Eversource Massachusetts EV rate analysis.

Why we focus on program design

As we've documented throughout Drive Economics, the base utility rate does most of the heavy lifting on EV total cost of ownership. In Massachusetts, that math is complicated by Eversource's bill structure: distribution rates are set by the utility and reviewed annually, but the Basic Service supply rate resets every six months and swings by 30–50% between the January and July revisions. Layered on top, Eversource offers two philosophically different EV-focused paths that don't combine well with each other.

The choice comes down to structure. R-4 Time-of-Use shifts your entire household's rate based on the clock — rewarding you overnight but penalizing you weekday afternoons. ConnectedSolutions leaves your household rate alone and instead pays you rewards for managed EV charging behavior. For most Eversource EV owners across eastern and western Massachusetts, one of these two paths is meaningfully better than the other. Which one wins depends on annual mileage and household usage patterns in ways worth understanding before enrolling.

Eversource’s EV options at a glance

Two options exist for Massachusetts EV owners. Both target the same behavior — shift charging away from weekday afternoons — but they structure the reward very differently.

Path 1: R-4 TOU — the whole-household TOU

R-4 restructures your entire household's distribution rate around the clock. Off-peak (weekday nights, weekends, and holidays — all told, roughly 137 of 168 hours per week) distribution drops to approximately $0.07/kWh. Add the Basic Service supply rate of ~$0.155/kWh and you land around $0.225/kWh total for anything charged in that window. That is meaningfully cheaper electricity than the standard R-1 flat rate of ~$0.315/kWh.

The trap is what happens weekday afternoons. Peak hours (noon to 9 PM, Monday through Friday) hit approximately $0.28/kWh in distribution alone — add supply and you're paying $0.435/kWh for every kilowatt-hour your household draws during those hours. That is roughly 40% higher than the R-1 flat rate.

For an EV-only comparison, R-4 looks compelling: charging exclusively overnight at ~$0.225/kWh beats the standard R-1 flat rate of ~$0.315/kWh by $0.09/kWh. But Eversource customers don't just charge EVs. Cooking dinner, running dishwashers, laundry, air conditioning, and streaming all cluster into the same weekday evening hours that R-4 penalizes. For a typical Massachusetts household with central AC running through July and August — or a heat-pump household running electric heat through the coldest winter afternoons — the non-EV peak-hour usage frequently costs $150 to $300 per year more on R-4 than it would on R-1. That penalty erodes and can fully offset the EV charging savings.

Path 2: ConnectedSolutions — the managed charging program

ConnectedSolutions takes a different structural approach. Your household electricity stays on Eversource's standard R-1 flat rate — no time-of-use variation, no weekday-afternoon peak penalty on your AC or heat pump. Instead, Eversource pays you rewards specifically for allowing managed EV charging.

The rewards come in two components. The primary reward is approximately $0.05/kWh cashback for every kWh of EV charging that Eversource manages — meaning the utility can throttle or delay your charging session during grid stress events. That effectively reduces your overnight EV charging cost from ~$0.315/kWh (R-1 flat) to ~$0.265/kWh. Still more expensive per-kWh than R-4's ~$0.225/kWh off-peak, but the difference matters less than it looks once you factor in the second reward.

The second reward is a summer enrollment bonus: approximately $25 per month for every summer month (June through September) that you remain enrolled and allow demand response events during 2 – 7 PM weekday windows. Add a $25 seasonal bonus and you're looking at roughly $125 per year in fixed summer credits, on top of the per-kWh cashback.

The trade-off is real but manageable. Eversource may throttle your charging during peak grid stress — typically hot summer afternoons or cold winter evenings — meaning your car might charge more slowly than expected on those specific days. For most drivers who plug in when they get home and don't need the car back on the road for 10+ hours, this is invisible. For rideshare drivers, delivery drivers, or households needing predictable fast recharge, the throttling can be inconvenient. Enrollment requires either a Level 2 charger from Eversource's approved-device list (the ChargePoint Home Flex is the most common) or a compatible EV with utility-integrated telematics.

The economics: which one wins?

The chart plots annual EV charging cost by mileage under both Eversource paths, assuming a compact EV (30 kWh/100mi) with all charging done overnight. The finding is more nuanced than most utility rate comparisons: there is a break-even mileage around ~10,400 mi/yr. Below that mileage, ConnectedSolutions wins on pure EV charging cost. Above it, R-4 TOU pulls ahead.

The mechanics are straightforward. R-4's lower off-peak per-kWh rate wins whenever there are enough kilowatt-hours to overcome ConnectedSolutions' fixed $125/yr summer bonus. Below ~10,400 miles per year, the compact-EV energy consumption is small enough that ConnectedSolutions' fixed reward dominates the variable per-kWh savings that R-4 provides.

Above ~10,400 miles per year — the range that includes most commuters, most two-EV households, and any driver with a longer commute — the per-kWh savings under R-4 accumulate faster than the fixed reward. At 20,000 miles per year, R-4 saves approximately $240 over ConnectedSolutions on pure EV charging cost.

