New Hampshire Cannabis Cultivation Facility Energy: ATC Caps, Winter Heat, and Eversource GV Demand

How Eversource meters a Therapeutic Cannabis Program grow room

From the wire side, cultivation looks like two stacked rectangles on an interval chart: a high, flat rectangle for the photoperiod, a lower rectangle for dark hours, and occasional spikes when hydronic loops or makeup-air heaters catch up. New Hampshire's 7,449 annual heating degree days push those spikes into November through March more often than into July [noaa-cag-new-hampshire].

The regulated cultivation base is tiny. RSA 126-X:7 allows no more than four Alternative Treatment Center registrations at any time, and RSA 126-X:8 requires them to operate not-for-profit [nh-rsa-126-x]. Three operators (GraniteLeaf Cannabis, Sanctuary Medicinals, Temescal Wellness) run vertically integrated cultivation, processing, and seven dispensary locations [hemp-gazette-nh-tcp-2026]. Any new cultivation load in the state is an expansion by one of those three, not a new licensee [nh-rsa-126-x].

At Eversource, Rate G serves general service accounts with demand not exceeding 100 kW and bills distribution, transmission, stranded cost, and reconciliation demand charges on kW above 5 kW [eversource-nh-summary-rates-2026]. Rate GV covers commercial and industrial accounts with demand up to 1,000 kW with a $242.13 customer charge, distribution demand of $8.73 per kW for the first 100 kW and $8.43 per kW above, and transmission demand of $13.05 per kW [eversource-nh-summary-rates-2026]. Rate LG applies above 1,000 kW with an $800 customer charge and kVA-based demand charges [eversource-nh-summary-rates-2026]. Demand is the highest half-hour in the billing period [eversource-nh-summary-rates-2026].

Fixture wattage picks Rate G, GV, or LG before HVAC runs

Picture 5,000 square feet of flowering canopy at 35 W per square foot under DLC-listed LEDs. That is a modeling input, not an OCP or DHHS requirement. Energized fixtures alone pull 175 kW on a twelve-on schedule. Mother and veg rooms might add another 35 kW, so lighting totals near 210 kW before any chiller or dehumidifier starts.

210 kW lands the account on Eversource Rate GV, where distribution demand bills at $8.73 per kW on the first 100 kW and $8.43 per kW above, plus $13.05 per kW transmission demand [eversource-nh-summary-rates-2026]. New Hampshire's Therapeutic Cannabis Program does not cap horticultural watts per square foot the way Massachusetts does under 935 CMR 500.120, but the three nonprofit ATCs still size circuits from fixture nameplates first and HVAC second.

Fixture efficacy and schedule drive this block more than any other single commissioning decision; the LED versus HPS cost walkthrough shows the napkin math.

Winter shoulder loads in a 7,449-HDD state

Statewide normals are 7,449 heating degree days against only 299 cooling degree days [noaa-cag-new-hampshire]. Southern-tier July dew points in the 60s F create a short latent season, but most calendar months ask the mechanical plant to add moisture and recover lamp heat instead of rejecting outdoor humidity [noaa-cag-new-hampshire]. Envelope specs that shrink infiltration are covered on the weatherization for indoor grows page.

Stick with the 210 kW lighting block. If hydronic loops and reheat coils need 100 kW on a sub-10 F morning but only 55 kW on a typical January afternoon, and pumps, fans, controls, and office circuits draw 25 kW continuously, January peak demand becomes 210 + 100 + 25 = 335 kW. August might peak near 210 + 35 + 25 = 270 kW with minimal mechanical cooling.

335 kW keeps the meter on Rate GV and far from the 1,000 kW LG breakpoint, yet delivery demand at that level still adds thousands of dollars each month before a single Default Energy Service kWh is priced [eversource-nh-summary-rates-2026]. The demand charge primer explains why overspecified chillers and boilers inflate peaks you never needed.

Napkin math: kWh for a 5,000-square-foot flowering canopy

The table below uses illustrative inputs; only cited rates and climate normals are facts. Annual energy:

Load	Assumption	Annual kWh
Flower lighting	175 kW, 12 hours a day, 365 days	766,500
Veg and mother lighting	35 kW, 18 hours a day, 365 days	229,950
HVAC and humidification	70 kW average across the year	613,200
Pumps, fans, controls, office	25 kW continuous	219,000
Total		1,828,650

At the EIA June 2026 New Hampshire commercial average of 21.22 cents per kWh, that is about $388,000 a year all-in on energy alone [eia-epm-5-6-a]. At the New Hampshire industrial average of 17.47 cents it would be about $319,000 [eia-epm-5-6-a]. Both figures sit roughly 50 percent above the U.S. commercial average of 14.19 cents [eia-epm-5-6-a]. Delivery demand charges and customer charges add on top and are not controlled by a supply contract.

