Concentrating Solar Power (CSP) has had a rough decade. Ten years ago, the technology, which uses concentrated sunlight to create steam and drive turbines, was all the rage, with multiple gigawatts of solar projects planned in the Mojave Desert following on major industry success in Spain.
But over the next few years CSP, like many other emerging technologies, fell prey to the falling costs of crystalline silicon solar. The fact that the plants operate optimally when located in areas with particularly intense sunlight didn’t help, as many of the locations chosen by developers led to lawsuits with conservationists and Native American groups.
And now, the developer which built one of the few large CSP plants to go online in the United States has a new concern. Last week SolarReserve filed suit against the LLC which owns Crescent Dunes and the U.S. Department of Energy. The lawsuit claims that DOE, which provided a loan guarantee for Crescent Dunes, is stacking the board and trying to push out its sole director.
According to the lawsuit filed last week (and put online by Bloomberg Law), SolarReserve says that DOE is replacing new director which it appointed, via a “notice of default” that the agency sent last month. According to SolarReserve:
The DOE’s actions interfere with SolarReserve’s right to participate in the management of Tonopah; and they result in a forfeiture of SolarReserve’s property rights in a $1 billion project which SolarReserve started in 2008, without an opportunity to contest that forfeiture.
SolarReserve also states that the “independent” managers which DOE has chosen now give it the ability to “exert substantial control” over the Tonopah project, and SolarReserve specifically mentions the ability to file for bankruptcy.
Operational issues
The alleged DOE takeover comes in light of other problems at the Crescent Dunes project. According to reporting by the lawsuit, NV Energy has terminated its power purchase agreement with Crescent Dunes after the project failed to generate the required amount of electricity.
Crescent Dunes appears to have struggled for some time; despite signing an engineering, procurement and construction agreement in 2011, the plant only “commenced commercial operations” in 2015. It appears that there is still a debate as to what went wrong with the molten salt storage system, which SolarReserve blames on the construction contractor.
This is not the first U.S. CSP plant that has had problems. This author has documented problems during the ramp up at the Ivanpah Concentrating Solar Power (CSP) plant, which like Crescent Dunes utilizes a “power tower” design instead of the more common parabolic trough design.
Either way, without a power contract and with DOE running the board, SolarReserve is warning that bankruptcy could be the next step:
Upon information and belief, SolarReserve believes that in connection with DOE’s purported takeover of Tonopah, on or before October 3, 2019, Tonopah now exposes SolarReserve’s equity to the uncertainly of a Tonopah bankruptcy filing
But whatever happens, this isn’t a good day for a technology that held so much promise.
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The Solana CSP trough power plant seems to be doing well in Arizona. If one can go from coal fired boilers, to natural gas fired boilers, then one can go from heliostat heat focusing on a tower to parabolic concentrating troughs with molten salt heat storage to firm up the plant’s operation.
While this argument has been going on since the proof of concept “power tower” tested near Dagget CA in the 1980’s and 1990’s. Apparently lesson’s “learned” in Dagget from (Solar One and Solar Two), were not necessarily applied to Ivanpah or Crescent Dunes.
Now there are options that have been proposed, tested and retested over the last couple of decades in “chemical energy storage”. Redox is ready to prove itself with the announcement of UET Inc. of large scale redox flow batteries built in a giga-factory in China for the utility scale energy storage market. NEC recently announced a partnership with AMBRI’s molten metal battery technology and lithium ion battery technologies are already being installed in the field. It has been announced by Kyocera that the 24M semi-solid lithium battery technology will be available from Kyocera by 2020 and is set to be introduced in the residential energy storage market in Japan.
I wish someone would provide an explanation of what difficulties technical and otherwise they were encountering!
Unfortunately I don’t think SolarReserve is talking about this publicly. There was limited information in the press release – they mostly blamed the EPC and said there were problems with the molten salt.
I would think that high temperature molten salt would be very corrosive and this would cause problems. Would like some explanation if this is possible.
Molten salt has been used successfully as an energy storage medium in many CSP projects. I haven’t looked deeply into the technology, but my guess is that it’s easy to use tanks with anti-corrosive lining.
Why does the DOE want to take over control, do you know? Is it to turn it into a CSP testing lab, like Sandia?
There are a lot of assets there for true full scale testing, which we otherwise do not have. China has the right approach for this novel technology. They test tower CSP at full scale, because you can only iron out the kinks at full size.
In my interviews with CSP researchers for the SolarPACES network, a French researcher (at EDF) working in China told me: “The way that people approach risk in China is different; I think they are more open for such innovation. They don’t trust so much the modeling work; so they build it. It’s quite sad that today it’s easier to do such projects in China than in a western country, but it makes working in China very exciting.” He is involved in testing new power cycles for CSP in China:
https://www.solarpaces.org/shouhang-and-edf-first-to-test-s-co2-cycle-in-concentrated-solar-power/
It is true that tower CSP does not have the plug&play operational ease of trough CSP, but because it has great potential for cost reduction once these issues are solved, we should be treating these first full scale tower plants as tests. Coal plants took several decades to iron out initial problems. Unfortunately, the 2010 Tea Party House came in with their hysteria, (“No more Solyndras!”) and promptly quashed all CSP funding since 2011. We literally get half-baked clean energy policy.
But it seems that China could reverse that for the world:
https://www.solarpaces.org/china-made-solar-pv-cheap-is-csp-next/
The Solana plant in Arizona has thermal storage, with a hot tank temperature of 725F. Solana has been reasonably successful, with a best annual capacity factor of 35%, versus the planned factor of 43%. Plant performance continues to improve.
Crescent Dunes has struggled. The hot tank temperature there is 1050F, which presents a much greater technical challenge. Supposedly the problems with the hot tank were corrected in 2017, but the best annual capacity factor is 20% versus the planned factor of 52%. The plant was shutdown in May of this year, but I can find no information on why the plant is out of service.
Crystalline silicon solar is not used at Tonopah.
Who said that it was?
(January 21 letter to the editor of the Wall Street Journal)
Dear Editor,
Your January 16th editorial piece about the demise of Crescent Dunes, the largest concentrated solar electric power (CSP) installation in the world, understated the cost to the US taxpayer. In addition to the $737 million quoted, Sandia National Labs spent a couple hundred million developing the underlining technology with their Solar 1 and Solar 2 CPS installations in the Mohave Desert. Combined, taxpayer cost is well over a billion dollars. An additional $140 million was lost by private investors, and $120 million by Nevada taxpayers. All were told this technology was sure thing. The truth is everyone knew twenty years ago that molten salts and ultra high temperatures was exotic and prohibitively expensive in the real world. Even if this technology worked exactly as envisioned, it would never be able to compete with other emerging solar technologies on a dollar per watt basis.
Perhaps to lessen their pain, Sandia National Labs created The National Solar Thermal Test Facility outside Albuquerque using a scaled down version of Solar 2, to entice private companies to test their new solar technology. But when NASA wanted to test their new solar panels for the highly successful Parker Solar Probe mission, their solar panel subcontractor chose our company, Practical Solar, Inc., a totally privately funded company. A telling sign on how things went terribly wrong.
Bruce Rohr, President
Practical Solar, Inc.
Canton, Massachusetts