GMP Solar + Battery TOU Rate Guide 2026

GMP's time-of-use peak hours are weekdays 4:00-9:00 PM from October through March (winter) and weekdays 2:00-7:00 PM from April through September (summer). All weekend and holiday hours are off-peak. The on-peak rate is $0.3407/kWh and the off-peak rate is $0.1452/kWh — a spread of $0.1955/kWh, which is the largest TOU spread in New England.

A 13.5 kWh battery (Tesla Powerwall 3) on GMP's TOU rate can generate approximately $500-$800/year in pure TOU arbitrage alone — charging at $0.1452 off-peak and discharging at $0.3407 on-peak. Add self-consumption savings (~$480/yr) and backup value (~$200/yr), and the total value reaches $1,200-1,500/year. This is significantly higher than any other New England state because VT's TOU spread ($0.1955) is roughly 5× larger than Connecticut's.

At $55/month ($660/year), the GMP lease provides 27 kWh of battery capacity (2× Powerwall 3) with $0 down, full maintenance, and monitoring included. The TOU arbitrage value alone for 27 kWh is approximately $1,000-$1,100/year, which more than covers the lease cost. You also get multi-day backup power and VPP participation. The main downside is the 1,200+ person waitlist — you may wait months for installation. If you can get on the list, it is worth it for most GMP customers.

BYOD (Bring Your Own Device): You buy and own the battery, and GMP pays you an upfront incentive of $850-$950/kW (max $10,500). You keep all TOU savings with no monthly payment. The GMP Lease: GMP installs and owns 2 battery units (27 kWh) on your property for $55/month or $5,500 upfront. GMP handles all maintenance. BYOD has better 10-year ROI ($9,150 vs $5,850 for a Powerwall 3), but the lease offers more capacity, zero maintenance, and $0 down.

No. Vermont Electric Cooperative (VEC) and Burlington Electric Department (BED) do not offer time-of-use rates as of 2026. TOU is exclusively available through Green Mountain Power (GMP), which serves approximately 75% of Vermont customers. VEC uses tiered rates and BED uses tiered rates. If you are a VEC or BED customer, a battery still provides backup value and self-consumption benefits, but you cannot earn TOU arbitrage savings.

TOU and net metering work together but serve different purposes. Net metering credits you for excess solar exported to the grid at VT's blended rate (~$0.1839/kWh for Category I, with a positive adjustor). TOU determines what you PAY for grid electricity at different times. With a battery, you can strategically export solar during off-peak hours (when you'd get NM credit) and discharge your battery during peak hours (when you avoid paying $0.3407/kWh). The optimal strategy is to self-consume during peak hours rather than export, since the $0.3407 avoided cost is much higher than the ~$0.22 NM credit.

During a grid outage, your battery automatically switches to backup mode regardless of TOU schedule. The battery powers your home from stored energy and, if paired with solar, can recharge during daylight hours for extended backup. GMP never dispatches your battery (for VPP events) during outages — home backup always takes priority. A single 13.5 kWh Powerwall 3 provides roughly 8-12 hours of essential loads backup. The GMP lease's 27 kWh capacity can power a home for 1-2+ days with careful management.

No. The Section 25D residential energy credit expired December 31, 2025 under the OBBBA (signed July 4, 2025). There is $0 federal tax credit for homeowner-purchased batteries in 2026. However, if you finance your solar + battery through a PPA or lease, the third-party system owner can still claim the Section 48/48E commercial ITC (30%) for projects beginning construction before July 4, 2026. GMP's battery lease is separate from the ITC — GMP offers it as a utility program, not a tax-credit-dependent financing product.

The GMP BYOD (Bring Your Own Device) enrollment deadline is September 30, 2026. After this date, the current incentive rates ($850/kW for 3-hour batteries, $950/kW for 4-hour batteries, max $10,500) may change or the program may close. There is also a $100/kW solar retrofit bonus for adding a battery to an existing solar installation. Eligible batteries must be at least 5 kW. Act before the deadline to lock in the current incentive levels.

Yes. TOU arbitrage and GMP virtual power plant (VPP) participation are complementary, not competing. Your battery performs daily TOU arbitrage (charge off-peak, discharge on-peak) as its baseline operation. On top of that, GMP may dispatch your battery during grid emergencies — typically 10-30 events per year during extreme cold snaps or heat waves. These VPP dispatch events often coincide with TOU peak hours, so you earn arbitrage value AND help stabilize the grid. Both lease and BYOD customers participate in the VPP.

With GMP's BYOD incentive, a Tesla Powerwall 3 (13.5 kWh) costs approximately $13,800 installed minus $10,500 BYOD incentive = $3,300 net cost. At ~$1,245/year total value (TOU arbitrage + self-consumption + backup), the payback is roughly 2.7 years — one of the fastest battery paybacks in the country. Without the BYOD incentive, payback stretches to 11-12 years, making the GMP program critically important for battery economics.

For full TOU peak coverage (5 hours), you need enough capacity to power your home through the entire peak window. A 13.5 kWh battery (Powerwall 3) covers most homes — average VT household uses 2-3 kWh/hour. Larger homes, EV owners, or homes with electric heat should consider 27 kWh (the GMP lease option with 2 units). A smaller 5 kWh battery (Enphase IQ 5P) provides partial peak coverage and works as an entry point for budget-conscious homeowners.