The Bundesnetzagentur and the Fraunhofer Institute for Wind Energy and Energy System Technology (IWES) in Kassel invited the delegates to a workshop focusing on “power-to-gas”.
Power-to-gas is the name for a process involving the use of excess power to produce hydrogen by electrolysing water and, if required, in a second step the conversion of hydrogen into synthetic methane by reaction with carbon dioxide (CO2). The existing natural gas infrastructure, namely the gas grid and its associated underground storage facilities, could be used to store this methane and, up to a certain volume also the elemental hydrogen.
"The idea of splitting water into its constituent hydrogen and oxygen atoms by electrolysis is not new, but it has become more important in the light of Germany's current change of direction in energy policy which is moving towards the use of renewable energy sources, most of which fluctuate," explains Matthias Kurth, President of the Bundesnetzagentur:
"In addition to grid expansion and intelligent load and generation management, considerably more storage capacity will in fact be required to balance fluctuations in solar and wind power generation. Pumped-storage power stations are a good solution for short-term load balancing, but there is only limited capacity available in Germany. Long-term storage is therefore a major challenge when it comes to transforming the energy supply system".
Fraunhofer IWES has jointly developed a “highly-promising” approach with the Center for Solar Energy and Hydrogen Research in Baden-Württemberg (ZSW).
"In future, wind and solar power stations will contribute the lion's share of electricity to the energy system," adds said Prof. Jürgen Schmid, Director of Fraunhofer IWES. "Our simulations have shown that if renewable energy sources are to meet all our energy requirements, storage capacity will be required to bridge a supply gap of up to two weeks when there is little wind and sunshine, for example in winter. Chemical storage based on hydrogen, methane or other gases or liquids is the only feasible solution for balancing longer term fluctuations extending over days or weeks".
Click here for the conference papers (in German).