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quote:Originally posted by realmswalkerCan you guys answer a few questiosn i have? Or provide useful links or information?I look but cant find any that are particuarly useful...Im looking for things like how mcuh energy per square foot falls on the earth from the sun. What is the current highest efficiency of solar panels(how much of the sunlight that hits them is converted to energy). What is the cost per foot of solar panel? How do solar panels work?I know solar panels need to be directly facing the sun for full efficiency, but i had an idea. Would it be possible to use prisms to bend light so that it didnt matter as much if the solar panel was not directly facing the sun?How does the intensity of the light on the solar panel affect it?Does color(or wavelength) matter at all?Why is silicon used in solar cells?Why not carbon or germanium?On a related topic, is it possible to, without using energy, convert a wavelength of light to a different one? Alot of questions i know, but im just curious.
quote:Code: [Select]Model Maximum Maximum Maximum Short Open Wt frame Price Power Operating Operating Circuit Circuit L x W x D Current Voltage Current Pm(W) Ipm (A) Vpm (V) Isc(A) Voc(V) (mm) SP9WC 9 0.55 17 0.57 21.6 1.5kg 346x286x25 £59SP15WC 15 0.83 17 0.88 21.6 2.2kg 436x286x25 £85 416x306x25SP22WC 22 1.25 17 1.5 20.2 2.8kg 616x286x25 £129 426x416x25SP60WC 60 3.31 17 4.0 20.7 6.2kg 976x446x38 £259
Model Maximum Maximum Maximum Short Open Wt frame Price Power Operating Operating Circuit Circuit L x W x D Current Voltage Current Pm(W) Ipm (A) Vpm (V) Isc(A) Voc(V) (mm) SP9WC 9 0.55 17 0.57 21.6 1.5kg 346x286x25 £59SP15WC 15 0.83 17 0.88 21.6 2.2kg 436x286x25 £85 416x306x25SP22WC 22 1.25 17 1.5 20.2 2.8kg 616x286x25 £129 426x416x25SP60WC 60 3.31 17 4.0 20.7 6.2kg 976x446x38 £259
quote:Solar photovoltaic panels contain arrays of solar cells that convert light into electricity. Solar cells, or PV cells, rely on the photovoltaic effect, which describes how certain materials can convert sunlight into electricity to absorb the energy of the sun and cause current to flow between two oppositely charged layers. Individual solar cells provide a relatively small amount of power, but electrical output is significant when connected together as an array making up a panel.On a bright day, the sun delivers about 1 kW/m² to the Earth's surface. Typical solar panels have an average efficiency of 12%, with the best commercially available panels at 20%, and recent prototype panels at around 30%. This would result in 200 W/m². However, not all days have bright sunlight, and therefore not enough solar energy can be captured.At middle northern latitudes, taking the daylight cycle and weather conditions into account, on average 100 W/m² in winter and 250 W/m² in summer reach the ground. With a conversion efficiency of about 20%, one can expect to obtain between 20 and 50 watts per square meter of solar cell. The Sahara desert, with less cloud cover and better solar angle, one can obtain closer to 83 W/m². The area of unpopulated Sahara desert is over 9 million km², which if covered with solar panels would provide 750 terawatts total. The Earth's total energy is around 14 TW at any given moment (including oil, gas, coal, nuclear, and hydroelectric power
quote:Solar photovoltaic panelsCrystalline silicon and gallium arsenide are typical choices of materials for solar cells. Gallium arsenide crystals are grown especially for photovoltaic use, while silicon crystals are available in less-expensive standard ingots. These ingots are produced mainly for consumption in the microelectronics industry. Polycrystalline silicon has lower conversion efficiency but also lower cost.Crystalline ingots are sliced into wafer-thin disks, polished to remove slicing damage, dopants are introduced into the wafers, and metallic conductors are deposited onto each surface: a thin grid on the sun-facing side and usually a flat sheet on the other. Solar panels are constructed of these cells cut into appropriate shapes, protected from radiation and handling damage on the front surface by bonding on a cover glass, and cemented onto a substrate (either a rigid panel or a flexible blanket). Electrical connections are made in series or in parallel to determine total output voltage. The cement and the substrate must be thermally conductive, because the cells heat up from absorbing infrared energy that is not converted to electricity. Since cell heating reduces the operating efficiency it is desirable to minimize the heating. The resulting assemblies are called solar panels or solar arrays.n