Florida Power & Light’s planned Manatee Energy Storage Center will be nothing more than a battery, but it will be a colossal, giant, enormous battery. Set to open in late 2021, the Storage Center will have a capacity of 409 megawatts—roughly equal to 300 million AA batteries—and the system will take up 40 acres of land, or 30 football fields.

But the most impressive fact about the new system is that it will store 100 percent renewable energy—all of it generated by the company’s massive array of solar panels in Parrish. Once built, the new battery will be the largest solar-powered battery in the world, four times larger than the world’s current biggest.

“If you live in Manatee County, you are at the center of a revolution in clean energy,” says Florida Power & Light spokesperson Chris McGrath. He says the new battery system is a key part of the company’s “30-by-30” plan, which calls for the installation of 30 million new solar panels statewide by 2030.

All the power generated by those panels has to go somewhere, and that’s where the new Storage Center will come in. The Parrish solar field has been up and running since 2016, but today, the power it generates flows directly into the grid. That means that at night, or on a cloudy day, the company has to burn fossil fuels to compensate for the drop in available solar power. The new battery system will capture all of the solar power generated in Parrish and will be able to push it out to homes even at nighttime or when it is overcast or rainy.

That doesn’t mean local customers will be getting 100 percent renewable energy. Since the grid is so diffuse and interconnected, it’s impossible to trace where exactly a single home’s electricity is coming from. But overall, Florida Power & Light’s goal is to be producing 40 percent of its electricity with zero emissions by 2030.

Why is Florida Power & Light moving more into solar now, and not 10 years ago? The economics of renewable energy have changed dramatically. The cost of battery storage technology has plunged, according to McGrath, making it cheaper to invest in solar than to build new fossil fuel plants.

Most cities and counties work with Florida Power & Light through what are known as “franchise agreements,” 30-year deals that grant the company a monopoly on energy production. The City of Sarasota is under contract with the company through 2040; the city has also set a goal of moving to a 100 percent renewable system citywide by 2045.

Sean Sellers, a co-organizer with Sarasota’s Ready for 100 campaign, which pushed the city to adopt that 100 percent renewable goal, credits Florida Power & Light for investing in large-scale solar and says huge solar fields are just a first step toward building a greener grid. “We also need to incentivize rooftop solar,” he says. “All those empty roofs on homes and shopping plazas remain a virtually untapped resource.” Rooftop solar panels are more expensive to install and more difficult to profit from, so utility monopolies like Florida Power & Light have been “dragging their heels,” Sellers says. State and local governments need to do more to force the development of a greener grid through new regulations, incentives and codes, according to Sellers.

Once its new battery goes live, Florida Power & Light will decommission two natural gas power plants adjacent to the Parrish solar field. The red and white stacks that are visible from miles around will be shut down. “Those two units are some of the most inefficient in our system,” says McGrath. “They date back to the 1970s and have not been modernized.” Shutting down those two plants will reduce the company’s carbon dioxide emissions by an estimated 1 million tons. In a region severely threatened by climate change and rising sea levels, Florida Power & Light’s new Parrish battery might jump-start a move toward clean energy statewide.