National Grid Massachusetts for Cannabis Facilities: G-3 Time-of-Use, Worcester Territory, and Supply Choice
National Grid serves Worcester, the Merrimack Valley, North Shore, South Coast, central Massachusetts, and Nantucket through Massachusetts Electric and Nantucket Electric. It is the second-largest Massachusetts IOU and hosts many gateway-city cultivation sites. Production facilities above 200 kW land on G-3 time-of-use with weekday peak hours 8 a.m. to 9 p.m., separate distribution and transmission demand charges, and monthly Basic Service unless they sign with a competitive supplier.
Service area and grid
National Grid serves Worcester, the Merrimack Valley, North Shore, South Coast, central Massachusetts, and Nantucket [national-grid-ma-rates]. It is the second-largest Massachusetts electric utility and serves many gateway cities where cultivation has clustered [ma-ccc-10b-sales-2026]. The territory is within ISO New England [ma-dpu-basic-service].
Cannabis operators choosing between a Worcester National Grid warehouse and a Boston Eversource storefront are choosing different tariff books even within the same state. Compare total delivered cost, not just lease rate.
Commercial delivery classes
| Schedule | Threshold | Demand billing |
|---|---|---|
| G-1 Small General Service | Below 10,000 kWh per month or 200 kW demand | No demand charge [national-grid-ma-rates] |
| G-2 General Service (Demand) | Above 10,000 kWh per month, demand not exceeding 200 kW | $15.06/kW distribution demand [national-grid-ma-rates] |
| G-3 Time-of-Use | Demand greater than 200 kW | Peak hours 8 a.m. to 9 p.m. weekdays; $10.48/kW distribution and $21.91/kW transmission demand [national-grid-ma-rates] |
G-2 and G-3 offer discounts for high-voltage metering and customer-owned transformers [national-grid-ma-rates]. Confirm current effective date on the service rates page before quoting [national-grid-ma-rates].
Time-of-use and cultivation scheduling
G-3 bills time-of-use energy with peak hours 8 a.m. to 9 p.m. weekdays [national-grid-ma-rates]. Indoor grows often run lights 12 on / 12 off or 18 on / 6 off. If the on-cycle overlaps weekday peak hours, TOU energy charges add cost beyond demand kW.
Massachusetts averages 6,132 heating degree days and 516 cooling degree days [noaa-cag-massachusetts]. Summer dehumidification during peak hours compounds the issue. Shifting non-critical loads off peak helps; flower-room lighting schedule is a business decision, not only an energy decision.
Worked G-3 demand example (assumed):
- Assume 450 kW monthly peak on G-3
- Distribution demand: 450 × $10.48/kW = $4,716 per month (assumed)
- Transmission demand: 450 × $21.91/kW = $9,860 per month (assumed)
- Combined demand before energy: $14,576 per month (assumed)
Rates from National Grid Massachusetts service rates page [national-grid-ma-rates].
Basic Service and competitive supply
Customers who do not choose a supplier receive Basic Service at cost [ma-dpu-basic-service]. Small commercial accounts get six-month fixed pricing; medium and large commercial accounts default to monthly pricing procured quarterly [ma-dpu-basic-service]. A G-3 grow on default supply is on an indexed product.
Enrollment follows the same DPU competitive supply rules as Eversource [ma-dpu-competitive-supply-overview]. Switching changes supply only. Delivery demand on G-2 and G-3 stays on the National Grid bill.
High-voltage discounts
G-2 and G-3 offer discounts for high-voltage metering and customer-owned transformers [national-grid-ma-rates]. A greenfield grow that can take primary service and own transformers should model those discounts against the capital cost of transformers and switchgear before finalizing electrical design.
Mass Save and efficiency
National Grid is a Mass Save sponsor [masssave-business-rebates]. Prescriptive lighting and controls, HVAC, custom incentives, and ConnectedSolutions demand response apply to National Grid C and I accounts [masssave-business-rebates]. Supply choice does not affect Mass Save eligibility because funding is on the delivery bill [ma-dpu-basic-service].
Billing format with competitive supply
Suppliers may use consolidated National Grid billing or issue a separate bill [ma-dpu-competitive-supply-overview]. Confirm format at signing. Delivery riders remain on the utility bill either way [ma-dpu-basic-service].
Nantucket considerations
Nantucket Electric is part of National Grid Massachusetts [national-grid-ma-rates]. Supply choice applies, but logistics and interconnection for a cultivation facility on Nantucket face constraints beyond tariff math. Confirm infrastructure availability early.
