial and a solar stove are also included. A glossary of energy related terms is provided. (BCS)

  6. Copper and Zinc Oxide Composite Nanostructures for Solar Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Wu, Fei

    Solar energy is a clean and sustainable energy source to counter global environmental issues of rising atmospheric CO2 levels and depletion of natural resources. To extract useful work from solar energy, silicon-based photovoltaic devices are extensively used. The technological maturity and the high quality of silicon (Si) make it a material of choice. However limitations in Si exist, ranging from its indirect band gap to low light absorption coefficient and energy and capital intensive crystal growth schemes. Therefore, alternate materials that are earth-abundant, benign and simpler to process are needed for developing new platforms for solar energy harvesting applications. In this study, we explore oxides of copper (CuO and Cu2O) in a nanowire morphology as alternate energy harvesting materials. CuO has a bandgap of 1.2 eV whereas Cu2O has a bandgap of 2.1 eV making them ideally suited for absorbing solar radiation. First, we develop a method to synthesize vertical, single crystalline CuO and Cu2O nanowires of ~50 microm length and aspect ratios of ~200. CuO nanowire arrays are synthesized by thermal oxidation of Cu foils. Cu2O nanowire arrays are synthesized by thermal reduction of CuO nanowires. Next, surface engineering of these nanowires is achieved using atomic layer deposition (ALD) of ZnO. By depositing 1.4 nm of ZnO, a highly defective surface is produced on the CuO nanowires. These defects are capable of trapping charge as is evident through persistent photoconductivity measurements of ZnO coated CuO nanowires. The same nanowires serve as efficient photocatalysts reducing CO2 to CO with a yield of 1.98 mmol/g-cat/hr. Finally, to develop a robust platform for flexible solar cells, a protocol to transfer vertical CuO nanowires inside flexible polydimethylsiloxane (PDMS) is demonstrated. Embedded CuO nanowires-ZnO pn junctions show a VOC of 0.4 V and a JSC of 10.4 microA/cm2 under white light illumination of 5.7 mW/cm2. Thus, this research provides broad

  7. Galactic Cosmic-Ray Energy Spectra and Composition during the 2009-2010 Solar Minimum Period

    NASA Technical Reports Server (NTRS)

    Lave, K. A.; Wiedenbeck, Mark E.; Binns, W. R.; Christian, E. R.; Cummings, A. C.; Davis, A. J.; deNolfo, G. A.; Israel, M. H..; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.; VonRosenvinge, T. T.

    2013-01-01

    We report new measurements of the elemental energy spectra and composition of galactic cosmic rays during the 2009-2010 solar minimum period using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer. This period of time exhibited record-setting cosmic-ray intensities and very low levels of solar activity. Results are given for particles with nuclear charge 5 <= Z <= 28 in the energy range approx. 50-550 MeV / nucleon. Several recent improvements have been made to the earlier CRIS data analysis, and therefore updates of our previous observations for the 1997-1998 solar minimum and 2001-2003 solar maximum are also given here. For most species, the reported intensities changed by less than approx. 7%, and the relative abundances changed by less than approx. 4%. Compared with the 1997-1998 solar minimum relative abundances, the 2009-2010 abundances differ by less than 2sigma, with a trend of fewer secondary species observed in the more recent time period. The new 2009-2010 data are also compared with results of a simple "leaky-box" galactic transport model combined with a spherically symmetric solar modulation model. We demonstrate that this model is able to give reasonable fits to the energy spectra and the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe. These results are also shown to be comparable to a GALPROP numerical model that includes the effects of diffusive reacceleration in the interstellar medium.

  8. Tandem photovoltaic solar cells and increased solar energy conversion efficiency

    NASA Technical Reports Server (NTRS)

    Loferski, J. J.

    1976-01-01

    Tandem photovoltaic cells, as proposed by Jackson (1955) to increase the efficiency of solar energy conversion, involve the construction of a system of stacked p/n homojunction photovoltaic cells composed of different semiconductors. It had been pointed out by critics, however, that the total power which could be extracted from the cells in the stack placed side by side was substantially greater than the power obtained from the stacked cells. A reexamination of the tandem cell concept in view of the development of the past few years is conducted. It is concluded that the use of tandem cell systems in flat plate collectors, as originally envisioned by Jackson, may yet become feasible as a result of the development of economically acceptable solar cells for large scale terrestrial power generation.

  9. Plasmonic Enhancement Mechanisms in Solar Energy Harvesting

    NASA Astrophysics Data System (ADS)

    Cushing, Scott K.

    Semiconductor photovoltaics (solar-to-electrical) and photocatalysis (solar-to-chemical) requires sunlight to be converted into excited charge carriers with sufficient lifetimes and mobility to drive a current or photoreaction. Thin semiconductor films are necessary to reduce the charge recombination and mobility losses, but thin films also limit light absorption, reducing the solar energy conversion efficiency. Further, in photocatalysis, the band edges of semiconductor must straddle the redox potentials of a photochemical reaction, reducing light absorption to half the solar spectrum in water splitting. Plasmonics transforms metal nanoparticles into antennas with resonances tuneable across the solar spectrum. If energy can be transferred from the plasmon to the semiconductor, light absorption in the semiconductor can be increased in thin films and occur at energies smaller than the band gap. This thesis investigates why, despite this potential, plasmonic solar energy harvesting techniques rarely appear in top performing solar architectures. To accomplish this goal, the possible plasmonic enhancement mechanisms for solar energy conversion were identified, isolated, and optimized by combining systematic sample design with transient absorption spectroscopy, photoelectrochemical and photocatalytic testing, and theoretical development. Specifically, metal semiconductor nanostructures were designed to modulate the plasmon's scattering, hot carrier, and near field interactions as well as remove heating and self-catalysis effects. Transient absorption spectroscopy then revealed how the structure design affected energy and charge carrier transfer between metal and semiconductor. Correlating this data with wavelength-dependent photoconversion efficiencies and theoretical developments regarding metal-semiconductor interactions identified the origin of the plasmonic enhancement. Using this methodology, it has first been proven that three plasmonic enhancement routes are

  10. ENERGY DISSIPATION PROCESSES IN SOLAR WIND TURBULENCE

    SciTech Connect

    Wang, Y.; Wei, F. S.; Feng, X. S.; Sun, T. R.; Zuo, P. B.; Xu, X. J.; Zhang, J.

    2015-12-15

    Turbulence is a chaotic flow regime filled by irregular flows. The dissipation of turbulence is a fundamental problem in the realm of physics. Theoretically, dissipation ultimately cannot be achieved without collisions, and so how turbulent kinetic energy is dissipated in the nearly collisionless solar wind is a challenging problem. Wave particle interactions and magnetic reconnection (MR) are two possible dissipation mechanisms, but which mechanism dominates is still a controversial topic. Here we analyze the dissipation region scaling around a solar wind MR region. We find that the MR region shows unique multifractal scaling in the dissipation range, while the ambient solar wind turbulence reveals a monofractal dissipation process for most of the time. These results provide the first observational evidences for intermittent multifractal dissipation region scaling around a MR site, and they also have significant implications for the fundamental energy dissipation process.

  11. Geostellar: Remote Solar Energy Assessments Personalized

    SciTech Connect

    2015-10-01

    Geostellar has produced an online tool that generates a unique solar profile for homeowners to learn about the financial benefits to installing rooftop solar panels on their home. The website incorporates the physical building characteristics of the home, including shading, slope, and orientation of the roof, and applies electricity costs and incentives to determine the best solar energy estimated energy production values against actual installed rooftop photovoltaic systems. The validation conducted by NREL concluded that over three-quarters of Geostellar's potential size estimates are at least as large as the actual installed systems, indicating a correct assessment of roof availability. In addition, 87% of Geostellar's 25-year production estimates are within 90% of the actual PV Watts results.

  12. Firing ceramic tiles in solar energy equipment

    SciTech Connect

    Pasichnyi, V.V.; Berezhetskaya, V.Ya.; Chop, Yu.I.; Kashket, G.I.

    1987-03-01

    In the interest of satisfying the growing demand for glazed ceramic tiles and conserving the natural gas ordinarily used to fire them, the authors assess the feasibility of using a solar kiln for the process. Their design incorporates a parabolic reflector and a tracking system to continuously focus radiant solar energy on the tile. Their energy analysis includes such factors as solar thermal input, radiant heat transfer, and heat flow, the relationship between the firing time and the heat flow density, and the surface quality of the glaze and colorizer. Their results indicate that when the heat flow density rises above a level at which the specific expenditure of heat is no longer dependent on the color of the pigment, this expenditure or input comes to a quarter of what is currently needed using existing technologies and fuels.

  13. Energy release in solar flares

    NASA Technical Reports Server (NTRS)

    Brown, John C.; Correia, Emilia; Farnik, Frantisek; Garcia, Howard; Henoux, Jean-Claude; La Rosa, Ted N.; Machado, Marcos E. (Compiler); Nakajima, Hiroshi; Priest, Eric R.

    1994-01-01

    Team 2 of the Ottawa Flares 22 Workshop dealt with observational and theoretical aspects of the characteristics and processes of energy release in flares. Main results summarized in this article stress the global character of the flaring phenomenon in active regions, the importance of discontinuities in magnetic connectivity, the role of field-aligned currents in free energy storage, and the fragmentation of energy release in time and space.

  14. Solar Energy Directory: A Directory of Domestic and International Firms Involved in Solar Energy.

    ERIC Educational Resources Information Center

    Centerline Co., Phoenix, AZ.

    This directory is intended to provide a link between suppliers of solar energy technology and information and potential users of these products. Included are over 1400 national and international entries. These listings include architects, associations, education sources, wind power technology and information sources, solar research organizations,…

  15. Energy in Mexico: a profile of solar energy activity in its national context

    SciTech Connect

    Hawkins, D.

    1980-04-01

    The geopolitical, economic, and cultural aspects of the United States of Mexico are presented. Mexico's energy profile includes the following: energy policy objectives, government energy structure, organizations for implementation, indigeneous energy sources, imported energy sources, solar energy research and development, solar energy organizations and solar energy related legislation and administrative policies. International agreements, contacts, manufacturers, and projects are listed. (MRH)

  16. Solar Energy Project, Activities: Junior High Science.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of the junior high science curriculum. Each unit presents an introduction; objectives; skills and knowledge needed; materials; methods; questions; recommendations for further work; and a teacher information sheet. The teacher…

  17. Solar Energy Project, Activities: Earth Science.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of earth science experiments. Each unit presents an introduction; objectives; skills and knowledge needed; materials; method; questions; recommendations for further study; and a teacher information sheet. The teacher…

  18. Solar Energy Installers Curriculum Guides. Final Report.

    ERIC Educational Resources Information Center

    Walker, Gene C.

    A project was conducted to develop solar energy installers curriculum guides for use in high school vocational centers and community colleges. Project activities included researching job competencies for the heating, ventilation, and air conditioning industry and determining through interviews and manufacturers' literature what additional…

  19. Electron energy flux in the solar wind.

    NASA Technical Reports Server (NTRS)

    Ogilvie, K. W.; Scudder, J. D.; Sugiura, M.

    1971-01-01

    Description of studies of electrons between 10 eV and 9.9 keV in the solar wind. The transport of energy in the rest frame of the plasma is evaluated and shown to be parallel to the interplanetary magnetic field. The presence of electrons from solar events causes this energy-flux density to exceed the heat flow due to thermal electrons. In one such event, the observations are shown to be consistent with the solar-electron observations made at higher energies. When observations are made at a point connected to the earth's bow shock by an interplanetary-field line, a comparatively large energy flux along the field toward the sun is observed, but the heat flow remains outwardly directed during this time interval. In either situation the heat flow is found to be consistent with measurements made on Vela satellites by a different method. These values, less than .01 ergs/sq cm/sec, are sufficiently low to require modifications to the Spitzer-Harm conductivity formula for use in solar-wind theories.

  20. Solar Energy Audio-Visual Materials.

    ERIC Educational Resources Information Center

    Department of Housing and Urban Development, Washington, DC. Office of Policy Development and Research.

    This directory presents an annotated bibliography of non-print information resources dealing with solar energy. The document is divided by type of audio-visual medium, including: (1) Films, (2) Slides and Filmstrips, and (3) Videotapes. A fourth section provides addresses and telephone numbers of audiovisual aids sources, and lists the page…

  1. Solar Energy Experiment for Beginning Chemistry.

    ERIC Educational Resources Information Center

    Davis, Clyde E.

    1983-01-01

    Describes an experiment illustrating how such chemical concepts as light absorption, thermodynamics, and solid-state photovoltaics can be incorporated into solar energy education. Completed in a three-hour period, the experiment requires about two hours for data collections with the remaining hour devoted to calculations and comparison of results.…

  2. Solar Energy Project, Activities: Chemistry & Physics.

    ERIC Educational Resources Information Center

    Tullock, Bruce, Ed.; And Others

    This guide contains lesson plans and outlines of science activities which present concepts of solar energy in the context of chemistry and physics experiments. Each unit presents an introduction to the unit; objectives; required skills and knowledge; materials; method; questions; recommendations for further work; and a teacher information sheet.…

  3. Prototype residential solar-energy system

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Complete solar-energy domestic-hot-water system for single-family residences is described in brochure. It contains data on procurement, installation, operation, and maintainance of system in residential or light commercial buildings. Appendix includes vendor brochures for major system components. Drawings, tables, and graphs complement text.

