tl;dr: Vermont's largest utility, Green Mountain Power, leases two home batteries to customers for $55/month, aggregating 5,500+ installations into a virtual power plant that's now the state's biggest power source and has replaced most of its fossil-fuel peaker plants. The system saved customers $11M last year and provides outage protection, with GMP aiming to offer storage to all 300,000 customers and eventually tap EV batteries via vehicle-to-grid. Nationally, virtual power plants could save $10B+ annually by 2030, though utility incentive structures remain a barrier to broader adoption.