When it comes to storing energy at the scale of the power grid, lithium-ion batteries have a lot of advantages -- and, critics say, some significant drawbacks.

Sure, lithium-ion is the dominant battery chemistry for consumer electronics and electric vehicles, which helps drive down costs and improve bankability for grid projects (see Tesla’s Giga factory for an example of how this future could unfold). And yes, they’ve been proven in many grid-tied projects around the world.

But there are two questions that continue to dog the potential for lithium-ion batteries at grid scale. Can they provide hours of energy at a time to serve grid needs, and can they last for the decade or more required for cost-effective grid use when they’re being discharged so deeply, over and over, day after day?  Cont'd...