ForgeAsset / Supercharger ROI / Maine
Tesla Supercharger ROI in Maine
Maine splits down the middle of the New England rate map. In the covered Versant Bangor Hydro District, supply is the most visible in the covered set — twelve fixed monthly standard-offer prices, competitively bid and filed in advance for the whole calendar year — and delivery demand is a plain flat charge on the current-month peak, no ratchet, no window. That plainness has a price: at about $37.95 per kilowatt-month all-in, it is the heaviest demand charge in the library. South of the line, Central Maine Power's large-customer class prices supply on hourly market quantities with capacity billed on ISO-NE coincident peaks — a structure the engine deliberately does not model — which is why Portland and the Turnpike corridor are named rather than covered.
What makes Maine economics distinct
Supply certainty, filed a year at a time
Maine's medium-class standard offer files twelve fixed monthly prices for the calendar year in advance — a stronger form of the New Hampshire pattern — and class membership follows the delivery rate class rather than a kilowatt threshold, so a Supercharger-scale secondary-service site in Bangor keeps fixed supply at any size. The modeled rate folds the CY2026 strip; the CY2027 prices file around November 2026.
The heaviest demand charge in the library
M-2 bills about $16.22 of distribution plus $19.75 of transmission per kilowatt-month before the electricity tax fold — roughly $37.95 all-in. There is no ratchet and no window, so the number is plain, but at Supercharger load factors it dominates the bill. Versant files an opt-in EV billing option that swaps the transmission charge to coincident-peak billing — potentially cheaper, stochastic by nature, and the model conservatively carries the default path.
Why Portland is not covered
Central Maine Power's supply class above 400 kilowatts prices energy at hourly market rates restated monthly and bills capacity on each customer's ISO-NE coincident-peak contribution — no filed fixed rate exists for the class, the same structure that keeps New York and Connecticut out of the library. The model does not guess at unfixed prices; CMP-territory addresses see a named-utility notice instead.
A live state grant channel, with a Tesla award on record
Efficiency Maine administers the state's roughly $19 million NEVI allocation plus its own trust-funded rounds, and its Phase 10 public DCFC solicitation was live in 2026. The March 2026 round funded twenty DC fast-charging ports across four projects — including a Tesla site at Newport, inside the covered Versant district. A won award enters the model through the grant inputs.
Utilities and tariffs modeled in Maine
| Utility & tariff | Energy | Demand |
|---|---|---|
| Versant Power BHD M-2 | 14.2¢/kWh flat | $37.95/kW of monthly peak |
Rates are digit-verified against each utility's own filed sheets and update within two weeks of any revision. Full derivations are on the methodology page.
Maine tax profile
- Sales tax on hardware: 5.5%
- Business personal property tax: 1.77% of equipment value (example rate)
- Clean-fuels credit: no program
- Per-kWh charging excise: none
Maine tax defaults applied: no clean-fuels credit program exists in Maine (the LCFS revenue line is $0), and LLC costs use the $85 annual report. Sales tax is the statewide 5.5% on hardware with separately stated installation labor untaxed; Maine's 5.5% tax on the whole commercial electric bill, delivery included, is already inside the modeled utility rate. Business personal property is carried at Bangor's mil rate — about 1.77% of value per year — under the conservative reading that a public charging site is a retail sales facility excluded from Maine's business-equipment exemption; if the exemption applies the line is zero, a reimbursement program may refund part of a denied claim, and the field is editable. No per-kWh charging tax exists in Maine.
Maine programs and incentives
Efficiency Maine public DCFC grants (NEVI + trust rounds)
Recurring competitive solicitations for public DC fast charging — the March 2026 round funded 20 ports across four projects, including a Tesla site in Newport; RFP EM-004-2026 (Phase 10) continued the channel. Awards are site-specific and enter the model through the grant inputs.
Versant DC Fast Charging and Storage Eco option
A filed opt-in billing option inside the M-1/M-2 rates that replaces the non-coincident transmission demand charge with coincident-peak billing for separately metered charging — a rate structure rather than a rebate; the model carries the default path.
Maine charging market
Maine hosts roughly a dozen to fifteen Supercharger sites. Most sit in Central Maine Power territory or municipal districts — Kittery, Falmouth, Augusta, Auburn, Rockport, and the two Kennebunk Turnpike plazas, which belong to a consumer-owned local district — and are not covered. The covered Versant Bangor Hydro District serves the Bangor, Brewer, and Ellsworth sites and the I-95 north corridor, with a Newport site funded by a 2026 state award; addresses outside it see a named-utility notice rather than a wrong auto-selection.
Maine Supercharger ROI — questions
- Does Maine charge a demand charge on EV charging?
- Yes — the covered Versant M-2 rate bills about $37.95 per kilowatt-month all-in, the heaviest in the library, on the plain current-month peak with no ratchet. Neither Maine utility files an EV-exclusive delivery rate; Versant's opt-in coincident-peak option can lower the transmission share and is stated rather than modeled.
- Why does the model cover Bangor but not Portland?
- Coverage follows expressible rates. Versant's medium class keeps filed fixed supply at any size; CMP customers above 400 kilowatts are priced on hourly market energy and coincident-peak capacity with no filed fixed alternative — a structure the model does not approximate. Portland-area addresses see a named-utility notice.
- Does Maine tax charging equipment as business property?
- By default yes — Maine's business-equipment exemption excludes retail-facility equipment, and the conservative reading treats a public charging site as retail, putting Bangor's rate near 1.77% of value per year. If the exemption were held to apply, the line would be zero; a state reimbursement program can also refund part of a paid tax. The field is editable.
Sources
- MPUC — Versant BHD rate filing (Docket 2026-00082)
- Versant Power — service districts
- Efficiency Maine — EV supply equipment initiative
- AFDC — Maine laws & incentives for electricity
Model a Tesla V4 Supercharger site in Maine — payback, NPV, IRR, and a 15-year cash flow from your own inputs.
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