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Solar Cell(Photovoltaics), : 20075418 Ju Dae-Hyun,Nonrenewable Enargy, (Renewable Energy), (Nonrenewable Energy),Renewable,What is a Solar Cell?,A structure that converts solar energy directly to DC electric energy. It supplies a voltage and a current to a resistive load (light, battery, motor). Power = Current x Voltage=Current2 x R= Voltage2/R It is like a battery because it supplies DC power. It is not like a battery because the voltage supplied by the cell changes with changes in the resistance of the load.,Basic Physics of Solar Cells,Silicon (Si) is from group 4 of the period table. When many Si atoms are in close proximity, the energy states form bands of forbidden energy states. One of these bands is called the band gap(Eg) and the absorption of light in Si is a strong function of Eg.,The Sun daily provides about 10 000 times more energy to the Earth than we consume Photovoltaic technology directly converts solar energy into electricity No moving parts no noise no emissions long lifetime Large industrial potential - cost reductions needed Feedstock for PV industry is silicon - the second most abundant element in the crust of the Earth,The Sun as Energy Source,Solar Energy status,Market is exploding The solar industry is very profitable Lack of highly purified silicon (polysilicon) Cost of solar electricity is too high, R metal, glass, plastic,They are simpler to design and fabricate. They do not require special optics, specially designed cells, or mounting structures that must track the sun precisely. plus, flat-plate collectors can use all the sunlight,Flat-Plate Systems,Uses for Solar Energy,Solar Home Systems,Space,Water Pumping,Telecom,Main Application Areas Off-grid,Residential Home Systems (2-8 kW),PV Power Plants ( 100 kW),Commercial Building Systems (50 kW),Main Application Areas Grid Connected,Solar energy will become the most important and cost-efficient energy source in the future. The present lack of silicon feedstock is promoting a rapid development of next generation technology. Immediate actions are taken to cut thinner wafers and increase cell efficiencies for crystalline silicon. New thin film technologies are being developed Stronger influence from semiconductor industry will accelerate the development of better technologies Nanosilicon and other third generation technologies may offer a long-term solution for the future solar energy technology.,Conclusions,
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