The Nevada solar-energy plant Crescent Dunes has gone under after receiving a $737 million federal loan guarantee during the Obama Administration. Crescent Dunes, a 110-megawatt facility, was supposed to use molten salt to store heat from the sun, produce steam, and generate electricity even when the sun was not shining. The Department of Energy finalized its loan guarantee on Sept. 23, 2011—a week before the federal loan program expired. Just prior to the finalization of the loan guarantee, Nevada approved $119.3 million in tax abatements for Crescent Dunes over 20 years. The plant also received roughly $140 million in private investment. NV Energy, the largest electric utility in Nevada, agreed to buy the electricity under a 25-year power purchase agreement.
Crescent Dunes began commercial operation in November 2015, missing the deadline established by its agreement with NV Energy. But, less than a year later, the facility went offline because of a massive leak in the hot salt tank. Crescent Dunes resumed operations in the latter half of 2017, but had frequent and prolonged outages. Because of Crescent Dunes’ performance problems, NV Energy was at risk in meeting its renewable portfolio standard obligations.
In the summer of 2019, Crescent Dunes’ hot salt tanks had a catastrophic failure, causing ground contamination and requiring the removal of the solar tower that is needed for the plant to generate electricity as designed, halting operations. The Department of Energy sent a formal default notice in September, followed by NV Energy terminating its power purchase agreement.
Crescent Dunes was not cost-effective. Its average price was over $132 per megawatt-hour, compared to Techren Solar II in Nevada’s Eldorado Valley priced at $31.15 per megawatt-hour.
How the Technology Works
Crescent Dunes has a solar receiver that sits on a tower and absorbs sunlight from over 10,000 mirrors. The mirrors magnify the sun’s power 1,200 times, heating salt to high temperatures. The molten salt circulates through the tower and is then used to heat a steam cycle that generates electricity. The plant also uses an automated system that controls the flow of molten salt to the receiver.
Plant operators manage dozens of valves and pumps to start, stop, and adjust the collection of solar energy and control electricity production. Even with changing weather patterns, the molten salt is supposed to heat over 60 million pounds of salt each day to reach 1,050 degrees Fahrenheit. The salt continually circulates in a loop, enabling its reuse by storing it in tanks for use at a later time.
Crescent Dunes was designed to meet peak energy demand, extending into the evening hours until about midnight. The plant’s energy storage integration delivers solar energy captured during the day to the grid during the late afternoon and evening when the demand for power is at its highest. According to the Department of Energy, the molten salt absorbs 90 percent of the solar energy it receives and is used as both a heat transfer fluid and a storage medium.
Information Available to the Obama Administration
In September 2011, the Energy Department indicated that Crescent Dunes would be the first of its kind in the United States and the tallest molten salt tower in the world based on Solar Two, a 10-megawatt test facility in the Mojave Desert decommissioned in 1999 that had shown it was technically feasible to use molten salt to store and generate power. However, in a 2006 report, the Energy Department said the pilot plant was never expected to be a viable commercial-scale plant and, in fact, did not validate economic feasibility. The Crescent Dunes project shows that government investments under the Obama Administration were based on politics more than feasibility.
Like Solyndra, Crescent Dunes is another Obama Administration failure in solar energy development. Despite Crescent Dunes’ power being priced over 4 times as high as the nearest photovoltaic plant in Nevada, the Obama Administration chose to invest in it with taxpayers’ money to further its development of renewable technology. It is well known that the government has a poor track record for picking winners and losers, and Solyndra and Crescent Dunes are notable examples. Americans should be cautious about government attempts to pursue technology in the name of climate change, a recipe for many more Crescent Dunes fiascoes.