With ‘Underground Sun Storage‘, the world‘s first pure hydrogen storage facility in an underground porous reservoir, RAG Austria AG and its project partners of the Austrian energy community are setting new international standards. This project builds on findings from predecessor projects, in which it was demonstrated that a hydrogen content of up to 20 % can be stored in natural gas reservoirs in a well-tolerated manner. In this unique cross-sector demonstration facility recently constructed in Gampern, Upper Austria, solar energy is converted into green hydrogen by water electrolysis and stored in pure form in an underground natural gas reservoir.
The scale of the storage corresponds to the summer surplus of about 1,000 photovoltaic systems on family homes. In summer, this surplus energy is stored and in winter the green energy can be provided again in the form of electricity and heat. We bring 4.2 million kWh (4.2 GWh) of summer electricity in the form of hydrogen into the winter and thus secure the supply of renewable energies.