Climate Law’s Tax Credit Powers Up Large-Scale Battery Making

Electric batteries the size of window air conditioners moved swiftly along an Eos Energy Enterprises assembly line near Pittsburgh last week.

Workers inserted frames into infrared welding machines to form the zinc-powered batteries, each weighing as much as 275 pounds once filled with electrolytes. A shipping container holding 144 batteries—amounting to half a megawatt of storage capacity, enough to power roughly 50 homes—was destined for a solar-plus-storage project in South Carolina.

Batteries will be supported by a new 30% investment tax credit under the climate-and-tax legislation that became law in August. And the law’s tax incentives for sourcing batteries and ...