In short: Vermillion has about 11,900 people and sits in Clay County. Southeastern Electric Coop Inc serves the county, averaging 12.41¢ per kWh for homes in 2024 (EIA). Rooftop solar here makes roughly 1,210 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 Vermillion: its utility, outage records, sunshine, weather risks and charging. Statewide rules such as net metering, incentives and electrician licensing are in our South Dakota energy guide.
Vermillion at a glance
- Place: Vermillion, Clay County, South Dakota; about 11,877 residents (Census Bureau estimate, July 2024).
- Utility: Southeastern Electric Coop Inc (member-owned cooperative). Homes paid an average 12.41¢ per kWh in 2024 (EIA-861); the average customer lost 71 minutes of power on normal days (utility-wide, not just Vermillion).
- Sun: 4.16 kWh per square meter per day on average, from 1.64 in December to 6.64 in July (NASA POWER). Our rough estimate: about 1,210 kWh a year per kW of panels.
- Climate: about 1,040 cooling degree-days and 6,770 heating degree-days a year (base 65°F, NASA POWER), so heating is the big load.
- Top hazards in Clay County: drought “relatively moderate”, winter weather “relatively moderate” and ice storms “relatively moderate” (FEMA National Risk Index; overall county risk rated “very low”).
- Public charging: 3 ports at 2 locations in Vermillion, 1 of them DC fast (AFDC, October 20, 2026).
Your utility and what it means
Southeastern Electric Coop Inc is a member-owned cooperative utility and served about 20,160 home customers in 2024; its 12.41¢ average was below the 15.37¢ 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, Southeastern Electric Coop Inc reported 71 minutes per customer without major storms in 2024, more than the statewide figure of 62 (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 South Dakota guide and then ask your utility for its current interconnection steps before you sign anything.
Backup power in Vermillion
- Drought (relatively moderate): Drought raises fire and heat risk and strains wells. If you rely on a well pump, include it in your backup plan.
- Winter weather (relatively moderate): 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.
- 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 Vermillion
By our rough estimate each kW of panels makes about 1,210 kWh a year in Vermillion (NASA sunshine data times 365 days times 0.80 for system losses). Valued at Southeastern Electric Coop Inc’s 2024 average of 12.41¢, that is about $150 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 6.64 and December the dimmest at 1.64, a 4.1-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. Vermillion has 3 public charging ports in the federal station list including 1 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 Vermillion: 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 Vermillion building or permitting department, or from Clay County if you live outside city limits, and often a utility interconnection approval. We have not verified a local permit page for Vermillion, so check the city and county websites or ask your electrician, who will know the process. Hire only a licensed electrician or installer; the South Dakota guide lists the state licensing rules.
Nearby guides
More local guides: Yankton, or the whole South Dakota energy guide.
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Vermillion energy FAQ
Who is my electric company in Vermillion?
Federal data lists Southeastern Electric Coop Inc as the main utility serving Clay 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 Vermillion?
About 1,210 kWh a year per kW of panels by our estimate, so a 6 kW system would make roughly 7,260 kWh. Shade, roof direction and tilt change this; run your address through the solar potential tool for a better number.
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 Vermillion?
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.