The Value of Long‑Duration Energy Storage

Overview

Long‑duration energy storage (LDES) is essential for achieving zero‑emissions electricity grids, yet its role across different grid configurations is not fully understood. This study models the Western Interconnect (a large power system in North America) under 39 scenarios, varying the generation mix, transmission expansion, storage costs and storage mandates. LDES is defined as any storage technology capable of more than 10 hours of discharge, with seasonal storage referring to charge–discharge cycles spanning several months [1].

Summary of LDES key findings chart
Figure 1 – Bar chart summarising long‑duration storage performance metrics: relative value in wind‑dominated regions, capital cost thresholds (US$/kWh) required for economic viability and peak price reductions (%) under LDES mandates.

Key Findings

The modelling results indicate that long‑duration energy storage (LDES) is most valuable in majority wind‑powered regions and in areas where hydropower resources are declining. Seasonal operation becomes cost‑effective only when capital costs fall below approximately USD 5 per kWh [1]. Mandating the installation of sufficient LDES to enable year‑long storage cycles can reduce electricity prices during periods of high demand by more than 70% [1]. These findings provide guidance for planners on how storage mandates, investment in research and development, and the choice of generation mix and transmission expansion influence the value of LDES across diverse grids.

Conclusions

The study underscores the importance of tailoring storage deployment to regional resource mixes. In wind‑heavy grids, LDES can reduce the reliance on costly firm capacity. Policymakers should support research to bring down capital costs below critical thresholds and consider mandates that encourage seasonal operation. Future work could explore the interplay between LDES and other flexibility options such as demand response, inter‑regional transmission and emerging firm low‑carbon technologies.

Scenario Summary

Scenario characteristic Implication for LDES
Wind‑dominated region High value – LDES provides flexibility when wind output drops
Diminishing hydropower High value – LDES compensates for loss of hydro flexibility
Capital cost <USD 5/kWh Seasonal storage becomes economical
LDES mandate (year‑long cycles) Peak prices fall by >70%; improves affordability

References

  1. M. Staadecker, J. Szinai, P. A. Sanchez‑Perez, S. Kurtz and P. Hidalgo‑Gonzalez, “The value of long‑duration energy storage for a fully renewable grid,” Nature Communications (2023).