If you heard a big sigh of relief today and were mystified where it came from, we have identified its origins: The Santa Monica, Calif., headquarters of SolarReserve, where word came down from the U.S. Department of Energy (DOE) that a $737 million loan guarantee to help build the Crescent Dunes Solar Energy Project in Nevada was finalized.
Confirmation of the federal support for the 110-megawatt (MW) concentrating solar power (CSP) plant arrived just two days before the end-of-the-fiscal-year deadline for the Section 1705 program to wrap up business. And as we’ve seen with First Solar and SolarCity, not all of the conditionally backed loans have been making it across the finish line.
But the loan for SolarReserve subsidiary Tonapah Solar Energy survived, seemingly ensuring that the plant – which will be the first of its kind in the country, the DOE said – will be built. What makes Crescent Dunes unique is that it will use “power tower” technology, with 17,500 mirrors (heliostats, as the industry calls them) collecting and focusing the sun’s energy, to heat molten salt flowing through a very tall tower. How tall? The tallest such tower in the world, according to the DOE, rising 540 feet into the sky above the desert about midway between Las Vegas and Reno.
An interesting note here is that this support for a CSP plant comes while some utility-scale solar developers have been rejecting the technology, lured away by the rapidly falling cost of photovoltaics – as we saw with the Blythe Solar Project. But CSP with molten salt can do something PV can’t, as the DOE explained in its loan-finalization announcement: “Excess thermal energy is stored in the molten salt and can be called upon at any time to create additional steady, clean, renewable power for up to 10 hours, even in the evening hours and when direct sunlight isn’t available.”