Gateway cities and warehouse stock
National Grid serves Worcester, Lowell, Lawrence, and other gateway cities where cultivation clustered [national-grid-ma-rates]. Compare lease cost to total delivered energy: G-3 transmission demand at $21.91/kW exceeds Eversource Eastern MA G-2 transmission at $13.74/kW on posted September 2026 schedules [eversource-ema-rates-2026] [national-grid-ma-rates].
High-voltage discounts on greenfield grows
G-2 and G-3 offer discounts for high-voltage metering and customer-owned transformers [national-grid-ma-rates]. Model transformer capital against years of demand charge savings before specifying service [national-grid-ma-rates]. Interconnection studies should start before cultivation license buildout milestones [ma-ccc-modernizing-act-2026].
Nantucket and island logistics
Nantucket Electric operates under National Grid Massachusetts tariffs [national-grid-ma-rates]. Cannabis facilities on Nantucket face fuel and equipment logistics beyond mainland rate math [national-grid-ma-rates]. Confirm interconnection capacity before license buildout [ma-ccc-10b-sales-2026].
TOU energy and lighting overlap
G-3 peak hours eight a.m. to nine p.m. weekdays overlap common twelve-on twelve-off lighting schedules [national-grid-ma-rates]. Moving veg rooms to off-peak hours may conflict with operational goals but lowers TOU energy charges [national-grid-ma-rates]. Demand kW charges still apply to the monthly peak regardless of hour [national-grid-ma-rates].
Worcester industrial corridor
Gateway city warehouses on National Grid G-3 remain attractive despite transmission demand at $21.91 per kW because lease rates and labor pools differ from Boston Eversource sites [national-grid-ma-rates]. Model total occupancy cost including demand [national-grid-ma-rates].
Merrimack Valley and North Shore grows
National Grid serves Merrimack Valley and North Shore industrial space where canopy expansion competes for transformer capacity [national-grid-ma-rates]. Request preliminary service studies early [national-grid-ma-rates]. G-3 TOU rewards peak shaving when operational schedules allow [national-grid-ma-rates].
Unitil fringe comparison
Operators near the Fitchburg Unitil footprint should compare Unitil Basic Service rules if siting just outside National Grid territory [ma-dpu-basic-service]. National Grid G-3 TOU peak hours differ from Eversource TOU definitions [national-grid-ma-rates].
Gateway cities and warehouse stock
National Grid serves Worcester, Lowell, Lawrence, and other gateway cities where cultivation clustered [national-grid-ma-rates]. Compare lease cost to total delivered energy: G-3 transmission demand at $21.91/kW exceeds Eversource Eastern MA G-2 transmission at $13.74/kW on posted September 2026 schedules [eversource-ema-rates-2026] [national-grid-ma-rates].
High-voltage discounts on greenfield grows
G-2 and G-3 offer discounts for high-voltage metering and customer-owned transformers [national-grid-ma-rates]. Model transformer capital against years of demand charge savings before specifying service [national-grid-ma-rates]. Interconnection studies should start before cultivation license buildout milestones [ma-ccc-modernizing-act-2026].
Cultivation licensing freeze and buildout timing
The Act Modernizing the Commonwealth's Cannabis Laws restructured the Cannabis Control Commission and imposed a temporary freeze on new cultivation licenses effective June 16, 2026 [ma-ccc-modernizing-act-2026]. Existing cultivators in National Grid territory focus on energy cost at licensed canopy rather than new buildouts [ma-ccc-modernizing-act-2026]. Interconnection and transformer lead times should still be modeled before any canopy expansion on an existing G-3 account [ma-ccc-modernizing-act-2026].
Eversource comparison for site selection
A 180 kW grow on National Grid G-2 bills $15.06/kW distribution demand [national-grid-ma-rates]. The same load on Eversource Eastern MA G-2 bills $20.21/kW distribution and $13.74/kW transmission using twelve-month average demand classification [eversource-ema-rates-2026]. Worcester warehouse rent may be lower than Boston, but total delivered cost depends on the tariff book, not geography alone [eversource-ema-rates-2026] [national-grid-ma-rates].
Merrimack Valley transformer capacity
Merrimack Valley and North Shore industrial space competes for transformer capacity [national-grid-ma-rates]. Request preliminary service studies early in lease negotiation [national-grid-ma-rates]. G-3 TOU rewards peak shaving when schedules allow [national-grid-ma-rates].
