By Jennifer Van Burkleo, Online Editor
The Ivanpah Solar Electric Generating System held its dedication Thursday in celebration of reaching commercial operation, delivering solar electricity to California’s power grid. Ivanpah went online December 31, 2013.
Ivanpah is the result of collaboration between NRG, Google, BrightSource Energy, and a $1.6 billion loan guarantee from the U.S. Department of Energy’s (DOE) Loan Programs Office. Bechtel is the engineering, procurement, and construction (EPC) contractor on the project.
“This is an exciting culmination of many years of hard work by all of our partners at Ivanpah. The completion of this world-class project is a watershed moment for solar thermal energy,” David Ramm, chairman and CEO of BrightSource Energy, said.
The facility consists of three 450-foot high towers, which is 150 feet taller than the Statue of Liberty. The towers produce 392-MW of total generating capacity and accounts for nearly 30 percent of all solar thermal energy operational in the U.S., making it the largest solar project in the world.
However, the project came with many challenges.
“The team had to address several first-of-a-kind challenges when developing the concept design. These included the design for the tower to support the 2,200-ton boiler, designing a process systems that met the 100 acre-feet water usage limit, developing a low impact earthwork design in accordance with the BrightSource’s design basis and developing a design to lift the boiler on top of the tower,” Andy Gillespie, Bechtel Project Manager on Ivanpah, said in an exclusive interview with Power Engineering magazine.
Reaching commercial operation, Ivanpah omits nearly 400,000 metric tons of carbon dioxide annually.
Ivanpah is the first to use BrightSource’s solar power tower technology to produce electricity, which includes 173,500 heliostats – each the size of a garage door – that follow the sun’s trajectory, solar field integration software and a solar receiver steam generator. The sunlight heats up water in the boilers and creates steam which result in generated electricity.
Since a project this size had yet to be achieved, there was no blueprint. Plans for assembling, transporting and installing had to be developed from scratch.
“The final design comprised a unique steel tower with a stick built lower section supporting 40’ cube modular tower construction – these modules were built at grade adjacent to each tower, filled with pipe and equipment and then lifted into place with a tower crane,” Gillespie said. “The team addressed the water usage challenge using a zero liquid discharge design in combination with an optimized Air Cooled Condenser (ACC) solution.”
The solar energy produced from Units 1 and 3 are being sold to Pacific Gas & Electric through two long-term power purchase agreements, while electricity generated from Unit 2 is being sold to Southern California Edison under a similar contract.
Gillespie added that Ivanpah is not affected by California’s storage mandates.
“Ivanpah does not have storage and it cannot be added to the current plant. However, the current design can be used as a starting point for adding storage to future projects,” he said.
The Ivanpah Solar Electric Generating System will be operated by NRG and is the largest of 11 operational utility-scale solar facilities in three states in which the company has ownership interest.
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