Concentrated solar power (also called concentrating solar power, concentrated solar thermal, and CSP) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight, or solar thermal energy, onto a small area. Electricity is generated when the concentrated light is converted to heat, which drives a heat engine (usually a steam turbine) connected to an electrical power generator or powers a thermochemical reaction.
There is considerable academic and commercial interest internationally in a new form of CSP, called STEM, for off-grid applications to produce 24-hour industrial scale power for mining sites and remote communities in Italy, other parts of Europe, Australia, Asia, North Africa and Latin America. STEM uses fluidized silica sand as a thermal storage and heat transfer medium for CSP systems.
CSP growth is expected to continue at a fast pace. As of January 2014, Spain had a total capacity of 2,300 MW making this country the world leader in CSP. United States follows with 1,740 MW. Interest is also notable in North Africa and the Middle East, as well as India and China. In Italy, a handful of companies are trying to get authorization for 14 plants, totalling 392 MW, despite a strong local and political opposition. The global market has been dominated by parabolic-trough plants, which account for 90% of CSP plants.
CSP is not to be confused with concentrator photovoltaics (CPV). In CPV, the concentrated sunlight is converted directly to electricity via the photovoltaic effect.