Worcester lab versus Boston grow comparison
Worcester National Grid G-2 at $15.06/kW distribution differs from Boston Eversource G-2 at $20.21/kW distribution on September 2026 schedules [national-grid-ma-rates] [eversource-ema-rates-2026]. Site selection should compare total demand dollars [national-grid-ma-rates].
Additional procurement and tariff notes
Gateway cities Worcester and Lowell cluster cultivation in National Grid territory [national-grid-ma-rates]. G-3 transmission demand $21.91/kW exceeds Eversource G-2 transmission $13.74/kW [national-grid-ma-rates] [eversource-ema-rates-2026].
Additional load and utility notes
High-voltage and customer-owned transformer discounts on G-2 and G-3 reduce demand dollars [national-grid-ma-rates]. Model transformer capex against savings [national-grid-ma-rates].
Additional load and utility notes
G-3 TOU peak hours overlap twelve-on twelve-off lighting [national-grid-ma-rates]. Demand kW still bills monthly peak regardless of hour [national-grid-ma-rates].
Interconnection studies for gateway grows
Request preliminary service studies early in Worcester and Lowell lease negotiations [national-grid-ma-rates]. Transformer discounts on G-2 and G-3 require modeling capex against demand savings [national-grid-ma-rates]. TOU peak overlap with lighting schedules affects energy but not monthly demand kW [national-grid-ma-rates].
G-3 TOU and lighting overlap
Peak hours 8 a.m. to 9 p.m. weekdays overlap veg and flower schedules [national-grid-ma-rates]. Demand kW bills monthly peak regardless of hour [national-grid-ma-rates]. High-voltage discounts require transformer capex modeling [national-grid-ma-rates].
Supplemental tariff and procurement detail
Gateway city lease cost should include G-3 transmission at $21.91/kW [national-grid-ma-rates]. High-voltage transformer discounts require capex modeling [national-grid-ma-rates]. TOU peak overlaps lighting but demand kW bills monthly peak [national-grid-ma-rates].
G-3 transmission at gateway sites
Transmission demand $21.91/kW at G-3 affects Worcester and Lowell total occupancy cost [national-grid-ma-rates]. Transformer discounts need capex modeling [national-grid-ma-rates].
Worcester service study timing
Request preliminary service studies during Worcester lease option period [national-grid-ma-rates]. G-3 TOU peak overlaps lighting schedules [national-grid-ma-rates].
Merrimack transformer queue
Ask National Grid about transformer queue length during lease diligence [national-grid-ma-rates].
Worcester service studies and G-3 TOU
Request preliminary service studies during Worcester lease option period because transformer queue length affects energization dates [national-grid-ma-rates]. G-3 time-of-use peak hours 8 a.m. to 9 p.m. weekdays overlap cannabis retail hours and batch processing starts [national-grid-ma-rates]. Merrimack Valley cultivators on G-2 should compare $15.06 per kW distribution demand against Eversource G-2 twelve-month averaging before site selection [national-grid-ma-rates] [eversource-ema-rates-2026]. Basic Service for medium and large C and I defaults to monthly pricing procured quarterly [ma-dpu-basic-service].
Where to go next
Eversource territory detail is on Eversource Massachusetts. Statewide rate comparison is on commercial electricity rates. Cultivation load profile is on the cultivation facility page.
Frequently asked questions
What National Grid class will my cannabis facility be on?
Dispensaries often stay on G-1 if usage stays below 10,000 kWh per month and demand stays under 200 kW. Mid-size grows sit on G-2 with a $15.06/kW distribution demand charge. Production facilities above 200 kW move to G-3 time-of-use.
What are G-3 peak hours?
Peak hours are 8 a.m. to 9 p.m. weekdays on G-3 time-of-use. Lighting schedules that ramp during peak hours affect TOU energy charges as well as monthly demand kW.
Does National Grid differ from Eversource for the same load?
Yes. Class thresholds, demand charge levels, and Eastern vs Western Eversource divisions all differ. A 180 kW grow might be G-2 on National Grid but approaching G-2 on Eversource under different averaging rules.
Can I switch suppliers on National Grid?
Yes. All National Grid Massachusetts customers may buy supply from a DPU-licensed supplier. Default Basic Service follows the same small vs medium/large commercial rules as Eversource.
