Life-cycle assessment of gravity energy storage systems for large-scale application

Interest in energy storage systems has been increased with the growing penetration of variable renewable energy sources. This paper discusses a detailed economic analysis of an attractive gravitational potential energy storage option, known as gravity energy storage (GES). The economic performance of this energy storage system is compared to other alternative energy storage technologies such as pumped hydro energy storage (PHES) and compressed air energy storage (CAES). Moreover, a life cycle costs and levelized cost of electricity delivered by this energy storage are analyzed to provide expert, power producers, and grid operators insight about the economic implications of this grid-scale gravitational energy storage technology. Depending on the considered scenarios and assumptions, the levelized cost of storage of GES varies between 7.5 (sic)ct/kWh and 15 (sic)ct/kWh, while it is between 3.8 (sic)ct/kWh and 7.3 (sic)ct/kWh for gravity energy storage with wire hoisting system (GESH). The LCOS of GES and GESH were then compared to other energy storage systems. The obtained results show that GESH is very cost-competitive with pumped hydro and Compressed Air Energy Storage technologies; while GES is competitive with PHES and may be cost-competitive with CAES depending on the operation cycles. The performed analysis has also shown that both GES and GESH offer interesting economic advantages for the provision of energy arbitrage service.