Minneapolis-based Xcel Energy Inc. has put into operation an experimental hybrid power plant, dubbed Cameo, which uses both coal and solar power to generate electricity. It will considerably reduce greenhouse gas emissions.
Designed by Abengoa Solar, a Spanish company that has its U.S. headquarters in Lakewood, the $4.5 million plant which is slated for shutdown by the end of 2010, has been converted to test the use of parabolic-trough mirrors.
The mirrors focus the Sun’s heat on tubes filled with mineral oil, which is then heated to about 575 degrees Fahrenheit. The heat is used to raise the water’s temperature to about 360 degrees Celsius.
According to Xcel, the project includes eight rows of mirrors (500 feet long), covering 6.4 acres. The steam produced by the process is used to power a turbine to produce electricity. Using solar heated water, they cut the amount of coal needed to produce steam.
“If this project produces the successful results we expect, this type of solar thermal integration will help move the use of solar energy one step closer to being a potential technology for improving the environmental performance of coal-fired power plants for Xcel Energy and for utilities around the country,” said Kent Larson, Xcel’s vice president and chief energy supply officer.
The power plan’s efficiency will be increased by up to 5 percent, due to the combination between solar power and coal, reducing also the use of coal by 900 tons per year and the plan’s carbon dioxide emissions by 2,000 tons per year.