Why do cultivators cluster on National Grid territory?
Worcester, Lowell, Lawrence, and other gateway cities with industrial space sit in National Grid territory. Licensed canopy capacity reached 4.57 million square feet statewide as of December 2025, with much of the warehouse stock in central Massachusetts.
Related reading
- Massachusetts Cannabis Energy: Electricity Choice, ISO-NE Rates, and CCC Licensing for Licensed Operators
Massachusetts cannabis power: DPU choice on Eversource and National Grid, Basic Service benchmarks, and 24.52 cents/kWh commercial average.
- Massachusetts Commercial Electricity Rates for Cannabis Facilities: Basic Service, ISO-NE, and Utility Classes
Massachusetts commercial power at 24.52 cents/kWh vs. the U.S. average, Eversource and National Grid G-1/G-2/G-3 demand charges, and Basic Service tiers.
- How to Switch Electricity Suppliers in Massachusetts: A Step-by-Step Guide for Cannabis Businesses
Step-by-step Massachusetts supplier switching for cannabis on Eversource, National Grid, and Unitil: Basic Service benchmarks, DPU rules, and enrollment timing.
- Massachusetts Cannabis Cultivation Energy: Lighting Caps, Winter Heat Loss, and Eversource G-2 Demand
Massachusetts indoor grow power: 935 CMR 500.120 lighting limits, 6,132 HDD climate, utility demand classes, and a worked cost example.
- Eversource Massachusetts for Cannabis Facilities: G-1, G-2, G-3, Basic Service, and Mass Save
Eversource Massachusetts cannabis billing: Eastern and Western MA G-1/G-2/G-3 classes, demand charges, Basic Service tiers, and competitive supply enrollment.
- Demand Charges Explained for Cannabis Cultivators
What a demand charge is, how utilities measure peak kW in 15- or 30-minute windows, why grow rooms get hit hard, how ratchets work, and a worked example.
- Peak Demand vs. Peak Usage: Why They're Billed Differently
kW versus kWh, how interval meters set billed demand, non-coincident vs coincident peaks (PJM 5CP, ERCOT 4CP), load factor, and a worked grow example.
- Illustrative Case: Boston-Area Dispensary Fixes Eversource G-1 Supply on Small Commercial Rates
Illustrative Eversource G-1 dispensary: 9,800 kWh per month on non-demand small commercial rates, Basic Service vs fixed supplier math.
- Demand Charge Questions for Cannabis Facilities
Answers on demand charges for grows: how kW is measured, why demand dominates bills, ratchets, load factor, LED vs HPS peak, staggering rooms, and ERCOT 4CP.
Jason Taken founded Jaken Energy, the commercial energy procurement practice behind this site. He works with licensed cannabis operators in deregulated electricity markets to lower supply rates, manage demand charges, and evaluate efficiency upgrades.
Sources
Inline citations in this article, such as [national-grid-ma-rates], refer to the entries below. Links open the primary source in a new tab.
- [national-grid-ma-rates]Massachusetts Business Service Rates (G-1, G-2, G-3) — National Grid. Accessed 2026-09-11.
- [ma-dpu-basic-service]Basic service information and rates (updated July 6, 2026) — Massachusetts Department of Public Utilities. Accessed 2026-09-11.
- [ma-dpu-competitive-supply-overview]Competitive electric supply product overview — Massachusetts Department of Public Utilities. Accessed 2026-09-11.
- [masssave-business-rebates]Mass Save Business Rebates and Incentives — Mass Save. Accessed 2026-09-11.
- [noaa-cag-massachusetts]Climate at a Glance: Massachusetts statewide heating and cooling degree days, 1991-2020 base period averages — NOAA National Centers for Environmental Information. Accessed 2026-09-11.
- [ma-ccc-10b-sales-2026]Massachusetts Marijuana Establishments Hit $10 Billion in Gross Sales (press release, September 9, 2026) — Massachusetts Cannabis Control Commission. Accessed 2026-09-11.
- [eversource-ema-rates-2026]2026 Summary of Eastern Massachusetts Electric Rates for Greater Boston Service Area, rates effective September 1, 2026 — Eversource Energy. Accessed 2026-09-11.
- [ma-ccc-modernizing-act-2026]Massachusetts Cannabis Control Commission to Implement An Act Modernizing the Commonwealth's Cannabis Laws (April 2026) — Massachusetts Cannabis Control Commission. Accessed 2026-09-11.