HomeWattCost

CMP A vs A-TOU

For a typical Maine home using 528 kWh a month, A is cheaper by about $52 a year ($152 against $156 a month). A is cheaper at every level of use from 200 to 2,500 kWh a month, with the same daily pattern of use.

Utility CMPTariffs checked 2026-09-28Typical use 528 kWh/mo, Maine

Head to head

ScenarioAA-TOUCheaper
Typical home, per month$152$156A
All-in price per kWh28.7¢29.6¢A
Home + EV, charged at the cheapest hour$220$208A-TOU
Home + EV, plugged in at 6 pm$220$280A
Fixed charge$27.37$24.18

Typical home: Maine average use by month (EIA), shaped hour by hour (NREL ResStock), before taxes. EV: Tesla Model Y Long Range AWD, 1,000 miles a month; cheapest start any hour on A, 12 am on A-TOU.

Month by month

Typical-home bill each month on each plan.

PlanJanFebMarAprMayJunJulAugSepOctNovDec
A$167$178$187$162$146$131$130$142$137$137$152$151
A-TOU$170$182$190$165$151$136$135$147$143$142$155$155

A: price by hour

July weekday.

Same price all day
24.7¢12a3a6a9a12p3p6p9p12a

A-TOU: price by hour

July weekday.

Off-peakPeak
18.9¢55.6¢18.9¢12a3a6a9a12p3p6p9p12a

A or A-TOU: common questions

Is A or A-TOU cheaper?

For a typical Maine home using 528 kWh a month, A is cheaper by about $52 a year ($152 against $156 a month). A is cheaper at every level of use from 200 to 2,500 kWh a month, with the same daily pattern of use. Adding an EV driven 1,000 miles a month and charged at each plan’s cheapest hour, A-TOU gives the lower total ($208 against $220 a month).

What is the difference between A and A-TOU?

A is tiered: the price per kWh rises with monthly use, with a fixed charge of $27.37 a month. A-TOU is time-of-use (summer weekdays: Peak 5 pm–9 pm; lowest price 9 pm–5 pm next day), with a fixed charge of $24.18 a month.

How the two 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 differ: off-peak all day.
  • Fixed charge: $24.18 a month.

Your own pattern of use decides the winner: compare every CMP plan on your usage, or see all CMP plans, sources and peak hours.