In solar thermal power plants, solar radiation is used to generate electricity in what is otherwise a conventional power plant process. Mirrors concentrate the sunlight on a radiation collector and heat up a heat-bearing medium, generally thermal oil. A turbine transforms this energy into electricity. In dry, hot zones with a high proportion of direct sunlight, solar thermal power plants are an efficient way of transforming solar energy into electricity.
Considerable quantities of solar thermal power plants are now being commercially built and operated. There continues to be a need for research and development so that the construction and operation of the power plants can be made cheaper, and the electricity generation costs thus significantly reduced. At present, electricity from solar thermal power plants is still three or four times as expensive as electricity from fossil-fuel power stations. As the market continues to develop (economies of scale) and further efficient research and development work is done, it may be possible (according to an EASAC study from November 2011) to reduce electricity generation costs by 50-60% in the coming 10 to 15 years.
Due to a lack of direct sunlight, the German climate is not suited to the commercial operation of solar thermal power plants. However, German firms and research establishments are world leaders in this field of technology, so there is a lot of potential for exports. A large proportion of solar thermal power plants around the world use the key components developed in Germany.
At present, the funding of research and development in the field of solar thermal power plants is mainly intended to help the technology to become competitive via cost reductions, efficiency gains and reliability of operation, and thus to become better established on the market (cf. ). In particular, the advantages offered by needs-based electricity generation are to be built up and made practicable.