For around five years, Swiss scientists have been working with industrial partners like the Amberg Group to investigate whether electricity can be stored in rock caverns in the form of compressed air. The interim results show: The technologies required for compressed air storage are available on the market, and such storage facilities could potentially be profitable in the future for the provision of secondary control power. At present, investors are being sought to further develop the technology, certain aspects of which have already been tested, to market maturity by building a comprehensive demonstration plant.
(1) Example of a radial compressor, as they could be used in an compressed air storage plant. © MAN Energy Solutions Schweiz AG
(2) Schematic representation of a compressed air storage facility. © Illustration: Andreas Haselbacher, ETH
For some years now, a new, fascinating idea has been circulating about how the mountain world could be used for the electricity industry: By building rock reservoirs that store electricity not in the form of dammed water but as compressed air. While reservoirs store energy seasonally, compressed air reservoirs are designed as short-term storage facilities: they could absorb temporary production surpluses of renewable electricity (e.g. solar power) in the Alps for hours or days until the electricity is needed by consumers, and this without impairing the landscape. Furthermore, they could provide so-called control power, i.e. control energy as required to stabilise the electricity grid.
In Switzerland, scientists from various universities have been researching compressed air storage facilities over the past five years. They were supported by the Swiss Federal Office of Energy (SFOE), the Swiss National Science Foundation (SNSF) and Innosuisse within the framework of the Swiss Competence Center for Energy Research (SCCER). Together with industrial partners such as Airlight SA (solar power production/storage), MAN Energy Solutions Schweiz AG (compressors/turbines), Lombardi SA (construction) and Amberg Group AG (tunnelling, measurement technology), the researchers investigated whether rock storage facilities are technically feasible and could be operated economically.
Sources: Swiss Federal Office of Energy SFOE
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