Lindsay Morris, Associate Editor, Power Engineering
September 20, 2012 | 16 Comments
The Ivanpah Solar Electric Generating System, expected to be the largest solar thermal project in the world when it comes online next year, reached the halfway mark of construction in August. Last week at Solar Power International in Orlando, Fla., I sat down with Jim Ivany, president of Bechtel's Renewable Power business, to discuss the company's work on the project and the future of Concentrating Solar Power (CSP) in the U.S.
This one-of-a-kind, $2.2 billion project, situated in the Mojave Desert northwest of Needles, Calif., will nearly double the amount of commercial solar thermal electricity produced in the U.S. when it is completed. Ivanpah is composed of three separate plants using BrightSource Energy’s Luz Power Tower technology that will have a combined capacity of 392 MW. The power will be sold to Pacific Gas & Electric and Southern California Edison.
Bechtel is providing engineering, procurement, construction and startup services for Ivanpah. The plant employs a steam turbine much like a fossil fuel or nuclear plant. But instead of using a fuel to create steam, BrightSource’s system uses the sun’s energy. The system is composed of more than 300,000 software-controlled mirrors, called heliostats, which reflect the sun’s energy to a boiler atop a tower to produce a high temperate and high-pressure steam.
“The scale and complexity of the Ivanpah project presented first-of-a-kind construction challenges that required innovative thinking and execution at every level,” Ivany said.
Attention to detail and streamlining the process of installing thousands of heliostats has been an imperative for Bechtel. “If you can save 10 to 15 seconds on a single process, the money adds up real quickly. We take a lot of time on the front-end to make sure we’re as efficient as we can be.”
Bechtel created lean approaches to multiple phases of the project, including heliostat assembly installation and construction of the project’s steel towers, which are each topped with 2,200-ton solar receiver steam generators. With a projection that 2,100 people will be employed by Bechtel, BrightSource, NRG Energy and Google at the peak of construction next year, Bechtel strives to get the most out of the man hours.
In terms of the market for solar thermal, it has been slow-moving in the U.S. However, Ivany said PV and CSP should not be compared apples to apples. “Solar thermal doesn’t have to chase PV; it’s a different kind of power.”
CSP will evolve significantly over the coming years, Ivany said. “The technology is improving such that the LCOE (levelized cost of electricity) is going to go down over the years.”
Additionally, the storage potential – like molten salts – at solar thermal plants could give it an advantage compared over PV, Ivany said. Solar thermal is also less intermittent than PV, he said. If cloud cover or other conditions threaten power production, the gas auxiliary boiler on a solar thermal site can be fired up to create steam.
*This article has been corrected from its original version to reflect that BrightSource is not planning to use molten salt storage at Ivanpah.
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