  4. Online National Solar Energy Directory and 2005 Solar Decathlon Product Directory. Final report

    SciTech Connect

    Hamm, Julia; Taylor, Mike

    2008-12-31

    The Solar Electric Power Association (SEPA), in partnership with the American Solar Energy Society, developed an online National Solar Energy Directory with clear, comprehensive information on suppliers and purchasing options. The site was originally located at FindSolar.com, but has recently been moved to Find-Solar.org. The original FindSolar.com domain name has been taken by the American Solar Energy Society (a partner in this project) and utilized for a similar but different project. This Find-Solar.org directory offers the rapidly growing base of potential solar customers a simple, straightforward destination to learn about their solar options. Members of the public are able to easily locate contractors in their geographic area and verify companies' qualifications with accurate third-party information. It allows consumers to obtain key information on the economics, incentives, desirability, and workings of a solar energy system, as well as competing quotes from different contractors and reviews from customers they have worked with previously. Find-Solar.org is a means of facilitating the growing public interest in solar power and overcoming a major barrier to widespread development of U.S. solar markets. In addition to the development of Find-Solar.org, SEPA developed a separate online product directory for the 2005 DOE Solar Decathlon to facilitate the communication of information about the energy efficiency and renewable energy products used in each university team's home.

  5. THE EFFECTS OF MAGNETIC FIELD MORPHOLOGY ON THE DETERMINATION OF OXYGEN AND IRON ABUNDANCES IN THE SOLAR PHOTOSPHERE

    SciTech Connect

    Moore, Christopher S.; Uitenbroek, Han; Criscuoli, Serena; Rempel, Matthias; Rast, Mark P.

    2015-02-01

    We have explored the impact of magnetic fields on the determination of the solar photospheric oxygen and iron abundances using three-dimensional radiation-magnetohydrodynamic (MHD) simulations of convection. Specifically, we examined differences in abundance deduced from three classes of atmospheres simulated with the MURaM code: a pure hydrodynamic (HD) simulation, an MHD simulation with a local dynamo magnetic field that has saturated with an unsigned vertical field strength of 80 G at τ = 1, and an MHD simulation with an initially imposed vertical mean field of 80 G. We use differential equivalent width analysis for diagnosing abundances derived from five oxygen and four iron lines of differing wavelength, oscillator strength, excitation potential, and Landé g-factor, and find that the morphology of the magnetic field is important to the outcome of abundance determinations. The largest deduced abundance differences are found in the vertical mean field simulations, where the O I and Fe I abundance corrections compared to the pure HD case are ∼+0.011 dex and +0.065 dex respectively. Small scale unresolved field resulting from the local dynamo has a smaller impact on abundance determinations, with corrections of –0.0001 dex and +0.0044 dex in the magnetized compared to the pure HD simulations. While the overall influence of magnetic field on abundance estimates is found to be small, we stress that such estimates are sensitive not only to the magnitude of magnetic field but also to its morphology.

  6. Is Solar Energy the Fuel of the Future?

    ERIC Educational Resources Information Center

    Cetincelik, Mauammer

    1974-01-01

    Describes the present distribution of solar energy, traces its use through history, explores its potential utilization in the future, and presents the effects of the use of solar energy on pollution. (GS)

  7. Solar energy utilization by physical methods.

    PubMed

    Wolf, M

    1974-04-19

    On the basis of the estimated contributions of these differing methods of the utilization of solar energy, their total energy delivery impact on the projected U.S. energy economy (9) can be evaluated (Fig. 5). Despite this late energy impact, the actual sales of solar energy utilization equipment will be significant at an early date. Potential sales in photovoltaic arrays alone could exceed $400 million by 1980, in order to meet the projected capacity buildup (10). Ultimately, the total energy utilization equipment industry should attain an annual sales volume of several tens of billion dollars in the United States, comparable to that of several other energy related industries. Varying amounts of technology development are required to assure the technical and economic feasibility of the different solar energy utilization methods. Several of these developments are far enough along that the paths can be analyzed from the present time to the time of demonstration of technical and economic feasibility, and from there to production and marketing readiness. After that point, a period of market introduction will follow, which will differ in duration according to the type of market addressed. It may be noted that the present rush to find relief from the current energy problem, or to be an early leader in entering a new market, can entail shortcuts in sound engineering practice, particularly in the areas of design for durability and easy maintenance, or of proper application engineering. The result can be loss of customer acceptance, as has been experienced in the past with various products, including solar water heaters. Since this could cause considerable delay in achieving the expected total energy impact, it will be important to spend adequate time at this stage for thorough development. Two other aspects are worth mentioning. The first is concerned with the economic impacts. Upon reflection on this point, one will observe that largescale solar energy utilization will

  8. Solar energy conversion using surface plasmons for broadband energy transport

    NASA Technical Reports Server (NTRS)

    Anderson, L. M.

    1982-01-01

    A new strategy for efficient solar energy conversion based on parallel processing with surface plasmons is introduced. The approach is unique in identifying: (1) a broadband carrier with suitable range for energy transport, and (2) a technique to extract more energy from the more energetic photons, without sequential losses or unique materials for each frequency band. The aim is to overcome the fundamental losses associated with the broad solar spectrum and to achieve a higher level of spectrum splitting than has been possible in semiconductor systems.

  9. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., alteration, or improvement to an existing or new structure which is designed to utilize wind energy or solar... 24 Housing and Urban Development 2 2011-04-01 2011-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by...

  10. 24 CFR 203.18a - Solar energy system.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., alteration, or improvement to an existing or new structure which is designed to utilize wind energy or solar... 24 Housing and Urban Development 2 2010-04-01 2010-04-01 false Solar energy system. 203.18a... § 203.18a Solar energy system. (a) The dollar limitation provided in § 203.18(a) may be increased by...

  11. Lithium Abundance in Solar-type Stars with Low Chromospheric Activity: Application to the Search for Maunder Minimum Analogs

    NASA Astrophysics Data System (ADS)

    Lubin, Dan; Tytler, David; Kirkman, David

    2010-06-01

    We use measurements of lithium abundance to examine the evolutionary history of stars frequently believed to be in a Maunder minimum (MM) state due to their low chromospheric activity. In a sample whose main-sequence membership has been verified using Hipparcos parallax data, we find that stars with very low chromospheric activity log R'HK <= -5.0 have substantially depleted lithium compared with the full sample, with half of these lithium abundances lying more than one standard deviation below the sample mean for their range of color index. One interpretation is that these stars are near the end of their main-sequence lifetime, and therefore their low activity does not necessarily signify a transient MM state in a solar-age star. Conversely, using information in published activity time series for some stars, and combined lithium and activity measurements from the Ursa Major moving group and M67, we find limited evidence that a low-activity star having lithium abundance in the normal range for its color index may be a viable MM candidate. Thus, lithium abundance, which can be readily observed or even retrieved from some of the spectroscopic data collected by recent planet-search surveys, may have value for expanding and refining the program star lists for long-term MM searches. Finally, we find that the use of Hipparcos parallax data to ascertain main-sequence membership sharpens the distinction in sample-mean lithium abundance between stars with planet detections and comparison stars.

  12. LITHIUM ABUNDANCE IN SOLAR-TYPE STARS WITH LOW CHROMOSPHERIC ACTIVITY: APPLICATION TO THE SEARCH FOR MAUNDER MINIMUM ANALOGS

    SciTech Connect

    Lubin, Dan; Tytler, David; Kirkman, David

    2010-06-10

    We use measurements of lithium abundance to examine the evolutionary history of stars frequently believed to be in a Maunder minimum (MM) state due to their low chromospheric activity. In a sample whose main-sequence membership has been verified using Hipparcos parallax data, we find that stars with very low chromospheric activity log R'{sub HK} {<=} -5.0 have substantially depleted lithium compared with the full sample, with half of these lithium abundances lying more than one standard deviation below the sample mean for their range of color index. One interpretation is that these stars are near the end of their main-sequence lifetime, and therefore their low activity does not necessarily signify a transient MM state in a solar-age star. Conversely, using information in published activity time series for some stars, and combined lithium and activity measurements from the Ursa Major moving group and M67, we find limited evidence that a low-activity star having lithium abundance in the normal range for its color index may be a viable MM candidate. Thus, lithium abundance, which can be readily observed or even retrieved from some of the spectroscopic data collected by recent planet-search surveys, may have value for expanding and refining the program star lists for long-term MM searches. Finally, we find that the use of Hipparcos parallax data to ascertain main-sequence membership sharpens the distinction in sample-mean lithium abundance between stars with planet detections and comparison stars.

  13. Utilization of solar energy and waste heat

    SciTech Connect

    Kaygusuz, K.

    1999-08-01

    A heat pump and thermal energy storage unit were combined in an experimental setup to utilize solar energy and waste heat efficiently at low temperatures (10--50 C). The calcium chloride hexahydrate was used as the thermal energy storage medium and water was used as the working liquid between storage tank and collectors. The performance of the experimental setup at different heat source temperatures for space heating in a laboratory building in Trabzon, Turkey, were investigated both experimentally and theoretically. The fraction of the space heating load that was supplied by the solar-assisted system was determined as a function of collector area and storage volume from a developed numerical method and results were compared with experimental results.

  14. Harnessing surface plasmons for solar energy conversion

    NASA Technical Reports Server (NTRS)

    Anderson, L. M.

    1983-01-01

    NASA research on the feasibility of solar-energy conversion using surface plasmons is reviewed, with a focus on inelastic-tunnel-diode techniques for power extraction. The need for more efficient solar converters for planned space missions is indicated, and it is shown that a device with 50-percent efficiency could cost up to 40 times as much per sq cm as current Si cells and still be competitive. The parallel-processing approach using broadband carriers and tunable diodes is explained, and the physics of surface plasmons on metal surfaces is outlined. Technical problems being addressed include phase-matching sunlight to surface plasmons, minimizing ohmic losses and reradiation in energy transport, coupling into the tunnels by mode conversion, and gaining an understanding of the tunnel-diode energy-conversion process. Diagrams illustrating the design concepts are provided.

  15. SOLAR CYCLE VARIATIONS IN THE ELEMENTAL ABUNDANCE OF HELIUM AND FRACTIONATION OF IRON IN THE FAST SOLAR WIND: INDICATORS OF AN EVOLVING ENERGETIC RELEASE OF MASS FROM THE LOWER SOLAR ATMOSPHERE

    SciTech Connect

    McIntosh, Scott W.; Kiefer, Kandace K.; Leamon, Robert J.; Kasper, Justin C.; Stevens, Michael L.

    2011-10-10

    We present and discuss the strong correspondence between evolution of the emission length scale in the lower transition region and in situ measurements of the fast solar wind composition during the most recent solar minimum. We combine recent analyses demonstrating the variance in the (supergranular) network emission length scale measured by the Solar and Heliospheric Observatory (and STEREO) with that of the helium abundance (from Wind) and the degree of iron fractionation in the solar wind (from the Advanced Composition Explorer and Ulysses). The net picture developing is one where a decrease in the helium abundance and the degree of iron fractionation (approaching values expected of the photosphere) in the fast wind indicate a significant change in the process loading material into the fast solar wind during the recent solar minimum. This result is compounded by a study of the helium abundance during the space age using the NASA OMNI database, which shows a slowly decaying amount of helium being driven into the heliosphere over the course of several solar cycles.

  16. Non-LTE analysis of copper abundances for the two distinct halo populations in the solar neighborhood

    NASA Astrophysics Data System (ADS)

    Yan, H. L.; Shi, J. R.; Nissen, P. E.; Zhao, G.

    2016-01-01

    Context. Two distinct halo populations were found in the solar neighborhood by a series of works. They can be clearly separated by [α/Fe] and several other elemental abundance ratios including [Cu/Fe]. Very recently, a non-local thermodynamic equilibrium (non-LTE) study revealed that relatively large departures exist between LTE and non-LTE results in copper abundance analysis. The study also showed that non-LTE effects of neutral copper vary with stellar parameters and thus affect the [Cu/Fe] trend. Aims: We aim to derive the copper abundances for the stars from the sample of Nissen & Schuster (2010) with both LTE and non-LTE calculations. Based on our results, we study the non-LTE effects of copper and investigate whether the high-α population can still be distinguished from the low-α population in the non-LTE [Cu/Fe] results. Methods: Our differential abundance ratios are derived from the high-resolution spectra collected from VLT/UVES and NOT/FIES spectrographs. Applying the MAFAGS opacity sampling atmospheric models and spectrum synthesis method, we derive the non-LTE copper abundances based on the new atomic model with current atomic data obtained from both laboratory and theoretical calculations. Results: The copper abundances determined from non-LTE calculations are increased by 0.01 to 0.2 dex depending on the stellar parameters compared with the LTE results. The non-LTE [Cu/Fe] trend is much flatter than the LTE one in the metallicity range -1.6 < [ Fe / H ] < -0.8. Taking non-LTE effects into consideration, the high- and low-α stars still show distinguishable copper abundances, which appear even more clear in a diagram of non-LTE [Cu/Fe] versus [Fe/H]. Conclusions: The non-LTE effects are strong for copper, especially in metal-poor stars. Our results confirmed that there are two distinct halo populations in the solar neighborhood. The dichotomy in copper abundance is a peculiar feature of each population, suggesting that they formed in different

  17. Solar energy converter using surface plasma waves

    NASA Technical Reports Server (NTRS)

    Anderson, L. M. (Inventor)

    1984-01-01

    Sunlight is dispersed over a diffraction grating formed on the surface of a conducting film on a substrate. The angular dispersion controls the effective grating period so that a matching spectrum of surface plasmons is excited for parallel processing on the conducting film. The resulting surface plasmons carry energy to an array of inelastic tunnel diodes. This solar energy converter does not require different materials for each frequency band, and sunlight is directly converted to electricity in an efficient manner by extracting more energy from the more energetic photons.

