To improve photovoltaic system efficiencies, concentrating spectral dividers are used to separate solar light, and to focus each spectral portion onto photovoltaic cells of matching spectral response. In this investigation, an optical analysis is developed to study the feasibility for use of a Fresnel half-lens as a concentrating spectral divider. To facilitate the analysis, an existing curved-base linear Fresnel lens ray-trace model has been modified and expanded. Solar limb-darkening has been incorporated into the theory by means of a digitized sun model. The lens model allows for variation of lens geometrical characteristics. Transmission losses due to Fresnel reflection and bulk absorption are taken into account. The distribution of the concentrated solar flux in the lens image plane is modeled such that spectral regions may be examined separately. Concentration ratio profiles are used to derive and evaluate a quantity of spectral separation.A computer program has been used to generate data, based on the theoretical model, for example lenses. The spectral separation, transmission and concentration properties for each example lens have been systematically studied with respect to lens geometry. The effects of solar limb-darkening are determined by comparison with the data from a model that assumes a uniform solar source. Results of the study are discussed in detail.Ball State UniversityMuncie, IN 47306

Legislation about the water use in Morocco including the watering of green spaces is about to change. Indeed, the watering of green spaces will have to be made from waste water treatment plant. This report focuses on a golf course located in Agadir which is subject to the new regulation. The option studied through this paper is the desalination of salt water powered by solar energy. This paper focuses specifically on the generation of solar energy. The aim of the report is to compare the levelized cost of water express in €/m3 for three different alternatives: A) water from the drinking water plant; B) water from a reverse osmosis desalination plant driven by electricity from the national grid; C) water from a reverse osmosis desalination plant driven mainly by solar energy and some electricity from the national grid.The paper will first present the boundary conditions for the case study (part I), the technical analysis (part II-A & B) and then the economic analysis (part II-C). Part III presents the results, based on the simulation results from the software PVsyst, for both the technical and economic analysis and part IV explains the technical part in more detail.In the conclusion, the writer of the report would recommend to another in depth economic analysis in few years as the capital cost for the system with the reverse osmosis desalination plant and the photovoltaic plant is at the moment too high. However, regarding at the levelized cost of water, this case study become competitive with the other alternative. Moreover, looking at the environmental issues (water depletion, greenhouse gas emission) one could decide to take action and therefore take some economic risks.

This candidate thesis contains the possibility of expand the Swedish photovoltaic market through photovoltaic cooperatives and a photovoltaic exchange. In the current situation there is a lot of problems with production of electricity from photovoltaic, that’s why we show some possibilities how to avoid these. To understand the problem with photovoltaic produced electricity we first give you a background. We show how to expand the Swedish photovoltaic market by describing how a photovoltaic cooperative and photovoltaic exchange could work in Sweden. It have been confirmed from our market research that the interest of photovoltaic cooperative and exchange is high. To find out how profitable photovoltaic is in Sweden, have three projections been made. These have been done to show how the price per kWh affect depending the size of the power plant. With the help of these results it can be decided which of the projected plants who is the most profitable for given conditions. The photovoltaic power plant that uses the Swedish grand scheme optimal and has the maximum size is the most profitable today. The thesis has been divided into five sections, background, projections, cooperative, photovoltaic exchange and market research. The thesis is limited to Swedish conditions and is based on information from literature, technical reports and interviews.

Due to entropy and Van der Waals¡¦ interaction, carbon nanotubes tend to aggregate degrading their excellent opto-electronic properties and limiting their applications. Chemical derivatizations were applied to the multi-wall carbon nanotube (MWCNT) by esterificating with different lengths of aliphatic pendants (COOC4H9, COOC10H21, and COOC18H37) to decrease the MWCNT aspect ratio to facilitate its dispersion, and to observe its percolation behavior. FTIR analysis revealed the more relevant absorption peaks of C-H at 2917 cm-1, 2846 cm-1 and C=O at 1733 cm-1 from the derivatization. H1-NMR showed that the aliphatic pendant functionalized MWCNT from the signals of OCH2 at £_ = 3.64 ppm, CH2 at £_ = 1.25 ppm, and CH3 at £_ = 0.88 ppm. Raman scattering indicated that esterification caused the ID/IG absorption peak area ratio to decrease. In applications, the electric conductivity was measured on thin-films of MWCNT:Poly-(3-hexylthiophene) (P3HT) as a function of nanotube content. Accompanied with nanotube doping concentration increased, the electric conductivity parallel to film surface (£m||) could range from an undoped value 1.4¡Ñ10-6 S/cm up to 1.2¡Ñ10-2 S/cm. The conductivity percolation threshold concentration decreased as the MWCNT aspect ratio increased due to the average distance between the nanotubes becoming sufficiently small for charges to hopping through P3HT. By incorporating [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM), bulk heterojunction photovoltaic (PV) cells of ITO/PEDOT:PSS/MWCNT:[PC61BM:P3HT]/LiF/Al were fabricated. By varying the ratio of MWCNT to the PC61BM:P3HT (0.8:1) mixtures, the PV cells showed the maximum power conversion efficiency (£bp) close to 4 % with MWCNT-COOC4H9 at a doping concentration of 0.01 wt. %.

