Renewable energies could theoretically provide all the electricity required by Germany in the future. This was confirmed by the “Combined Renewable Energy Power Plant” project, in which 28 plants were interconnected. This project was awarded the Climate Protection Prize in 2009.
Image Credit: Fraunhofer Institute for Wind Energy and Energy System Technology (IWES)
“Renewable energy sources could in theory provide Germany with a reliable electricity supply twenty-four hours a day,” says Dr. Kurt Rohrig, department head at the Fraunhofer Institute for Wind Energy und Energy System Technology (IWES) in Kassel. Commissioned by – and in cooperation with – Enercon GmbH, Schmack Biogas AG and Solar World AG, Rohrig has developed a virtual combined power plant (www.kombikraftwerk.de). “Every source of energy – whether wind, sun or biogas – has its strengths and weaknesses.”
“If we skillfully combine the characteristics of different renewable energies, we can ensure that Germany is provided with all the electricity it needs,” he enthuses. “We have already developed and installed the software and hardware required for the control system. In the model project, for example, three wind farms, four biogas installations, twenty solar plants and a virtual pump storage station are interconnected via a primary control unit at our institute. In this simulation the local power plant center can cover one ten thousandth of German electricity needs in real-time, around the clock and in all weather conditions.”
Even when the sun goes behind the clouds and there is no more than the gentlest of breezes, factories and houses still need energy. If there is no wind or solar power available, biogas plants and pump storage stations must activate within seconds to supply the electricity required; otherwise the network will collapse. If it’s cloudy in the south of Germany, the wind in the north can make up the deficit. And if it’s not windy there either, biogas plants help out, producing the necessary electricity within seconds. If there is an overall surplus of energy available, the pump storage station steps into action – water is pumped into an impounding reservoir and can be drained out again when required. The generators then start producing electricity again.
Dr. Kurt Rohrig, scientific project manager, has now been awarded the “German Climate Protection Prize 2009” for his research work. He and his colleagues have succeeded in running the combined 28 plants as a single large power installation. What’s possible on a small scale can be applied to the whole of Germany, he stresses. “To ensure nationwide electricity supply in the future, however, we need to build many more plants, expand the existing grid and significantly enhance the storage technology,” adds Rohrig.