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

    SciTech Connect

    Not Available

    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)

  19. Development of low-cost technology for the next generation of high efficiency solar cells composed of earth abundant elements

    SciTech Connect

    Agrawal, Rakesh

    2014-09-28

    The development of renewable, affordable, and environmentally conscious means of generating energy on a global scale represents a grand challenge of our time. Due to the “permanence” of radiation from the sun, solar energy promises to remain a viable and sustainable power source far into the future. Established single-junction photovoltaic technologies achieve high power conversion efficiencies (pce) near 20% but require complicated manufacturing processes that prohibit the marriage of large-scale throughput (e.g. on the GW scale), profitability, and quality control. Our approach to this problem begins with the synthesis of nanocrystals of semiconductor materials comprising earth abundant elements and characterized by material and optoelectronic properties ideal for photovoltaic applications, namely Cu2ZnSn(S,Se)4 (CZTSSe). Once synthesized, such nanocrystals are formulated into an ink, coated onto substrates, and processed into completed solar cells in such a way that enables scale-up to high throughput, roll-to-roll manufacturing processes. This project aimed to address the major limitation to CZTSSe solar cell pce’s – the low open-circuit voltage (Voc) reported throughout literature for devices comprised of this material. Throughout the project significant advancements have been made in fundamental understanding of the CZTSSe material and device limitations associated with this material system. Additionally, notable improvements have been made to our nanocrystal based processing technique to alleviate performance limitations due to the identified device limitations. Notably, (1) significant improvements have been made in reducing intra- and inter-nanoparticle heterogeneity, (2) improvements in device performance have been realized with novel cation substitution in Ge-alloyed CZTGeSSe absorbers, (3) systematic analysis of absorber sintering has been conducted to optimize the selenization process for large grain CZTSSe absorbers, (4) novel electrical

  20. Solar energy, conservation, and rental housing

    SciTech Connect

    Levine, A.; Raab, J.

    1981-03-01

    Renters must pay the majority of energy costs either directly or in their rents. They have limited financial and legal abilities to make improvements necessary to increase substantially the energy efficiency of rental housing. This report discusses the problem of how to increase investments in energy conservation and solar energy devices for rental housing, which constitutes over one-third of US housing. As background, this report characterizes the rental-housing market, including owners' decision-making criteria. Federal, state, and local policies that affect energy-related investments in rental housing are described. Programs are divided into five major categories: (1) programs for tenants, (2) financial incentives for owners, (3) leasing of solar energy equipment, (4) mediation between tenants and landlords, and (5) regulation. The report concludes that energy and conservation programs aimed at the residential sector must disaggregate owner-occupied housing from rental housing for maximum effect. No one program is advocated since local rental-housing markets differ substantially. For improvements greater than no-cost or low-cost items, programs must be directed at rental-housing owners and not only at tenants.

  1. Solar energy conversions: solar-electric thermophotovoltaic systems and solar-powered gas lasers

    SciTech Connect

    Yesil, O.

    1980-12-01

    This paper deals with conversions of solar energy efficiently into electricity and into gas laser radiation. In the first section, a review study of the possibility of a solar-electric thermophotovoltaic (TPV) device has been done. In a proposed extension of the TPV concept, a Cassagranian optical system concentrates solar radiation to heat a blackbody cavity to 2400/sup 0/K. A double-layer solar cell, GaAs and Si, forming the cylindrical surface concentric to the blackbody cavity, receives the blackbody radiation and converts it into electricity efficiently. A cell conversion efficiency of 50% or more would be possible with the TPV system. The second section explores the concept of blackbody radiation pumping of gas laser media as a step toward utilization of solar energy as a laser pumping source. To demonstrate this concept, an experiment was performed in which various gas mixtures of CO/sub 2/ and He were exposed to 1500/sup 0/K thermal radiation for brief periods of time. A gain coefficient of 2.8 x 10/sup -3/cm/sup -1/ has been measured at 10.6..mu.. and 1 Torr of pressure. At 2 Torr and 0.5 Torr, the measured optical gain is less than that at 1 Torr. A simple analytical model was used to describe the rate of change of energy distribution of the vibrational modes of CO/sub 2/ and to predict the gain. There is a good agreement between prediction and experiment.

  2. Solar Energy Research Center Instrumentation Facility

    SciTech Connect

    Meyer, Thomas, J.; Papanikolas, John, P.

    2011-11-11

    SOLAR ENERGY RESEARCH CENTER INSTRUMENTATION FACILITY The mission of the Solar Energy Research Center (UNC SERC) at the University of North Carolina at Chapel Hill (UNC-CH) is to establish a world leading effort in solar fuels research and to develop the materials and methods needed to fabricate the next generation of solar energy devices. We are addressing the fundamental issues that will drive new strategies for solar energy conversion and the engineering challenges that must be met in order to convert discoveries made in the laboratory into commercially available devices. The development of a photoelectrosynthesis cell (PEC) for solar fuels production faces daunting requirements: (1) Absorb a large fraction of sunlight; (2) Carry out artificial photosynthesis which involves multiple complex reaction steps; (3) Avoid competitive and deleterious side and reverse reactions; (4) Perform 13 million catalytic cycles per year with minimal degradation; (5) Use non-toxic materials; (6) Cost-effectiveness. PEC efficiency is directly determined by the kinetics of each reaction step. The UNC SERC is addressing this challenge by taking a broad interdisciplinary approach in a highly collaborative setting, drawing on expertise across a broad range of disciplines in chemistry, physics and materials science. By taking a systematic approach toward a fundamental understanding of the mechanism of each step, we will be able to gain unique insight and optimize PEC design. Access to cutting-edge spectroscopic tools is critical to this research effort. We have built professionally-staffed facilities equipped with the state-of the-art instrumentation funded by this award. The combination of staff, facilities, and instrumentation specifically tailored for solar fuels research establishes the UNC Solar Energy Research Center Instrumentation Facility as a unique, world-class capability. This congressionally directed project funded the development of two user facilities: TASK 1: SOLAR

  3. Solar energy in Italy: a profile of renewable energy activity in its national context

    SciTech Connect

    Shea, C.A.

    1980-12-01

    The following are included: country overview; energy summary; Italian Republic-geopolitical, economic, and cultural aspects; the energy profile; imported energy sources; solar energy research and development; solar energy organizations; solar energy related legislation and administration policies; and international agreements, contacts, manufacturers, and projects. (MHR)

  4. Solar Energy Education. Reader, Part I. Energy, Society, and the Sun

    SciTech Connect

    Not Available

    1981-05-01

    A collection of magazine articles which were selected for information on solar energy is presented in this booklet. This booklet is the first of a four part series of the Solar Energy Reader. The articles provide brief discussions on topics such as the power of the sun, solar energy developments for homes, solar energy versus power plants, solar access laws, and the role of utilities with respect to the sun's energy. (BCS)

  5. Operational Experience from Solar Thermal Energy Projects

    NASA Technical Reports Server (NTRS)

    Cameron, C. P.

    1984-01-01

    Over the past few years, Sandia National Laboratories were involved in the design, construction, and operation of a number of DOE-sponsored solar thermal energy systems. Among the systems currently in operation are several industrial process heat projects and the Modular Industrial Solar Retrofit qualification test systems, all of which use parabolic troughs, and the Shenandoah Total Energy Project, which uses parabolic dishes. Operational experience has provided insight to both desirable and undesirable features of the designs of these systems. Features of these systems which are also relevant to the design of parabolic concentrator thermal electric systems are discussed. Other design features discussed are system control functions which were found to be especially convenient or effective, such as local concentrator controls, rainwash controls, and system response to changing isolation. Drive systems are also discussed with particular emphasis of the need for reliability and the usefulness of a manual drive capability.

  6. Resource Letter SE-2: Solar Energy

    NASA Astrophysics Data System (ADS)

    Hodges, Laurent

    1982-10-01

    This resource letter provides a source of information about the main types of solar energy and their uses, updating Resource Letter SE-1 issued seven years ago. It is intended for the use of high school and college teachers both in developing courses and in guiding students to the literature of solar energy applications. Articles marked with an asterisk have been selected for publication in an accompanying reprint book. The letter E after the reference number denotes a relatively elementary item, useful for high school and introductory college use and the educated public; the letter I denotes intermediate level references, sophomore to senior level; and the letter A denotes advanced material, principally for senior and graduate-level courses.

  7. Water Desalination Systems Powered by Solar Energy

    NASA Astrophysics Data System (ADS)

    Barseghyan, A.

    2015-12-01

    The supply of potable water from polluted rivers, lakes, unsafe wells, etc. is a problem of high priority. One of the most effective methods to obtain low cost drinking water is desalination. Advanced water treatment system powered by Solar Energy and based on electrodialysis for water desalination and purification, is suggested. Technological and economic evaluations and the benefits of the suggested system are discussed. The Advanced Water Treatment System proposed clears water not only from different salts, but also from some infections, thus decreasing the count of diseases which are caused by the usage of non-clear water. Using Solar Energy makes the system stand alone which is convenient to use in places where power supply is problem.

  8. The Department of Energy`s Solar Industrial Program: 1994 review

    SciTech Connect

    1995-03-01

    This is a report on DOE`s Solar Industrial Program. The topics of the report include an overview of the program, it`s participants and it`s objectives; solar detoxification--using solar energy to destroy environmental contaminants in air, water, and soil; solar process heat--generating industrial quantities of hot water, steam, and hot air from solar energy; and advanced processes--using concentrated solar energy to manufacture high-technology materials and develop new industrial processes.

  9. Solar energy parking canopy demonstration project

    SciTech Connect

    Cylwik, Joe; David, Lawrence

    2015-09-24

    The goal of this pilot/demonstration program is to measure the viability of using solar photovoltaic (PV) technology at three locations in a mountain community environment given the harsh weather conditions. An additional goal is to reduce long-term operational costs, minimize green house gas emissions, lower the dependency on energy produced from fossil fuels, and improve the working environment and health of city employees and residents.

  10. Solar energy collector/storage system

    SciTech Connect

    Bettis, J.R.; Clearman, F.R.

    1983-05-24

    A solar energy collector/storage system which includes an insulated container having working fluid inlets and outlets and an opening, a light-transmitting member positioned over the opening, and a heat-absorbing member which is centrally situated, is supported in the container, and is made of a mixture of gypsum , lampblack, and water. A light-reflecting liner made of corrugated metal foil preferably is attached to the internal surface of the container. The opening of the container is positioned in optical alignment with a source of solar energy. A light-reflecting cover optionally can be hingedly attached to the container, and can be positioned such as to reflect solar energy rays into the container. The system is adaptable for use with a working gas (e.g., air) and/or a working liquid (e.g., water) in separated flows which absorb heat from the heat-absorbing member, and which are useable per se or in an associated storage and/or circulatory system that is not part of this invention. The heatabsorbing mixture can also contain glass fibers. The heatabsorbing member is of such great load-bearing strength that it can also be used simultaneously as a structural member, e.g., a wall or ceiling of a room; and, thereby, the system can be used to heat a room, if a window of the room is the light-transmitting member and is facing the sun, and if the heat-absorbing member is a wall and/or the ceiling of the room and receives solar energy through the window.

  11. Combined Solar and Wind Energy Systems

    NASA Astrophysics Data System (ADS)

    Tripanagnostopoulos, Y.; Souliotis, M.; Makris, Th.

    2010-01-01

    In this paper we present the new concept of combined solar and wind energy systems for buildings applications. Photovoltaics (PV) and small wind turbines (WTs) can be install on buildings, in case of sufficient wind potential, providing the building with electricity. PVs can be combined with thermal collectors to form the hybrid photovoltaic/thermal (PV/T) systems. The PVs (or the PV/Ts) and WT subsystems can supplement each other to cover building electrical load. In case of using PV/T collectors, the surplus of electricity, if not used or stored in batteries, can increase the temperature of the thermal storage tank of the solar thermal unit. The description of the experimental set-up of the suggested PV/T/WT system and experimental results are presented. In PV/T/WT systems the output from the solar part depends on the sunshine time and the output of the wind turbine part depends on the wind speed and is obtained any time of day or night. The use of the three subsystems can cover a great part of building energy load, contributing to conventional energy saving and environment protection. The PV/T/WT systems are considered suitable in rural and remote areas with electricity supply from stand-alone units or mini-grid connection. PV/T/WT systems can also be used in typical grid connected applications.

  12. Solar Energy Systems for Lunar Oxygen Generation

    NASA Technical Reports Server (NTRS)

    Colozza, Anthony J.; Heller, Richard S.; Wong, Wayne A.; Hepp, Aloysius F.

    2010-01-01

    An evaluation of several solar concentrator-based systems for producing oxygen from lunar regolith was performed. The systems utilize a solar concentrator mirror to provide thermal energy for the oxygen production process. Thermal energy to power a Stirling heat engine and photovoltaics are compared for the production of electricity. The electricity produced is utilized to operate the equipment needed in the oxygen production process. The initial oxygen production method utilized in the analysis is hydrogen reduction of ilmenite. Utilizing this method of oxygen production a baseline system design was produced. This baseline system had an oxygen production rate of 0.6 kg/hr with a concentrator mirror size of 5 m. Variations were performed on the baseline design to show how changes in the system size and process (rate) affected the oxygen production rate. An evaluation of the power requirements for a carbothermal lunar regolith reduction reactor has also been conducted. The reactor had a total power requirement between 8,320 to 9,961 W when producing 1000 kg/year of oxygen. The solar concentrator used to provide the thermal power (over 82 percent of the total energy requirement) would have a diameter of less than 4 m.

