Cloudy days for solar thermal

by Drew Thornley
“$2.2 billion California project generates 40% of expected electricity”

This past weekend’s Wall Street Journal has some unsurprising news about solar-thermal technology. Excerpts to follow, but, in short: It’s very expensive to build, it doesn’t deliver nearly the amount of projected power, and it kills birds:

The $2.2 billion Ivanpah solar power project in California’s Mojave Desert is supposed to be generating more than a million megawatt-hours of electricity each year. But 15 months after starting up, the plant is producing just 40% of that, according to data from the U.S. Energy Department.

Built by BrightSource Energy Inc. and operated by NRG Energy Inc., Ivanpah has been advertised as more reliable than a traditional solar panel farm, in part, because it more closely resembles conventional power plants that burn coal or natural gas. NRG co-owns the plant with Google Inc. and other investors.

Turns out, there is a lot more to go wrong with the new technology. Replacing broken equipment and learning better ways to operate the complex assortment of machinery has stalled Ivanpah’s ability to reach full potential, said Randy Hickok, a senior vice president at NRG.

One big miscalculation was that the power plant requires far more steam to run smoothly and efficiently than originally thought, according to a document filed with the California Energy Commission. Instead of ramping up the plant each day before sunrise by burning one hour’s worth of natural gas to generate steam, Ivanpah needs more than four times that much help from fossil fuels to get the plant humming every morning. Another unexpected problem: not enough sun. Weather predictions for the area underestimated the amount of cloud cover that has blanketed Ivanpah since it went into service in 2013.

Ivanpah isn’t the only new solar-thermal project struggling to energize the grid. A large mirror-powered plant built in Arizona almost two years ago by Abengoa SA of Spain has also had its share of hiccups. Designed to deliver a million megawatt hours of power annually, the plant is putting out roughly half that, federal data show.

Solar-thermal developers including Abengoa and BrightSource continue to build new plants in South Africa, Chile and China. But Lucas Davis, an economics professor at the University of California, Berkeley, says it is unlikely more U.S. projects will gain traction as utilities opt for cheaper solar farms that use panels.

“I don’t expect a lot of solar thermal to get built. It’s just too expensive,” he said.

American solar farms generate nearly 16 million megawatt-hours of electricity each year. That satisfies less than 1% of U.S. electricity demand, but six times the amount of power that solar-thermal plants currently produce. And the vast arrays of solar panels that blanket the ground cost roughly half as much to build as new mirror-powered plants, according to the U.S. Energy Department.

Electricity prices from new solar farms average around 5 cents a kilowatt-hour, according to GTM Research, which tracks renewable energy markets. That compares with between 12 and 25 cents a kilowatt-hour for electricity generated by the Ivanpah power plant, state and federal data show.

The Ivanpah plant was delayed several months and had millions of dollars in cost overruns because of wildlife protections for the endangered Desert Tortoise. Once built, U.S. government biologists found the plant’s superheated mirrors were killing birds. In April, biologists working for the state estimated that 3,500 birds died at Ivanpah in the span of a year, many of them burned alive while flying through a part of the solar installment where air temperatures can reach 1,000 degrees Fahrenheit.