Duty-free Energy from the Sun

Concentrated Sunlight

Marc Röger, the fellow in the Spanish desert, supervises the “Systems” team at the DLR Institute for Solar Research and is working on concentrated solar thermal energy in Tabernas. Unlike the better-known photovoltaic approach, solar radiation is used to heat a fluid. Water is transformed into steam by the heat that is produced. The steam drives a turbine, which in turn drives an electric generator. In Röger’s view, the major advantage is that this decouples the timeframes for the concentration of solar radiation and the production of electric current. “If installations of this kind are used on a grand scale, you don’t have to worry about storage and grid stabilization anymore.” The technology, often called “concentrating solar power,” mainly holds appeal for arid regions. In 2009, the DLR escalated its know-how transfer to Africa, especially into North African countries. “This ranges from support for lecturers in universities to practical training at our test facility,” Röger explained. The cooperation with Moroccan partners is especially indepth. The kingdom is pursuing a plan to use renewable sources to handle more than half of its electricity production. The solar thermal Ouarzazate power plant, which is partly financed by Germany’s KfW development bank, is considered to be an international showcase project. It has already demonstrated one of the technology’s advantages: While entire installations have to be imported in the case of photovoltaics, a large portion of a solar thermal system can be installed or produced locally. For example, heliostats, the mirrors that reflect sunlight onto an absorber, have been assembled and installed in Morocco. Does it hurt German industry when a government-financed research institute transfers know how to Africa? “No,” Röger replies. “The knowledge must be broadly accessible if we want to enter into partnerships with these countries.” Only pan-Mediterranean partnerships enable Europe to establish stable supplies of energy totally based on renewables. Besides, European industry certainly isn’t walking away empty-handed. The steam turbine comes from Siemens Energy, and the hydraulics for the mirror adjuster from the Spanish machine-builder Hine Renovables, both customers of Freudenberg Sealing Technologies.