Plug-in batteries kept NYC renters cool during record heat wave

A New York City startup called Every Electric, working with utility Con Edison, is letting apartment renters plug their window air conditioners into small home batteries instead of straight into the wall. The battery charges from the grid during calm periods, then powers the AC during peak demand, so the unit keeps running at whatever temperature you like while easing pressure on the grid. During the recent heat wave, when temperatures hit 104°F in the city, the program's roughly 600 apartments and 1,000-plus batteries helped absorb a spike in air-conditioner demand without straining the system.

The program is free to join, though participants pay a refundable $50 deposit for the power bank. Renters can also earn money through Con Edison's Smart Usage Rewards program, which pays customers for cutting energy use during certain hours on the hottest days. Every Electric acts as the go-between, passing along a share of those payments — up to $150 per battery — to participants. In an outage, the battery can run a typical window AC for about four hours.

This approach is notable because it's built for renters, not just homeowners who can install solar panels or big battery systems. About 10,000 window units have requests in for batteries, and the company is working through that list this summer. The program currently runs only in Con Edison's New York City service area, so it won't apply everywhere, but it points to a growing trend of utilities paying ordinary households to help balance the grid during extreme heat.