Concentrated Solar Power

Concentrated solar power (CSP) systems use lenses or mirrors to focus a large area of sunlight onto a small area. Electrical power is produced when the concentrated light is directed onto photovoltaic surfaces or used to heat a transfer fluid for a conventional power plant.

Types
Concentrated solar power systems are divided into:
 * concentrated solar thermal (CST)
 * concentrated photovoltaics (CPV)
 * concentrating photovoltaics and thermal (CPT)

Concentrated solar thermal (CST) is used to produce renewable heat or electricity (generally, in the latter case, through steam). CST systems use lenses or mirrors and tracking systems to focus a large area of sunlight onto a small area. The concentrated light is then used as heat or as a heat source for a conventional power plant (solar thermoelectricity).

Concentrated photovoltaics (CPV) systems employ sunlight concentrated onto photovoltaic surfaces for the purpose of electrical power production. Solar concentrators of all varieties may be used, and these are often mounted on a solar tracker in order to keep the focal point upon the cell as the Sun moves across the sky.

Concentrating Photovoltaics and Thermal (CPVT) technology produces both electricity and thermal heat in the same module. Thermal heat that can be employed for hot tap water, heating and heat-powered air conditioning (solar cooling), desalination or solar process heat. .

Future of Concentrated Solar Power
A study done by Greenpeace International, the European Solar Thermal Electricity Association, and the International Energy Agency's Solar PACES group investigated the potential and future of concentrated solar power. The study found that concentrated solar power could account for up to 25% of the world's energy needs by 2050. Also, with this expansion of concentrated solar power, thousands of new jobs would be created and millions of tonnes of carbon dioxide would be prevented from being released. The increase in investment would be from 2 billion euros worldwide to 92.5 billion euros in that time period.

Spain is the leader in concentrated solar power technology, with more than 50 projects approved by the government in the works. Also, it exports its technology, further increasing the technology's stake in energy worldwide. Because of the nature of the technology needing a desert like area, experts predicted the biggest growth in places like Africa, Mexico, the southwest United States. The study examined three different outcomes for this technology: no increases in CSP technology, investment continuing as it has been in Spain and the US, and finally the true potential of CSP without any barriers on its growth. The findings of the third part are shown in the table below:

Finally, the study acknowledged how technology for CSP was improving and how this would result in a drastic price decrease by 2050. It predicted a drop from the current range of .23 to .15 euros per kilowatt, down to .14 to .10 euros a kilowatt. Recently the EU has begun to look into developing a €400 billion ($774 billion) solar power plant based in the Sahara region using CSP technology known as Desertec. It is part of a wider plan to create "a new carbon-free network linking Europe, the Middle East and North Africa". The plan is backed mainly by German industrialists and predicts production of 15% of Europe's power by 2050. Morocco is a major partner in Desertec and as it has barely 1% of the electricity consumption of the EU, it will produce more than enough energy for the entire country with a large energy surplus to deliver to Europe.

Other organizations expect CSP to cost $0.06(US)/kWh by 2015 due to efficiency improvements and mass production of equipment. That would make CSP as cheap as conventional power. Investors such as venture capitalist Vinod Khosla expect CSP to continuously reduce costs and actually be cheaper than coal power after 2015.

On September 9, 2009, Google said that the firm was conducting research on the heliostat mirrors and gas turbine technology, which they expect will drop the cost of solar thermal electric power to less than $0.05/kWh in 2 or 3 years.

In 2009, scientists at the National Renewable Energy Laboratory (NREL) and SkyFuel teamed to develop large curved sheets of metal that have the potential to be 30% less expensive than today's best collectors of concentrated solar power by replacing glass-based models with a silver polymer sheet that has the same performance as the heavy glass mirrors, but at a much lower cost and much lower weight. It also is much easier to deploy and install. The glossy film uses several layers of polymers, with an inner layer of pure silver.

Related SourceWatch articles

 * alternative fuels
 * Alternatives to coal plants
 * CLEAN Energy Act of 2007
 * climate change / global warming
 * Concentrating solar power land use
 * Conservation and efficiency programs as an alternative to coal
 * Energy Bulletin
 * National Commission on Energy Policy
 * National Energy Policy
 * Nuclear power as an alternative to coal
 * Nuclear PR
 * oil depletion
 * peak oil / peak oil: we have oil
 * Peak Oil Caucus
 * Photovoltaic power as an alternative to coal
 * Renewable and Sustainable Energy APG
 * Richard H. Truly
 * Solar energy
 * U.S. tax breaks for renewable energy
 * Wind power as an alternative to coal

External resources

 * "U.S. installed solar capacity up 17 percent in 2008", Reuters, March 20, 2009.
 * Andrew Eilbert, "The Trade-Off Between Water and Energy: CSP Cooling Systems Dry Out in California", ;Revolt (Worldwatch Institute blog on climate and energy), December 31, 2010.