Comparative Life Cycle Assessment of Energy Storage Systems for Connecting Large-Scale Wind Energy to the Grid

To help achieve a sustainable society, power generation from variable renewable energy (VRE) is increasing even though a stable power supply cannot be ensured because of its intermittent nature. To supply power on demand, the installation of energy storage systems is essential. This study conducts a life cycle assessment of an energy storage system with batteries, hydrogen storage, or thermal energy storage to select the appropriate storage system. To compare storage systems for connecting large-scale wind energy to the grid, we constructed a model of the energy storage system and simulated the annual energy flow. We calculated the amount of power based on the wind and energy storage installation amounts and evaluated greenhouse gas (GHG) emissions and abiotic resource depletion. The smallest GHG emissions and abiotic resource depletion varied depending on the type and amount of energy storage. Improvements in technology that can store energy based on the intermittency of VRE and energy storage operation could enhance the performance of the energy storage system. A quantitative evaluation of the energy supply capacity and the environmental impacts of the energy storage system while considering regional energy supply can contribute to determining the installation conditions of VRE and energy storage systems.