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[en] This proceedings is the compilation of all papers presented at the 11th PV Performance and Reliability Workshop held at the Doubletree Hotel in Cocoa Beach, Florida, on November 3-5, 1998. The workshop was hosted by the Florida Solar Energy Center. This year's workshop included presentations from 29 speakers and had 110 attendees
[en] The efficiency of materials developed for solar energy and technological applications depends on the interplay between molecular architecture and light-induced electronic energy redistribution. The spatial localization of electronic excitations is very sensitive to molecular distortions. Vibrational nuclear motions can couple to electronic dynamics driving changes in localization. The electronic energy transfer among multiple chromophores arises from several distinct mechanisms that can give rise to experimentally measured signals. Atomistic simulations of coupled electron-vibrational dynamics can help uncover the nuclear motions directing energy flow. Through careful analysis of excited state wave function evolution and a useful fragmenting of multichromophore systems, through-bond transport and exciton hopping (through-space) mechanisms can be distinguished. Such insights are crucial in the interpretation of fluorescence anisotropy measurements and can aid materials design. Finally, this Perspective highlights the interconnected vibrational and electronic motions at the foundation of nonadiabatic dynamics where nuclear motions, including torsional rotations and bond vibrations, drive electronic transitions.
[en] We report on the design of two hybrid lighting luminaires that blend light from a fiber optic end-emitted solar source with electric T8 fluorescent lamps. Both designs involve the retrofit of a commercially-available recessed fluorescent luminaire with minimal reductions in the original luminaire's optical efficiency. Two methods for high-angle dispersion of fiber optic end-emitted solar light are described and the resulting spatial intensity distributions, simulated using ZEMAX, are compared with standard cylindrical fluorescent tubes. Differences in spatial intensity distribution are qualitatively characterized and potential design improvements discussed
[en] Geothermal energy is a varied discipline that challenges many separate scientific domains. Geological constraints limit access to thermal reservoirs, strength of materials limits the ability to drill into hot strata, mechanical constraints limit the extraction of energy from fluid at a small temperature difference and environmental concerns restrict the fluids production because of the gases released. These problems are all being investigated, and progress is constant and hopeful. The uses of geothermal energy are varied. They range from direct use in space heating to using geothermal steam to power turbines. Ground source heat pumps are a popular alternative to conventional air conditioning systems, and water source heat pumps are another proven alternative. Many other applications are on the horizon, including absorption chillers able to operate at a small temperature difference, higher tonnage ground source equipment and new approaches to hot dry rock power production
[en] The development of microsatellites requires the development of engines to modify their orbit. It is natural to use solar energy to drive such engines. For an unlimited energy source the optimal thruster must use a minimal amount of expendable material to minimize launch costs. This requires the ejected material to have the maximal velocity and, hence, the ejected atoms must be as light as possible and be ejected by as high an energy density source as possible. Such a propulsion can be induced by pulses from an ultra-short laser. The ultra-short laser provides the high-energy concentration and high-ejected velocity. We suggest a microthruster system comprised of an inflatable solar concentrator, a solar panel, and a diode-pumped fiber laser. We will describe the system design and give weight estimates.
[en] The difficulties arising in the calculation of the nuclear curvature energy are analyzed in detail, especially with reference to relativistic models. It is underlined that the implicit dependence on curvature of the quantal wave functions is directly accessible only in a semiclassical framework. It is shown that also in the relativistic models quantal and semiclassical calculations of the curvature energy are in good agreement. copyright 1996 The American Physical Society
[en] In today's electricity generation system, different resources make different contributions to the electricity grid. This fact sheet illustrates the roles of distributed and centralized renewable energy technologies, particularly solar power, and how they will contribute to the future electricity system. The advantages of a diversified mix of power generation systems are highlighted.
[en] Lessons learned about how well past federal approaches to providing information and incentives worked to encourage consumers to purchase solar systems will be presented. Some background information on federal programs is provided as context to the lessons learned discussion
[en] This market and technical assessment illustrates that the Southwestern power market can support the commercialization needs of Solar Power Tower (SPT) technology over the next 10 to 15 years. Realizing full commercial development during this time is contingent on successful completion of Solar Two and development of an initial follow-on plant around 2000. After 2002, the power market will become increasingly robust, presenting new opportunities for SPT development. The important conclusion of this analysis is that SPT projects can reach a cost level that puts them at or below the expected norm of costs for their main competitor, combined cycle natural gas. This means that with the same competitive focus on minimizing costs and finding opportunities to be more competitive that characterize combined cycle project developers, SPT has a realistic chance of competing and winning market share. The ability of SPT technology to compete in this market will be greatly affected by the rate of cost-reductions and technological improvements, but perhaps as importantly, by the environmental and regulatory climate which will unfold over the next decade and the availability of low cost financing options