Investigation and simulation based optimization of an energy storage system with pressurized air

As a central goal of the energy transition in Germany, the share of renewable energies is to be increased to over 80% by 2050. Due to fluctuating wind conditions or the day-night cycle, storage systems must be integrated into the supply grid for a continuous regenerative power supply from wind and solar energy. In addition to pumped storage systems, batteries and Power2Gas approaches, compressed gases (optimally air) can also be used for this purpose. The aim of the research and development project presented is to develop such a storage unit with the best possible efficiency and long service life. To this end, basic calculations were first made on possible efficiencies depending on the assumed changes in the state of the working gas. Furthermore a piston compressor for compressed air generation was investigated experimentally with regard to its efficiency. In addition, the compressor was modelled and simulated in a corresponding software. Thus, on the one hand, the efficiency of the existing piston compressor could be determined experimentally and, on the other hand, the simulation model could be assessed with regard to its suitability for the purpose of simulation-based optimization. Measures to increase efficiency can be derived from the results. In addition, it becomes possible to forecast the achievable overall efficiency of such an energy storage system with compressed air.