No description available.

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

No description available.

No description available.

No description available.

No description available.

Concentrator solar cells operate under the conditions of non-uniform illumination and varying spectral content of incident sunlight. To predict the performance of such cells, an analytical model must account for varying carrier photogeneration rates within the cell. Further, the back surface junction fabricated to reduce recombination at the back contact must be included in the analysis.Most models of n+-p-p+ cells assume uniform generation rates within individual layers. In this study, a one-dimensional n+-p-p+ concentrator solar cell is modeled for all levels of illumination of incident sunlight. The photocarrier generation rate is considered as non-uniform in each layer of the cell. An absorption model is incorporated to permit the application for various spectral mixes of incident sunlight. The model also includes the effects of finite surface recombination velocities at the surfaces. Carrier transport equations for the three layers of the cell are developed and solved for the excess carrier concentrations under the assumptions of the model. Junction current density-voltage relationships for the two junctions of the cell are derived. The use of the current density equations in the evaluation of cell performance is discussed. / Department of Physics and Astronomy

Since the 1980s, approximately 10 MWp photovoltaic (PV) power has been installed in off-grid areas in Indonesia for powering lighting, water pumping, communications, health clinics, etc. However, PV energy systems (PVES) have yet to prove their sustainability and remain inaccessible to many remote Indonesian communities. The objective of this interdisciplinary thesis is to draw on social and engineering perspectives to address sustainability issues related to off-grid PVES delivery in Indonesia. By employing the Brundtland definition of sustainability, off-grid PVES delivery is analysed with respect to its institutional, financial, technical, social and ecological sustainability. In parallel, the thesis also investigates PVES Accessibility, Availability and Acceptability (3A), referring to the three energy goals proposed by the World Energy Council. The concepts of Sustainable Development, Social Capital, and Diffusion of Innovation are employed to examine the potential for off-grid PVES to contribute to improving the sustainability of remote Indonesian communities. The I3A (Implementation, 3A) Sustainable PVES Delivery framework is proposed to investigate PVES sustainability and the extent to which local communities can continue to socially innovate to meet their evolving needs beyond initial project completion. Sound project management (PM) is essential as off-grid PVES projects can only access limited resources (time, funds, and scope) and project failure can undermine a community???s capacity to innovate. The research methodologies include literature research, qualitative field research in villages where PVES has been installed and interviews with a wide range of PVES stakeholders in Indonesia. The I3A framework is tested against three off-grid PVES case studies from Lampung, West Java and NTT Provinces and is also proposed as a design tool. A key conclusion is that, to be sustainable and equitable, off-grid PVES projects should be implemented in an institutional framework that provides sound project management and addresses PVES accessibility (financial, institutional and technological), availability (technical quality and continuity) and acceptability (social and ecological). The overall objectives are to acknowledge the interests of all stakeholders, maximise equity, assure PVES continuity, and institutionalize PVES by utilizing and enhancing preexisting community resources to leave the community with the capacity to socially innovate. While this might be regarded as idealistic, enhanced local autonomy and capability will be essential in the context of the energy security and climate change challenges that humanity now faces.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: photovoltaic; solar satellite; optimize; dc-dc. Includes bibliographical references (leaves 51).

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1992. / Vita. Abstract. Includes bibliographical references (leaves 87-90). Also available via the Internet.