To accommodate the crisis of global warming and fossil fuel shortage, the world starts to value continual development and application of all sorts of green energy. Among various renewable sources of energy, solar energy is distinct for its low pollution and renewability. Under the standard of zero harm to the environment and low-carbon emission, solar energy is deemed the new green energy to replace fossil fuel. Consequently, governments around the world, one after the other, invest in research and development, and make solar energy the highest potential energy industry in industrial development by means of governmental policy and subsidy. This research focuses on the development and current status of solar cell industry in Greater China and other developed countries, and sets out to identify the co-opetition of current solar energy development of solar cell industry in Greater China in light of analysis based on Michael Porter diamond model and industry life cycle with the secondary data gathered in relation to solar photovoltaic industry chain. This research discovers that, in recent years, the solar cell industry has phenomenon of hasty expansion, intensive competition, petty profit at the middle range of industry chain, and manufacture switching to regions with low production cost. It is suggested in this research that to combine strength of industrially connected parties, make the economic industry more open, create a win-win situation, and embrace the upcoming of low-carbon economy, a series of actions may be considered. They are (1) strategic alliance of vertical integration and division by profession, (2) enhance industrial technology communication and cooperation to solve problem of technology and manufacturer, (3) elaborate complementary strengths and optimize integration of industry chain, (4) combine with comprehensive policy and actuate the solar photovoltaic market of Greater China.

Photo reflectance¡]PR¡^ and Contactless electroreflectance¡]CER¡^spectra of Zn and O-faces of a c-plane ZnO bulk have been measured at room temperature, respectively. It was found that the phase of PR is the same as that of CER for the Zn-face and they are inverted for the O-face. This indicates a polarization induced field existing in the c- plane ZnO bulk due to nonzero spontaneous polarization. In addition, a mercury lamp was focused on the ZnO sample in the CER measurements to provide a photovoltaic voltage to reduce electric field in the sample. The CER spectrum with Hg lamp is more blue-shifted and its amplitude is smaller than that without Hg lamp. Hence, the type of transitions was classified as excitonic transition. The A, B, and C excitonic transition energies were obtained by fitting experimental spectra.

Fully conjugated heterocyclic aromatic rod-like polymer poly-p-phenylene- benzobisoxazole (PBO) and coil-like poly-(3-hexylthiophene) (P3HT) were applied as opto-electronically active layer. The two polymers mixed with nano-carbon particles, having excellent optical absorption and electric conductivity, of [6,6]-phenyl C61-butyric acid methyl ester (PCBM) or esterified multi-wall carbon nano-tube (MWNT-COOC10H21) as well as a hole transporting layer of PEDOT:PSS. Photovoltaic (PV) cells of indium-tin-oxide (ITO)/PEDOT:PSS/nano-carbon particle:fully conjugated polymer/Al were fabricated for optical and electrical characterizations. Tri-layered structure of ITO/PEDOT:PSS/PBO/PCBM/Al produced a straight current-voltage relation showing no PV effects. Upon changing the active layer into PCBM doped P3HT layer (PCBM:P3HT), it produced good PV effects suggesting that the doped layer had a penetrating network to facilitate the PV effects. When PCBM or MWNT-COOC10H21 was doped into P3HT, the device PV effects were increased significantly with nano-carbon particle concentration. The direct-current electric conductivity parallel to the film surface (£m¡ü)was increased with the nano-carbon particle concentration. By changing the thickness of hole transporting PEDOT:PSS and of opto-electronically active layers, it was found that when the PEDOT:PSS layer was decreased from 90 nm to 32 nm, there was a slight increase of PV cell efficiency. The active layer of PCBM:P3HT with a thickness of 99 nm had the best optical absorption and charge transport leading to an increase of PV cell efficiency.

Photovoltaic (PV) conversion of solar energy appears to be one of the most promising ways of meeting the increasing energy demand. In space, photovoltaic power source is the only safe alternative. Conventional silicon solar cell technologies have seen several improvements and off late GaAs/Ge and multijunction solar cells are developed to improve conversion efficiency. Demand for higher power, smaller size, lesser weight and higher efficiency has necessitated the use of high frequency switching power conditioners, which requires a better understanding of the AC characteristics of the solar cell, especially its capacitance. Solar cell is large p-n junction diode, whose AC parameters (capacitance and resistance) varies nonlinearly with its operating voltage, temperature and depend on the method (frequency or time domain) of measurement.Hence, studies on AC parameters of solar cells is taken up involving development of instrumentation, measurements on various types of solar cells and applications of AC parameters on switching shunt regulators. In the present research work a measurement set-up to measure the solar cell AC parameters using impedance spectroscopy technique is established first with the commercial instruments. Here a small AC voltage (<VT) is applied about the operating voltage (DC bias) and its complex impedance is measured from the resultant current over a wide range of frequencies. Cell capacitance, parallel resistance, series resistance and inductance are estimated from the impedance spectrum, which is plot of the cell impedance in a complex plane. The principle of measurement, details of measurement set-up with calibration, testing and limitations observed when applied to solar cells, are presented. To over come the limitations in the measurement set-up, a dedicated userfriendly instrument called Solar Cell Impedance Analyser is developed to measure solar cell AC parameters. It is a personal computer based virtual instrument, which has a power amplifier, a high-speed data acquisition card and an arbitrary function generator card with a custom built micro controller based hardware with an application specific software developed using graphical programming language. A novel concept of software range extender is introduced, which virtually increases the dynamic range of the power amplifier.

Thesis (M.S.)--Marshall University, 2009. / Title from document title page. Includes abstract. Document formatted into pages: contains vi, 43 p. Includes bibliographical references p. 41-43.

Master's thesis. / Format: PDF. Bibl.