Vermont’s largest energy source is now a virtual power plant
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- Green Mountain Power dispatched 90 MW from its virtual power plant during Vermont's early July heat wave, cutting an estimated $6 million from all customers' peak electricity costs — equivalent to taking 50,000 homes off the grid.
- Green Mountain Power's VPP now has 110 MW of capacity, making it Vermont's largest single power resource, with more than half (53 MW) coming from residential battery systems across more than 5,000 enrolled customers housing 10,000+ batteries.
- The battery network can supply nearly 10% of Vermont's summer peak electricity demand, which GMP says is the highest storage-to-state-peak ratio in New England.
- GMP's home battery lease program — the first US utility with a state-approved, tariffed home battery lease — offers two Tesla Powerwalls for $55 per month or $5,500 upfront for a 10-year lease in exchange for grid access during peaks.
- Peaker plants in Vergennes and Rutland have already been permanently closed through an ISO-New England retirement process as the VPP grew, with GMP planning additional retirements as battery capacity expands.
- The $6 million heat-wave savings follows $11 million that GMP says its VPP saved customers last year, with customer Pollyanna Bladyka noting the program keeps homes powered through damaging storms while cutting costs for all ratepayers.
Why it matters: The $6 million in peak-cost savings flows to all GMP customers, not just the 5,000+ households with enrolled batteries — a community-wide rate benefit from behind-the-meter storage. GMP has already used the VPP to permanently retire peaker plants in Vergennes and Rutland, and at 110 MW the battery network is now Vermont's single largest power resource, reshaping how the state's peak demand is met.
![Hurricanes, heat domes, and holding up the grid with home batteries [update]](https://electrek.co/wp-content/uploads/sites/3/2025/06/power_lines.jpg?quality=82&strip=all&w=1600)