Just one hour of sunlight provides enough solar energy to power the world's homes for an entire year. There are two basic forms of solar energy, heat and light, which are used to produce solar power through different processes:
Solar panels turn the suns solar energy into electricity via photovoltaics. Photovoltaics allow electrons on the surface of a solar panel to be knocked loose by the incoming rays of the sun. These loose electrons create a direct current (DC) of electricity as they follow a pre-determined pathway on the solar panel. The DC electricity is then either stored in batteries, sent to the grid, or converted into alternating current (AC) using an inverter for use at the location.
2009 saw the enactment of a new 30% federal energy tax credit on purchases of solar panels, equipment and solar panel installation. The tax credit has ushered in a new era of residential solar energy in the US. Solar companies are also now developing more efficient photovoltaic cells and solar panels. Indeed, as solar panel prices drop, the amount of power they generate continues to increase. A virtuous cycle of higher output and lower prices is now happening in the solar energy industry.
Thermal solar energy uses the sun's warmth to directly heat air or water. The heated air or water can then be circulated to heat your house. Solar hot water heaters do not use photovoltaics or create electricity - they use simple concepts to collect the heat from the sun. Solar hot water heaters harness the same principle that makes the water in your backyard hose become very hot after sitting in the sun for a few hours. Solar hot water heaters are very effective at collecting the solar energy and storing it in a hot water tank for home solar heating or showering. They are simple, inexpensive devices that can dramatically cut home energy costs by efficiently providing hot water - your homes single largest energy expense. Thermal solar energy is used widely around the world to provide free hot water for everyday uses.
Solar hot air collectors are another simple device which is placed outside the home. They collect solar energy heat and circulate it throughout the house with a small fan. There are commercial solar hot air products as well as many ingenious Do-It-Yourself or DIY solar versions.
Utility scale solar thermal projects harnessing solar energy are growing in size and scope. The first solar thermal plant, Solar One, was built in the early 1980's located in the Mojave Desert near Barstow, CA. Solar One, and subsequent utility scale solar energy plants have used a simple method to concentrate the sun's rays on a tower using a giant array of mirrors or heliostats. The mirrors track the sun and focus on the tower, causing the tower to reach very high temperatures. Inside the tower is liquid molten salt which carries heat away from the tower to a turbine. The turbine is driven by steam created when the molten salt boils a reservoir of water. Electricity is generated by the turbine spinning - the same way we get electricity from hydroelectric power plants, nuclear power plants, wind power or geothermal.
Additional information on the sun and solar energy from Stanford University.
Tags: Solar Energy, Solar Enrgy, Solar Panels, Solar Power