What is Solar Energy?

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What is solar power?  


Electromagnetic energy transmitted from the sun (solar radiation) is referred to as solar energy. Power in general is energy per unit time. Only a very small portion of total solar power reaches the earth. Numerically, this amount is characterized by solar constant- the average amount of solar radiation that reaches the earth’s upper atmosphere on a surface perpendicular to the sun’s rays. Solar constant is approximately 1366-1367 watts per square meter or 433 Btu/hr per square foot (see power unit conversion calculator).

How to convert solar power to electricity?
Solar power can be converted to electricity in photovoltaic (PV) cells, which are also called solar cells. A solar cell is made of specially treated silicon wafer with p-n junction. When photon of light strikes the top of the wafer, it can penetrate through the p-n junctions and free an electron, which can cross the junction into the n-type region. Free electrons are then held in the n-region, being unable to return into the p-region. This creates a voltage of about 0.5-0.6 volts under open circuit (no-load) condition. When connected to a load a typical commercial PV cell can produce about from 0.5 to 2.0 watt of electrical power.  In conventional small solar electric systems 32 to 40 cells are connected in series into modules (or panels). Such panels can produce open circuit voltage of up to 20 V and about 16-17 V at peak power.  These voltages are suitable for charging 12V batteries via regulators. There are also modules, which have nominal voltages 24V or 48V.
Multiple modules can be wired together in an array to produce higher voltages, currents and power levels. Parallel connection of the modules increase the maximum available load current while series connection increases the output voltage.

  
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Creative Energies A Renewable Energy Company:  Wyoming’s full-service renewable energy company featuring solar, wind, and water solutions for business and residential customers.
Google says, ‘Here comes the sun’:  Google Inc. is converting its renowned headquarters to run partly on solar power, hoping to set an example for corporate America.  The undertaking will be the largest solar project by a U.S. company. Google believes the sun eventually can deliver as much as 30 percent of the power at its 1-million-square-foot campus in Mountain View — a suburb about 35 miles south of San Francisco….
NEW    Bright Green Energy: Source for Solar and Photovoltaic Panels, Wind Turbines, Rutland wind chargers, Aerogen wind generators, Batteries, Inverters and other solar powered products. 
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The Solar Guide:  new link — website that makes solar energy accessible and understandable to you. The Solar Guide aims to give consumers the practical information they want, about buying solar and renewable energy systems.
University College Dublin:  Energy Research Group Carry out research on low-energy and passive solar building design and host the site for the European Solar Industry Federation ESIF. Many excellent well-illustrated reports on EU funded research projects are available in pdf format but you’ll need a fast link to deal with the monster file sizes!
US Solar Signs:  Manufacturer of solar powered signs for real estate, business and commercial applications. Patented design. No electrical wiring or maintenance is required. Battery-operated signs are recharged daily with solar energy. Signs can be customized to meet your application.
Next Energy:  NextEnergy provides SunPower Intelegant systems for homes in Northern California. For over 30 years, we’ve been turning around our customers PGE bills and helping to make Northern California a cleaner, safer place to live.

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