Evaluating the Benefits of Long Duration Storage: Modeling and Analysis of a Seasonal Energy Storage System against a Decarbonizing Power System

Abstract

Long Duration Energy Storage (LDES) will play a critical role in successful decarbonization of the electric sector. LDES is needed to manage weather-driven energy needs and resources across time and will significantly reduce the required investment in energy production and transmission. LDES benefits accrue at multiple time scales ranging from days to seasons to years. An adequate evaluation of these benefits is a challenging analytical task as it requires the use of multiple modeling techniques: (1) Capacity Expansion Modeling to size and site LDES based on its impact on future generation and transmission; (2) Operational Scheduling to ration use of storage inventory across time; and (3) Energy and Ancillary Services Modeling to emulate storage operations at daily and intra-day timescales. In this paper, we discuss the coordination of these three models to assess LDES within a large regional electricity market. Our methodology uses sequentially optimized and coordinated decision cycles. From this, we provide a range of simulated metrics assessing benefits of a large-scale LDES at various time scales.