Long-duration Energy Storage: Useful Considerations for Procuring Entities

In recent years, the integration of an ever-increasing amount of intermittent renewables coupled with severe weather has challenged the operation of energy markets across the United States. Most notably, the recent storm-induced power crisis in Texas due to Winter Storm Uri in February resulted in ERCOT implementing rotating power outages.

High temperatures in California resulted in the CAISO issuing flex alerts for power conservation and ultimately implementing rolling power outages as well. Policymakers across both regional transmission organizations (RTOs) have responded by elevating the importance of reliability, but there remains a lack of clear direction regarding the most efficient and cost-effective alternatives.

Many energy industry leaders see long duration energy storage (LDES) as a leading solution. To be successful in rolling out LDES, utilities and procuring entities must, at a minimum:

Engage early on with developers to determine the universe of options.
Establish an ongoing dialogue with policy and regulatory stakeholders.
Structure offtake agreements that maximize benefits to the utility while mitigating risk over the contract’s duration.

LDES Technology Landscape and Current Challenges

Despite the current popularity of LDES, the concept is wellestablished. Any energy storage that discharges more than 10 hours of rated energy qualifies as LDES.¹ Pumped-storage, hydropower, which has been around for decades, is the most common form of long-duration storage in the United States. According to the U.S. Department of Energy, 43 pumpedstorage hydropower facilities were built in the latter half of last century, providing nearly 100 GW of storage.²

Footnotes:

1: https://www.energy.gov/articles/secretary-granholm-announces-new-goal-cut-costs-long-duration-energy-storage-90-percent

2: https://www.energy.gov/sites/prod/files/2021/01/f82/us-hydropower-market-report-full-2021.pdf