On May 7 last week, the U.S. Department of Energy Secretary Steven Chu announced that up to $62 million would go to selected projects to develop, research, and demonstrate a concentrating solar power (CPS) system that would produce low-cost electrical power. The U.S. Department of Energy has multiple goals and motives for dispersing the money. It is hoped that improvements in system components and thermal energy storage will be made. Market as well as technological improvements are seen as the success of these projects that will mean more energy independence for the future.
This is a breath of fresh air to people across the United States in favor of developing low-cost energy alternatives. Solar power is tricky because even though solar rays are abundant and essentially free, the technology to harness and transform solar energy into electrical energy is expensive and usually not economical in frequently cloudy areas. The CPS technology specializes in capturing the sun's energy as heat that then drives turbines or engines thus producing electrical energy.
The key that makes CPS practical in a variety of environments is its unique ability to provide low-cost energy storage. Thus, power can be drawn upon even when the sun is not shinning. However, with improvements in system and component design some plants may even produce on cloudy days. The goal is to extend operation for 18 hours per day. At this rate CPS plants would have the production capacity to stand toe-to-toe with traditional fossil (coal-burning) plants and perhaps even displace them entirely.
Not only will these projects help produce for our nation’s large energy demand in the future, but they will also help to furnish a great many jobs:
“Developing low-cost, renewable energy generation is crucial to meeting our nation’s increasing demands for electricity. By investing in the development of low-cost solar technologies we can create new jobs and pave the way toward a clean-energy future,” said Secretary Chu in a U.S. Dept. of Energy Press Release, May 7, 2010.
The following are the projects awarded to evaluate the feasibility of a complete CPS system and to support development of prototypes for field testing. Abengoa Solar Inc. was awarded up to $10.6 million to develop their power tower technology that uses a 360 degree receiver at the top of a tower to collect the suns rays and reflect them back to the ground to heat a salt-fluid to make steam and drive a turbine. This CPS will use energy storage technology that will deliver needed energy on dark or cloudy days. This plant is currently ahead of the game as they already have the tower in place and will probably reach commercial potential ahead of demand.
Another CPS in funding is produced by eSolar Inc. out of Pasadena, Calif. ESolar will employ multiple towers using new CPS technology that will still heat a salt-fluid. This salt-fluid will then be transported using a special system to a generator that will produce steam from the solution and then spin a turbine. ESolar will receive up to $10.8 million for the project and will also include thermal power storage for those cloudy days.
The final awarded CPS project is by Pratt &Whitney Rocketdyne out of Canoga Park, Calif. They will build on and advance the current power tower design and explore new materials for the central receiver as well as developing and using a novel thermal storage system. The project will also try to develop a more efficient power cycle hat will help produce more electricity. They will be receiving up to $10.2 million. The remaining funding awards will awarded to nearly a dozen organizations and companies like University of South Florida and General Atomics of San Diego, Calif., to research and develop components for the CPS system.