Who still be the choice for energy storage systems?

If Duke Energy were asked to redesign a 7.3-hour duration energy storage system today, it would still opt for lithium-ion batteries, an industry source said.

The company recently brought online a series of 50MW/94MWh battery storage projects in Florida, which vary in size and duration, with the last project being a 2.475MW/18MWh system due to be commissioned later this year For this, lithium-ion batteries are used as energy storage units.

They explained that the system was used in a hurricane emergency shelter, so they wanted to make the battery larger and last longer. When asked if other battery technologies had been considered when designing the project, and whether lithium-ion batteries would still be an option if redesigned today, they said:

"At the time this project was designed, no other technology was cost-competitive with lithium-ion batteries."

“Duke Energy will continue to test new technologies and pilot new chemistries in the future, however, if the project were to be redesigned today, lithium-ion batteries remain the technology of choice due to cost, performance characteristics and proven reliability.”

It is worth noting that Duke Energy's above response is a strong point in the discussion about whether lithium batteries are suitable for long-term energy storage compared to flow batteries, but at the same time many long-term energy storage companies believe that the 8-hour duration does not count at all. Not for long.

According to system integrator Wärtsilä, the cost of lithium-ion battery energy storage projects has increased by 25% year-on-year, mainly driven by the cost of cells, as the price of lithium carbonate has soared by 1,000%.

Additionally, flow battery companies claim their solutions will be cheaper in the long run, although lithium-ion batteries continue to be used in many 6-hour and 8-hour projects, including a 50MW/400MWh system in California in March.

Earlier, Thomas Cornell, head of energy storage at Mitsubishi Electric Americas, said that even for a 10-12 hour duration, lithium is still the best technology.

Haresh Kamath, director of distributed energy and energy storage at EPRI, a power industry R&D and demonstration project organization, also said that lithium-ion batteries could eventually become cost-competitive for up to 24 hours, while flow battery company ESS Inc told Kamath. comments against it.