Electricity storage; Heat storage; Compressed air energy storage; Cycle analysis; Phase change materials; Pumped hydro energy storage
Becattini V., Haselbacher A. (2019), Toward a new method for the design of combined sensible/latent thermal-energy storage using non-dimensional analysis, in Applied Energy
, 247, 322-334.
Geissbühler L., Becattini V., Zanganeh G., Zavattoni S., Barbato M., Haselbacher A., Steinfeld A. (2018), Pilot-scale demonstration of advanced adiabatic compressed air energy storage, Part 1: Plant description and tests with sensible thermal-energy storage, in Journal of Energy Storage
, 17, 129-139.
Becattini V., Geissbühler L., Zanganeh G., Haselbacher A., Steinfeld A. (2018), Pilot-scale demonstration of advanced adiabatic compressed air energy storage, Part 2: Tests with combined sensible/latent thermal-energy storage, in Journal of Energy Storage
, 17, 140-152.
Becattini Viola, Motmans Thomas, Zappone Alba, Madonna Claudio, Haselbacher Andreas, Steinfeld Aldo (2017), Experimental investigation of the thermal and mechanical stability of rocks for high-temperature thermal-energy storage, in Applied Energy
, 203, 373-389.
The increased reliance on renewable energy sources as part of the Energy Strategy 2050 requires energy storage to reconcile their availability and the demands of society and industry. Pumped hydro energy storage (PHES) is an efficient storage technology that is widely used in Switzerland. To meet the goals of the Energy Strategy 2050, further PHES plants must be built. This requires surmounting significant obstacles such as very high cost and environmental impact. An alternative to PHES is advanced adiabatic compressed air energy storage (AA-CAES). Plants based on AA-CAES use low-cost electricity to power an electric motor that drives a compressor. The heat contained in the compressed air is extracted and stored. The working fluid is thereby cooled and stored in a hermetically sealed reservoir. To generate CO2-neutral electricity during periods of high demand, the air is released from the reservoir, absorbs heat from the storage, and expanded through a turbine that drives a generator. With an efficient heat-storage design, the efficiency of an AA-CAES plant is projected to be around 75%. This project argues that AA-CAES is a particularly attractive storage technology for Switzerland because by using unused tunnels and military caverns as high-pressure reservoirs, the environmental impact is reduced. Furthermore, the projected costs of AA-CAES plants are lower than those of PHES plants. This project focuses on the thermal storage, which is key to a highly efficient AA-CAES plant. It is proposed that the storage is based on combined sensible/latent heat storage to keep the temperature leaving the storage and entering the turbine constant. Preliminary results obtained with a laboratory-scale prototype storage have confirmed the promise of combined sensible/latent heat storage. The project is composed of three technical projects: design and optimization of the combined sensible/latent heat storage, cycle analysis, and development of advanced phase-change materials. Close collaboration with industrial partner Airlight Energy Ltd. will ensure industrial relevance.