What type of progress is being made in solar plants? Ask SolarReserve LLC, a privately-owned energy company in California. According to the Las Vegas Review-Journal, the Santa Monica-based organization announced plans this month to build the world’s largest solar energy facility in Nevada. It is a $5 billion concentrating solar power (CSP) plant which gathers and focuses the sun’s energy to heat a fluid to drive an engine that produces electricity.
SolarReserve’s project, called “Sandstone,” would include up to 10 concentrated solar arrays, each equipped with a molten salt system capable of storing the sun’s energy to generate power after dark. This would require at least 100,000 mirrors and 10 towers as tall as any building in the state. CEO Kevin Smith explained that project Sandstone would generate between 1,500 and 2,000 megawatts, enough to supply about a million homes. That’s on par with a nuclear power plant or the Hoover Dam and far bigger than any of the world’s existing solar facilities. According to Bloomberg, the biggest solar-thermal plant in the world is the current 392-megawatt Ivanpah facility in California’s Mojave Desert which has three towers and went into operation in 2014.
SolarReserve has already built a 110-megawatt facility, the Crescent Dunes Solar Energy Plant. It sits on 1,600 acres of federal land outside of Tonopah, 225 miles northwest of Las Vegas. This $1 billion array began delivering power to NV Energy late last year.
The Crescent Dunes plant uses more than 10,000 mirrored heliostats, each with the square footage of a small house, to focus sunlight on a 640-foot-tall central tower, heating the molten salt inside to more than 1,000 degrees. The heat stored in the molten salt is then used to boil water, creating steam that drives generators to produce electricity day or night. SolarReserve says its patented storage system allows Crescent Dunes to deliver power on demand like a coal, natural gas or nuclear plant, but with zero emissions, little water use and no hazardous waste.
The Crescent Dunes plant took more than four years to construct, significantly longer than company officials predicted. Smith expects both the cost and construction time to decrease significantly with each new facility SolarReserve builds.
NV Energy agreed to buy the entire output of the Crescent Dunes’ plant at 13.5 cents per kilowatt hour — roughly twice the cost of power from a natural gas-fueled plant — for the next 25 years. Smith said the bulk of the power from the Sandstone project likely will be “exported to the California market,” which already has a variety of solar power options when the sun is out but has a growing need for renewable energy that can be delivered reliably day or night.
Not everyone shares Smith’s optimism. Some energy analysts are worried about the large capital and maintenance costs associated with CSP projects since comparatively cheap and easy-to-build photovoltaic arrays produce power at a lower cost.
In addition to energy analysts’ worries, there are likely to be environmentalists who have concerns about the impact of the Sandstone plant on wildlife and the landscape. The Crescent Dunes facility in Nevada and the Ivanpah facility in California have already drawn the wrath of environmentalists for the number of birds that are killed in collisions with the mirrors and central towers or incinerated in beams of concentrated sunlight that can top 900 degrees.
Smith believes the problem is overblown, especially at Crescent Dunes, where the full-time biologists on site have logged around 60 bird deaths over the past year. He said this number is probably less than the office building where they work in Santa Monica.
Smith expects to be able to announce a 16,000-acre site for the new project within the next six to nine months. He said company officials have looked at about a dozen locations over the past year and narrowed the list to two, both on federal land in Nevada’s Nye County.
With more national interest focusing on alternative energy sources, solar plants are getting more attention. The Sandstone project will be a good litmus test to see how strong the commitment is to continue to build them.