German chancellor Angela Merkel visits Accumotive's plant in Kamenz, Germany.

Battery production is booming, and Tesla is far from the only game in town.

According to Bloomberg New Energy Finance, global battery production is forecast to more than double between now and 2021. The expansion is in turn driving prices down, good news both for the budding electric-car industry and for energy companies looking to build out grid-scale storage to back up renewable forms of energy.

While Tesla gets tons of attention for its “gigafactories”—one in Nevada that will produce batteries, and another in New York that will produce solar panels—the fact is, the company has a lot of battery-building competition.

Exhibit A is a new battery plant in Kamenz, Germany, run by Accumotive. The half-billion-euro facility broke ground on Monday with a visit from German chancellor Angela Merkel and will supply batteries to its parent company, Daimler, which is betting heavily on the burgeoning electric-vehicle market.