In short: South Portland has about 27,000 people and sits in Cumberland County. Central Maine Power Co serves the county, averaging 23.43¢ per kWh for homes in 2024 (EIA). FEMA rates Cumberland County winter weather “very high”. Rooftop solar here makes roughly 1,100 kWh a year per kW of panels by our estimate, which is on the modest side, so price and incentives matter more.
This page covers what is local to South Portland: its utility, outage records, sunshine, weather risks and charging. Statewide rules such as net metering, incentives and electrician licensing are in our Maine energy guide and the wider area is covered in the Greater Portland, Maine guide.
South Portland at a glance
- Place: South Portland, Cumberland County, Maine; about 26,994 residents (Census Bureau estimate, July 2024).
- Utility: Central Maine Power Co (investor-owned). Homes paid an average 23.43¢ per kWh in 2024 (EIA-861); the average customer lost 215 minutes of power on normal days and 1,894 counting major storms, with 1.8 interruptions a year (utility-wide, not just South Portland).
- Sun: 3.76 kWh per square meter per day on average, from 1.37 in December to 5.90 in July (NASA POWER). Our rough estimate: about 1,100 kWh a year per kW of panels.
- Climate: about 140 cooling degree-days and 6,460 heating degree-days a year (base 65°F, NASA POWER), so heating is the big load.
- Top hazards in Cumberland County: winter weather “very high”, ice storms “very high” and lightning “relatively high” (FEMA National Risk Index; overall county risk rated “relatively low”).
- Public charging: 52 ports at 25 locations in South Portland, 4 of them DC fast (AFDC, October 20, 2026).
Your utility and what it means
Central Maine Power Co is an investor-owned utility and served about 519,295 home customers in 2024; its 23.43¢ average was below the 32.41¢ statewide average for July 2026. Those are utility-wide averages, not a quote for your address; your own bill is the real number.
For reliability, Central Maine Power Co reported 215 minutes per customer without major storms in 2024, less than the statewide figure of 274 (EIA-861). Utility-wide numbers hide a lot: a home at the end of a long rural line usually has more outages than the average.
Net metering, export rates and incentives are set at state level and by each utility. Start with the Maine guide and then ask your utility for its current interconnection steps before you sign anything.
Backup power in South Portland
- Winter weather (very high): Winter storms and cold snaps combine outages with heating demand. Plan for the furnace blower or heat pump, not just lights, and keep a fuel supply you can reach in snow.
- Ice storms (very high): Ice storms bring down lines for days. A standby generator with a transfer switch, or a battery sized for the fridge, furnace blower and well pump, matters more than a small power station.
- Heating load: a winter outage can stop a furnace blower, boiler pump or heat pump. List what your heat needs to run before choosing a generator or battery.
- Short outages: a portable power station covers phones, Wi-Fi, a CPAP and lights; a home battery switches over automatically.
Size your setup with the generator sizing tool and the battery backup calculator, and compare options in backup power. Generator safety (CPSC): outdoors only, at least 20 feet from the house, exhaust away from doors and windows, never in a garage, and battery-powered carbon monoxide alarms inside. A licensed electrician should install any transfer switch, with a permit; see generator installation.
Solar in South Portland
By our rough estimate each kW of panels makes about 1,100 kWh a year in South Portland (NASA sunshine data times 365 days times 0.80 for system losses). Valued at Central Maine Power Co’s 2024 average of 23.43¢, that is about $258 a year per kW if all of it offsets your own use (an estimate, not a promise). Production swings with the seasons: July is the sunniest month at 5.90 and December the dimmest at 1.37, a 4.3-to-1 gap, so a battery or a bigger system helps in winter.
Check your own roof with the solar potential tool, see solar costs and net metering vs net billing, and read the steps in solar installation.
Batteries and EV charging
A home battery earns its place when outages are frequent, when your utility pays little for exported solar, or when evening prices are high; compare in home batteries and battery costs. South Portland has 52 public charging ports in the federal station list including 4 DC fast, but home charging is cheaper and easier: see the EV charging cost calculator and EV charger installation.
Drive on another fuel? See every alternative fuel station in South Portland: hydrogen, propane, natural gas, E85 ethanol, biodiesel and renewable diesel.
Permits and inspections
Solar, generator transfer switches and EV chargers normally need an electrical permit from the South Portland building or permitting department, or from Cumberland County if you live outside city limits, and often a utility interconnection approval. We have not verified a local permit page for South Portland, so check the city and county websites or ask your electrician, who will know the process. Hire only a licensed electrician or installer; the Maine guide lists the state licensing rules.
Nearby guides
More local guides: Greater Portland, Maine energy guide, Westbrook, Saco, Biddeford and Sanford, or the whole Maine energy guide.
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South Portland energy FAQ
Who is my electric company in South Portland?
Federal data lists Central Maine Power Co as the main utility serving Cumberland County. Small areas can be served by a different company or a co-op, so confirm on your bill.
How much power will solar make in South Portland?
About 1,100 kWh a year per kW of panels by our estimate, so a 6 kW system would make roughly 6,600 kWh. Shade, roof direction and tilt change this; run your address through the solar potential tool for a better number.
Is a generator or a battery better for winter weather in Cumberland County?
It depends how long the outage lasts. A battery is quiet, automatic and good for short outages and for pairing with solar; a standby generator keeps going as long as it has fuel, which suits multi-day events. Many homes use a battery for everyday outages and add a generator for the rare long one.
Will a home battery keep my heat on in an outage?
It can keep a furnace blower, boiler pump or a heat pump running for a while, but long cold outages drain a battery fast without solar to recharge it. Pair it with a generator or wood or propane heat if outages here run for days.
Do I need a permit for solar or a generator in South Portland?
Almost always an electrical permit for a transfer switch, solar or an EV charger, issued by the city or county where you live. Your licensed electrician or installer normally pulls it. Never connect a generator to your house wiring without a transfer switch.
Sources: EIA Form 861 (2024) for utility prices and outages; NASA POWER climatology (2001 to 2025) for sun and degree-days; FEMA National Risk Index for county hazards; AFDC station locator for public charging; Census Bureau for population. Estimates are ours and are not promises; see our editorial policy. Prices and programs change, so check each program page.