Deployment Pathways for Long Duration Energy Storage

Abstract

We apply a least-cost generation expansion model of the continental United States to assess how optimal investments in long-duration energy storage (LDES) technologies are impacted by changes in system generation portfolios and technology costs, assessing 180 capacity expansion scenarios in total. The expansion model considers 8,760 hours of chronological operations for the entire target year, 2040. We find that low-cost LDES technologies can reduce generation investments and system costs. Specifically, once costs for 24-hour and 100-hour storage reach $38/kWh and $14/kWh, respectfully, substantial deployments are observed. The distribution of storage investments across durations is strongly influenced by the system generation portfolio. We also demonstrate that a high-fidelity temporal representation is required to capture the value of LDES in generation expansion. Finally, we find that LDES deployments in the generation expansion are positively correlated with the combined wind and solar capacity share and negatively correlated with peaking and baseload shares.

Keywords: Long duration energy storage, generation expansion modeling, electricity system decarbonization, technology adoption, least-cost portfolio optimization, scenario analysis