Solar thermal power plant to demonstrate key technologies

More modular, scalable solar thermal power technology will result from an NRG Energy agreement with eSolar to develop solar power plants with a total generation capacity of up to 500 MW at sites in California and the Southwest. The units could power more than 400,000 homes with solar electricity. At the first plant, ABB provides the control system, automation equipment, and engineering services.
By Control Engineering Staff May 22, 2009

NRG Energy Inc. has signed an agreement with eSolar , a provider of modular, scalable solar thermal power technology, to develop solar power plants with a total generation capacity of up to 500 MW at sites in California and the Southwest. When at peak capacity, these units could power more than 400,000 homes with 100% clean solar electricity.

Reflectors follow the sun across the sky to concentrate its energy on the receiving tower.
eSolar is currently completing its first commercial CSP (concentrated solar power) demonstration plant in southern CA. The Sierra project is a solar thermal power plant design consisting of two solar light receivers, with each receiver being supported by a field of 12,000 heliostat reflectors. The reflected light from each heliostat is captured at the receiver and used to convert water to steam.

The facility will be the first fully functioning solar thermal power tower plant built in the U.S., the companies say. In building this first plant, eSolar is obtaining valuable design, construction and operational insights to provide NRG the foundation for the implementation of commercial scale facilities. NRG’s 48 plants provide approximately 24,000 megawatts of generation capacity– enough to power nearly 20 million homes.

Each of the 12,000 reflectors is individually aimed, but they move as a group.
“eSolar’s breakthrough modular power plants use more software and less steel to allow solar energy to be competitive with fossil fuels for the first time ever,” says Bill Gross, CEO of eSolar. “NRG Energy’s extensive project skills and focus on advancing a diverse portfolio of energy generation technology will help accelerate the deployment of eSolar’s CSP technology in locations across the US.”

ABB is providing equipment and engineering services for the new plant, including its System 800xA for power plant control. eSolar says it selected ABB because of its power generation balance of plant expertise, and because ABB is an established international power and automation solutions provider.

“We quickly realized that ABB possessed the elements to play a critical role in the development of our Sierra project,” says Gross. “Coupling ABB’s technology expertise with eSolar’s CSP innovation, our first demonstration site in Sierra will be a model for industry success and also demonstrate the viability of this technology moving forward.”


“The solar power niche within the renewable power industry is in its infancy and will soon be in exponential growth mode,” said Kevin McAllister, head of ABB’s power generation division. “ABB is contracted to work with eSolar to deploy a solution that makes a dramatic reduction in the cost of solar thermal technology by tackling the key obstacles that have characterized large solar installations in the past: price, scalability, speed of deployment and grid impact.”

Also read: Greening coal-fired power with solar .

– Edited by Peter Welander, process industries editor

Control Engineering News Desk, www.controleng.com

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