Preface.  Concentrating solar power (CSP) projects usually sprawl in a circle over several square miles and can cost over a billion dollars. They use mirrors and lenses to capture the high temperatures needed to efficiently produce or store electricity. Almost 100 of these plants have been built around the world.

This post has several article summaries related to the unreliability and problems

Castro (2018) concludes that because of a low capacity factor and Energy Returned on Invested, an intensive use of materials—some scarce, and the significant seasonal intermittence — the potential contribution of current CSP technologies in a future 100% RES system seems very limited.

CEC (2020) reports that Ivanpah, a 5 square mile billion dollar CSP plant is falling apart and Zhang (2016) reports that part of it caught on fire. Fialka (2020) cites a National Renewable Laboratory report that found nearly all CSP plants are unreliable and plagued with problems.

Related articles:

2016 Zhang S: A Huge Solar Plant Caught on Fire, and That’s the Least of Its Problems. wired.com

Alice Friedemann  www.energyskeptic.com  Author of Life After Fossil Fuels: A Reality Check on Alternative Energy; When Trucks Stop Running: Energy and the Future of Transportation”, Barriers to Making Algal Biofuels, & “Crunch! Whole Grain Artisan Chips and Crackers”.  Women in ecology  Podcasts: WGBH, Crazy Town, Collapse Chronicles, Derrick Jensen, Practical Prepping, Kunstler 253 &278, Peak Prosperity,  Index of best energyskeptic posts

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Too expensive: New ones not being built, old ones shutting down

EIA (2021) World’s longest-operating solar thermal facility is retiring most of its capacity U.S. Energy Information Administration.

The Solar Energy Generating Systems (SEGS) facility in California’s Mojave Desert retired five of its solar plants (SEGS 3 through 7) in July 2021 and plans to retire a sixth (SEGS 8) in September 2021, based on information submitted to EIA and published in our Preliminary Electric Generator Inventory. After SEGS 8 is retired, only one solar thermal unit at SEGS will remain operating (SEGS 9). SEGS, which began operating in 1984, is the world’s longest-operating solar thermal power facility.

Solar thermal power plants use mirrors to focus sunlight onto a receiver, which absorbs and converts the sunlight into thermal energy (heat). The heat is used to drive a turbine, which produces electricity. The SEGS units are parabolic trough concentrating solar thermal power (CSP) systems, meaning that parabolic (u-shaped) mirrors capture and concentrate sunlight to heat synthetic oil in a central tube, which then boils water to create steam. The steam drives the turbine, generating electricity.

Solar thermal plants account for a relatively small share of utility-scale U.S. solar electric generating capacity. As of June 2021, the United States had about 52,600 MW of utility-scale solar capacity. Of that total, 3.3% was solar thermal; the remaining 96.7% was utility-scale solar PV.

2020 A $1 Billion Solar Plant Was Obsolete Before It Ever Went Online. Bloomberg 

The Crescent Dunes solar plant looks like something out of a sci-fi movie with 10,000 mirrors forming a spiral almost 2 miles wide that winds around a skyscraper rising above the desert between Las Vegas and Reno. The operation soaks up enough heat from the sun’s rays to spin steam turbines and store energy in the form of molten salt.

Today, it’s mired in litigation and accusations of mismanagement at Crescent Dunes, where taxpayers remain on the hook for $737 million in loan guarantees. Late last year, Crescent Dunes lost its only customer, NV Energy Inc., which cited the plant’s lack of reliability. The steam generators at Crescent Dunes require custom parts and a staff of dozens to keep things humming and to conduct regular maintenance. By the time the plant opened in 2015, the increased efficiency of cheap solar panels had already surpassed its technology, and today it’s obsolete—the latest panels can pump out power at a fraction of the cost for decades with just an occasional hosing-down.

The plant’s technology was designed to generate enough power night and day to supply a city the size of nearby Sparks, Nev. (population 100,000), but it never came close. Its power cost NV about $135 per ­megawatt-hour, compared with less than $30 per MWh today at a new Nevada photovoltaic solar farm.

The plant is mostly a punchline in a part of Nevada that’s seen its share of booms and busts. The ­nearest town, Tonopah, was the site of a silver rush in the early 1900s. It’s now home to 2,400 people, a motley collection of saloons and casinos, a mining museum, and the Clown Motel, which calls itself “America’s scariest motel” because it’s close to a cemetery and filled with creepy red-nosed tchotchkes.

Neuman S (2013) Flush With Oil, Abu Dhabi Opens World’s Largest Solar Plant. NPR.