  13. USING SCHUMANN RESONANCE MEASUREMENTS FOR CONSTRAINING THE WATER ABUNDANCE ON THE GIANT PLANETS-IMPLICATIONS FOR THE SOLAR SYSTEM'S FORMATION

    SciTech Connect

    Simoes, Fernando; Pfaff, Robert; Klenzing, Jeffrey; Freudenreich, Henry; Bromund, Kenneth; Martin, Steven; Rowland, Douglas; Takahashi, Yukihiro; Yair, Yoav

    2012-05-01

    The formation and evolution of the solar system is closely related to the abundance of volatiles, namely water, ammonia, and methane in the protoplanetary disk. Accurate measurement of volatiles in the solar system is therefore important for understanding not only the nebular hypothesis and origin of life but also planetary cosmogony as a whole. In this work, we propose a new remote sensing technique to infer the outer planets' water content by measuring Tremendously and Extremely Low Frequency (TLF-ELF) electromagnetic wave characteristics (Schumann resonances) excited by lightning in their gaseous envelopes. Schumann resonance detection can be potentially used for constraining the uncertainty of volatiles of the giant planets, mainly Uranus and Neptune, because such TLF-ELF wave signatures are closely related to the electric conductivity profile and water content.

  14. Using Schumann Resonance Measurements for Constraining the Water Abundance on the Giant Planets—Implications for the Solar System's Formation

    NASA Astrophysics Data System (ADS)

    Simões, Fernando; Pfaff, Robert; Hamelin, Michel; Klenzing, Jeffrey; Freudenreich, Henry; Béghin, Christian; Berthelier, Jean-Jacques; Bromund, Kenneth; Grard, Rejean; Lebreton, Jean-Pierre; Martin, Steven; Rowland, Douglas; Sentman, Davis; Takahashi, Yukihiro; Yair, Yoav

    2012-05-01

    The formation and evolution of the solar system is closely related to the abundance of volatiles, namely water, ammonia, and methane in the protoplanetary disk. Accurate measurement of volatiles in the solar system is therefore important for understanding not only the nebular hypothesis and origin of life but also planetary cosmogony as a whole. In this work, we propose a new remote sensing technique to infer the outer planets' water content by measuring Tremendously and Extremely Low Frequency (TLF-ELF) electromagnetic wave characteristics (Schumann resonances) excited by lightning in their gaseous envelopes. Schumann resonance detection can be potentially used for constraining the uncertainty of volatiles of the giant planets, mainly Uranus and Neptune, because such TLF-ELF wave signatures are closely related to the electric conductivity profile and water content.

  15. Using Schumann Resonance Measurements for Constraining the Water Abundance on the Giant Planets - Implications for the Solar System Formation

    NASA Technical Reports Server (NTRS)

    Simoes, Fernando; Pfaff, Robert; Hamelin, Michel; Klenzing, Jeffrey; Freudenreich, Henry; Beghin, Christian; Berthelier, Jean-Jacques; Bromund, Kenneth; Grard, Rejean; Lebreton, Jean-Pierre; Martin, Steven; Rowland, Douglas; Sentman, Davis; Takahashi, Yukihiro; Yair, Yoav

    2012-01-01

    The formation and evolution of the Solar System is closely related to the abundance of volatiles, namely water, ammonia, and methane in the protoplanetary disk. Accurate measurement of volatiles in the Solar System is therefore important to understand not only the nebular hypothesis and origin of life but also planetary cosmogony as a whole. In this work, we propose a new, remote sensing technique to infer the outer planets water content by measuring Tremendously and Extremely Low Frequency (TLF-ELF) electromagnetic wave characteristics (Schumann resonances) excited by lightning in their gaseous envelopes. Schumann resonance detection can be potentially used for constraining the uncertainty of volatiles of the giant planets, mainly Uranus and Neptune, because such TLF-ELF wave signatures are closely related to the electric conductivity profile and water content.

  16. Energy transfer processes in solar energy conversion

    SciTech Connect

    Fayer, M.D.

    1986-11-01

    By combining picosecond optical experiments and detailed statistical mechanics theory we continue to increase our understanding of the complex interplay of structure and dynamics in important energy transfer situations. A number of different types of problems will be focused on experimentally and theoretically. They are excitation transport among chromophores attached to finite size polymer coils; excitation transport among chromophores in monolayers, bilayers, and finite and infinite stacks of layers; excitation transport in large vesicle systems; and photoinduced electron transfer in glasses and liquids, focusing particularly on the back transfer of the electron from the photogenerated radical anion to the radical cation. 33 refs., 13 figs.

  17. Energy transfer processes in solar energy conversion

    SciTech Connect

    Fayer, M.D.

    1989-11-01

    We have made substantial progress in experimental and theoretical studies in two areas: Photoinduced donor to acceptor electron transfer followed by back transfer in random solutions; and electronic excitation transport in systems with complex inhomogeneous spatial geometries and inhomogeneous energy distributions. Through the development of accurate statistical mechanical theories, we have been able to relate dynamics in complex systems to experimental observables. We have then used the experimental observables, time resolved fluorescence depolarization and transient grating experiments, to examine well defined molecular systems. The agreement between theory and experiment is excellent. 11 refs.

  18. High-precision abundances of Sc, Mn, Cu, and Ba in solar twins. Trends of element ratios with stellar age

    NASA Astrophysics Data System (ADS)

    Nissen, P. E.

    2016-09-01

    Aims: A previous study of correlations between element abundances and ages of solar twin stars in the solar neighborhood is extended to include Sc, Mn, Cu, and Ba to obtain new information on the nucleosynthetic history of these elements. Methods: HARPS spectra with S/N ≳ 600 are used to derive very precise (σ ~ 0.01 dex) differential abundances of Sc, Mn, Cu, and Ba for 21 solar twins and the Sun. The analysis is based on MARCS model atmospheres with parameters determined from the excitation and ionization balance of Fe lines. Stellar ages with internal errors less than 1 Gyr are obtained by interpolation in the log g - Teff diagram between isochrones based on the Aarhus Stellar Evolution Code. Results: For stars younger than 6 Gyr, [Sc/Fe], [Mn/Fe], [Cu/Fe], and [Ba/Fe] are tightly correlated with stellar age, which is also the case for the other elements previously studied; linear relations between [X/Fe] and age have χ^2red ˜ 1, and for most stars the residuals do not depend on elemental condensation temperature. For ages between 6 and 9 Gyr, the [X/Fe] - age correlations break down and the stars split up into two groups having respectively high and low [X/Fe] for the odd-Z elements Na, Al, Sc, and Cu. Conclusions: While stars in the solar neighborhood younger than ~ 6 Gyr were formed from interstellar gas with a smooth chemical evolution, older stars seem to have originated from regions enriched by supernovae with different neutron excesses. Correlations between abundance ratios and stellar age suggest that: (i) Sc is made in Type II supernovae along with the α-capture elements; (ii) the Type II to Ia yield ratio is about the same for Mn and Fe; (iii) Cu is mainly made by the weak s-process in massive stars; (iv) the Ba/Y yield ratio for asymptotic giant branch stars increases with decreasing stellar mass; (v) [Y/Mg] and [Y/Al] can be used as chemical clocks when determining ages of solar metallicity stars. Based on data products from observations made

  19. Conversion of concentrated solar thermal energy into chemical energy.

    PubMed

    Tamaura, Yutaka

    2012-01-01

    When a concentrated solar beam is irradiated to the ceramics such as Ni-ferrite, the high-energy flux in the range of 1500-2500 kW/m(2) is absorbed by an excess Frenkel defect formation. This non-equilibrium state defect is generated not by heating at a low heating-rate (30 K/min), but by irradiating high flux energy of concentrated solar beam rapidly at a high heating rate (200 K/min). The defect can be spontaneously converted to chemical energy of a cation-excess spinel structure (reduced-oxide form) at the temperature around 1773 K. Thus, the O(2) releasing reaction (α-O(2) releasing reaction) proceeds in two-steps; (1) high flux energy of concentrated solar beam absorption by formation of the non-equilibrium Frenkel defect and (2) the O(2) gas formation from the O(2-) in the Frenkel defect even in air atmosphere. The 2nd step proceeds without the solar radiation. We may say that the 1st step is light reaction, and 2nd step, dark reaction, just like in photosynthesis process.

  20. Energy Conservation and Passive Solar Techniques in Campus Renovation.

    ERIC Educational Resources Information Center

    Probasco, Jack; And Others

    1981-01-01

    The analysis of a building from an energy conservation and passive solar potential has three aspects: building envelope, landscaping, and room utilization. Typical conservation and solar control modifications are listed. (Author/MLF)

  1. Solar Energy Research Institute Validation Test House Site Handbook

    SciTech Connect

    Burch, J.; Wortman, D.; Judkoff, R.; Hunn, B.

    1985-05-01

    The Validation Test House at the Solar Energy Research Institute in Golden, Colorado, is being used to collect performance data for analysis/design tool validation as part of the DOE Passive Solar Class A Performance Evaluation Program.

  2. Solar: A Clean Energy Source for Utilities (Fact Sheet)

    SciTech Connect

    Not Available

    2010-09-01

    The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts with utilities to remove the technical, regulatory, and market challenges they face in deploying solar technologies.

  3. Solar and wind energy utilization in broiler production

    SciTech Connect

    Brinsfield, R.B.; Yaramanoglu, M.; Wheaton, F.

    1984-01-01

    Available solar and wind energy and both the electrical and thermal energy demand of a typical broiler facility were mathematically modeled based on 10 years of weather data for Salisbury, Maryland. The available energy was then compared with the broiler facility demands as a means of sizing solar and wind energy collection equipment to meet the demands.

  4. Meeting the Energy Needs--Solar Technician Training Programs.

    ERIC Educational Resources Information Center

    Panitz, Theodore

    1980-01-01

    Differentiates between solar technicians and energy technicians; points out that, with the energy crisis, there has been much activity in the solar energy field, with the result that it could become saturated. Describes a program to train energy technicians that was developed at Cape Cod Community College. (JOW)

  5. Solar energy collection by the tower system

    SciTech Connect

    Taguchi, T.; Takemoto, M.

    1981-01-01

    Solar energy collecting tests were carried out under Japan's Sunshine Project, as part of the solar thermal electric power system. The total mirror area of the heliostats was increased by a factor of three to 300 sq m, making the dimensional ratio between the tower height and field diameter equivalent to that of the pilot plant, as well as achieving a similar heat flux magnitude as the pilot plant. The absorbing efficiency of the No. 4 receiver was studied and proven to be inferior to the No. 7 receiver, with its improved wind shield cavity, reducing reflection losses at higher wind velocities. The difference in convection heat losses between the two receivers in the solar energy collecting apparatus did not, however, directly correspond to the difference between them measured in the pilot plant. Thus, a heat loss test was applied to the No. 7 receiver, and fluctuations in the measured values of absorbing efficiencies were shown to be due to fluctuations of convection heat loss. Future plans include the design of external receivers suitable for low towers, with a lighter weight and a greater compactness for minimum heat loss potential.

  6. The case for solar/hydrogen energy

    NASA Astrophysics Data System (ADS)

    Escher, W. J. D.

    Available solar technologies for producing H2-based fuels for all uses by the turn of the century are discussed. Although the annual global insolation is over 20 times the total remaining fossil fuels, the source is diffuse and variable, and areas of greatest input are not collocated with sites of greatest use. Therefore, the H2 supply must be transportable and storable, and the production facilities require large areas. Hydrogen fuels have a naturally occurring, nearly limitless supply, water, are nonpolluting, recyclable, and have the highest energy conversion efficiency of all liquid fuels. The production energy sources feasible before the year 2000 are identified as thermal heat engines, solar cells, hydroelectric plants, and wind turbines. Water electrolysis is concluded to be the sole method available for solar/hydrogen systems, and it is shown that ocean cryotanker transport of H2 fuels could be accomplished at the same efficiency and cost as with LNG fuels. Systems for production and/or storage of H2 fuels for the home, in automobiles, and on ocean platforms are described, and an international program to develop the H2-based fuel system is recommended.

  7. Argonne OutLoud presents: The Solar Energy Challenge

    ScienceCinema

    Seth Darling

    2016-07-12

    To better understand the current and future role of solar energy, Argonne's Seth Darling framed the global energy supply and demand outlook over the next 40 years while examining potential energy sources from a feasibility and sustainability perspective. He also discussed the promise and challenges of solar energy while providing a broad overview of related research taking place at Argonne as well as his group's work on organic solar cells.

  8. Solar energy market penetration models - Science or number mysticism

    NASA Technical Reports Server (NTRS)

    Warren, E. H., Jr.

    1980-01-01

    The forecast market potential of a solar technology is an important factor determining its R&D funding. Since solar energy market penetration models are the method used to forecast market potential, they have a pivotal role in a solar technology's development. This paper critiques the applicability of the most common solar energy market penetration models. It is argued that the assumptions underlying the foundations of rigorously developed models, or the absence of a reasonable foundation for the remaining models, restrict their applicability.

  9. Energy balance in solar and stellar chromospheres

    NASA Technical Reports Server (NTRS)

    Avrett, E. H.

