World's Largest Concentrated Solar Power Plant Opens

An aerial view of the Ivanpah Solar Electric Generating System with Tower 3 in the foreground, Tower 2 in the middle and Tower 1 in the background. The towers are surrounded by 173,500 heliostats that follow the sun's path[/caption]

World's Largest Concentrated Solar Power Plant Opens

Turbomachinery International recently visited the newly opened Ivanpah Solar Electric Generating System, now the world’s largest concentrated solar power (CSP) plant. At 392 MW, the $2.2 billion complex is owned by NRG Energy, Google and BrightSource Energy. Bechtel acted as the EPC contractor. NRG will be the operator. “

We see Ivanpah changing the energy landscape by proving that utility-scale solar is not only possible, but incredibly beneficial to both the economy and in how we produce and consume energy,” said Tom Doyle, president, NRG Solar.

Sitting in the California desert less than 50 miles from Las Vegas, the facility includes three steam generating units situated inside 450-foot towers. This is the first solar plant to use BrightSource CSP technology, which includes 173,500 heliostats (large mirrors) that follow the sun’s trajectory, solar field integration software and a solar receiver steam generator. The project received a $1.6 billion loan guarantee from the U.S. Department of Energy’s Loan Programs Office.

In one fell swoop, Ivanpah now accounts for nearly 30% of all solar thermal energy currently operational in the U.S. This utilityscale solar plant is truly vast in scope, covering around five square miles of federal land. It can be clearly seen beside the road from Los Angeles to Las Vegas, near the town of Primm.

As seen from the top of Tower 1, just below the boiler section, heliostats reflect sunlight toward the tower's top at the Ivanpah Solar Electric Generating System[/caption]

This will not be the biggest U.S. solar plant for much longer. A series of larger projects are already in the pipeline as the government pushes for greener power. The federal government has set up 17 solar energy zones to direct solar development to land it has identified as having fewer wildlife and natural-resource obstacles (Ivanpah faced several environmental hold ups such as having to relocate endangered tortoises).

These zones comprise about 450 square miles in California as well as New Mexico, Nevada, Arizona, Utah and Colorado. It will take many more solar facilities of this size and scope, though, to move solar up from its current position of providing less than 1% of the nation’s power output.

According to the U.S. Energy Information Administration, the cost of building and operating a solar thermal power plant of this scale over its lifetime remains greater than natural gas, coal or nuclear — around $261 per MWh not counting state and federal tax credits or the possibility of a tax on carbon. That said, the price of solar continues to drop steadily. And with some states mandating that one-third of their power come from renewable sources, price is not the only consideration.

In terms of availability, the Ivanpah site has bright sunshine for almost the entire year. Further, transmission lines are already in place to carry its output to consumers.

On the technology side, this solar thermal plant uses computerized controls to monitor its array of heliostats as they follow the sun. Each mirror is roughly seven feet by ten feet and reflects sunlight up to the top of a central tower to heat water inside massive boilers and generate steam to drive turbines.

The energy from Ivanpah Units 1 and 3 is being sold to Pacific Gas & Electric under two long-term power purchase agreements, while electricity from Unit 2 is being sold to Southern California Edison under a similar contract.