In short: Wilmington has about 73,200 people and sits in New Castle County. Delmarva Power, City of Newark and Town of Middletown serves different parts of New Castle County, so your utility depends on your address; their 2024 home averages range from 17.12¢ to 18.99¢ per kWh (EIA). FEMA rates New Castle County winter weather “very high”. Rooftop solar here makes roughly 1,190 kWh a year per kW of panels by our estimate, which is about average for the U.S..
This page covers what is local to Wilmington: its utility, outage records, sunshine, weather risks and charging. Statewide rules such as net metering, incentives and electrician licensing are in our Delaware energy guide and the wider area is covered in the Wilmington and New Castle County guide.
Wilmington at a glance
- Place: Wilmington, New Castle County, Delaware; about 73,176 residents (Census Bureau estimate, July 2024).
- Utility: Delmarva Power (investor-owned). Homes paid an average 17.23¢ per kWh in 2024 (EIA-861); the average customer lost 68 minutes of power on normal days and 127 counting major storms, with 0.7 interruptions a year (utility-wide, not just Wilmington).
- Utility: City of Newark (city-owned). Homes paid an average 18.99¢ per kWh in 2024 (EIA-861); the average customer lost 84 minutes of power on normal days, with 0.8 interruptions a year (utility-wide, not just Wilmington).
- Utility: Town of Middletown (city-owned). Homes paid an average 17.12¢ per kWh in 2024 (EIA-861) (utility-wide, not just Wilmington).
- Sun: 4.07 kWh per square meter per day on average, from 1.75 in December to 6.17 in June (NASA POWER). Our rough estimate: about 1,190 kWh a year per kW of panels.
- Climate: about 1,250 cooling degree-days and 4,800 heating degree-days a year (base 65°F, NASA POWER), so heating and cooling both matter.
- Top hazards in New Castle County: winter weather “very high”, river and heavy-rain flooding “relatively high” and cold waves “relatively high” (FEMA National Risk Index; overall county risk rated “relatively high”).
- Public charging: 105 ports at 35 locations in Wilmington, 22 of them DC fast (AFDC, October 20, 2026).
Your utility and what it means
Delmarva Power is an investor-owned utility and served about 275,018 home customers in 2024; its 17.23¢ average was below the 18.48¢ statewide average for July 2026. City of Newark is a city-owned utility and served about 11,888 home customers in 2024; its 18.99¢ average was above the 18.48¢ statewide average for July 2026. Town of Middletown is a city-owned utility and served about 9,071 home customers in 2024; its 17.12¢ average was below the 18.48¢ 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, City of Newark reported 84 minutes per customer without major storms in 2024, more than the statewide figure of 66 (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 Delaware guide and then ask your utility for its current interconnection steps before you sign anything.
Backup power in Wilmington
- 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.
- River and heavy-rain flooding (relatively high): Heavy rain can flood basements and take out power. Put sump pumps on backup power and keep equipment above the flood line.
- 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 Wilmington
By our rough estimate each kW of panels makes about 1,190 kWh a year in Wilmington (NASA sunshine data times 365 days times 0.80 for system losses). Valued at Delmarva Power’s 2024 average of 17.23¢, that is about $205 a year per kW if all of it offsets your own use (an estimate, not a promise). Production swings with the seasons: June is the sunniest month at 6.17 and December the dimmest at 1.75, a 3.5-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. Wilmington has 105 public charging ports in the federal station list including 22 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 Wilmington: 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 Wilmington building or permitting department, or from New Castle County if you live outside city limits, and often a utility interconnection approval. We have not verified a local permit page for Wilmington, so check the city and county websites or ask your electrician, who will know the process. Hire only a licensed electrician or installer; the Delaware guide lists the state licensing rules.
Nearby guides
More local guides: Wilmington and New Castle County energy guide, Elsmere, New Castle, Newark and Middletown, or the whole Delaware energy guide.
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Wilmington energy FAQ
Who is my electric company in Wilmington?
Delmarva Power, City of Newark and Town of Middletown all serve parts of New Castle County. Which one serves you depends on your street, so check the top of your bill. Their 2024 home price averages differ (Delmarva Power 17.23¢, City of Newark 18.99¢, Town of Middletown 17.12¢) so it matters for solar math.
How much power will solar make in Wilmington?
About 1,190 kWh a year per kW of panels by our estimate, so a 6 kW system would make roughly 7,140 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 New Castle 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.
Do I need a permit for solar or a generator in Wilmington?
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.