Comparison of pumped hydro, hydrogen storage and compressed air energy storage for integrating high shares of renewable energies-Potential, cost-comparison and ranking

This paper presents results of a research project which analyzes three large scale energy storage technologies (pumped hydro, compressed air storage and hydrogen storage (power-to-gas)) in regard to their potential and the cost of storing energy. Principal findings: There is plenty of technical potential for all analyzed storage technologies in Lower Saxony, a federal state in Northern Germany. In regard to Levelized Electricity Cost (LEC),1 today pumped storage plants outperform the other technologies analyzed if designed as short or medium storage. In terms of long-term storage compressed air storage is the most favorable storage technology today, followed by hydrogen storage. For 2030, hydrogen storage technologies significantly reduce their LEC. This changes the picture dramatically for deployment as long-term storage. In this case, in 2030 for all storage-discharge paths hydrogen storage is clearly the most favorable technology.