The age of the battery is here. With lithium-ion battery prices falling 76% since 2012 and 35% in the past year alone, energy storage is becoming an increasingly cost-competitive option to pair with large-scale solar, in an increasing number of locations.

Less than a day after Hawaii regulators approved 247 MW/988 megawatt-hours (MWh) of solar+storage projects across the state, utility Florida Power and Light has announced that it will deploy a 409 MW/900 MWh battery co-located with an existing solar plant in Manatee County.

And since it is hard for many of us to comprehend projects of this size, FPL has offered that this is the equivalent of 300 million AA batteries, or enough to power 329,000 homes for two hours.

The FPL Manatee Energy Storage Center is scheduled to come online in 2021, and will replace two natural gas-fired units at a nearby power plant. FPL notes that it will use this battery to meet costly evening power demand, meaning that it will be a solar+storage “peaker”, replacing the flexibility that the gas plants offered.

And while FPL did not give estimates for the cost of the battery, it does state that the project will save customers more than $100 million, a figure which likely covers the useful life of the project.

It is also being presented as a complement to FPL’s 30 x 30 plan, under which the utility plans to deploy 30 million solar panels at utility-scale projects by 2030 – or roughly 10-13 GW at today’s standard utility-scale solar panel wattages.

Everything is bigger in Texas

FPL estimates that the Manatee project will be four times as large as the biggest battery currently online. It also has a larger capacity – though not a higher energy rating – than Dynegy’s 300 MW battery project in Monterey County, which California regulators approved last November.

But the “world’s biggest battery” is an ongoing contest, and there are other contenders. Buried in the hundreds of projects in the interconnection queue of Texas’ grid operator are the Juno Solar and Juno Storage projects, 495 MW of solar and 495 MW of batteries which developer Intersect Power is planning for West Texas’ Borden County.

The Juno projects already have interconnection agreements, and together are easily the largest solar+storage project seen by pv magazine. However the project is not expected until May 2021, and in the next two years it is likely that even larger batteries will be announced.