But that's the EV-only comparison. R-4 also changes how you pay for the rest of your household electricity, and this is where the analysis gets interesting. For a typical Massachusetts household with central AC and any evening cooking or laundry, R-4 imposes an additional $150 to $300 per year in household costs — enough to fully offset the EV charging savings shown above. Households with heat pumps that run heavily during winter evenings (a growing share of the Massachusetts residential stock) face similar exposure. The true finding is therefore this: on a whole-bill basis, R-4 only wins for very high-mileage EV owners whose household usage happens to avoid weekday afternoons.

Which path should you choose?

Choose ConnectedSolutions if: your annual EV mileage is below ~10,400 miles, or if your household has significant summer AC use, evening cooking patterns, or electric heat that competes with the R-4 peak window. Also choose it if you value flat, predictable household bills — no seasonal supply-rate anxiety, no worrying about the dishwasher running during peak hours. The utility takes the demand-response risk; you take the modest $125/yr rewards.

Choose R-4 TOU if: your annual EV mileage is well above ~10,400 miles (two-EV households, long commutes, delivery/rideshare drivers), and your household usage genuinely avoids weekday afternoons — daytime workers who eat dinner after 9 PM, second-home households with low weekday occupancy, or households where laundry and cooking already happen on weekends. Also choose R-4 if you have a heat pump but no central AC, and your winter heating loads run mostly overnight rather than during peak evening hours.

Choose R-1 flat (neither program): if you drive under ~6,000 miles per year and don't want to deal with enrollment complexity. The cost delta at that mileage is small enough that program overhead — approved-device requirements, throttling risk, TOU discipline — may not be worth the ~$50-100/yr saving.

The New England winter heating factor

Massachusetts is in the middle of a heat-pump transition. State-level MassSave incentives, federal Inflation Reduction Act credits (still active for heat pumps even after the EV credit expired), and rising natural gas prices have all combined to push Eversource residential customers off oil and gas heating and onto electric heat pumps at a meaningful pace. That transition matters for the R-4 versus ConnectedSolutions calculation in a way that isn't obvious.

Heat pumps run hardest when it's coldest — typically overnight and in the early morning, which coincides with R-4's off-peak window. A cold Massachusetts winter night can see a heat pump consuming 30-60 kWh in a 12-hour heating cycle. Under R-4, all of that overnight demand runs at ~$0.225/kWh instead of R-1's ~$0.315/kWh — savings of $2.70 to $5.40 per cold night. Over a full New England heating season (roughly 120 heating days), that adds up to $324 to $648 in additional annual savings for heat-pump households on R-4.

That flips the analysis. For a heat-pump household with even modest EV mileage (say 8,000-10,000 mi/yr), R-4 can win handily on total household cost — the winter heating savings alone can exceed the summer AC penalty two- or threefold. The exception: households running electric baseboard heat with thermostats set high during peak evening hours, or heat pumps sized for a large home that need to run continuously during cold snaps. Both scenarios can put peak-window kilowatt-hours in play.

The practical guidance: if you have or plan to install a heat pump within your ownership horizon, model R-4 with your heating load included, not just your EV charging. The winter savings frequently change the answer.

Where this analysis fits

Massachusetts case studies are in development for the Drive Economics library. In the meantime, the analytical framework here — TOU vs managed charging, whole-household exposure vs EV-only rewards, break-even mileage in the 8,000-12,000 mi/yr range — mirrors what we've documented for other utilities. The Eversource MA analysis follows a structurally identical pattern (whole-household R-4 TOU vs ConnectedSolutions behavioral cashback) with a very different conclusion, largely because Eversource's ConnectedSolutions offers a much richer per-kWh cashback ($0.10/kWh vs Eversource's ~$0.05/kWh).

The PG&E EV2-A analysis and the SCE TOU-D-PRIME analysis both illustrate what happens when a utility offers a dedicated EV-only TOU rate rather than a whole-household TOU: the household exposure risk disappears and the math becomes much cleaner. Eversource does not currently offer a dedicated EV-only TOU rate — one reason R-4 requires the additional household usage analysis.

Rate values reflect Eversource published tariff data as of September 2026 and are subject to change. R-4 TOU distribution rates ($0.072/kWh off-peak, $0.2786/kWh summer peak, $0.1711/kWh winter peak) reflect current published tariffs. Supply costs are variable, averaging $0.10 to $0.13/kWh in off-peak and winter months and $0.14 to $0.18/kWh during summer peak months; verify current supply rates at coned.com. Standard flat rate of $0.25 to $0.30/kWh total reflects typical all-in residential pricing. ConnectedSolutions program terms ($0.05/kWh cashback, $35 monthly summer bonus plus $25 seasonal bonus) reflect current published program terms; verify at fleetcarma.com or coned.com. Break-even mileage of approximately 3,300 miles per year assumes 30 kWh/100mi EV efficiency and a compact EV. Household TOU impact estimates assume typical Boston / Cambridge / Worcester summer air conditioning usage of approximately 240 kWh per month during peak hours across four summer months; actual household impact varies substantially with building type, AC efficiency, and behavior. Massachusetts gasoline price of $4.48/gallon reflects current statewide average as of September 2026. Case study specific numbers reflect the scenarios documented in the linked case study and may not directly translate to all Eversource EV owners.