Energy Storage Systems: A state-of-the-art study

Abstract

A high-level penetration of intermittent renewable energy sources such as wind and solar into the grid will require new solutions to control the temporal mismatch between supply and demand. Long duration energy storage (LDES) is a promising solution to enhance grid flexibility. The principles of several LDES technologies are described in this review. Sensible heat storage technologies, including aquifer thermal energy storage (ATES), borehole thermal energy storage (BTES), tank thermal energy storage (TTES), pit thermal energy storage (PTES), cavern thermal energy storage (CTES) and fractured thermal energy storage (FTES) methods, are reviewed. Additionally, latent heat storage (LHS) systems as well as thermochemical storage (TCES) are discussed. The review also describes mechanical storage systems such as novel pumped hydro storage (PHS), compressed air energy storage (CAES), liquid air energy storage (LAES), pumped heat energy storage (PHES) and gravity based energy storage technologies. Finally, Power-to-X technologies such as Power-to-Hydrogen are briefly reviewed.

This state-of-the-art study on energy storage systems has been written within the project Heat Circulation Innovation Platform North-Savo (HCIP-NS) realized from 1.8.2021 to 30.10.2023. The project was realized by Savonia UAS Energy Research Centre organisation at Varkaus Campus.