Converting mine shaft into compressed air energy storage – shafts screening and assessment

Increase in the share of renewables in the energy mix of European Union gained interest in the large scale energy storage technologies. One of the promising technologies is the Compressed Air Energy Storage (CAES) where in conventional approach compressed air is stored in the cavern. An alternative solution that was developed at the Silesian University of Technology is to use a post-mining shaft for adiabatic compressed air energy storage (A-CAES). Availability of post-mining infrastructure and large number of shafts in European coal basins (over 178 shafts only in the Upper Silesia Coal Basin) shows a significant potential of this solution. In order to select a proper shaft with a considerable volume a screening tool was developed that uses multicriteria analysis for an initial selection of shafts that could be used for this technology. This tool takes into account shaft depth, diameter, type of shaft collar lining, water inflow rates and other criteria that are important for safety and energy capacity of the system. The presentation shows results of analysis of the shafts screening tool and case study for one of the shaft located in Poland.