Green Mountain Power Rate Selection Guide
Green Mountain Power is Vermont's largest electric utility, serving roughly 275,000 customers statewide. It has deployed AMI smart meters across its territory and lets customers export hourly interval data as CSV through its Oracle-based My Account portal, though it has not published a formal Green Button or developer API.
Green Mountain Power Rate Schedule Comparison
| Schedule | Type | Rate | Best For |
|---|---|---|---|
| Rate 6 | Commercial (energy-only) | $0.779/day + $0.21815/kWh | Small commercial loads under 200 kW with no demand-charge exposure. |
| Rate 8 | Commercial (demand) | $0.794/day + $22.765/kW (>5 kW) + tiered kWh | Small commercial customers who can control peak demand. |
| Rate 63/65 | C&I time-of-use | $5.068/day; peak/off-peak kW $19.939/$5.741; kWh $0.14069/$0.10692 | Larger C&I loads (>7,600 kWh-mo or >200 kW) that can shift usage off-peak. |
| Critical Peak Rider | C&I demand response | Critical-peak pricing in exchange for lower regular peak/off-peak charges | Flexible C&I loads that can curtail during called critical-peak events. |
Market Overview
Vermont operates a fully regulated retail electric market. Green Mountain Power is the integrated distribution and supply utility for its territory, with rates approved by the Vermont Public Utility Commission. Commercial and industrial customers take bundled service under GMP's filed tariffs and cannot select a competitive retail supplier.
Need to pull your actual usage data to compare rates? See the Green Mountain Power Data Access Guide →
Current Rate Schedules
GMP's current tariffs (Tariff v. V.P.U.C. 10) are effective with bills rendered on or after October 1, 2025, and are set by the Vermont Public Utility Commission. Small commercial accounts take Rate 6 (energy-only) or Rate 8 (demand-billed); accounts above 7,600 kWh/month or 200 kW must take Commercial & Industrial Time-of-Use Rate 63/65. A 7.5% rate increase has been filed for bills rendered on or after October 1, 2026 (PUC Case No. 26-0096-TF). All rates are subject to adjustment.
Effective: October 1, 2025 · Full Tariff Book →
| Schedule | Type | Applicability | Structure | Rate |
|---|---|---|---|---|
| Rate 6 - General Service | commercial | Small commercial/general service customers under 200 kW measured demand and under 7,600 kWh/month average over four consecutive months. | Customer charge $0.779/day; energy charge $0.21815/kWh. 3% kWh reduction for primary-voltage metering. Subject to adjustment. | — |
| Rate 8 - General Service (Demand) | commercial | Small commercial customers able to control maximum demand, under 200 kW and under 7,600 kWh/month average over four consecutive months. | Customer charge $0.794/day; demand charge $0.000/kW first 5 kW then $22.765/kW additional; energy $0.23219/kWh on first block, $0.14018/kWh additional. Transformer-ownership credit $1.0712/kW. Billing demand = highest 15-min monthly peak with seasonal ratchet. | — |
| Rate 63/65 - Commercial & Industrial Time-of-Use | industrial | Required for customers averaging more than 7,600 kWh/month or 200 kW over four consecutive months; optional for all other non-residential/farm customers. | Daily customer charge $5.068; peak kW $19.939, off-peak kW $5.741; peak kWh $0.14069, off-peak kWh $0.10692. Primary voltage discount 4.00%, sub-transmission 21.65% (23.04% over 20 MW). 16-hour peak window (6 AM-11 PM weekdays). 95% power-factor requirement. | — |
| Critical Peak Rider (to Rate 63/65) | industrial | Optional add-on for Rate 63/65 C&I customers willing to curtail during critical peak events. | Adds a high-cost critical peak pricing period in exchange for lower usage and demand charges during regular peak/off-peak periods. See rider for current critical-peak pricing. | — |
Rate Recommendations by Use Case
Mid-size commercial facility near the eligibility threshold
Facilities approaching 7,600 kWh/month or 200 kW should plan for the cutover to Rate 63/65 and its demand/time-of-use structure.
Crossing the threshold over four consecutive months forces a transfer to Rate 63/65; modeling the bill under each rate helps decide whether to manage load down or optimize for the TOU structure.
- Pull 12+ months of hourly CSV from the Usage dashboard to model each rate.
- Watch the four-consecutive-month trigger.
- If demand-controllable, compare Rate 8 vs Rate 6 before any forced move.
Industrial plant on Rate 63/65
Large industrial loads should treat peak demand, power factor, and service voltage as the primary cost levers.
Peak kW is priced ~3.5x off-peak, a 95% power-factor floor applies, and primary/sub-transmission discounts plus the transformer-ownership credit materially lower the bill.