Abu Dhabi built a new 100-megawatt concentrated solar power plant for $750 million that can provide electricity to 20,000 homes (NPR). That’s $37,500 per home. There are 132,419,000 housing units in the United States in 2011 (census.gov).  At that price, it would cost $5 trillion dollars to provide electricity to Americans using solar thermal plants, and that doesn’t include the cost of upgrading the electric grid and many other costs.

Fialka J (2020) Futuristic Solar Plants Plagued by Glitches, Poor Training. The rush to complete concentrating solar power projects led to multiple reliability problems. Scientific American.

A hectic pace of development spurred by expiring national and state incentive programs has caused multiple reliability problems among the world’s most advanced solar energy plants, according to a study by the National Renewable Energy Laboratory (NREL) “Concentrating Solar Power Best Practices Study”.

Hurrying to complete plants and meet operational and financial deadlines often left crews assigned to operate the plants with too little training about how to deal with glitches. There were a welter of low-tech problems including difficulties making steam, leaking salt water, cleaning mirrors and poorly designed control systems were the major complaints of plant owners.

Described as a “first-of-its-kind report,” it shows how a lack of quality controls caused cost overruns and poor preparedness dating back to 1991. That was the year when the U.S. pioneer of CSP technology, Luz International Ltd., went bankrupt after completing nine solar plants in California.

After visiting owners or operators of nearly 80% of the operating CSP plants worldwide, NREL researchers found over 1,000 problems. More than half of them were operational and maintenance issues.

Expensive problems could and often did happen, such as the need to promptly find and fix tanks that leak salt water onto a concrete floor. Once salt has leaked into the foundation, there is no mechanism to remove the salt other than removing the floor, elevating the tank, removing the foundation, replacing the foundation, replacing the floor and then lowering the tank back into place.

CEC (2020) IVANPAH SOLAR ELECTRIC GENERATING SYSTEM 2018-2019 AVIAN & BAT MONITORING PLAN. California Energy Commission.

The California Energy Commission reports that a major hailstorm damaged between 10,000 and 12,000 heliostats (reflector mirrors) of the 173,500 garage door-sized mirrors.  Replacing them will perhaps push Ivanpah into negative EROI territory. And it takes a lot of energy to move these mirrors around. Each mirror has a motor controlled by a computer, which angles the reflective surface to track the location of the sun.  All those moving parts make Ivanpah more challenging to maintain than static solar panels.

Fialka J (2020) Futuristic Solar Plants Plagued by Glitches, Poor Training The rush to complete concentrating solar power projects led to multiple reliability problems. Scientific American.

Castro, C., et al. 2018. Concentrated Solar power: actual performance and foreseeable future in high penetration scenarios of renewable energies. Biophysical economics and resource quality.

Analyses proposing a high share of concentrated solar power (CSP) in future 100% renewable energy scenarios rely on the ability of this technology, through storage and/or hybridization, to partially avoid the problems associated with the hourly/ daily (short-term) variability of other variable renewable sources such as wind or solar photovoltaic. However, data used in the scientific literature are mainly theoretical values. In this work, the actual performance of CSP plants in operation from publicly available data from four countries (Spain, the USA, India, and United Arab Emirates) has been estimated for three dimensions: capacity factor (CF), seasonal variability, and energy return on energy invested (EROI).

The authors used real data from 34 CSP plants to find actual capacity factors, which were much lower than had been assumed.

OVERALL AVERAGE: ACTUAL CF 0.15–0.3, ASSUMED 0.25 to 0.75

CSP plant	Technology	Storage Hours	Expected CF	Literature CF	Real CF
Nevada Solar One	Parabolic	0.5	0.2	0.42–0.51	0.18
Solana Generating	Parabolic	6	0.38	0.42–0.51	0.27
Genesis	Parabolic	No	0.26	0.25–0.5	0.28
Martin Next Generation	Parabolic	No	0.24	0.25–0.5	0.16
Mohave	Parabolic	No	0.24	0.25–0.5	0.21
SEGS III–IX	Parabolic	No		0.25–0.5	0.17
Crescent Dunes	Tower	10	0.52	0.55–0.71	0.14
Ivanpah 1, 2, 3	Tower	No	0.31	0.25–0.28	0.19
Maricopa	Dish stirling	No		0.25–0.28	0.19

Table 2 United States only, not shown: UAE, Spain, and India.  Estimates of the CF of several individual CSP plants, sets of plants and global USA and Spanish CSP systems: expected values from the industry, values used in the scientific literature and the results obtained in the work for real plants

In fact, the results obtained show that the actual performance of CSP plants is significantly worse than that projected by constructors and considered by the scientific literature in the theoretical studies:

low standard EROI of 1.3:1–2.4:1, 12 other researchers gave a range of 9.6 to 67.6 (see Table 7). Given that CSP plants cost more than any other kind of RES, it’s not surprising that the EROI is so low.