    1981-01-01

    Net radiative cooling rates for quiet and active regions of the solar chromosphere and for two stellar chromospheres are calculated from corresponding atmospheric models. Models of chromospheric temperature and microvelocity distributions are derived from observed spectra of a dark point within a cell, the average sun and a very bright network element on the quiet sun, a solar plage and flare, and the stars Alpha Boo and Lambda And. Net radiative cooling rates due to the transitions of various atoms and ions are then calculated from the models as a function of depth. Large values of the net radiative cooling rate are found at the base of the chromosphere-corona transition region which are due primarily to Lyman alpha emission, and a temperature plateau is obtained in the transition region itself. In the chromospheric regions, the calculated cooling rate is equal to the mechanical energy input as a function of height and thus provides a direct constraint on theories of chromospheric heating.

  10. Solar energy in California industry - Applications, characteristics and potential

    NASA Technical Reports Server (NTRS)

    Barbieri, R. H.; Pivirotto, D. S.

    1978-01-01

    Results of a survey to determine the potential applicability of solar thermal energy to industrial processes in California are presented. It is found that if the heat for all industrial processes at temperatures below 212 F were supplied by solar energy, total state energy consumption could be reduced by 100 trillion Btus (2%), while the use of solar energy in processes between 212 and 350 F could displace 500 trillion Btus. The issues and problems with which solar energy must contend are illustrated by a description of fluid milk processing operations. Solar energy application is found to be technically feasible for processes with thermal energy requirements below 212 F, with design, and degree of technical, economic and management feasibility being site specific. It is recommended that the state provide support for federal and industrial research, development and demonstration programs in order to stimulate acceptance of solar process heat application by industry.

  11. Solar Thermal Energy Storage Device: Hybrid Nanostructures for High-Energy-Density Solar Thermal Fuels

    SciTech Connect

    2012-01-09

    HEATS Project: MIT is developing a thermal energy storage device that captures energy from the sun; this energy can be stored and released at a later time when it is needed most. Within the device, the absorption of sunlight causes the solar thermal fuel’s photoactive molecules to change shape, which allows energy to be stored within their chemical bonds. A trigger is applied to release the stored energy as heat, where it can be converted into electricity or used directly as heat. The molecules would then revert to their original shape, and can be recharged using sunlight to begin the process anew. MIT’s technology would be 100% renewable, rechargeable like a battery, and emissions-free. Devices using these solar thermal fuels—called Hybrisol—can also be used without a grid infrastructure for applications such as de-icing, heating, cooking, and water purification.

  12. Off-farm applications of solar energy in agriculture

    SciTech Connect

    Berry, R.E.

    1980-01-01

    Food processing applications make up almost all present off-farm studies of solar energy in agriculture. Research, development and demonstration projects on solar food processing have shown significant progress over the past 3 years. Projects have included computer simulation and mathematical models, hardware and process development for removing moisture from horticultural or animal products, integration of energy conservation with solar energy augmentation in conventional processes, and commercial scale demonstrations. The demonstration projects include solar heated air for drying prunes and raisins, soy beans and onions/garlic; and solar generated steam for orange juice pasteurization. Several new and planned projects hold considerable promise for commerical exploitation in future food processes.

  13. Optical Waveguide Solar Energy System for Lunar Materials Processing

    NASA Technical Reports Server (NTRS)

    Nakamura, T.; Case, J. A.; Senior, C. L.

    1997-01-01

    This paper discusses results of our work on development of the Optical Waveguide (OW) Solar Energy System for Lunar Materials Processing. In the OW system as shown, solar radiation is collected by the concentrator which transfers the concentrated solar radiation to the OW transmission line consisting of low-loss optical fibers. The OW line transmits the solar radiation to the thermal reactor of the lunar materials processing plant. The feature of the OW system are: (1) Highly concentrated solar radiation (up to 104 suns) can be transmitted via flexible OW lines directly into the thermal reactor for materials processing: (2) Solar radiation intensity or spectra can be tailored to specific materials processing steps; (3) Provide solar energy to locations or inside of enclosures that would not otherwise have an access to solar energy; and (4) The system can be modularized and can be easily transported to and deployed at the lunar base.

  14. WIYN Open Cluster Study. LVII. Oxygen Abundances of Solar-type Dwarfs in the Hyades and NGC 752

    NASA Astrophysics Data System (ADS)

    Maderak, Ryan M.; Deliyannis, Constantine P.; King, Jeremy R.; Cummings, Jeffery D.

    2013-12-01

    Oxygen has been proposed to be a superior tracer, compared to iron, for studying galactic chemical evolution. In the context of improving our understanding of the evolution of Galactic oxygen using open clusters, we present a spectroscopic analysis of oxygen and iron abundances in the 650 Myr old Hyades cluster and in the 1.45 Gyr old cluster NGC 752, using high-dispersion 7774 Å O I triplet region spectra of dwarfs in these clusters acquired with the Hydra MOS on the WIYN 3.5 m telescope. Motivated by recent improvements in analysis of the triplet, we use a strictly differential analysis in solar-type stars to obtain reliable O abundances. Using stars whose radial velocities and spectral cross-correlation analyses are consistent with single-star membership, we report Hyades cluster averages of [O/H] = 0.195 ± 0.010 and [Fe/H] = 0.130 ± 0.009 based on 22 stars, and NGC 752 cluster averages of [O/H] = -0.077 ± 0.02 and [Fe/H] = -0.063 ± 0.013 based on 36 stars (where the errors are σμ we discuss possible additional systematic errors). These cluster abundance averages are in very good agreement with most previous determinations. Whereas the [O/H] cluster averages utilize only stars found in the "prime" T eff range straddling the solar T eff, the [Fe/H] cluster averages come from stars exhibiting a flat [Fe/H]-T eff relation of over 1000 K for the Hyades and nearly 2000 K for NGC 752. Previous studies of open clusters younger than NGC 752 have reported oxygen triplet over abundances in cool dwarfs, as compared to oxygen abundances of the prime-T eff range. We report that NGC 752 also shows such overabundances, at a higher level than the Hyades overabundances, and thus contradicts the idea of a decline of such overabundances with increasing age. We discuss evidence for and against correlations of the oxygen overabundances with rotation, X-ray luminosity, chromospheric activity, and metallicity.

  15. WIYN OPEN CLUSTER STUDY. LVII. OXYGEN ABUNDANCES OF SOLAR-TYPE DWARFS IN THE HYADES AND NGC 752

    SciTech Connect

    Maderak, Ryan M.; Deliyannis, Constantine P.; Cummings, Jeffery D.; King, Jeremy R. E-mail: con@astro.indiana.edu E-mail: jcummings@astro-udec.cl

    2013-12-01

    Oxygen has been proposed to be a superior tracer, compared to iron, for studying galactic chemical evolution. In the context of improving our understanding of the evolution of Galactic oxygen using open clusters, we present a spectroscopic analysis of oxygen and iron abundances in the 650 Myr old Hyades cluster and in the 1.45 Gyr old cluster NGC 752, using high-dispersion 7774 Å O I triplet region spectra of dwarfs in these clusters acquired with the Hydra MOS on the WIYN 3.5 m telescope. Motivated by recent improvements in analysis of the triplet, we use a strictly differential analysis in solar-type stars to obtain reliable O abundances. Using stars whose radial velocities and spectral cross-correlation analyses are consistent with single-star membership, we report Hyades cluster averages of [O/H] = 0.195 ± 0.010 and [Fe/H] = 0.130 ± 0.009 based on 22 stars, and NGC 752 cluster averages of [O/H] = –0.077 ± 0.02 and [Fe/H] = –0.063 ± 0.013 based on 36 stars (where the errors are σ{sub μ}; we discuss possible additional systematic errors). These cluster abundance averages are in very good agreement with most previous determinations. Whereas the [O/H] cluster averages utilize only stars found in the ''prime'' T {sub eff} range straddling the solar T {sub eff}, the [Fe/H] cluster averages come from stars exhibiting a flat [Fe/H]-T {sub eff} relation of over 1000 K for the Hyades and nearly 2000 K for NGC 752. Previous studies of open clusters younger than NGC 752 have reported oxygen triplet over abundances in cool dwarfs, as compared to oxygen abundances of the prime-T {sub eff} range. We report that NGC 752 also shows such overabundances, at a higher level than the Hyades overabundances, and thus contradicts the idea of a decline of such overabundances with increasing age. We discuss evidence for and against correlations of the oxygen overabundances with rotation, X-ray luminosity, chromospheric activity, and metallicity.

  16. Analysis of PURPA and solar energy

    SciTech Connect

    Rice, M.

    1980-03-01

    The Public Utility Regulatory Policies Act of 1978 (PURPA) is designed to promote energy conservation, the efficient use of utility resources, and equitable rates. PURPA specifically directs the Federal Energy Regulatory Commission (FERC) to encourage small power production from renewable resources (and also cogeneration of electric energy as well as heat) by setting standards under which facilities qualify for interconnection, and guidelines for sales between utilities and independent facilities. The way FERC carries out this mandate may critically affect the development of solar alternatives to electric power production from fossil and nuclear resources. This report comments on proposed FERC regulations and suggests ways to encourage small power production within the PURPA mandate. In addition, some internal strains within PURPA are analyzed that seem to limit the effectiveness with which FERC can encourage independent facilities, and possible modifications to PURPA are suggested. 255 references.

  17. Two-Point Observations of High- and Low-Frequency Variations of Helium Abundance in the Solar Win

    NASA Astrophysics Data System (ADS)

    Safrankova, J.; Cagas, P.; Nemecek, Z.; Prech, L.; Zastenker, G. N.; Riazantseva, M.

    2014-12-01

    Variations of the abundance of heavy species observed in the solar wind are usually attributed to spacecraft encounters with streams emanating from different places and altitudes in the source region and their further evolution is considered as being negligible. These conclusions are based on an analysis of highly averaged data and much less attention was devoted to variations on the time scale of seconds. The BMSW instrument onboard the Spektr-R spacecraft provides a high-time resolution data of the helium and proton fluxes and proton velocity, density, and temperature that suitable for investigations of rapid variations. The paper compares measurements in two points (Spektr-R and Wind) and focuses on the changes of helium abundance on this middle scale and on their correlations with variations of other parameters. We have found that only a low-frequency part of He abundance variations can be attributed to changes of the source region, whereas a significant portion of them could be generated by in-transit turbulence that is probably driven by the speed difference between the ion species.

  18. Solar Forecasting Challenges and Opportunities for Enabling High Penetration of Solar Energy

    NASA Astrophysics Data System (ADS)

    Mishra, S.

    2015-12-01

    In 2011, DOE launched the SunShot Initiative to reduce the total cost of solar energy systems by about 75% to make them cost competitive with other forms of energy (without subsidies) by 2020. This translates to a total cost of installed solar energy at 1/Watt or 0.06/kWh, incentivizing high penetration of solar on the utility grid. In the past four years, the SunShot Initiative has catalyzed revolutionary advancements in solar technologies, stimulating significant growth and accelerating deployment of solar energy systems. However, as solar deployment increases, integrating solar energy into the utility grid poses difficult challenges due to the variability in solar resource and the impact of clouds and aerosols on surface irradiance. Accurate forecasting of solar resource and its variability at high temporal and spatial resolution at least a day ahead is crucial to large scale integration of solar energy into the utility grid. However, this is limited by current errors in forecasting that are as high as 25% for clear sky forecasts of Global Horizontal Irradiance (GHI), and as large as 40-80% for cloudy conditions. Forecasting errors are even higher for the direct normal irradiance (DNI). For solar energy to be seamlessly integrated into the utility grid under the scenarios of high penetration of solar, significant improvements in surface solar irradiance modeling and observations of both Global Horizontal Irradiance (GHI) and Direct Normal Irradiance (DNI) are essential to accurately predict power outputs from photovoltaic (PV) and concentrating solar power (CSP) systems. Furthermore, forecasting improvements have to be closely tied to utility needs and operation timelines. Details about the ongoing research efforts supported through the SunShot initiative and the challenges and needs for solar forecasting improvements in regards to the SunShot Initiative will be presented at the conference.

  19. Energy from the biological conversion of solar energy

    NASA Astrophysics Data System (ADS)

    Boardman, N. K.

    1980-02-01

    The paper examines the possible energy contributions by employing trees and other biological solar collectors. Attention is given to the potential availability of biomass for fuel production, emphasizing the average annual production of various types of biomass. It is concluded that biomass will not be able to contribute a substantial fraction of the world's energy demands but it was also noted that photosynthesis can make a useful contribution, particularly in countries with a relatively low per capita consumption of energy or with large areas of rain-fed productive land.

  20. Discovery of abundant, accessible hydrocarbons nearly everywhere in the solar system

    SciTech Connect

    Zuppero, A.

    1996-05-01

    analysis of the data gathered during the Comet Halley encounter during 1987 resulted in a body of literature asserting that all comets contain substantial percentages of hydrocarbon solids. These solids appear to have a strong similarity to petrochemicals. Arguments are made that the amount of hydrocarbon material in the accessible comets of the inner Solar system can substantially exceed the known reserves of hydrocarbons on Earth. An example is given of at least one conceptually simple method to use comet material as feedstock for space transportation schemes that can move masses through the solar system comparable to the mass carried by oil supertankers. The presentation concludes we need to send prospecting and assay probes to a sampling of the accessible comets to determine the amount of hydrocarbons and the form and location of materials needed for space transportation systems.