Default Energy Service and the winter spike

Customers who do not choose a Competitive Electric Power Supplier take Default Energy Service procured through competitive solicitations under RSA 374-F [nh-rsa-374-f]. Prices reset on February 1 and August 1 each year. For Eversource Rate GV and LG customers, the default energy charge is set month by month within the period [eversource-nh-summary-rates-2026]:

Month	Default energy charge (GV/LG)
August 2026	11.862 cents/kWh
September	10.645
October	10.528
November	12.119
December	18.350
January 2026	19.760

A grow that crosses into GV without signing a supplier contract carries full winter exposure. A fixed, index, or block-and-index contract with a registered supplier is the hedge. New Hampshire sits in ISO New England, so supplier prices carry Forward Capacity Market and regional network transmission costs [nh-rsa-374-f]. The Stranded Cost Recovery Charge and System Benefits Charge (0.618 cents/kWh, funding NHSaves) remain on the utility delivery bill regardless of supplier [nh-rsa-374-f].

Burner CO2 and hidden reheat in cold months

Tanked CO2 barely registers on the meter beyond solenoids and monitors. A gas-fired CO2 generator dumps sensible heat and moisture that sealed rooms must handle mechanically. In New Hampshire that load usually appears as boiler or electric reheat on makeup air, not as chiller tonnage. Run the indirect kWh on the CO2 supplementation cost page.

Three commissioning choices ATC operators regret

1. Picking the wrong wires. Eversource Public Service of New Hampshire serves about seven in ten meters statewide, including Manchester, Nashua, and the Lakes Region [eversource-nh-summary-rates-2026]. Unitil covers Exeter and Concord; Liberty serves Salem, Pelham, and Upper Valley towns; NHEC members in rural Coos and Carroll counties may still shop RSA 374-F suppliers [nh-rsa-374-f]. Each territory has different demand breakpoints.
2. Requesting service for licensed canopy you will not energize for years. A 600 kW transformer reservation creates billing demand before the first flower room lights.
3. Treating R-value as optional. With 7,449 heating degree days, air sealing and roof insulation often trim winter peaks more than swapping a few fixture batches [noaa-cag-new-hampshire].

Three ATC operators and nonprofit structure

RSA 126-X:7 caps Alternative Treatment Center registrations at four; three operators run seven dispensary locations [nh-rsa-126-x]. Each ATC is vertically integrated and must operate not-for-profit [nh-rsa-126-x]. Any new cultivation load is expansion by GraniteLeaf, Sanctuary, or Temescal, not a new licensee [nh-rsa-126-x].

Unitil and Liberty territory breakpoints

Unitil serves Exeter, Hampton, and Concord with demand-tiered G1/G2/G3 classes [nh-rsa-374-f]. Liberty serves Salem, Pelham, and Upper Valley towns [nh-rsa-374-f]. NHEC members in rural Coos and Carroll counties may still shop RSA 374-F suppliers [nh-rsa-374-f]. Per-kW figures on this page use Eversource 2026 summary rates; confirm other utilities before quoting [eversource-nh-summary-rates-2026].

Nonprofit ATC expansion limits

RSA 126-X:8 requires ATCs to operate not-for-profit [nh-rsa-126-x]. Expansion load at GraniteLeaf, Sanctuary, or Temescal is the only cultivation growth path [nh-rsa-126-x]. Plan GV class before requesting service above 1,000 kW [eversource-nh-summary-rates-2026].

GV class before 1,000 kW expansion

Model Eversource Rate GV before requesting service above 1,000 kW [eversource-nh-summary-rates-2026]. Default energy monthly table shows sixty to eighty-five percent winter spike over fall [eversource-nh-summary-rates-2026]. NHSaves custom path for dehumidifiers precedes supplier signature [nhsaves-business].

Default energy winter table use

Use the GV/LG monthly default energy table when comparing supplier fixed offers [eversource-nh-summary-rates-2026]. January 19.760 cents/kWh versus October 10.528 cents/kWh shows winter exposure [eversource-nh-summary-rates-2026]. NHSaves custom for dehumidification precedes supplier contract [nhsaves-business].

Additional procurement and tariff notes

Three ATC operators are vertically integrated nonprofits under RSA 126-X [nh-rsa-126-x]. Expansion is the only cultivation growth path [nh-rsa-126-x].

Additional load and utility notes

7,449 heating degree days dominate load; 299 cooling degree days define a short dehumidification season [noaa-cag-new-hampshire].

Additional load and utility notes

NHSaves Large Business funds custom dehumidification and process work [nhsaves-business]. Shaving 10 kW peak beats 10,000 kWh supply savings at $13.05/kW transmission [eversource-nh-summary-rates-2026].

NHSaves before you sign a supplier contract

When Eversource bills $13.05 per kW of transmission demand, shaving ten peak kW beats saving ten thousand kWh on supply. NHSaves Large Business Energy Solutions funds custom HVAC, controls, retrocommissioning, and industrial process work with engineering-verified savings [nhsaves-business]. Horticultural dehumidifiers and grow-room air handlers typically ride the custom path, not prescriptive lighting lists.

Cross-border comparisons help benchmark quotes. Maine documents CMP Medium General Service thresholds and Versant's NMISA split; Massachusetts covers Eversource G-2 classes and state lighting density caps. Local delivery tables sit on the New Hampshire commercial rates page.