The hybrid works combine the energy carriers gas, electricity and district heating (convergence of networks or sector coupling). The implemented technology successfully demonstrates how energy can be transferred between the energy carriers for storage purposes. The project is oriented towards storing future power surplus production from photovoltaics and making it seasonally available on a transferable basis. Using electrolysis, the surplus production of power is broken down into hydrogen and oxygen. The hydrogen can be fed into the local 5-bar gas supply network (seasonal storage) and the unavoidable incidental process heat can be used all year round in the district heating supply (daily storage). The hybrid works have aroused great interest in the wider public and amongst experts from a wide range of disciplines. The approach has been explained in many tours, presentations and press releases. The hybrid works have also gained international attention, which has led to the start of a remarkable follow-on project for biological methanation with European support (Horizon 2020). The implementation of the demonstrated approach in a commercial energy supply is quite possible and should be aspired to; however it requires a change in the legal framework.
