All About Solar | Green Energy News

January 15, 2006 – Vol.10 No.43

All ABOUT SOLAR.

This week’s news...

Most of the interest in solar energy seems focused on photovoltaics - the direct conversion of the Sun’s rays to electricity. Yet steadfastly and reliably chugging along behind the scenes is solar thermal energy - the hot Sun making hot water, steam, and power too.

Solar thermal domestic hot water systems are common throughout the world and solar thermal power generating plants have been operating for more than a decade.

To the end user the simplicity of solar photovoltaics gives the technology great appeal: Buy a panel, plug it in, convert the power to alternating current (if you need it) and you’re up and running. It’s the manufacturing process and the materials used that make solar cells complex and thus expensive.

Conversely the systems used to convert hot sunlight to useable thermal energy are more complex - there are many parts - but manufacturing the systems uses common processes that have been used for a century or more. Common processes are generally inexpensive.

The power purchase contracts for a possible 1750 megawatts awarded to Stirling Energy Systems has put solar thermal power generation into the limelight. Now there’s to be another large solar thermal power plant planned for the U.S. Southwest.

Solel Solar Systems of Israel has been awarded a $10 million contract with Solargenix Energy of North Carolina to build a solar thermal power generation plant that will provide enough power for 150,000 customers in Nevada.

Nevada Solar One, a 64-megawatt facility, will be located in Boulder City. As the largest solar power plant built worldwide in the last 14 years it will make the Nevada a major producer of solar generated electricity.

The plant will use Solel’s solar trough system which uses long parabolic mirrors to concentrate sunlight on a fluid filled pipe inside a vacuum tube. The fluid is heated as high as 752 degrees F (400 degrees C) . Heat is then exchanged to water to produce steam to spin a turbine and thus generate electricity. The systems can also provide hot water for heating, cooling, or industrial purposes

The company’s technology is already employed in nine solar power plants in California which together produce 350 megawatts of electricity. Those plants, known as Solar Electric Generating Stations (SEGS), also have natural gas fired boilers to provide back-up or nighttime power. Biofueled boilers are also possible. (Waste thermal energy could heat biomass digesters to generate methane fuel burned in those boilers.)

Solel can build large power plants, or can provide solar thermal power plants small enough to power one building (and its hot water needs, too.) The company also makes traditional solar domestic hot water systems.

Solargenix is the former Duke Solar.

Visit Solel at http://www.solel.com/ Solargenix Energy at http://www.solargenix.com and Stirling Energy Systems at http://www.stirlingenergy.com/ .