Solar Thermal too expensive, too vulnerable, negative EROEI, take up too much space

Too Expensive

It would cost at least $37,500 per home if you consider how much the latest facility cost. Abu Dhabi built a new 100-megawatt concentrated solar power plant for $750 million that can provide electricity to 20,000 homes (NPR).  There are 132,419,000 housing units in the United States in 2011 (  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.

Solar One was so expensive that no costs were publicly revealed.

Solar Two would have cost more than $14,000 per kilowatt if Solar One’s equipment hadn’t been used

Negative EROEI (Energy Returned on Energy Invested)

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.

A 1,000 MW solar plant needs:

  • 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 many 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 (Beckmann).

From Day 1, the metals rust and the plant decays and grows brittle from harsh sunlight.

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.

Solar thermal in California (CEC 2014)

Solar thermal technologies represent a growing share of the total solar portfolio under construction in the United States. The Energy Commission engaged Navigant and Itron to survey the available data, extract the relevant information, and adjust nationwide estimates in to California- specific values. Among solar thermal facilities, the parabolic trough and power tower designs are considered to be the most viable in the near future. In addition, these technologies are capable of using thermal storage technologies to extend their hours of operation beyond dusk when PV technologies would stop producing. For both technologies, installations without storage and with 6 hours of storage were explored. In addition, for solar power tower designs, an 11-hour storage option was researched to help provide estimates appropriate to the direction some developers have taken recently by maximizing the storage capacity of these installations.

Trends in Solar Thermal Development

Solar thermal plants, also known as concentrating solar power plants (CSP), collect and convert solar energy into power using conventional steam turbines. There are two predominant commercial embodiments of solar thermal plants-parabolic troughs and solar towers-both of which collect sunlight over large “solar fields.” The captured solar energy generates heat that is transferred to a working fluid (such as pressurized oil). The working fluid is used to generate steam, which is routed through steam turbines to generate electricity. Parabolic trough solar plants use linear parabolic collectors to focus the sun’s rays on a pipe at the focal point. These collectors rotate to concentrate direct sunlight onto a pipe located along the focal line of their reflective surfaces. About 50 trough plants are operational worldwide as of 2012. Solar tower plants are surrounded by a field of reflectors (known as heliostats) that move to focus direct sunlight onto a receiver atop a central tower. There are about a half-dozen commercial tower plants operational worldwide.

NREL Concentrating Solar Power Projects

Trough and tower CSP plants may include thermal energy storage (TES). TES stores the working fluid at high temperatures and allows the plant operator to have some control over when electricity is generated, thereby increasing the plant’s dispatchability. Energy collected earlier in the day can be drawn from storage to generate additional power in the afternoon, even as solar input declines. TES is an important CSP component since it adds both significant additional capital costs and significant expansion of the operational profile, greatly reducing the levelized cost of energy. However, few existing commercial CSP plants include TES. Available CSP plant cost and performance data reflect trough plants both with and without TES. Tower plants are primarily described with TES. This cost of generation analysis considers trough plants with 6 and 11 hours of TES and without TES, while parabolic trough configurations are presented with 6 hours of storage as well as without storage.

Operating and Maintenance Costs. The 354 MW Solar Energy Generating Systems (SEGS) parabolic trough solar thermal plants have been operational in California since 1984. While there has been some construction of parabolic trough plants since the SEGS plants became operational (that is, Nevada Solar One), these are relatively few, and the public data on O&M costs are similarly limited. Therefore, the SEGS costs are used as the best proxy for these costs, with little change since the last COG update in 2009.

The mid-cost power tower case without storage is based on information on the $1.6 billion U.S. DOE loan guarantee to the Ivanpah project.34 Using the debt-to-equity ratio of 81.6 percent debt/18.4 percent equity (About BrightSource, 2013), this translates to $5,004/kW installed.


Beckmann, Petr. 1979. Why “Soft” Technology Will Not Be America’s Energy Salvation. Golem Press, p. 6.

Bradley, Robert. 27 Aug 1997. Renewable Energy: Not Cheap, Not “Green”

CEC. 2014. Estimated cost of new renewable and fossil generation in California. California Energy Commission. CEC-200-2014-003-SD. 254pages

Robert Bradley. Why Renewable Energy is not cheap and not green. NCPA.

Hayden, Howard. 2005. The Solar Fraud: Why Solar Energy Won’t Run the World.

NPR. 19 March 2013. Flush With Oil, Abu Dhabi Opens World’s Largest Solar Plant.

NREL. 2014. Renewable Electricity Futures Study Exploration of High-Penetration Renewable Electricity Futures. National Renewable Energy Laboratory.

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