Guest post by David Middleton
SolarReserve’s Crescent Dunes Project in Tonopah, Nevada is quietly providing clean, green solar energy to 75,000 homes in the Silver State even when the sun isn’t shining.
Crescent Dunes is the first utility-scale facility in the world to use molten salt for power energy storage capabilities, a technology also known as concentrated solar.
With a concentrated solar plant such as Crescent Dunes—including other plants like it around the world—more than 10,000 movable mirrors, or heliostats, reflect solar energy to a central, 640-foot tower that heats up salt to 1,050 degrees Fahrenheit.
This salt is used for two purposes, as SolarReserve points out on its website. First, it retains very high levels of heat, making it like a thermal battery that can be used night and day, whether or not the sun is out. Second, when electricity is needed on the grid, the molten salt gets dispatched through a heat exchanger to create super-heated steam to power a traditional steam turbine.
This process is similar to a conventional fossil fuel or nuclear power plant except with zero carbon emissions or hazardous waste and without any fuel costs, the California-based solar company says.
“The whole project cost slightly under $1 billion and SolarReserve holds a 25-year contract to supply power to NV Energy for $135 per megawatt hour,” OilPrice.com observed. “The tower produces 110 megawatts of energy for 12 hours a day according to the company, which works out to roughly 1 million megawatts per year. This in turn implies a gross [return on assets] of ~13.5 percent—not bad as investments go.”
I have to assume that this is a typo:
The tower produces 110 megawatts of energy for 12 hours a day according to the company, which works out to roughly 1 million megawatts per year.
Surely they mean 1 million megawatt-hours per year… But, then again, I doubt the EcoWatch “journalist” knows or even cares about the difference between megawatts and megawatt-hours. And there’s a bit of a math problem
110 MW * 12 hr/day * 365 days/yr = 481,800 MWh/yr
481,800 is not roughly 1 million.
This power plant cost $975,000,000 to build ($8.9 million per MW, ten times the cost of a natural gas fired power plant). Taxpayers are on the hook for 76% of this cost through Federal loan guarantees. The 25-yr wholesale price guarantee of $135/MWh, about 30% higher than the average US retail price (all sectors). This is the “good news.”
While the plant has barely started operating, there is some production history.
While the production will almost certainly improve this summer, “SolarReserve’s Crescent Dunes Project in Tonopah, Nevada [isn’t even] quietly providing clean, green solar energy to 75,000 homes in the Silver State even when the sun [is] shining”…
The average U.S. residential utility customer uses about 900 kWh per month.
75,000 homes * 900 KWh/month = 67,500,000 kWh/month = 67,500 MWh/month
In its best month so far, Crescent Dunes generated 9,095 MWh… About 3 hours of electricity per day for 75,000 homes. This is the Venezuela version of 24/7 /SARC.
Some of the comments have suggested that the generation data for this plant are not representative of its potential. While the data for February and March are from its first two fully operational months and this is not some sort of “pilot project,” the plant is still in its “infancy”… So I thought I might take a look at a more mature concentrated solar power plant: Ivanpah…