New Hampshire regulators have given Liberty Utilities final approval to test a first-of-its-kind home battery storage project.
Liberty will sell Tesla Powerwall batteries to 500 of its customers in Southeastern New Hampshire and the Upper Valley.
Spokesman John Shore says the batteries will charge overnight, storing power when demand and rates are lowest. They can also be charged with solar power installed at the user's home.
During peak demand and higher rates, or in a power outage, the batteries will switch on and begin powering customers’ homes with that cheaper, stored electricity.
Besides that direct benefit, Shore says the pilot project should lower Liberty's overall demand on the grid, which would cut costs for all their customers.
“That’s the idea of the pilot – to sort of test it out and see if it really does save money, see if it’s something that customers want,” Shore says. “We believe it is, but that’s why we’re doing the pilot.”
Customers will receive two batteries apiece for $50 a month, or a little under $5,000 up front, on a first-come, first-served basis and with a 10-year agreement.
The project required more than a year of negotiation with the Public Utilities Commission and other stakeholders.
Shore says Liberty’s project is the first in the country to focus on times of peak demand.
He says they chose these Tesla batteries, which can store up to 13.5 kilowatt-hours or 5 kilowatts of energy, in part because they’re the highest capacity on the market right now.
Federal data says the average residential ratepayer uses a little more than twice that much power each day.
A Vermont utility also began trying the Tesla batteries in customers’ homes in 2016.