Other significant issues for CSP

• intensive use of materials—some scarce
• Substantial seasonal intermittence.

Conclusion

Analyses proposing a high share of CSP in future 100% RES scenarios rely on the ability of this technology, through storage and/or hybridization, to partially avoid the problems associated with the hourly/ daily (short-term) variability of other renewable variable sources, such as wind or PV.

But this advantage seems to be more than offset by the overall performance of real CSP plants. In fact, the results from CSP plants in operation, using publicly available data from four countries (Spain, the USA, India, and UAE) show that the actual performance of CSP plants is shown to be significantly worse than projected by the builders and in the scientific literature which has been using theoretical numbers.  In fact, the exaggeration in scientific literature is paradoxical given that there have been publicly available data for many power plants for years.

By overestimating the capacity factor, the life cycle analyses that estimate the energy and material requirements, EROI, environmental impacts, and economic costs are exaggerated as well.

The capacity factor turns out to be quite low, on the same order as wind and PV, CSP has very low EROI, intensive use of materials—some scarce—and significant seasonal intermittence problems, with seasonal variability worse than for wind or PV in Spain and the USA, where the output can be zero for many days in winter.

Since CSP has to be put in hot deserts with a lot of sunlight, they’re vulnerable to damage from wind, dust, sand, extreme temperatures, water scarcity, and more.

Negative EROEI (Energy Returned on Energy Invested)  

In a 1978 study by K. A. Lawrence of the Solar Research Institute, Beckmann states, “To construct a 1,000 MW solar plant needs an excessive amount of materials: 35,000 tons of aluminum, 2 million tons of concrete, 7,500 tons of copper, 600,000 tons of steel, 75,000 tons of glass, 1,500 tons of chromium and titanium, and other materials. . . . The energy that goes into the construction of a solar thermal-electric plant is, in fact, so large that it raises serious questions of whether the energy will ever be paid back.” Petr Beckmann, Why “Soft” Technology Will Not Be America’s Energy Salvation (Boulder, Colo.: Golem, 1979),p. 6

So much energy goes into and mining, materials, fabrication, delivery, maintenance and so on, that the energy returned from the solar plant is less than the energy that went into making it.

Solar Plants require 1,000 times more material than a gas-fired power plant.

Too Vulnerable

Solar farms are vulnerable to damage and destruction from:

• High winds, tornadoes, & hurricanes
• Storms and hail
• Sand storms, which scour the mirrors.

Where’s the water?

They’re all located in deserts, which makes it hard to find the water needed to rinse off the mirrors.

The Abu Dhabi plant will need 600 acre-feet of groundwater to wash off dust and cool auxiliary equipment.  Desert groundwater is not renewable.

Too much space required

Central-station solar requires between five and 17 acres per megawatt (Beckmann).

Solar Two took up quite a bit of land for the power being generated. There were 1,900 mirrored panels, each one over 100 square yards, and the results were only one megawatt per 17 acres of capacity. A natural gas facility taking up that much space would generate 150 times as much power (Bradley).

Howard Hayden estimates Solar Two would need to take up 127 square miles to produce as much energy as a 1000-MWe power plant does in one year. (Hayden, p. 187).

Too few places to put it

Concentrating solar power (CSP) capacity grew by about 100 MW from 2009–2011, bringing the cumulative total to approximately 520 MW. This corresponds to approximately 0.2% of U.S. electricity demand being met by PV and 0.015% by CSP.

Solar energy contains a direct component (sunlight that has not been scattered by the atmosphere) and a diffuse component (sunlight that has been scattered by the atmosphere). This distinction is important because only the direct solar component can be focused effectively by mirrors or lenses. The direct component typically accounts for 60%–80% of surface solar insolation74 in clear-sky conditions and decreases with increasing relative humidity, cloud cover, and atmospheric aerosols (e.g., dust, urban pollution). Technologies that concentrate solar intensity—such as CSP and concentrating PV—perform best in arid regions with high direct normal irradiance. Solar technologies that do not concentrate sunlight, such as most PV and passive solar heating applications, can use both the direct and diffuse components of solar radiation and thus are suitable for use in a wider range of locations and conditions than concentrating technologies.

The solar resource available to CSP is highest in the southwestern United States and falls off in eastern and northern states. This is because CSP technologies can only effectively concentrate the direct component of solar radiation, which is highest in arid regions.