ForgeAsset / Supercharger ROI / Massachusetts
Tesla Supercharger ROI in Massachusetts
Both Massachusetts investor-owned utilities file EV-specific rates that price demand from the site's load factor rather than at a single rate, and that structure decides Massachusetts charging economics. A fast-charging site drawing a multi-megawatt peak against modest energy runs a load factor near 9% at default utilization, which lands in the second of four filed groups: about $3.87 per kilowatt-month on Eversource's Rate EV-2 in Greater Boston and about $2.78 on National Grid's EV Pricing around Worcester, against roughly $36 and $11 on the standard schedules those rates replace. Energy is flat near 16.7¢ at Eversource and near 19¢ at National Grid once the quarterly default-supply strip and the 6.25% electricity sales tax fold in. Both books re-price supply quarterly, and the modeled rows carry the published August-through-October 2026 strips.
What makes Massachusetts economics distinct
A demand charge set by load factor
Both utilities file four demand prices and assign one from the site's load factor — energy divided by the billed peak across the hours in the period. Below 5% the demand charge is zero and a per-kWh distribution adder carries the recovery instead; the price steps up through two middle groups and reaches the standard schedule above 15%. The model derives load factor from projected energy and the billed peak and re-assigns the group each model year, so a site growing into higher utilization moves up the groups across the fifteen years. The filed versions assign from trailing metered data — Eversource continuously, National Grid each June 1.
What the model leaves out of the EV rates
Both filed rates carry a first-decade discount phase-down, so the relief starts fuller and steps down over the schedule's opening years. The model prices the group rates as filed for all fifteen years without the phase-down, which understates the early-year relief. National Grid's per-kWh adder applies to peak-window energy in the filing and to all energy in the model, the conservative reading of the two.
Supply re-prices every quarter
Both utilities' default Basic Service is procured on quarterly fixed-price strips — the modeled rows seed from the published August–October 2026 strips and the library re-derives each quarter. Eversource's fixed price is an election with a twelve-month term and six months' notice to exit; supply zones move the energy rate a few tenths of a cent between Boston, Worcester, and the southeast.
A sales-tax exemption a small operator might actually hold
Massachusetts levies 6.25% sales tax on commercial electricity, folded into the modeled rates as the conservative default. A genuine exemption exists for businesses with five or fewer employees and under $1 million of gross income — a single-site entity can qualify, and the certificate removes the entire fold, worth roughly $10,000 to $15,000 per year at default volumes.
Utilities and tariffs modeled in Massachusetts
| Utility & tariff | Energy | Demand |
|---|---|---|
| National Grid MA EV Pricing (G-3) | 18.8¢/kWh–19.0¢/kWh by time of day | none |
| Eversource MA Rate EV-2 | 16.7¢/kWh flat | none |
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.
See Massachusetts in the US Supercharger Economics Map — every US Supercharger over utility territories colored by the derived effective electricity cost per dispensed kWh.
Massachusetts tax profile
- Sales tax on hardware: 6.25%
- Business personal property tax: 2.6% of equipment value (example rate)
- Clean-fuels credit: no program
- Per-kWh charging excise: none
Massachusetts tax defaults applied: no clean-fuels credit program exists in Massachusetts (the LCFS revenue line is $0; a clean-fuel-standard bill sits in committee). LLC costs use the $500 annual report — the largest fixed entity cost in the covered set after California. Sales tax is the statewide 6.25% on hardware with separately stated installation labor untaxed; the electricity sales tax is already inside the modeled utility rates, and a small-business exemption (five or fewer employees and under $1 million of gross income) can remove it for a qualifying single-site entity — the conservative default models the tax. Business personal property bills at Boston's $25.96 per $1,000 of fair cash value — about 2.6% per year, with Worcester running higher; the field is editable by municipality.
Massachusetts programs and incentives
Utility make-ready programs (DPU 21-90/21-91)
Roughly $400 million approved across Eversource and National Grid for 2023–2026 make-ready infrastructure and charger rebates; 2026 is the current program term's final year, and successor-term filings were unresolved as of the research date. A specific award enters the model through the grant inputs.
NEVI (federal, MassDOT-administered)
Federal corridor DC fast-charging funding along I-90, I-95, and I-93, administered in award rounds.
Massachusetts charging market
Massachusetts carries roughly 62 Supercharger stations across the I-90/I-95/I-93 corridors and the Boston metro. Eversource serves Boston and Cambridge; National Grid serves Worcester and much of central Massachusetts. Municipal light plants — Braintree, Taunton, and dozens more — run their own systems the model does not cover; addresses there see a named-utility notice rather than a wrong auto-selection.
Massachusetts Supercharger ROI — questions
- Why do Boston and Worcester sites model so differently?
- Two filed EV rate designs that tier the same way at different prices. At the second load-factor group — where a fast-charging site lands at default utilization — Eversource's Greater Boston EV-2 bills about $3.87 per kilowatt-month against flat energy near 16.7¢, while National Grid's Worcester EV Pricing bills about $2.78 against time-of-use energy near 19¢ plus a per-kWh adder. Utilization and TOU mix decide which book prices a given load better, and the model runs both from the address.
- How stable are the Massachusetts rates?
- The delivery components move on commission-approved schedules, but default supply re-prices every quarter — the modeled rows carry the published August–October 2026 strips, and the library re-derives at each reset. Eversource's fixed supply price is also an election with a twelve-month term and six months' notice, which the tariff note states.
- Does Massachusetts tax EV charging per kilowatt-hour?
- No per-kWh charging tax exists and none was found pending. The 6.25% sales tax on commercial electricity is folded into the modeled rates; a small-business exemption — five or fewer employees and under $1 million of gross income — can remove it for a qualifying single-site entity. A charger registration mandate exists in statute but no fee schedule had been issued as of the research date.
Sources
- National Grid MA — Rate G-3 tariff (M.D.P.U. No. 1591)
- Eversource — EMA Greater Boston rates summary
- Eversource — MA business energy sales-tax exemption
- AFDC — Massachusetts laws & incentives for electricity
Model a Tesla V4 Supercharger site in Massachusetts — payback, NPV, IRR, and a 15-year cash flow from your own inputs.
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ForgeAsset is software, not investment, tax, or legal advice — outputs are model estimates from your inputs, not guarantees. Rates and programs current as of research; verify current terms with each source before committing capital.