Some long-duration energy storage systems now cheaper than Lithium says BNEF

Numerous long-duration energy storage systems have promised to offer energy storage cheaper than lithium ion, but the rapidly falling prices of lithium batteries and the early stage in the learning curve of these technologies have often left them chasing a moving target they can not catch.

However while most long-duration energy storage (LDES) technologies are still early-stage and costly compared to lithium-ion batteries, some have already or are set to achieve lower costs for longer durations, finds BloombergNEF.

BNEF has surveyed seven LDES technology groups and 20 technology types in its report and found that the least expensive technologies are already providing cheaper storage than lithium-ion batteries for durations over eight hours.

Thermal energy storage and compressed air storage had an average capital expenditure, or capex, of $232/kWh and $293/kWh, respectively. For comparison, lithium-ion systems had an average capex of $304/kWh for four-hour duration systems in 2023, so generally shorter-term storage.

Storage duration, project size, and location are key factors affecting LDES capex. Gravity energy storage systems, which elevate weights when charging and controllably drop them when discharging, have the highest average capex, at $643/kWh.

The cost reduction rate of LDES technologies will largely depend on the expansion of deployment and the development of routes to market in major regions, BNEF notes.