Economic and financial appraisal of novel large-scale energy storage technologies

Energy storage can store surplus electricity generation and provide power system flexibility. A Generation Integrated Energy Storage system (GIES) is a class of energy storage that stores energy at some point along with the transformation between the primary energy form and electricity. The investigation of the economic and financial merits of novel energy storage systems and GIES is relevant as these technologies are in their infancy, and there are multiple technological, economic, and financial uncertainties and opportunities. This paper presents and applies a state-of-the-art model to compare the economics and financial merits for GIES (with pumped-heat energy storage) and non-GIES (with a Lithium-ion battery) systems coupled with wind generation in the United Kingdom. The deterministic, risk, and sensitivity analyses show that, for GIES’s economics, the key driver is the generator capital cost; for non-GIES, the energy storage capital cost is the most important factor. A Monte Carlo analysis shows that the levelized cost of electricity values for GIES and non-GIES are 0.05 £/kWh - 0.12 £/kWh and 0.07 £/kWh - 0.11 £/kWh, respectively, for a 100 MW wind power generator and 100 MWh energy storage. The internal rate of return values for GIES and non-GIES are uncertain and range between 2%-22% and 5%–14%, respectively.