Global Solar Thermal Power Stations

Solar farms generate utility-scale electricity for integration with the local and regional grids. The largest solar farms are GW scale, use photovoltaic panels, and are located primarily in Asia. An alternative to PV is solar thermal, which uses the heat of the solar radiation, either in a parabolic trough (a long curved mirror focusing the light onto a central pipe containing a fluid which is heated, or a solar thermal tower at the centre of a field of mirrors.

Power Generation extended by Heat Storage

Molten salts are proving an efficient way of storing the heat for use after direct solar radiation is no longer available. This can extend power generation several hours after sunset, and represents a major advantage of CSP over PV panels.

In many cases PV has out-performed CSP. This is due to falling costs of panels. PV can continue to generate power with cloud cover, while CSP needs to maintain a high level of concentrated light. This has restricted its application to desert regions. Globally, in 2017 CSP still only accounts for 2% of world installed solar power generation capacity. Falling prices for CSP plants are now bringing the performance to the point of presenting a serious competitor to conventional fossil and nuclear power plants. Chile has a CSP plant in the Atacama region providing baseload at less than 5c per kWh.

CSP Plant types

Trough Systems
The USA SEGS (Solar Energy Generating Systems) were the world’s first commercial parabolic trough plants (Nameplate capacity 354 MW = 474,799 HP, 539 GWh in 2015, 19.2% capacity factor, 75MWe). Other examples: Nevada Solar One (Nevada). Andasol (Europe’s first). Plataform Solar de Almeria SSPS-DCS (Spain) test facilities.

The parabolic trough focuses light from a linear reflector onto a central tube along the focal line (receiver) containing a working fluid, usually molten salt or water. The reflector can follow the sun by rotating through a single axis. The working fluid can be heated to 150-350°C, and flows to a central power generating system.

Solar Power Tower
The solar tower uses an array of dual-axis tracking reflectors called heliostats to concentrate light to a central receiver located on a tower. An example is the PS10 (Planta Solar 10) in Andalucia, Spain (11MW from 624 heliostats). The working fluid can reach temperatures of 500-1000°C. Solar towers can have higher efficiencies than trough systems, and provide better energy storage capability.

Other Designs
Fresnel reflectors use flat mirrors rather than parabolic. This reduces the cost and allows more mirrors to be used, making more use of the available sunlight. The Dish Stirling is a single array of mirrors and a mounted receiver. The main advantage is high efficiencies, reaching 30-34%.

Global Largest Solar Thermal Power Stations

Name /year operationalLocationCapacity /MWp (h)***Type
Ivanpah SP* Facility /2014USA California392Tower
SEGS** /1990USA Mojave CA361PT
Quarzazate /2018Morocco Ghassate360PT
Mojave Solar Project /2014USA Barstow CA280PT
Solana /2013USA Arizona280 (6)PT
Genesis /2014USA Blythe CA280PT
Solaben /2013Spain Logrosán200PT
Solnova /2010Spain Sanlúcar la Mayor150 PT
Andasol /2011Spain Guadix150 (7.5) PT
Extresol /2012Spain TMS****150 (7.5)PT
Dhursar /2014India Jaisalmer125FR
Crescent Dunes /2015USA Nevada125 (10)Tower
Kathu Solar Park /2018S. Africa N. Cape100 (4.5)PT


*SP = Solar Power ** SEGS = Solar Energy Generating Systems ***hours thermal storage ****Torre de Miguel Sesmero Tower = Solar power tower PT = Parabolic trough FR = fresnel reflector