With microorganisms against the winter power shortage
At depths of over a thousand metres, microorganisms combine hydrogen and CO2 to produce renewable methane. This so-called geo-methanisation is a promising process for storing renewable summer electricity for the winter.
The joint study by Energie 360° and partners now shows that implementation is possible and economically interesting if existing gas storage facilities are used. These exist in Switzerland’s neighbouring countries. To this end, Switzerland must agree on rules for the import of renewable gas with its neighbouring countries. In geo-methanisation, surplus renewable energy, for example solar power, is converted into hydrogen (H2) in summer. This is injected into a natural underground storage facility together with CO2, which comes from biogas plants, for example. At a depth of more than 1000 metres, microorganisms – primeval bacteria known as archaea – combine hydrogen and carbon to form renewable methane gas (CH4). In winter, when the demand for electricity and heat is high, the renewable gas can be stored and used in a variety of ways.
Realisation possible in nearby countries
The research project “Underground Sun Conversion – Flexible Storage” (USC-FlexStore) by Energie 360° and the Austrian energy storage company RAG Austria AG investigated technical, operational, economic, ecological and regulatory aspects of the innovative process. The University of Bern, Empa and the University of Applied Sciences of Eastern Switzerland collaborated as Swiss research partners. The results of the project now show that such storage facilities are feasible – ideally, for economic reasons, where storage facilities already exist, for example in the Austrian Pilsbach.
Enormous potential for energy demand in Switzerland
The existing and good international cooperation on energy supply issues remains central. Thus, the existing infrastructure, i.e. the European gas grid, can be used and the stored energy can be used as renewable gas or electricity for industrial processes and peak load coverage, for example. Jörg Wild, CEO of Energie 360°: “The potential is enormous: annually, renewable energy of several terawatt hours can be stored seasonally with this process. This will substantially alleviate the winter electricity shortfall in Switzerland.” However, a prerequisite for the use of winter energy is that Switzerland concludes binding regulations with its neighbouring countries for the purchase of renewable gases.
Energie 360° is examining participation in the project
In a next step, Energie 360° wants to deepen the expertise it has gained for geo-methanisation and storage and to contribute its know-how to future projects in Switzerland and internationally. In addition, the company is looking into participating in a renewable gas storage project in a neighbouring country.