  1. Extinct nuclides - much ado about nothing. [Abundance in early solar system

    SciTech Connect

    Wasserburg, G.J.

    1985-06-01

    Attention is given to the status of research on short lived nuclei, whose importance is considerable despite their essential absence (outside cosmic ray products) in virtue of their place in the theoretical understanding of broader cosmological problems. It is presently suggested that they are a key to the earliest processes in solar system formation, and may furnish a link with presolar processes in the interstellar medium or in the intense activity of the early sun. 71 references.

  2. Defect Tolerant Semiconductors for Solar Energy Conversion.

    PubMed

    Zakutayev, Andriy; Caskey, Christopher M; Fioretti, Angela N; Ginley, David S; Vidal, Julien; Stevanovic, Vladan; Tea, Eric; Lany, Stephan

    2014-04-01

    Defect tolerance is the tendency of a semiconductor to keep its properties despite the presence of crystallographic defects. Scientific understanding of the origin of defect tolerance is currently missing. Here we show that semiconductors with antibonding states at the top of the valence band are likely to be tolerant to defects. Theoretical calculations demonstrate that Cu3N with antibonding valence band maximum has shallow intrinsic defects and no surface states, in contrast to GaN with bonding valence band maximum. Experimental measurements indicate shallow native donors and acceptors in Cu3N thin films, leading to 10(16)-10(17) cm(-3) doping with either electrons or holes depending on the growth conditions. The experimentally measured bipolar doping and the solar-matched optical absorption onset (1.4 eV) make Cu3N a promising candidate absorber for photovoltaic and photoelectrochemical solar cells, despite the calculated indirect fundamental band gap (1.0 eV). These conclusions can be extended to other materials with antibonding character of the valence band, defining a class of defect-tolerant semiconductors for solar energy conversion applications.

  3. Solar energy in the context of energy use, energy transportation and energy storage.

    PubMed

    MacKay, David J C

    2013-08-13

    Taking the UK as a case study, this paper describes current energy use and a range of sustainable energy options for the future, including solar power and other renewables. I focus on the area involved in collecting, converting and delivering sustainable energy, looking in particular detail at the potential role of solar power. Britain consumes energy at a rate of about 5000 watts per person, and its population density is about 250 people per square kilometre. If we multiply the per capita energy consumption by the population density, then we obtain the average primary energy consumption per unit area, which for the UK is 1.25 watts per square metre. This areal power density is uncomfortably similar to the average power density that could be supplied by many renewables: the gravitational potential energy of rainfall in the Scottish highlands has a raw power per unit area of roughly 0.24 watts per square metre; energy crops in Europe deliver about 0.5 watts per square metre; wind farms deliver roughly 2.5 watts per square metre; solar photovoltaic farms in Bavaria, Germany, and Vermont, USA, deliver 4 watts per square metre; in sunnier locations, solar photovoltaic farms can deliver 10 watts per square metre; concentrating solar power stations in deserts might deliver 20 watts per square metre. In a decarbonized world that is renewable-powered, the land area required to maintain today's British energy consumption would have to be similar to the area of Britain. Several other high-density, high-consuming countries are in the same boat as Britain, and many other countries are rushing to join us. Decarbonizing such countries will only be possible through some combination of the following options: the embracing of country-sized renewable power-generation facilities; large-scale energy imports from country-sized renewable facilities in other countries; population reduction; radical efficiency improvements and lifestyle changes; and the growth of non-renewable low

  4. Solar energy in the context of energy use, energy transportation and energy storage.

    PubMed

    MacKay, David J C

    2013-08-13

    Taking the UK as a case study, this paper describes current energy use and a range of sustainable energy options for the future, including solar power and other renewables. I focus on the area involved in collecting, converting and delivering sustainable energy, looking in particular detail at the potential role of solar power. Britain consumes energy at a rate of about 5000 watts per person, and its population density is about 250 people per square kilometre. If we multiply the per capita energy consumption by the population density, then we obtain the average primary energy consumption per unit area, which for the UK is 1.25 watts per square metre. This areal power density is uncomfortably similar to the average power density that could be supplied by many renewables: the gravitational potential energy of rainfall in the Scottish highlands has a raw power per unit area of roughly 0.24 watts per square metre; energy crops in Europe deliver about 0.5 watts per square metre; wind farms deliver roughly 2.5 watts per square metre; solar photovoltaic farms in Bavaria, Germany, and Vermont, USA, deliver 4 watts per square metre; in sunnier locations, solar photovoltaic farms can deliver 10 watts per square metre; concentrating solar power stations in deserts might deliver 20 watts per square metre. In a decarbonized world that is renewable-powered, the land area required to maintain today's British energy consumption would have to be similar to the area of Britain. Several other high-density, high-consuming countries are in the same boat as Britain, and many other countries are rushing to join us. Decarbonizing such countries will only be possible through some combination of the following options: the embracing of country-sized renewable power-generation facilities; large-scale energy imports from country-sized renewable facilities in other countries; population reduction; radical efficiency improvements and lifestyle changes; and the growth of non-renewable low

  5. Progress in passive solar energy systems. Volume 8. Part 1

    SciTech Connect

    Hayes, J.; Andrejko, D.A.

    1983-01-01

    This book presents the papers given at a conference sponsored by the US DOE, the Solar Energy Research Institute, SolarVision, Inc., and the Southern California Solar Energy Society. The topics considered at the conference included sizing solar energy systems for agricultural applications, a farm scale ethanol production plant, the EEC wind energy RandD program, the passive solar performance assessment of an earth-sheltered house, the ARCO 1 MW photovoltaic power plant, the performance of a dendritic web photovoltaic module, second generation point focused concentrators, linear fresnel lens concentrating photovoltaic collectors, photovoltaic conversion efficiency, amorphous silicon thin film solar cells, a photovoltaic system for a shopping center, photovoltaic power generation for the utility industry, spectral solar radiation, and the analysis of insolation data.

  6. Schools Going Solar: A Guide to Schools Enjoying the Power of Solar Energy. Volume 2.

    ERIC Educational Resources Information Center

    Hitchcock, Susan Tyler

    This companion document updates an April 1998 volume on designing schools to use solar energy as a power source. Volume 2 presents numerous case studies of solar installations in new and existing schools across the United States and Europe, updates and presents new examples of solar education programs, and offers an updated resource listing of…

  7. Residential Solar Design Review: A Manual on Community Architectural Controls and Solar Energy Use.

    ERIC Educational Resources Information Center

    Jaffe, Martin; Erley, Duncan

    Presented are architectural design issues associated with solar energy use, and procedures for design review committees to consider in examining residential solar installation in light of existing aesthetic goals for their communities. Recommended design review criteria include the type of solar system being used and the ways in which the system…

  8. Design and measured performance of a solar chimney for natural circulation solar energy dryers

    SciTech Connect

    Ekechukwu, O.V.; Norton, B.

    1996-02-01

    An experimental solar chimney consisted of a cylindrical polyethylene-clad vertical chamber supported by steel framework and draped internally with a selectively absorbing surface. The performance of the chimney which was monitored extensively is reported. Issues related to the design and construction of solar chimneys for natural circulation solar energy dryers are discussed.

  9. Organohalide Perovskites for Solar Energy Conversion.

    PubMed

    Lin, Qianqian; Armin, Ardalan; Burn, Paul L; Meredith, Paul

    2016-03-15

    Lead-based organohalide perovskites have recently emerged as arguably the most promising of all next generation thin film solar cell technologies. Power conversion efficiencies have reached 20% in less than 5 years, and their application to other optoelectronic device platforms such as photodetectors and light emitting diodes is being increasingly reported. Organohalide perovskites can be solution processed or evaporated at low temperatures to form simple thin film photojunctions, thus delivering the potential for the holy grail of high efficiency, low embedded energy, and low cost photovoltaics. The initial device-driven "perovskite fever" has more recently given way to efforts to better understand how these materials work in solar cells, and deeper elucidation of their structure-property relationships. In this Account, we focus on this element of organohalide perovskite chemistry and physics in particular examining critical electro-optical, morphological, and architectural phenomena. We first examine basic crystal and chemical structure, and how this impacts important solar-cell related properties such as the optical gap. We then turn to deeper electronic phenomena such as carrier mobilities, trap densities, and recombination dynamics, as well as examining ionic and dielectric properties and how these two types of physics impact each other. The issue of whether organohalide perovskites are predominantly nonexcitonic at room temperature is currently a matter of some debate, and we summarize the evidence for what appears to be the emerging field consensus: an exciton binding energy of order 10 meV. Having discussed the important basic chemistry and physics we turn to more device-related considerations including processing, morphology, architecture, thin film electro-optics and interfacial energetics. These phenomena directly impact solar cell performance parameters such as open circuit voltage, short circuit current density, internal and external quantum efficiency

  10. Organohalide Perovskites for Solar Energy Conversion.

    PubMed

    Lin, Qianqian; Armin, Ardalan; Burn, Paul L; Meredith, Paul

    2016-03-15

    Lead-based organohalide perovskites have recently emerged as arguably the most promising of all next generation thin film solar cell technologies. Power conversion efficiencies have reached 20% in less than 5 years, and their application to other optoelectronic device platforms such as photodetectors and light emitting diodes is being increasingly reported. Organohalide perovskites can be solution processed or evaporated at low temperatures to form simple thin film photojunctions, thus delivering the potential for the holy grail of high efficiency, low embedded energy, and low cost photovoltaics. The initial device-driven "perovskite fever" has more recently given way to efforts to better understand how these materials work in solar cells, and deeper elucidation of their structure-property relationships. In this Account, we focus on this element of organohalide perovskite chemistry and physics in particular examining critical electro-optical, morphological, and architectural phenomena. We first examine basic crystal and chemical structure, and how this impacts important solar-cell related properties such as the optical gap. We then turn to deeper electronic phenomena such as carrier mobilities, trap densities, and recombination dynamics, as well as examining ionic and dielectric properties and how these two types of physics impact each other. The issue of whether organohalide perovskites are predominantly nonexcitonic at room temperature is currently a matter of some debate, and we summarize the evidence for what appears to be the emerging field consensus: an exciton binding energy of order 10 meV. Having discussed the important basic chemistry and physics we turn to more device-related considerations including processing, morphology, architecture, thin film electro-optics and interfacial energetics. These phenomena directly impact solar cell performance parameters such as open circuit voltage, short circuit current density, internal and external quantum efficiency

  11. Design of an energy efficient solar powered water desalting plant

    SciTech Connect

    Nadler, M.

    1981-01-01

    A preliminary design was completed for a 6000 m/sup 3//day totally solar thermal energy powered seawater desalting plant. The objective was to design a process which would produce water at minimum cost using leading edge but commercial or near-commercial technology. Because the cost of solar energy is high, about half the cost of the plant is for solar equipment, minimum product water cost is achieved by minimizing energy consumption.

  12. U.S. Department of Energy Solar Decathlon

    SciTech Connect

    2011-12-16

    The U.S. Department of Energy Solar Decathlon is an award-winning program that challenges 20 collegiate teams to design, build, and operate solar-powered houses that are cost-effective, energy-efficient, and attractive. In addition to showcasing the cost savings and environmental benefits of market-ready solar technologies, the event encourages participating students to think in new ways about incorporating practical, affordable clean-energy solutions into residential applications.

  13. Thermodynamic Inefficiency of Conversion of Solar Energy to Work.

    ERIC Educational Resources Information Center

    Adamson, Arthur W.; And Others

    1984-01-01

    Considers the thermodynamic limitation to the efficiency with which light energy can be converted into work, indicating that no single chemical system converting solar energy into useful work can be very efficient. Also indicates that if solar energy is absorbed as heat for heating purposes, it is almost completely used. (JN)

  14. Modular assembly of a photovoltaic solar energy receiver

    DOEpatents

    Graven, Robert M.; Gorski, Anthony J.; Schertz, William W.; Graae, Johan E. A.

    1978-01-01

    There is provided a modular assembly of a solar energy concentrator having a photovoltaic energy receiver with passive cooling. Solar cell means are fixedly coupled to a radiant energy concentrator. Tension means bias a large area heat sink against the cell thereby allowing the cell to expand or contract with respect to the heat sink due to differential heat expansion.

  15. Solar Energy: Progress and Design Concerns of Nanostructured Solar Energy Harvesting Devices (Small 19/2016).

    PubMed

    Leung, Siu-Fung; Zhang, Qianpeng; Tavakoli, Mohammad Mahdi; He, Jin; Mo, Xiaoliang; Fan, Zhiyong

    2016-05-01

    Nanoengineered materials and structures can harvest light efficiently for photovoltaic applications. Device structure design optimization and material property improvement are equally important for high performance. On page 2536, X. Mo, Z. Fan, and co-workers summarize the design guidelines of solar energy harvesting devices to assist with a better understanding of device physics. PMID:27167321

  16. Solar Energy: Progress and Design Concerns of Nanostructured Solar Energy Harvesting Devices (Small 19/2016).

    PubMed

    Leung, Siu-Fung; Zhang, Qianpeng; Tavakoli, Mohammad Mahdi; He, Jin; Mo, Xiaoliang; Fan, Zhiyong

    2016-05-01

    Nanoengineered materials and structures can harvest light efficiently for photovoltaic applications. Device structure design optimization and material property improvement are equally important for high performance. On page 2536, X. Mo, Z. Fan, and co-workers summarize the design guidelines of solar energy harvesting devices to assist with a better understanding of device physics.

