Concentrated solar power (CSP) is a type of solar thermal technology that uses mirrors or lenses to concentrate sunlight onto receivers that collect the sun’s heat. This concentrated sunlight can then be used to generate electricity, produce steam for industrial processes, or provide heat for other purposes.
CSP systems can be classified according to the type of collector used to Concentrate Sunlight: parabolic troughs, parabolic dishes, Fresnel reflectors, or central towers (also called “power towers”). The coolest temperatures are reached using fresnel reflectors and the highest efficiency is achieved with parabolic troughs. Central towers require less land area than either parabolic troughs or dishes but more than fresnel reflectors.
The first CSP plant was built in 1981 in California’s Mojave Desert. The 354 megawatt (MW) SEGS plants use parabolic trough technology and remain the largest CSP installation in the world today. In 2007, Spain became the global leader in installed CSP capacity with a total of 1147 MW. By 2013, global CSP capacity had grown to nearly 4 GW.
While early CSP deployment has been focused in areas with high direct normal irradiance (DNI), such as the southwestern United States and North Africa, newer plants are being built in a wider variety of locations including Australia, China, India, Italy and Portugal. A number of different technologies are being developed for concentrating solar radiation including linear Fresnel reflectors, dish concentrators and heliostats (tracker-mounted mirrors).
CSP plants can be co-located with conventional power plants providing what is known as hybrid generation. For example, Solar Tres – a 110 MW central tower plant under construction in Spain – will use waste heat from a nearby coal plant to improve its overall efficiency. molten salt storage can also enable some types of CSP plants to continue generating electricity long after the sun has set or when cloudy conditions prevail