Solar power may finally be getting the respect it deserves. The sun is the world’s greatest source of energy. Every hour enough sunlight reaches the earth to meet the world’s energy demands for the entire year. Sadly this almost limitless supply of clean energy has long remained all but untouched.
Solar power has been effective for a while at powering small electronic devices. Turning the sun’s power into electricity, however, is a trickier situation. As demand worldwide for electricity increases, so does the burning of fossil fuels to meet that demand, and with it comes all the hazards of global warming and all the undesirable climate conditions that may result.
Now is the time to take a serious look at solar power as an energy source, one that could potentially revolutionize power production. The solar energy sector has been revitalized as the worldwide demand for clean energy grows. New technologies, giant solar plants and the levels of interest from scientists and entrepreneurs are all very encouraging.
‘Thermal trough’ solar power plant
The worlds largest solar power plant is built on a chunk of land larger than New York’s Central Park. In the Mojave Desert, about three hours from Los Angeles, the Kramer Junction Plant has been steadily providing about 350 megawatts of peak to the LA grid, enough to power more than 150,000 homes.
Using improved technology, a second major “thermal trough” plant of this type, called Nevada Solar One, is expected to open in spring 2007 outside Las Vegas. It will provide 64 megawatts to the grid, enough to power 32,000 homes. With thermal trough technology, rows of trough-shaped mirrors collect and concentrate the sun’s heat and ultraviolet radiation to cook tubes of synthetic oil up to 750 degrees Fahrenheit. The hot oil is then piped to a generating station where it flash-boils water, making steam that drives a conventional turbine.
Mirrored dish solar radiation electricty generator
These giant mirrored dishes collect solar radiation and use it to generate electricity in a fairly novel way. Resembling large satellite dishes, each dish bears its own Stirling engine. This works by using heat to expand a gas that drives pistons to produce electricity. Early versions are in use at Sandia National Laboratories in New Mexico.
Two large California utilities have signed contracts to buy 800 to 1,750 megawatts of electricity from 32,000 to 70,000 of thee Stirling dishes, to be located in southern California deserts. Construction was slated to begin in late 2008.
Solar films aren’t as efficient as silicon panels at converting sunlight into electricity. The materials however, which are made by United Solar Ovonic, are so flexible that they can be made into aesthetically pleasing shingles.
Take the roof of New York’s Stillwell Avenue subway station. Flexible thin-film modules form the roof. It is one of the world’s largest thin film building installations. Sixty thousand square feet of thin film panels generate 210 kilowatts of power, enough to meet two-thirds of the station’s energy requirements.
Highly concentrated sunlight
Produced by Amonix Corp., these giant panels use optical lenses to concentrate an intense amount of sunlight onto solar cells. Since each lens channels “250 suns” worth of light onto each square in the panel, the same amount of electricity can be produced using a fraction of the silicon material typically required. Each array generates 25 kilowatts of electricity, enough to power about a dozen homes.
Just think if you could generate electricity with the paint on your business or house. Nano-solar paint, currently under development lets you do just that. It works like a silicon solar panel but at a fraction of the cost. At its core is a dark, sunlight-absorbing paint. This is coated onto the surface of aluminized mylar, which conducts electricity. Covering the paint is a protective clear layer of indium tin oxide that also conducts electricity. When sunlight strikes the paint, electrons are knocked loose, reaching wires that channel electricity to the home.
The momentum behind solar power and solar technology is already there – and it can’t be stopped. How long before our homes are at least partially powered by the sun? Exciting isn’t it!
“How Solar Cells Work”, How Stuff Works