Solar Thermal Power Coming to a Boil

The lesser-known type of solar energy has enormous potential to create affordable renewable energy.

| July 22, 2008

Concentrated solar thermal power

A recent study indicates that over 90 percent of fossil fuel generated electricity in the United States and the majority of U.S. oil usage for transportation could be eliminated using solar thermal power plants — and for less than it would cost to continue importing oil.


After emerging in 2006 from 15 years of hibernation, the solar thermal power industry experienced a surge in 2007, with 100 megawatts of new capacity coming online worldwide. During the 1990s, cheap fossil fuels, combined with a loss of state and federal incentives, put a damper on solar thermal power development. However, recent increases in energy prices, escalating concerns about global climate change, and fresh economic incentives are renewing interest in this technology.

Considering that the energy in sunlight reaching the earth in just 70 minutes is equivalent to annual global energy consumption, the potential for solar power is virtually unlimited. With concentrating solar thermal power (CSP) capacity expected to double every 16 months over the next five years, worldwide installed CSP capacity will reach 6,400 megawatts in 2012 — 14 times the current capacity. (Click here to see the history of concentrated solar thermal power capacity since 1980.)

Unlike solar photovoltaics, which use semiconductors to convert sunlight directly into electricity, concentrated solar thermal plants generate electricity using heat. Much like a magnifying glass, reflectors focus sunlight onto a fluid-filled vessel. The heat absorbed by the fluid is used to generate steam that drives a turbine to produce electricity. Power generation after sunset is possible by storing excess heat in large, insulated tanks filled with molten salt. Since CSP plants require high levels of direct solar radiation to operate efficiently, deserts make ideal locations. [Click here to read a New York Times article about the potential of concentrated solar power.]

Two big advantages of solar thermal plants over conventional power plants are that the electricity generation is clean and carbon-free and, since the sun is the energy source, there are no fuel costs. Energy storage in the form of heat is also significantly cheaper than battery storage of electricity, providing CSP with an economical means to overcome intermittency and deliver dispatchable power.

The United States and Spain are leading the world in the development of solar thermal power, with a combined total of over 5,600 megawatts of new capacity expected to come online by 2012. Representing over 90 percent of the projected new capacity by 2012, the output from these plants would be enough to meet the electrical needs of more than 1.7 million homes.

The largest solar thermal power complex in operation today is the Solar Electricity Generating Station in the Mojave Desert in California. Coming online between 1985 and 1991, the 354-megawatt complex has been producing enough power for 100,000 homes for almost two decades. In June 2007, the 64-megawatt Nevada Solar One plant became the first multi-megawatt commercial CSP plant to come online in the United States in 16 years.

sandy s
9/4/2008 9:12:00 PM

ME needs to contact this company and do an article & updates on a technology that may be perfect for the self sufficient homesteader; Generating electric from heat; I would love to learn the pros and cons of this new product and be there to help support their implementation and integration into my needs.

9/2/2008 11:14:24 AM

This sounds really good, but so does Batha's Comments on the Black Box. Can you tell us how these Black Boxes were made, etc? Thanks

9/1/2008 7:28:03 AM

As always, I find your articles interesting and informative, especially when it comes to one of my favorites topics, alternative energy! Solar thermal power, at 13 to 17 cents per kilowatt, and projected to decline to 5 to 7 cents per kilowatt in the future seems like a bargain when you think about it from a financial and global perspective. Your article commmented that it would be competitive with fossil fuels when it reached the 5 to 7 cents per kilowatt range. Realistically, if we look at the true cost of fossil fuels, more specifically, crude oil, solar thermal power among other numerous alternative sources of energy seems like an inexpensive solution to our energy problems. When you consider the amount of money the US spends on keeping the middle east shipping lanes open with our expensive military machine to provide safe passage for our tankers to transport crude oil to the US; the grave mistake that President Bush made invading Iraq; and the tax breaks the federal goverment gives to the oil companies that break their own record quarterly profits on a regular basis, alternative energy seems very inexpensive, especially when you factor in job creation and supporting your own country with your hard earned money. There is another very important matter to consider regarding solar thermal power and other sources of alternative energy that could be used to wean us off of our unrealistic appetite for foreign oil at a cost of approximately $700 billion per year. If our elected leadership in Washington had finished the job in Afghanistan after 911, and had focused on our domestic priorities, one of which is out of sight energy prices and creating a bonafide energy policy for the long term benefit of the US, how far would the current $500 billion dollar tab in Iraq-with seemingly no end in sight-gone in converting the US to numerous domestically produced forms of alternative energy and most importantly, the preservation of lives?

sandy s
8/31/2008 9:45:23 PM

dairy goat


Aug. 5-6, 2017
Albany, Ore.

Discover a dazzling array of workshops and lectures designed to get you further down the path to independence and self-reliance.