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.”
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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.
Addendum
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…
Having lived in the Mojave Desert for 30 years now I am astounded and dismayed at the apparent ease that these projects have of getting permits to literally blade off square miles of precious “habitat”. Over the last few decades environmental groups working through the BLM have systematically reduced access (beyond walking) into vast areas, usually in the name of some endangered animal – e.g. Desert Tortoise or Mojave Ground Squirrel. Generally I am against this creeping closing of public lands and have put my money where my mouth is fighting it. But now all you have to do is put together some hairbrained (from a practical engineering point) scheme and you are on your way with gov financial backing and some kind of rammed through from above environment impact process (for Kali – CEQA Ca Environmental Quality Act), and you get to spend a billion dollars while conducting habitat (and scenic) destruction on a massive scale.
SoCal born & raised desert rat. I also am dismayed over much of the desert encroachment but would be much more positive for these projects if they actually delivered as promised.
The bird flares etc. are a real bummer though and if the power generated isn’t cost-effective these places should be shuttered and experimental stations should be kept small till they are.
Closed – like the ARCO project in the 80s. Not one can come even close to meeting the low cost of nuclear or natural gas. The west coast is littered with closed solar, geothermal, and wind projects.
Do not accept lies and misrepresentations – demand proof and valid numbers. Include required 100% grid load back up generators.
If these are the three collection fields south of town (Tonopah) then I flew over these on Monday on my way to SLC. I had no idea they had built these. The bright foci were very similar to Ivanpah.
The real problem is, to energize Los Angeles, we would have to cover all of the Mohave Desert with these monstrous things.
I would point out that since it is a molten salt – theoretically it can generate 24 hours a day.
The rated capacity is likely due to the molten salt –> electricity process, which is not a solar PV number.
Of course, as noted, reality isn’t the same as theory, but there may be a very fundamental math assumption/error in the article.
The only math necessary is this: burning C02 = Death by global warming or climate change while renewable energy=hope for the future.