Since December 2020, the “Underground Sun Conversion – Flexible Storage” (USC-FlexStore) project is investigating seasonal storage of large quantities of renewable energy to be made available year-round.
It aims at developing a seasonal, high-volume transformation and storage solution for erratic renewable generation. Energy will be stored safely in gaseous form in underground facilities at depths of over 1,000 metres.
The aim of the project is to take RAG Austria AG’s patented “Underground Sun Conversion” (USC) technology (which involves methanation of CO2 and green H2) to the next level, and to design services based on it. Field tests are carried out at RAG‘s research facility in Pilsbach (Upper Austria).
In the first project year following topics can be highlighted:
- Experimental field tests were initiated to assess the geo-methanation potential and further optimize the overall process with respect to process parameters.
- Laboratory experiments: A series of high-pressure bioreactor experiments for central geo-methanation experiments involving non-stoichiometric gas mixtures have been conducted.
- Flow charts for USC geo-methanation facilities have been developed and finalized. Four different operational concepts will be further processed, such as combination of geo-methanation and natural gas storage, combined methanation (geo- and aboveground- methanation) and 100% H2 storage with aboveground methanation.
- To apply the underground storage and methanation concept in Switzerland the most promising geological units and their regional distribution have been identified.
- The project team met for an internal workshop including a field trip to RAG´s research facility in Pilsbach in October 2021.