What is the Concentrating Solar Power Alliance (CSPA)?

CSPA is the first organization in the U.S. dedicated solely to promoting the advancement of solar thermal electric power plants.

What is the organization’s mission?

The Alliance’s mission is to promote the increased acceptance, adoption and implementation of solar thermal electric power plants in the United States. The Alliance will articulate the value of solar thermal electric power and thermal energy storage and create an awareness of this value among regulators, utilities and grid operators. The Alliance will also promote policies to encourage and advance solar thermal electric technology deployment.

Who are the founding members of CSPA?

Abengoa, BrightSource Energy and Torresol Energy.

Can any company join the CSPA?

Membership is open to those companies with a significant percentage of their business relating to solar thermal electric either as a supplier or as a solar thermal electric technology provider/developer.

Why is it necessary to have an organization dedicated solely to CSP?

solar thermal electric technologies provide unique benefits to utilities and grid operators relative to other renewable energy resources.  We believe that solar thermal electric has a critical role to play in meeting the world’s growing demand for reliable and cost-effective clean energy. This organization is designed specifically to educate utilities, grid operators and regulators on these specific benefits.

Are there other solar thermal electric organizations around the world?  Will CSP Alliance associate with these groups?

The formation of the CSP Alliance builds on the momentum of the newly formed World Solar Thermal Electricity Association (STELAWorld), a consortium of industry associations representing the solar thermal electricity industry in Europe, Australia and South Africa. STELAWorld was created to work specifically with international agencies to assist policy-makers and energy investors to access information on solar thermal electricity development. While independent of STELAWorld, the CSP Alliance will work closely with these associations to further advance the solar thermal power industry in the U.S. and abroad.

Why do utilities and grid operators highly value CSP?

Utilities and grid operators worldwide value solar thermal electric plants because of the technology’s unique characteristics for harnessing the sun’s energy. These include:

  • Production of electricity at peak demand when it is needed most during the late afternoon or early evening hours
  • The inclusion of cost-effective, efficient thermal energy storage to provide a flexible and dispatchable clean energy source, day or night
  • Incorporation into coal or gas power plants as “hybrids” for cleaner baseload power


How does solar thermal electric power work?

Solar thermal electric technologies produce electricity the same way as a conventional power plant – by producing high temperature steam to drive a conventional steam turbine. However, instead of using fossil fuels or nuclear energy as a fuel source, solar thermal electric uses the abundant and free energy from the sun to produce steam.

What are the different types of solar thermal electric technologies?

Different solar thermal electric designs include power towers, parabolic troughs and linear reflectors, each based on proven engineering principles. Solar thermal electric plants are made primarily of glass (for mirrors and receiver tubes), steel or aluminum (for the structures that hold the mirrors and move them to track the sun as it passes across the sky), concrete (for foundations), and many other components.

How does solar thermal electric with storage work?

Solar thermal electric plants typically store heat in a molten salt mix and use that heat to make steam during long cloudy periods or when the sun has gone down in the evening, thereby keeping the turbine operating and generating electricity when power is needed.  Some solar thermal electric plants directly heat these salts in the receiver tubes, while other technologies store the heated salt in separate tanks.

What are the benefits of adding storage?

There are five main benefits of a solar thermal electric plant with storage:

  • Reducing the electricity costs by increasing a plant’s capacity factor – the amount of hours that a plant runs annually
  • Shifting electricity production to periods of highest demand during late afternoon and evening hours
  • Providing firm capacity to the power system; replacing the need for conventional power plants as opposed to just supplementing their output
  • Providing ancillary services such as spinning reserves (on-line reserve capacity that can be made available to a transmission system within ten minutes notice) to help support a reliable grid
  • Avoiding the variability and integration costs that intermittent renewable resources create for utilities and grid operators; reducing the need for additional fossil fuel units to back up intermittent renewables that put a hidden financial burden on ratepayers


What is the history of solar thermal electric in the U.S.?

The first commercial solar thermal electric plants were built in California in the mid-1980’s and are operating today with a higher output than when they were new.  There are currently over 500 MW of solar thermal electric plants operating in the U.S and more than 1,300 megawatts of solar thermal electric plants under construction in the U.S with many gigawatts more under development.

How many solar thermal electric plants are planned around the world?

The International Energy Agency estimates that solar thermal electric projects now in development or under construction in more than a dozen countries (including China, India, Morocco, Spain and the United States) total 15 gigawatts.

How much of the world’s energy could be met with solar thermal electric power?

solar thermal electric power is poised to grow worldwide, creating clean power and jobs as it expands to meet the world’s energy needs. Current solar thermal electric projects demonstrate the technology’s viability and a recent study from the International Energy Agency shows that with sufficient investment and the right government policies, more than ten percent of the world’s electricity demand could be met using solar thermal electric power by 2050.

Do solar thermal electric plants create economic benefits via jobs and supply chains?

Yes, solar thermal electric plants are a leader among renewable energy technologies in creating economic benefits not only in the regions where they are built, but also across the United States. A recent study by Deloitte found that compared to other power generation sources, solar thermal electric plants are a strong generator of local jobs during construction, operation and maintenance, as well as jobs nationwide. The supply chain feeding solar thermal electric plants creates jobs nationwide due largely to the plant’s high percentage of domestically-sourced components. Another study commissioned by the U.S. National Renewable Energy Lab for the Department of Energy found that a 100 megawatt solar thermal electric plant creates more than $600 million to gross state output, ten times that of a combined cycle fossil plant due to the local content and job creation of a solar thermal electric plant.

Today, in the U.S. Southwest alone, thousands of construction workers are building solar thermal electric plants in areas that have been hard hit by the downturn in the construction industry. Additional thousand or so jobs have been created in companies across America that make the components and provide the services needed for these solar thermal electric plants.

What are the environmental benefits of solar thermal electric power?

The primary environmental benefits of using solar thermal electric plants instead of fossil fuel plants is the reduction in the amount of greenhouse gas emissions and avoidance of air-borne pollutants. If, for example, a 100 MW solar thermal electric trough plant with six hours of storage were to replace the same amount of power generated from a combined cycle natural gas plant, there would be a reduction in atmospheric emissions of 191,000 tons/yr of CO2, 4.5 tons/yr of CO, and 7.4 tons/yr of NOx.[1] solar thermal electric plants also significantly avoid air-borne pollutants associated with fossil fuel generating plants.  The avoidance range is dependent on the type of plant replaced and whether or not a solar thermal electric plant is hybridized.

How much water does a solar thermal electric plant need?

Solar thermal electric plants can use air or water to cool the power block and clean the mirrors. Because water is more efficient, it is preferred in areas where there is no limitation of water. In most areas where solar thermal electric power will be deployed, however, water is scarce. In these areas, dry cooling will be used. Dry cooling reduces water usage by approximately 90% – from 740 gal/MWh to 80 gal/MWh. This includes 20 gal/MWh for cleaning the mirrors. For comparison, dry cooled solar thermal electric plants use only 10% of the water consumed per acre at a golf course and 6% of that used for agricultural purposes, such as growing alfalfa.

[1] Economic, Energy, and Environmental Benefits of Concentrating Solar Power in California. Stoddard, J. Abiecunas, and R. O’Connell, Black & Veatch Overland Park, Kansas, NREL/SR-550-39291 April 2006