Concentrated solar power
Concentrated solar power (CSP, also known as concentrating solar power, concentrated solar thermal) systems generate solar power by using mirrors or lenses to concentrate a large area of sunlight into a receiver.[1] Electricity is generated when the concentrated light is converted to heat (solar thermal energy), which drives a heat engine (usually a steam turbine) connected to an electrical power generator[2][3][4] or powers a thermochemical reaction.[5][6][7]
Not to be confused with concentrator photovoltaics.As of 2021, global installed capacity of concentrated solar power stood at 6.8 GW.[8] As of 2023, the total was 8.1 GW, with the inclusion of three new CSP projects in construction in China[9] and in Dubai in the UAE.[9] The U.S.-based National Renewable Energy Laboratory (NREL), which maintains a global database of CSP plants, counts 6.6 GW of operational capacity and another 1.5 GW under construction. [10]
Comparison between CSP and other electricity sources[edit]
As a thermal energy generating power station, CSP has more in common with thermal power stations such as coal, gas, or geothermal. A CSP plant can incorporate thermal energy storage, which stores energy either in the form of sensible heat or as latent heat (for example, using molten salt), which enables these plants to continue supplying electricity whenever it is needed, day or night.[11] This makes CSP a dispatchable form of solar. Dispatchable renewable energy is particularly valuable in places where there is already a high penetration of photovoltaics (PV), such as California,[12] because demand for electric power peaks near sunset just as PV capacity ramps down (a phenomenon referred to as duck curve).[13]
CSP is often compared to photovoltaic solar (PV) since they both use solar energy. While solar PV experienced huge growth during the 2010s, due to falling prices,[14][15] solar CSP growth has been slow due to technical difficulties and high prices. In 2017, CSP represented less than 2% of worldwide installed capacity of solar electricity plants.[16]
However, CSP can more easily store energy during the night, making it more competitive with dispatchable generators and baseload plants.[17][18][19][20]
The DEWA project in Dubai, under construction in 2019, held the world record for lowest CSP price in 2017 at US$73 per MWh[21] for its 700 MW combined trough and tower project: 600 MW of trough, 100 MW of tower with 15 hours of thermal energy storage daily.
Base-load CSP tariff in the extremely dry Atacama region of Chile reached below $50/MWh in 2017 auctions.[22][23]
Carbon neutral fuels production[edit]
Carbon neutral synthetic fuel production using concentrated solar thermal energy at nearly 1500 °C temperature is technically feasible and will be commercially viable in the future if the costs of CSP plants decline.[75] Also carbon neutral hydrogen can be produced with solar thermal energy (CSP) using sulfur–iodine cycle, hybrid sulfur cycle, iron oxide cycle, copper–chlorine cycle, zinc–zinc oxide cycle, cerium(IV) oxide–cerium(III) oxide cycle, etc.