Regulatory framework and market development
In order to operate cost-effectively, solar thermal power plants require a high proportion of direct solar radiation, and therefore are typically used in very sunny regions (e.g. southern Europe, North Africa and the southwestern USA).
Parabolic trough power plants with a total output capacity of around 350 MW were installed in California from 1984 to 1991. They are still in operation today, having since produced more than 16,000 gigawatt hours (GWh) of electricity. German companies supplied key components such as reflectors and flexible tube connectors to these plants. Many years of experience with this type of power plant is a major reason why the majority of power plant projects initiated since 2004 in Spain, the USA and a few countries in North Africa utilise parabolic troughs. However, in the course of the current dynamic market development, many solar tower power plants are also being planned and built, as well as large-scale systems utilising dish-Stirling and Fresnel technology.
The world’s first commercial solar tower power plant, PS10, was commissioned near Seville, Spain, in 2007 by Abengoa. It has since been expanded with the addition of PS20, a solar tower plant with double the output capacity. In Guadix in the Spanish province of Granada, three 50 MW parabolic trough plants are in operation or under construction. Each incorporates thermal storage which allows around seven hours of operation even when there is no sun. They supply approximately 600,000 people with electricity. A total capacity of around 800 MW is currently in operation in Spain while another 900 MW is under construction. By 2013, approx. 2,400 MW should be in operation.
A massive expansion of solar thermal power plant capacity is also expected in the USA, where construction of several plants with capacities ranging between 250 and 280 MW was begun in 2010. The total capacity of the projects, which are in various stages of planning and implementation, is approximately 9 GW. German companies have made a considerable contribution to these projects as developers, constructors and suppliers of key components, such as absorber tubes, as well as in engineering and quality assurance.
Since the end of 2008, a solar tower power plant with an electrical output of 1.5 MW has been running in Jülich, Germany. It operates as a reference power plant and research platform, reflecting the many years of experience German research institutions and companies have in this field. It uses air as a heat transfer medium in what is known as a volumetric absorber. It also utilises energy storage to balance out fluctuations in available solar energy. Experience gained during the construction and operation of this reference plant will form the basis for the further optimisation of future projects. German companies have very large market shares worldwide in the supply of many key components such as precision reflectors for parabolic trough power plants.
