Solar Energy Guide

Solar energy, radiant light and heat from the Sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available renewable energy on Earth. Only a minuscule fraction of the available solar energy is used.

Solar powered electrical generation relies on heat engines and photovoltaics. Solar energy's uses are limited only by human ingenuity. A partial list of solar applications includes space heating and cooling through solar architecture, potable water via distillation and disinfection, daylighting, solar hot water, solar cooking, and high temperature process heat for industrial purposes.

Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and designing spaces that naturally circulate air.

Solar photovoltaics (PVs) are arrays of cells containing a material that converts solar radiation into direct current electricity. Materials presently used for photovoltaics include amorphous silicon, polycrystalline silicon, microcrystalline silicon, cadmium telluride, and copper indium selenide/sulfide. Due to the growing demand for renewable energy sources, the manufacture of solar cells and photovoltaic arrays has advanced dramatically in recent years.German PV marketBP Solar to Expand Its Solar Cell Plants in Spain and IndiaLarge-Scale, Cheap Solar Electricity

Photovoltaic production has been doubling every 2 years, increasing by an average of 48 percent each year since 2002, making it the world's fastest-growing energy technology.[http://www.socialfunds.com/news/article.cgi/2639.html Solar Expected to Maintain its Status as the World's Fastest-Growing Energy Technology] At the end of 2008, the cumulative global PV installations reached 15,200 megawatts.REN21 (2009). Renewables Global Status Report: 2009 Update p. 12.Global Solar Photovoltaic Market Analysis and Forecasts to 2020 Roughly 90% of this generating capacity consists of grid-tied electrical systems. Such installations may be ground-mounted (and sometimes integrated with farming and grazing)

[http://www.huliq.com/18313/ge-invests-delivers-one-of-worlds-largest-solar-power-plants GE Invests, Delivers One of World's Largest Solar Power Plants]

or built into the roof or walls of a building, known as Building Integrated Photovoltaics or BIPV for short.Building integrated photovoltaics Solar PV power stations today have capacities ranging from 10-60 MW although proposed solar PV power stations will have a capacity of 150 MW or more.Mark Z. Jacobson (2009). Review of Solutions to Global Warming, Air Pollution, and Energy Security p. 4.

Driven by advances in technology and increases in manufacturing scale and sophistication, the cost of photovoltaics has declined steadily since the first solar cells were manufactured.Richard M. Swanson. Photovoltaics Power Up, Science, Vol. 324, 15 May 2009, p. 891. Net metering and financial incentives, such as preferential feed-in tariffs for solar-generated electricity, have supported solar PV installations in many countries.