Brief overview of the technology
CSP comprises a family of technologies that concentrate the Sun's energy through large mirrors and utilises that concentrated thermal energy to produce steam to drive a conventional steam turbine for electricity generation. The technologies are hence similar to conventional power plants in that steam is used to power a turbine and generator, but the fossil fuel combustion is replaced with free, non-polluting solar energy. In other words, the entire boiler plant from coal stockpile to conveyors, bunkers, mills, fans, dust suppression plant and ash dams etc. are replaced with a solar field.
Eskom has focussed on the "Central Receiver" or "Power Tower" type technology as opposed to the Parabolic Trough, Linear Fresnel, or Parabolic dish technologies for its first demonstration plant, because of its higher potential for local manufacture, higher temperatures (same as fossil plants) thus higher efficiencies, lower levelised energy cost and scope for significant capital cost reduction in future plants due to economies of scale.