Battery-Powered Air Conditioning Turns Homes Into VPPs

Next month, when summer heat and winter cold near their peak in each of Earth’s hemispheres, grid operators will face their highest electricity demands of the year. Space heating and cooling make up about 50 percent of all energy end uses worldwide, putting enormous strain on grids and sometimes forcing utilities to use more expensive, polluting plants.

But it doesn’t have to be that way. To take some of the load off during peak demand, manufacturers are pairing batteries with residential air conditioners and heat pumps. The batteries charge when power is plentiful and discharge, running the heating or cooling system, when the grid is strained.

A company offering this service in New York City is the startup Every Electric. The company distributes briefcase-size, 2-kilowatt-hour portable power banks that connect to plug-in air conditioners. It then uses software to aggregate those units into a virtual power plant (VPP).

The strategy of reducing power demand at key times of the day, known as demand response, enables individual electricity customers to partake in good grid citizenship. It also turns what have been traditionally energy-guzzling machines into grid assets.

Every Electric’s program makes “watts drop off the face of the Earth” during peak grid use, says Andrew Wang, co-founder and CEO of the company. “The air conditioner plugs into the power bank, the power bank plugs into the wall, and then as a company, we essentially manage whether the electrons come from the wall or come from the power bank to keep the air conditioner powered while helping reduce strain on the grid,” Wang says.

Residents can request a power bank for each plug-in air conditioner in their home at no cost or for a refundable deposit. Every Electric further incentivizes participation in the program by giving back to residents a portion of its earnings, which it draws from partnering with New York’s electric utility, Con Edison. Wang says the total yearly rebate for a home amounts to a typical July or August electricity bill.

Over 10,000 of Every Electric’s batteries have been requested by New York City residents, but only about 1,000 have been shipped, resulting in a waitlist, says Wang. Last month, he told the Associated Press that his company planned on shipping about 2 megawatts worth of power banks this summer. But now he says the company has already exceeded that figure. Fulfilling all requests this summer would mean Every Electric would provide over 20 MW of flexibility to the grid—enough energy to power a few thousand homes.

“I think people really feel the air conditioning hit their bills,” Wang says of the response to the program so far.

Air conditioners become grid assets

Heating and cooling systems that respond to grid needs are just one element of VPPs—a term that describes the aggregation of small power contributions or load shedding from the grid in a decentralized way. VPPs might include residential solar panels, battery storage…