HomeWattCost

Central Maine Power rates

CMP has 2 residential plans modelled here. For a typical Maine home using 532 kWh a month, the cheapest is A, at about $153 a month.

Investor-owned 577,955 residential customers (EIA-861, 2024) Tariffs checked September 28, 2026

Typical all-in priceA

01234567890123456789.0123456789¢/kWh
A$153/mo
A-TOU$157/mo

Residential plans

PlanTypeFixed/moJuly pricesJanuary pricesJuly weekday windows
A
Residential Service, Standard Offer
Tiered $27.37 12.7¢ 0–50 kWh · 24.7¢ over 50 kWh 12.7¢ 0–50 kWh · 24.7¢ over 50 kWh None
A-TOU
Residential Time-of-Use
Time-of-use $24.18 Off-peak 18.9¢ · Peak 55.6¢ Off-peak 18.9¢ · Peak 55.6¢ Peak 5 pm–9 pm

A-TOU: price by hour

July weekday. Same pricing all year.

Off-peakPeak
18.9¢55.6¢18.9¢12a3a6a9a12p3p6p9p12a

Charging an EV on CMP

1,000 miles a month in a Tesla Model Y Long Range AWD (275 kWh from the wall, EPA 27.5 kWh/100 mi) at 7.2 kW, added to a typical Maine home’s use, on each plan’s cheapest start hour versus plugging in at 6 pm. Averaged over the year.

PlanBest startCharging, best startCharging from 6 pmWhole bill with EV
AAny$68/mo$68/mo$221/mo
A-TOU12 am$52/mo$124/mo$209/mo

With an EV charged at its best hour, the cheapest plan overall is A-TOU. Compare plans on your own usage.

How CMP’s plans work

A (Residential Service, Standard Offer). In July the first 50 kWh a month cost 12.7¢ each; then 24.7¢ above 50 kWh a month. An average Maine home (441 kWh in July) goes past the first tier, so extra load such as an EV is priced higher. Fixed charge: $27.37 a month.

A-TOU (Residential Time-of-Use). Peak 5 pm–9 pm on July weekdays; 4 of 24 hours carry the top price of 55.6¢. The cheapest July weekday hour costs 18.9¢, so moving 1 kWh out of the top hours saves 36.7¢. January weekdays range from 18.9¢ to 55.6¢. Weekends follow a different schedule from weekdays. Fixed charge: $24.18 a month.

Prices on this page are all-in per kWh, before taxes: base rates, supply and every per-kWh rider in the utility’s current tariff sheets. Your bill shows them as separate lines, and riders can change between tariff revisions.

As a cross-check, CMP billed its residential customers an average of 23.43¢ per kWh in 2024 (revenue ÷ sales, EIA-861). A plan taken from URDB is shown only if its all-in price is consistent with that figure, adjusted for Maine’s price change since.

Sources for each plan

Plans marked “Checked” were transcribed from the utility’s current tariff and rider sheets, all charges included, and are re-checked on the date shown in each file. Other plans come from the OpenEI U.S. Utility Rate Database (CC BY 4.0) and have not yet been checked line by line against the utility’s tariff. Always confirm the current rates on your utility’s website before switching plans.

Run the numbers on CMP