Vermont’s biggest utility will let 200 of its customers use their home batteries to help balance the regional power grid, in the first such program in New England and perhaps the first in the country.

Green Mountain Power (GMP) said Thursday the pilot program will involve customers who have a pair of Tesla Powerwall batteries in their home as part of the utility’s power-sharing program, in which GMP draws electricity from the batteries when power prices on the open market get too high. They will also become part of their Frequency Regulation Pilot overseen by ISO-New England, the group that runs the six-state power grid.

Under the Frequency Regulation Pilot program, GMP uses software to combine all these customer batteries so they can act as a single power plant that will respond to ISO-NE commands when the grid needs to balance supply and demand, a task normally performed by quick-startup plants burning fossil fuels, known as “peaker plant” because they respond to peaks in demand.

Replacing peaker plants with “virtual power plants” using distributed energy is often seen as an important tool to help transition the nation’s electrical system so it can use more renewable and clean energy.

The GMP customers will be paid $13.50 per month on their energy statements in return for being part of the program.

GMP has 266,000 customers throughout Vermont, both business and residential. Its four-year-old Powerwall program includes 3,000 batteries from Tesla; most participants have two batteries in their house. Although it involves only one half of one percent of GMP customers, the utility says the Powerwall program saved more than $3 million in 2020 alone because GMP didn’t have to buy as much electricity when power prices skyrocketed during heat waves or cold snaps.

GMP said it “takes steps to ensure that customers have backup power available if weather is predicted to cause outages. All GMP customers also benefit from the Frequency Regulation Pilot program because additional payments from ISO-NE flow to customers to lower costs.”

The utility statement about the new frequency regulation pilot said:

Typically, the cycling of energy is done by ISO-NE with fossil fuel generators through the Regulation Market, a wholesale energy market that pays participants for quick and accurate responses to grid needs that can shift minute-to-minute.


Using their network of Powerwall batteries and Tesla Autobidder software, GMP is the first utility to perform this essential grid service in the wholesale power market with clean stored energy distributed from customers’ homes.  In addition to cutting carbon, this pioneering project is also benefitting all GMP customers through reduced power supply costs. …


GMP successfully entered the Regulation Market with this network of residential power sources after three months of testing with ISO-NE, and partnerships with ISO-NE, Tesla and Customized Energy Solutions (CES), a software solutions company. Tesla coordinates the distributed batteries to respond to signals from ISO-NE and aggregates critical data about the response. CES provides the key integrations between Tesla and ISO-NE.

GMP said it plans to expand the pilot in the future.

Pin It on Pinterest