- Target the 16-hour weekday peak window for demand shaving.
- Correct power factor to >=95%.
- Evaluate owning transformers for the discount and $1.0712/kW credit.
- Mind the Dec-Mar seasonal ratchet.
Multi-site commercial portfolio
Operators with several Vermont premises should consolidate accounts under one login and export hourly data for portfolio-level benchmarking.
GMP's My Account supports multiple account numbers under a single login, and per-site hourly CSV exports enable normalized cross-site comparison.
- Use 'Add/Manage Accounts' to centralize premises.
- Export each site's CSV for benchmarking.
- Flag any site trending toward the Rate 63/65 threshold.
C&I customer with flexible/curtailable load
Customers who can curtail during called events should evaluate the Critical Peak Rider on Rate 63/65.
The rider adds a high-cost critical-peak period but lowers regular peak/off-peak usage and demand charges, rewarding loads that can curtail.
- Quantify curtailable kW before opting in.
- Model critical-peak event frequency against the rider's regular-period discounts.
- Pair with battery/Powerwall participation where available.
Historical Rate Trends
GMP files rate changes with the Vermont Public Utility Commission under its alternative regulation plan. The current tariff version (V.P.U.C. 10) took effect October 1, 2025. A further increase is pending for October 1, 2026.
October 1, 2025
Tariff v. V.P.U.C. 10 took effect for all rate schedules, including C&I Rate 63/65.
n/aOctober 1, 2026
Filed 7.5% rate increase (PUC Case No. 26-0096-TF) pending approval.
+7.5%Overall trend: Rising; GMP has filed for a 7.5% increase effective October 1, 2026.
Next expected change: 7.5% rate increase effective with bills rendered on or after October 1, 2026, pending in PUC Case No. 26-0096-TF.
Cost Optimization Strategies
Because GMP exposes hourly AMI data and prices larger C&I customers on peak/off-peak demand and energy, the biggest savings come from demand management, load shifting into off-peak hours, and power-factor correction. The 7,600 kWh/200 kW threshold also makes load management strategically important for mid-size accounts near the cutover.
Peak demand reduction on Rate 63/65
For: C&I customers on Rate 63/65
Shave the 15-minute peak demand established during the 16-hour weekday peak window, since peak kW ($19.939) is priced ~3.5x off-peak kW ($5.741). Beware the seasonal Dec-Mar ratchet that locks 60% of winter peaks for 11 months.
Off-peak load shifting
For: C&I customers on Rate 63/65
Move flexible loads (charging, pumping, batch processes) outside the 6 AM-11 PM weekday peak window to capture lower off-peak kWh ($0.10692 vs $0.14069) and off-peak demand pricing.
Power-factor correction
For: C&I customers on Rate 63/65
Maintain a power factor of 95% or higher to avoid the penalty that increases the peak investment charge proportionally for lower power factors.
Voltage-level / transformer-ownership discounts
For: Larger industrial customers with their own electrical infrastructure
Customers taking delivery at primary (4.00%) or sub-transmission voltage (21.65%, or 23.04% above 20 MW) and owning their transformers can earn discounts and a $1.0712/kW transformer-ownership credit.
To implement these strategies, you need your 15-minute interval data. Learn how to download Green Mountain Power interval data →
Frequently Asked Questions
Can a commercial customer get hourly interval data from GMP?▾
Yes. GMP deployed AMI smart meters territory-wide and presents hourly interval data on the My Account Usage dashboard. Commercial customers can export it as CSV using either the 30-day quick download or the advanced custom-date-range export, with 12+ months of history available.
Does GMP offer Green Button or an official API for third parties?▾
No. GMP has not published a Green Button Connect My Data / ESPI API or an official developer portal. The Oracle Utilities platform supports ESPI conceptually, but it is not enabled. The only programmatic option is an unofficial community Python client that uses the customer's own credentials.
How can a consultant access a commercial client's GMP data?▾
There is no formal third-party authorization portal. In practice, the customer exports their CSV usage and PDF bills and shares them, or the consultant calls GMP at (888) 835-4672 to arrange written customer authorization for a data request.
Which rate applies to larger commercial and industrial accounts?▾
Accounts averaging more than 7,600 kWh/month or 200 kW over any four consecutive months are required to take service on Commercial & Industrial Time-of-Use Rate 63/65, which has peak/off-peak demand and energy charges. Smaller commercial accounts take Rate 6 (no demand) or Rate 8 (demand-billed).
Can one login manage multiple commercial premises?▾
Yes. Through 'Manage User Settings' then 'Add/Manage Accounts', a single login can hold multiple GMP account numbers, which is useful for property managers and multi-site commercial customers exporting usage across locations.
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