Empowering off-river pumped hydro energy storage: An economic and environmental analysis of renewable energy production - storage systems

Off-river pumped hydro energy storage (PHES) is a developing technology that requires ongoing evidence to support its growth. Economic and environmental analyses demonstrating off-river PHES as a promising energy storage system (ESS) are explained in this study. A case study was conducted using Java-Bali data, Indonesia. This study compares the economic and environmental potential of off-river PHES with lithium-ion battery (LiB) and compressed air energy storage (CAES) systems. Additionally, this study examines the integration of these technologies with offshore wind, solar, and geothermal energy mixes using hourly weather and supply-demand data. Results indicate that off-river PHES is superior economically and environmentally. For Java and Bali, off-river PHES requires the lowest investment for annual electricity generation, with total project costs ranging from $0.04 billion/year to $157 billion/year and annual operation and maintenance (O&M) cost or OPEX from $0.02 billion/year to $76 billion/year. Despite high annual OPEX, off-river PHES emits the least CO 2 at 3 Mt/year, reducing emissions by approximately 97 % compared to coal-based power plants. Next, social and technical considerations provide a more comprehensive feasibility comparison between the involved ESS. Ultimately, this paper provides scientific evidence supporting off-river PHES for renewable energy-based hourly electricity generation. • Off-river pumped hydro energy storage (PHES) is an alternative to conventional PHES • Off-river PHES on Java-Bali has total project cost of around $1.16-$157 billion • Off-river PHES with a geo-based energy mix is the most budget-friendly option • Off-river PHES, compared to Li battery and CAES, emits the least CO 2 with 3 Mt/year • Off-river PHES with wind-based energy mix is the most environmentally friendly one