Achieving the Biden administration’s goal of decarbonizing the power sector by 2035 will require a slew of energy storage technologies beyond just lithium-ion batteries, and multiple players are bringing new technology solutions to the market to fill that gap.

Lithium-ion batteries can provide four to eight hours of storage capabilities, but as the grid becomes more renewables-heavy it will require technologies with longer durations and different characteristics to mimic a “baseload” generation combination, experts say. 

“When we think about the path to net-zero, we’re going to need a lot of different technologies in our ecosystem to really get us to where we need to go,” Marlene Motyka, Deloitte’s U.S. renewable energy leader, said. 

This will include lithium-ion batteries as well as what she refers to as “mid-term” duration storage, like iron-air or zinc-based batteries. In addition, the system is going to need some very long-duration – even seasonal – energy storage, that can pitch in for months at a time, like hydrogen-based storage. 

Multiple players are bringing these technologies to the market, and utility regulators are showing interest in them. In May, the California Public Utilities Commission gave the green light to Pacific Gas & Electric to move forward with an 8.5 MW microgrid, comprising a hybrid battery and hydrogen fuel cell system, developed by Energy Vault and located at a Northern California substation that experiences wildfire-related outages. The system is expected to generate up to 293 MWh over a 48-hour period, according to PG&E’s filing. 

Energy Vault is also working on a gravity energy storage solution, which uses a mechanical process of lifting and lowering composite blocks made from soil and waste materials to store and dispatch energy. In August, the company announced it had executed its first license and royalty agreement for the technology with an as-yet undisclosed U.S.-based renewables developer.