Solar thermal technology may be better suited to electric utilities than solar photovoltaics.

With BrightSource’s Ivanpah concentrated solar power plant about to come online, the company looks to its next projects for the economics to improve.

BrightSource Energy is planning to complete construction of one of world’s largest solar thermal power plants this year, and is now betting on an even more massive project that it hopes will come online by 2016.

The Oakland, California, company’s first utility-scale plant, its 370-megawatt Ivanpah facility in the Mojave Desert, uses thousands of software-controlled mirrors to direct sunlight at three central towers that produce steam and power a turbine. PG&E and Southern California Edison have entered long-term contracts to buy power from the three units of the project, a sprawling 3,500-acre installation that cost $2.2 billion and is slated to start firing up this summer.

In the more than five years Ivanpah took to permit, finance, and build, the solar market has changed dramatically around it. Today, there is more than 7,000 megawatts of photovoltaic solar power online in the U.S., compared to 546 megawatts of concentrating solar power, or CSP, according to GTM Research and the Solar Energy Industries Association.

Rapidly dropping prices for photovoltaic panels have made large farms and distributed installations attractive to electric utilities that need to meet mandates to supply lower-carbon power. Partly because of these shifts, solar thermal companies have struggled to finance projects. At least one, Solar Millennium, went bankrupt last year. Siemens exited the business entirely last year.  

BrightSource announced this week it is partnering with its Spanish competitor Abengoa Solar for help financing, building, and operating the two 750-foot tall towers at its next site, the Palen project in Riverside County, California. Last summer, BrightSource won its bid to purchase the project site after Solar Millennium, its owner, went bankrupt. The company has yet to secure financing for a project expected to cost $2.6 billion and is now awaiting final permits. BrightSource hopes to begin construction by next year, Woolard says.

The Riverside project’s even larger size (each 250 megawatts, rather than Ivanpah’s three at up to 130 each), more advanced mirror systems that track the sun, and more efficient turbines could bring capital costs down further, says Woolard. Abengoa’s long track record of building and operating giant CSP plants will also help. One of its other massive projects opened this week.

Notably, neither Ivanpah nor Palen will have what is likely crucial to the long-term success of solar thermal power in the marketplace: the ability to store energy using molten salts, which could help make up for the unevenness of other renewable sources. “Every utility out there is saying my problem is not at noon at all; in fact my peak is 4 o’clock, moving to 6 o’clock,” says Woolard, referring to the fact that many western U.S. utilities are using more and more solar PV power that ramps down just as people come home from work and turn on their appliances.

Woolard says future BrightSource projects will eventually use molten salt energy storage. The company hasn’t done so yet because project financiers can only tolerate so much new risk in each project.

BrightSource faces significant challenges as it seeks opportunities to prove the benefits of its technology. Its costs are still high, as noted by the California Energy Commission when it did not approve three of its five proposed power purchase contracts with Southern California Edison last year. And, facing permitting delays, BrightSource shelved its Rio Mesa project in California in January to focus on the Palen site. However, despite these barriers, California utilities are still looking seriously at the technology because they must deliver a third of their power to consumers from renewables by 2020.

In addition to slow permitting and uncertain national climate policies and tax incentives, the need to build new transmission lines to support a large number of new projects in the desert is also a major barrier to large growth of the technology in the United States. As a result, BrightSource’s next projects will likely be international. It is in the final stages of securing a contract in Israel, and is scouting in South Africa, Saudi Arabia, and Morocco. Ultimately, Woolard says, the biggest market could be China, where demand for electricity is exploding and new transmission has to be built no matter what.


Jessica Leber,