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Solar panel refers to a panel designed to absorb the sun's rays as a source of energy for generating electricity or heating. A photovoltaic (in short PV) module is a packaged, connected assembly of typically 6×10 solar cells. Solar Photovoltaic panels constitute the solar array of a photovoltaic system that generates and supplies solar electricity in commercial and residential applications. Each module is rated by its DC output power under standard test conditions, and typically ranges from 100 to 365 watts. The efficiency of a module determines the area of a module given the same rated output an 8% efficient 230 watt module will have twice the area of a 16% efficient 230 watt module. There are a few solar panels available that are exceeding 19% efficiency. A single solar module can produce only a limited amount of power; most installations contain multiple modules. A photovoltaic system typically includes a panel or an array of solar modules, a solar inverter, and sometimes a battery and/or solar tracker and interconnection wiring. The price of solar power, together with batteries for storage, has continued to fall so that in many countries it is cheaper than ordinary fossil fuel electricity from the grid (there is "grid parity"). For example in 2015, an average home in Europe or the US could use around 3,000 kilowatt-hour (kWh) in electricity each year.〔See (ofgem.gov.uk ) quoting statistics for 2011, not including gas.〕 Twelve 280 watt solar PV modules (each generating 250 kWh annually) would generate at least 3,000 kWh each year, even in a cloudy country like the UK. An example market price would be about £8,000 in the UK, $12,000 in the US, or €10,000 in the Eurozone in 2015, which is certain to continually fall,〔Examples come from an assumption of £5500 for the twelve panels and £2,500 for batteries that can store 10 kWh. See (quoting LG solar panel prices ) and (midsummenergy.co.uk ) explaining relation between solar panel Wattage and annual output.〕 allowing permanent energy independence for each household. Most governments have feed-in tariff systems that allow homeowner to sell surplus energy back into the grid, and make a future profit on their investment. == Theory and construction == Solar modules use light energy (photons) from the sun to generate electricity through the photovoltaic effect. The majority of modules use wafer-based crystalline silicon cells or thin-film cells based on cadmium telluride or silicon. The structural (load carrying) member of a module can either be the top layer or the back layer. Cells must also be protected from mechanical damage and moisture. Most solar modules are rigid, but semi-flexible ones are available, based on thin-film cells. These early solar modules were first used in space in 1958. Electrical connections are made in series to achieve a desired output voltage and/or in parallel to provide a desired current capability. The conducting wires that take the current off the modules may contain silver, copper or other non-magnetic conductive transition metals. The cells must be connected electrically to one another and to the rest of the system. Externally, popular terrestrial usage photovoltaic modules use MC3 (older) or MC4 connectors to facilitate easy weatherproof connections to the rest of the system. Bypass diodes may be incorporated or used externally, in case of partial module shading, to maximize the output of module sections still illuminated. Some recent solar module designs include concentrators in which light is focused by lenses or mirrors onto an array of smaller cells. This enables the use of cells with a high cost per unit area (such as gallium arsenide) in a cost-effective way. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Solar panel」の詳細全文を読む スポンサード リンク
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