Long-duration energy storage in a decarbonized future: Policy gaps, needs, and opportunities

Abstract The future U.S. electric grid is being transformed with deep decarbonization of generation (i.e., removing or reducing reliance on fossil fuels and replacing them renewable clean energy resources), which in practice not achievable without a dramatic increase the long-duration storage (LDES) technologies. Regulators at both state federal level are well advised to take steps address current policy gaps, build frameworks that will enable greater role for LDES contribute reliability be fairly compensated its services. . Decarbonization by definition dependent an increasing variable energy, primarily wind solar resources, needs stored longer durations maintain provide operational flexibility operators. However, despite growing realization need technologies, persistent gap levers creates vacuum terms defining how where technologies can utilized support grid, along inadequate regulatory framework wherein these resources valued services they provide. This paper—which intended US decision makers, but should value all professionals general public—addresses needs, opportunities require urgent attention from US-based policymakers level. paper also provides background information E&U industry structured regulated, perspectives applications, have direct relevance paper’s primary focus policymaking. Discussion Despite generally accepted directly tied rapid there lack policymaking, market designs, compensation mechanisms goal fuels) cannot achieved aggressive levels envisioned utilizing LDES. Policymakers must now recognize unique ways increasingly resilience, receive appropriate it provides. Graphical abstract