  17. On global energy scenario, dye-sensitized solar cells and the promise of nanotechnology.

    PubMed

    Reddy, K Govardhan; Deepak, T G; Anjusree, G S; Thomas, Sara; Vadukumpully, Sajini; Subramanian, K R V; Nair, Shantikumar V; Nair, A Sreekumaran

    2014-04-21

    One of the major problems that humanity has to face in the next 50 years is the energy crisis. The rising population, rapidly changing life styles of people, heavy industrialization and changing landscape of cities have increased energy demands, enormously. The present annual worldwide electricity consumption is 12 TW and is expected to become 24 TW by 2050, leaving a challenging deficit of 12 TW. The present energy scenario of using fossil fuels to meet the energy demand is unable to meet the increase in demand effectively, as these fossil fuel resources are non-renewable and limited. Also, they cause significant environmental hazards, like global warming and the associated climatic issues. Hence, there is an urgent necessity to adopt renewable sources of energy, which are eco-friendly and not extinguishable. Of the various renewable sources available, such as wind, tidal, geothermal, biomass, solar, etc., solar serves as the most dependable option. Solar energy is freely and abundantly available. Once installed, the maintenance cost is very low. It is eco-friendly, safely fitting into our society without any disturbance. Producing electricity from the Sun requires the installation of solar panels, which incurs a huge initial cost and requires large areas of lands for installation. This is where nanotechnology comes into the picture and serves the purpose of increasing the efficiency to higher levels, thus bringing down the overall cost for energy production. Also, emerging low-cost solar cell technologies, e.g. thin film technologies and dye-sensitized solar cells (DSCs) help to replace the use of silicon, which is expensive. Again, nanotechnological implications can be applied in these solar cells, to achieve higher efficiencies. This paper vividly deals with the various available solar cells, choosing DSCs as the most appropriate ones. The nanotechnological implications which help to improve their performance are dealt with, in detail. Additionally, the

  18. On global energy scenario, dye-sensitized solar cells and the promise of nanotechnology.

    PubMed

    Reddy, K Govardhan; Deepak, T G; Anjusree, G S; Thomas, Sara; Vadukumpully, Sajini; Subramanian, K R V; Nair, Shantikumar V; Nair, A Sreekumaran

    2014-04-21

    One of the major problems that humanity has to face in the next 50 years is the energy crisis. The rising population, rapidly changing life styles of people, heavy industrialization and changing landscape of cities have increased energy demands, enormously. The present annual worldwide electricity consumption is 12 TW and is expected to become 24 TW by 2050, leaving a challenging deficit of 12 TW. The present energy scenario of using fossil fuels to meet the energy demand is unable to meet the increase in demand effectively, as these fossil fuel resources are non-renewable and limited. Also, they cause significant environmental hazards, like global warming and the associated climatic issues. Hence, there is an urgent necessity to adopt renewable sources of energy, which are eco-friendly and not extinguishable. Of the various renewable sources available, such as wind, tidal, geothermal, biomass, solar, etc., solar serves as the most dependable option. Solar energy is freely and abundantly available. Once installed, the maintenance cost is very low. It is eco-friendly, safely fitting into our society without any disturbance. Producing electricity from the Sun requires the installation of solar panels, which incurs a huge initial cost and requires large areas of lands for installation. This is where nanotechnology comes into the picture and serves the purpose of increasing the efficiency to higher levels, thus bringing down the overall cost for energy production. Also, emerging low-cost solar cell technologies, e.g. thin film technologies and dye-sensitized solar cells (DSCs) help to replace the use of silicon, which is expensive. Again, nanotechnological implications can be applied in these solar cells, to achieve higher efficiencies. This paper vividly deals with the various available solar cells, choosing DSCs as the most appropriate ones. The nanotechnological implications which help to improve their performance are dealt with, in detail. Additionally, the

  19. Employment from Solar Energy: A Bright but Partly Cloudy Future.

    ERIC Educational Resources Information Center

    Smeltzer, K. K.; Santini, D. J.

    A comparison of quantitative and qualitative employment effects of solar and conventional systems can prove the increased employment postulated as one of the significant secondary benefits of a shift from conventional to solar energy use. Current quantitative employment estimates show solar technology-induced employment to be generally greater…

  20. Solar Energy Education. Industrial arts: student activities. Field test edition

    SciTech Connect

    Not Available

    1981-02-01

    In this teaching manual several activities are presented to introduce students to information on solar energy through classroom instruction. Wind power is also included. Instructions for constructing demonstration models for passive solar systems, photovoltaic cells, solar collectors and water heaters, and a bicycle wheel wind turbine are provided. (BCS)

  1. Space satellite power system. [conversion of solar energy by photovoltaic solar cell arrays

    NASA Technical Reports Server (NTRS)

    Glaser, P. E.

    1974-01-01

    The concept of a satellite solar power station was studied. It is shown that it offers the potential to meet a significant portion of future energy needs, is pollution free, and is sparing of irreplaceable earth resources. Solar energy is converted by photovoltaic solar cell arrays to dc energy which in turn is converted into microwave energy in a large active phased array. The microwave energy is beamed to earth with little attenuation and is converted back to dc energy on the earth. Economic factors are considered.

  2. Role of the Atmospheric Sciences for Solar Energy

    NASA Astrophysics Data System (ADS)

    Kleissl, J. P.; Lave, M.; Urquhart, B. G.; Mathiesen, P. J.; Bosch, J. L.; Chow, C. W.; Luoma, J. K.; Jamaly, M.; Nottrott, A. A.; Wegener, J.

    2011-12-01

    Solar energy is the fastest growing renewable energy source. Public interest, practically unlimited solar resources, and dramatic cost reductions have fueled the hopes for grid parity of solar energy production and dramatic growth of the industry. However, the variability of the solar fuel presents perceived and real challenges that can increase grid-integration costs of solar energy. Variability in global irradiance at the surface is dominated by solar geometry and atmospheric transmissivity effects with clouds explaining the majority of the non-geometry variance. Atmospheric scientists can play a major role in quantifying resource variability and improving solar forecasting models. I will start by presenting the state of the solar energy industry. Various studies of scaling of solar variability in space and time will be reviewed. Solar forecasting tools such as satellites, sky imagery, and numerical weather prediction will be introduced and state-of-the-art applications in the solar forecasting industry will be reviewed. Directions for RD&D in the atmospheric sciences will be presented.

  3. Optical analysis of solar energy tubular absorbers.

    PubMed

    Saltiel, C; Sokolov, M

    1982-11-15

    The energy absorbed by a solar energy tubular receiver element for a single incident ray is derived. Two types of receiver elements were analyzed: (1) an inner tube with an absorbing coating surrounded by a semitransparent cover tube, and (2) a semitransparent inner tube filled with an absorbing fluid surrounded by a semitransparent cover tube. The formation of ray cascades in the semitransparent tubes is considered. A numerical simulation to investigate the influence of the angle of incidence, sizing, thickness, and coefficient of extinction of the tubes was performed. A comparison was made between receiver elements with and without cover tubes. Ray tracing analyses in which rays were followed within the tubular receiver element as well as throughout the rest of the collector were performed for parabolic and circular trough concentrating collectors.

  4. GALACTIC COSMIC-RAY ENERGY SPECTRA AND COMPOSITION DURING THE 2009-2010 SOLAR MINIMUM PERIOD

    SciTech Connect

    Lave, K. A.; Binns, W. R.; Israel, M. H.; Wiedenbeck, M. E.; Christian, E. R.; De Nolfo, G. A.; Von Rosenvinge, T. T.; Cummings, A. C.; Davis, A. J.; Leske, R. A.; Mewaldt, R. A.; Stone, E. C.

    2013-06-20

    We report new measurements of the elemental energy spectra and composition of galactic cosmic rays during the 2009-2010 solar minimum period using observations from the Cosmic Ray Isotope Spectrometer (CRIS) onboard the Advanced Composition Explorer. This period of time exhibited record-setting cosmic-ray intensities and very low levels of solar activity. Results are given for particles with nuclear charge 5 {<=} Z {<=} 28 in the energy range {approx}50-550 MeV nucleon{sup -1}. Several recent improvements have been made to the earlier CRIS data analysis, and therefore updates of our previous observations for the 1997-1998 solar minimum and 2001-2003 solar maximum are also given here. For most species, the reported intensities changed by less than {approx}7%, and the relative abundances changed by less than {approx}4%. Compared with the 1997-1998 solar minimum relative abundances, the 2009-2010 abundances differ by less than 2{sigma}, with a trend of fewer secondary species observed in the more recent time period. The new 2009-2010 data are also compared with results of a simple ''leaky-box'' galactic transport model combined with a spherically symmetric solar modulation model. We demonstrate that this model is able to give reasonable fits to the energy spectra and the secondary-to-primary ratios B/C and (Sc+Ti+V)/Fe. These results are also shown to be comparable to a GALPROP numerical model that includes the effects of diffusive reacceleration in the interstellar medium.

  5. Effects of Flow on Structure and Abundances in Multispecies Solar Coronal Loops

    NASA Astrophysics Data System (ADS)

    Lenz, Dawn D.

    2004-03-01

    We investigate the effects of large-scale bulk flows on coronal abundances using a multispecies numerical model. The model assumes that electrons, protons, and helium are in thermal equilibrium and constitute the bulk of the coronal plasma. Thermal diffusion and Coulomb friction are included. Temperature profiles for the bulk component and for each ion species are assumed, so the model reduces to a solution of mass and force balance for each component. We further assume that the bulk component has an upward bulk velocity at the base, and that ion flow speeds along field lines are negligible relative to the bulk flow. Coulomb coupling of the electrons and ions induces drag that counteracts the tendency of the ions to gravitationally settle. In regions of small ∇T, such as the outer regions of the corona, Coulomb drag is the only significant force counteracting gravitational settling in this model. We find that relatively modest bulk flows of tens of km s-1 can enhance ion abundances by 2-3 orders of magnitude over their values in low- or no-flow cases.

  6. The evolution of the lithium abundances of solar-type stars. III - The Pleiades

    NASA Technical Reports Server (NTRS)

    Soderblom, David R.; Jones, Burton F.; Balachandran, Suchitra; Stauffer, John R.; Duncan, Douglas K.; Fedele, Stephen B.; Hudon, J. D.

    1993-01-01

    New measurements of lithium in more than 100 Pleiades F, G, and K dwarfs are reported. Abundances are determined from spectrum synthesis fits to the data as well as from use of new covers of growth from the Li 6708-A feature. It is argued that most Late-F and early-G dwarfs in the Pleiades are consistent with the tight N(Li) vs mass relation seen in the Hyades in the same mass range. Most Li-rich stars have abundances at or near the primordial level for Population I, and none exceed that level by a significant amount. At any given color the stars that rotate fast have the most Li and have the strongest chromospheric activity. Ways in which an apparent spread in N(Li) could arise from an intrinsically tight n(Li)-mass relation are considered, and it is concluded that the spread is probably real and is not an artifact of line formation conditions or inhomogeneous atmospheres on the stars.

  7. Model for Cumulative Solar Heavy Ion Energy and LET Spectra

    NASA Technical Reports Server (NTRS)

    Xapsos, Mike; Barth, Janet; Stauffer, Craig; Jordan, Tom; Mewaldt, Richard

    2007-01-01

    A probabilistic model of cumulative solar heavy ion energy and lineary energy transfer (LET) spectra is developed for spacecraft design applications. Spectra are given as a function of confidence level, mission time period during solar maximum and shielding thickness. It is shown that long-term solar heavy ion fluxes exceed galactic cosmic ray fluxes during solar maximum for shielding levels of interest. Cumulative solar heavy ion fluences should therefore be accounted for in single event effects rate calculations and in the planning of space missions.

  8. On solar ponds: salty fare for the world's energy appetite

    SciTech Connect

    Edesess, M.

    1982-11-01

    It is shown how a uniquely simple salt-gradient solar-energy trap is proving an economical source of electricity and low-temperature heat at various sites around the world. Problems with solar ponds include the thickening of the surface layer despite grids of wave-suppressors; the economics of using solar ponds to generate power and desalt water depend largely on the ability to operate without a synthetic liner; and some solar ponds lose much more heat to the ground than predicted. It is concluded that development of solar ponds is likely to depend on energy demand.

  9. Fundamentals and applications of solar energy. Part 2

    NASA Astrophysics Data System (ADS)

    Faraq, I. H.; Melsheimer, S. S.

    Applications of techniques of chemical engineering to the development of materials, production methods, and performance optimization and evaluation of solar energy systems are discussed. Solar thermal storage systems using phase change materials, liquid phase Diels-Alder reactions, aquifers, and hydrocarbon oil were examined. Solar electric systems were explored in terms of a chlorophyll solar cell, the nonequilibrium electric field effects developed at photoelectrode/electrolyte interfaces, and designs for commercial scale processing of solar cells using continuous thin-film coating production methods. Solar coal gasification processes were considered, along with multilayer absorber coatings for solar concentrator receivers, solar thermal industrial applications, the kinetics of anaerobic digestion of crop residues to produce methane, and a procedure for developing a computer simulation of a solar cooling system.

