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ePaper created 2012-11-06, 16:43:12 | version 1.24.0
Annual Report 2011 | Forschungszentrum Jülich 21 Storing Energy in a Restructured Energy Supply An increasing proportion of our power should come from renewable energy sources. But the wind blows where it will, and wind turbines therefore produce a lot of power at some times and at others only a little. And solar cells are dependent on sunshine. Efficient solutions for storing energy are therefore essential. Scientists at Jülich are paving the way towards the use of hydrogen, which is generated using intermittent surplus electricity, and they are also working on solid-state batteries. H ydrogen can be used to store large amounts of energy from the electricity grid for months on end in times of excess pro- duction,” says Dr. Bernd Emonts from the Institute of Energy and Climate Re- search 3. Hydrogen is produced by chemically splitting water with excess electricity by means of electrolysis. It could then later be pumped through pipelines to filing stations and used to power fuel cell vehicles. Using computer models, Jülich ener- gy researchers have calculated how such a pipeline infrastructure can be constructed as cost-effectively as possi- ble in Germany. They compared differ- ent types of such infrastructures. In so doing, they differentiated between a transmission grid for transport across regions using existing natural gas pipe- lines and a distribution grid for regional distribution. One of their findings: in or- der to meet the energy requirements of 40 million vehicles in 2050 using hydro- gen from wind power, around 9,800 hy- drogen filling stations will be required along with 12,000 kilometres of trans- mission pipelines and 36,000 kilometres of distribution pipelines. For compari- son: the natural gas network covers over 400,000 kilometres. The total cost of the pipeline system would be around € 23 billion. Other researchers at Jülich are im- proving the electrolysis systems used to produce hydrogen. They hope that new polymer electrolyte membranes will in- crease the efficiency of these systems and that catalysts free of noble metals will decrease costs. As increased variability in the quanti- ty of electricity being fed into the grid is expected in the future, a different type – albeit essentially well-known – of energy storage will become even more important. Improving re- chargeable batteries is what the Helmholtz Energy Alliance on “stationary electrochemical storage and conversion” is focusing on. The alliance was set up in early 2012 and in- volves Forschungszentrum Jülich, two other Helm- holtz centres and the uni- versities of Münster, Aachen and Bochum. “At Jülich, our re- search concentrates mainly on batteries with a large thin solid electrolyte as they have a high storage capacity and are more reli- able than conventional batteries with a liquid electrolyte,” says Dr. Hans-Peter Buchkremer from the Institute of Ener- gy and Climate Research 1. Solid-state batteries can also be operated at tem- peratures above room temperature – which actually increases the conductivity of the electrolyte. Hydrogen is one of the energy storage media that will become even more important in the future.