  10. Photovoltaic and photoelectrochemical conversion of solar energy.

    PubMed

    Grätzel, Michael

    2007-04-15

    The Sun provides approximately 100,000 terawatts to the Earth which is about 10000 times more than the present rate of the world's present energy consumption. Photovoltaic cells are being increasingly used to tap into this huge resource and will play a key role in future sustainable energy systems. So far, solid-state junction devices, usually made of silicon, crystalline or amorphous, and profiting from the experience and material availability resulting from the semiconductor industry, have dominated photovoltaic solar energy converters. These systems have by now attained a mature state serving a rapidly growing market, expected to rise to 300 GW by 2030. However, the cost of photovoltaic electricity production is still too high to be competitive with nuclear or fossil energy. Thin film photovoltaic cells made of CuInSe or CdTe are being increasingly employed along with amorphous silicon. The recently discovered cells based on mesoscopic inorganic or organic semiconductors commonly referred to as 'bulk' junctions due to their three-dimensional structure are very attractive alternatives which offer the prospect of very low cost fabrication. The prototype of this family of devices is the dye-sensitized solar cell (DSC), which accomplishes the optical absorption and the charge separation processes by the association of a sensitizer as light-absorbing material with a wide band gap semiconductor of mesoporous or nanocrystalline morphology. Research is booming also in the area of third generation photovoltaic cells where multi-junction devices and a recent breakthrough concerning multiple carrier generation in quantum dot absorbers offer promising perspectives. PMID:17272237

  11. Photovoltaic and photoelectrochemical conversion of solar energy.

    PubMed

    Grätzel, Michael

    2007-04-15

    The Sun provides approximately 100,000 terawatts to the Earth which is about 10000 times more than the present rate of the world's present energy consumption. Photovoltaic cells are being increasingly used to tap into this huge resource and will play a key role in future sustainable energy systems. So far, solid-state junction devices, usually made of silicon, crystalline or amorphous, and profiting from the experience and material availability resulting from the semiconductor industry, have dominated photovoltaic solar energy converters. These systems have by now attained a mature state serving a rapidly growing market, expected to rise to 300 GW by 2030. However, the cost of photovoltaic electricity production is still too high to be competitive with nuclear or fossil energy. Thin film photovoltaic cells made of CuInSe or CdTe are being increasingly employed along with amorphous silicon. The recently discovered cells based on mesoscopic inorganic or organic semiconductors commonly referred to as 'bulk' junctions due to their three-dimensional structure are very attractive alternatives which offer the prospect of very low cost fabrication. The prototype of this family of devices is the dye-sensitized solar cell (DSC), which accomplishes the optical absorption and the charge separation processes by the association of a sensitizer as light-absorbing material with a wide band gap semiconductor of mesoporous or nanocrystalline morphology. Research is booming also in the area of third generation photovoltaic cells where multi-junction devices and a recent breakthrough concerning multiple carrier generation in quantum dot absorbers offer promising perspectives.

  12. Bidirectional control system for energy flow in solar powered flywheel

    NASA Technical Reports Server (NTRS)

    Nola, Frank J. (Inventor)

    1987-01-01

    An energy storage system for a spacecraft is provided which employs a solar powered flywheel arrangement including a motor/generator which, in different operating modes, drives the flywheel and is driven thereby. A control circuit, including a threshold comparator, senses the output of a solar energy converter, and when a threshold voltage is exceeded thereby indicating the availability of solar power for the spacecraft loads, activates a speed control loop including the motor/generator so as to accelerate the flywheel to a constant speed and thereby store mechanical energy, while also supplying energy from the solar converter to the loads. Under circumstances where solar energy is not available and thus the threshold voltage is not exceeded, the control circuit deactivates the speed control loop and activates a voltage control loop that provides for operation of the motor as a generator so that mechanical energy from the flywheel is converted into electrical energy for supply to the spacecraft loads.

  13. Solar energy grid integration systems "SEGIS"

    SciTech Connect

    None, None

    2007-10-01

    The inevitable transformation of the electrical grid to a more distributed generation configuration requires solar system capabilities well beyond simple net-metered, grid-connected approaches. Time-of-use and peak-demand rate structures will require more sophisticated systems designs that integrate energy management and/or energy storage into the system architecture. Controlling power flow into and from the utility grid will be required to ensure grid reliability and power quality. Alternative protection strategies will also be required to accommodate large numbers of distributed energy sources. This document provides an overview of the R&D needs and describes some pathways to promising solutions. The solutions will, in many cases, require R&D of new components, innovative inverter/controllers, energy management systems, innovative energy storage and a suite of advanced control algorithms, technical methodologies, protocols and the associated communications. It is expected that these solutions will help to push the “advanced integrated system” and “smart grid” evolutionary processes forward in a faster but focused manner.

  14. Procedures for acceptance testing of solar energy systems

    NASA Astrophysics Data System (ADS)

    Johnson, D. L.; Joncich, D. M.

    1984-04-01

    This report describes research on the use of simple, low-cost meters for measuring the performance of solar energy systems in Army buildings and for comparing the measured performance with the design specification requirements. The requirements of meters for measuring the performance of solar energy systems were defined. A BTU-Meter for measuring heat transfer was designed, and commercial meters for taking other measurements were obtained. The meters were installed in a solar system in the laboratory and a pilot test of the acceptance test was done. Suggested draft revisions to Corps of Engineers design documents were prepared; designers could use these revisions to include acceptance testing provisions in solar energy system design. It was found that in a short-duration test, simple, low-cost meters can be used to determine whether a newly installed solar energy system is operating as specified. The simplicity of the metering approach allows designers to routinely include metering in the solar system design. The contractor can easily install the meters with the other solar components. Since the meters are so versatile, they can be used continuously for long-term performance monitoring. This gives the designer performance data and allows maintenance personnel to detect and diagnose solar equipment malfunctions. Thus, solar energy system metering can provide a unified, low-cost approach for meeting the wide range of measurement needs of Army solar energy systems.

  15. How Solar Energy Can Work for You

    ERIC Educational Resources Information Center

    Iker, Sam

    1978-01-01

    The future of solar heated homes looks bright. The increase in availability of solar hardware and information along with tax credits point to an increase in both solar water and space heating. Solar systems can add to the value of a house. (BB)

  16. A LOWER INITIAL ABUNDANCE OF SHORT-LIVED {sup 41}Ca IN THE EARLY SOLAR SYSTEM AND ITS IMPLICATIONS FOR SOLAR SYSTEM FORMATION

    SciTech Connect

    Liu, Ming-Chang; Chaussidon, Marc; Srinivasan, Gopalan; McKeegan, Kevin D.

    2012-12-20

    The short-lived radionuclide {sup 41}Ca plays an important role in constraining the immediate astrophysical environment and the formation timescale of the nascent solar system due to its extremely short half-life (0.1 Myr). Nearly 20 years ago, the initial ratio of {sup 41}Ca/{sup 40}Ca in the solar system was determined to be (1.41 {+-} 0.14) Multiplication-Sign 10{sup -8}, primarily based on two Ca-Al-rich Inclusions (CAIs) from the CV chondrite Efremovka. With an advanced analytical technique for isotopic measurements, we reanalyzed the potassium isotopic compositions of the two Efremovka CAIs and inferred the initial ratios of {sup 41}Ca/{sup 40}Ca to be (2.6 {+-} 0.9) Multiplication-Sign 10{sup -9} and (1.4 {+-} 0.6) Multiplication-Sign 10{sup -9} (2{sigma}), a factor of 7-10 lower than the previously inferred value. Considering possible thermal processing that led to lower {sup 26}Al/{sup 27}Al ratios in the two CAIs, we propose that the true solar system initial value of {sup 41}Ca/{sup 40}Ca should have been {approx}4.2 Multiplication-Sign 10{sup -9}. Synchronicity could have existed between {sup 26}Al and {sup 41}Ca, indicating a uniform distribution of the two radionuclides at the time of CAI formation. The new initial {sup 41}Ca abundance is 4-16 times lower than the calculated value for steady-state galactic nucleosynthesis. Therefore, {sup 41}Ca could have originated as part of molecular cloud materials with a free decay time of 0.2-0.4 Myr. Alternative possibilities, such as a last-minute input from a stellar source and early solar system irradiation, could not be definitively ruled out. This underscores the need for more data from diverse CAIs to determine the true astrophysical origin of {sup 41}Ca.

  17. Comparison of photovoltaic energy systems for the solar village

    NASA Astrophysics Data System (ADS)

    Piercefrench, Eric C.

    1988-08-01

    Three different solar photovoltaic (PV) energy systems are compared to determine if the electrical needs of a solar village could be supplied more economically by electricity generated by the sun than by existing utility companies. The solar village, a one square mile community of 900 homes and 50 businesses, would be located in a semi-remote area of the Arizona desert. A load survey is conducted and information on the solar PV industry is reviewed for equipment specifications, availability, and cost. Three specific PV designs, designated as Stand-Alone, Stand-Alone with interconnection, and Central Solar Plant, were created and then economically compared through present worth analysis against utility supplied electrical costs. A variety of technical issues, such as array protection, system configuration and operation, and practicability, are discussed for each design. The present worth analysis conclusively shows none of the solar PV designs could supply electricity to the solar village for less cost than utility supplied electricity, all other factors being equal. No construction on a solar village should begin until the cost of solar generated electricity is more competitive with electricity generated by coal, oil, and nuclear energy. However, research on ways to reduce solar PV equipment costs and on ways to complement solar PV energy, such as the use of solar thermal ponds for heating and cooling, should continue.

  18. Increased energy expenditure by a seabird in response to higher food abundance

    USGS Publications Warehouse

    Jodice, P.G.R.; Roby, D.D.; Suryan, R.M.; Irons, D.B.; Turco, K.R.; Brown, E.D.; Thedinga, J.F.; Visser, G.H.

    2006-01-01

    Variability in forage fish abundance strongly affects seabird behavior and reproductive success, although details of this relationship are unclear. During 1997 and 1998, we measured (1) daily energy expenditure (DEE) of 80 parent black-legged kittiwakes Rissa tridactyla at 2 colonies in Prince William Sound, Alaska (North Icy Bay and Shoup Bay), (2) abundance of surface-schooling forage fishes within the foraging range of each colony, and (3) diet composition, energy delivery rates to nestlings, and reproductive success of kittiwakes at these same colonies. Female DEE was highest at North Icy Bay in 1998, while male DEE did not differ by colony year. Abundances of Pacific herring Clupea pallasi and sand lance Ammodytes hexapterus were highest near North Icy Bay in 1998 and nearly egual in density, although Age 1+ herring comprised the majority of the diet there. Energy delivery rates to nestlings, nestling growth rates, and productivity were also highest at North Icy Bay in 1998. We suggest that female kittiwakes responded to the increased abundance of Age 1+ herring near North Icy Bay in 1998 by increasing their DEE, which in turn positively affected reproductive success. Given that adult kittiwakes have been shown to suffer decreased survival as a response to increased energy expenditure during brood rearing, the positive correlation we observed between increased abundance of a high quality food source, parental effort, and productivity is consistent with maximizing lifetime reproductive success. The lack of a response in male DEE suggests that brood-rearing roles in kittiwakes differ between genders. ?? Inter-Research 2006.

  19. Luminescent solar concentrators and all-inorganic nanoparticle solar cells for solar energy harvesting

    NASA Astrophysics Data System (ADS)

    Sholin, Veronica

    Increasing energy demand and the parallel increase of greenhouse gas emissions are challenging researchers to find new and cleaner energy sources. Solar energy harvesting is arguably the most promising candidate for replacing fossil-fuel power generation. Photovoltaics are the most direct way of collecting solar energy; cost continues to hinder large-scale implementation of photovoltaics, however. Therefore, alternative technologies that will allow the extraction of solar power, while maintaining the overall costs of fabrication, installation, collection, and distribution low, must be explored. This thesis focuses on the fabrication and testing of two types of devices that step up to this challenge: the luminescent solar concentrator (LSC) and all-inorganic nanoparticle solar cells. In these devices I make use of novel materials, semiconducting polymers and inorganic nanoparticles, both of which have lower costs than the crystalline materials used in the fabrication of traditional photovoltaics. Furthermore, the cost of manufacturing LSCs and the nanoparticle solar cells is lower than the manufacturing cost of traditional optics-based concentrators and crystalline solar cells. An LSC is essentially a slab of luminescent material that acts as a planar light pipe. The LSC absorbs incoming photons and channels fluoresced photons toward appropriately located solar cells, which perform the photovoltaic conversion. By covering large areas with relatively inexpensive fluorescing organic dyes or semiconducting polymers, the area of solar cell needed is greatly reduced. Because semiconducting polymers and quantum dots may have small absorption/emission band overlaps, tunable absorption, and longer lifetimes, they are good candidates for LSC fabrication, promising improvement with respect to laser dyes traditionally used to fabricate LSCs. Here the efficiency of LSCs consisting of liquid solutions of semiconducting polymers encased in glass was measured and compared to the

  20. Solar wind and high energy particle effects in the middle atmosphere

    NASA Technical Reports Server (NTRS)

    Lastovicka, Jan

    1989-01-01

    The solar wind variability and high energy particle effects in the neutral middle atmosphere are not much known. These factors are important in the high latitude upper mesosphere, lower thermosphere energy budget. They influence temperature, composition (minor constituents of nitric oxide, ozone), circulation (wind system) and airflow. The vertical and latitudinal structures of such effects, mechanisms of downward penetration of energy and questions of energy abundance are largely to be solved. The most important recent finding seems to be the discovery of the role of highly relativistic electrons in the middle atmosphere at L = 3 - 8 (Baker et al., 1987). The solar wind and high energy particle flux variability appear to form a part of the chain of possible Sun-weather (climate) relationships. The importance of such studies in the nineties is emphasized by their role in big international programs STEP and IGBP - Global Change.