In short: Spearfish has about 13,800 people and sits in Lawrence County. Black Hills Power, Inc. and Black Hills Electric Coop, Inc serves different parts of Lawrence County, so your utility depends on your address; their 2024 home averages range from 14.37¢ to 14.76¢ per kWh (EIA). FEMA rates Lawrence County winter weather “relatively high”. Rooftop solar here makes roughly 1,240 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 Spearfish: 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 and the wider area is covered in the Rapid City guide.
Spearfish at a glance
- Place: Spearfish, Lawrence County, South Dakota; about 13,803 residents (Census Bureau estimate, July 2024).
- Utility: Black Hills Power, Inc. (investor-owned). Homes paid an average 14.37¢ per kWh in 2024 (EIA-861); the average customer lost 57 minutes of power on normal days, with 0.9 interruptions a year (utility-wide, not just Spearfish).
- Utility: Black Hills Electric Coop, Inc (member-owned cooperative). Homes paid an average 14.76¢ per kWh in 2024 (EIA-861); the average customer lost 102 minutes of power on normal days and 229 counting major storms, with 0.8 interruptions a year (utility-wide, not just Spearfish).
- Sun: 4.25 kWh per square meter per day on average, from 1.58 in December to 6.99 in July (NASA POWER). Our rough estimate: about 1,240 kWh a year per kW of panels.
- Climate: about 700 cooling degree-days and 7,100 heating degree-days a year (base 65°F, NASA POWER), so heating is the big load.
- Top hazards in Lawrence County: winter weather “relatively high”, wildfires “relatively moderate” and hail “relatively moderate” (FEMA National Risk Index; overall county risk rated “relatively low”).
- Public charging: 11 ports at 5 locations in Spearfish, 8 of them DC fast (AFDC, October 20, 2026).
Your utility and what it means
Black Hills Power, Inc. is an investor-owned utility and served about 60,951 home customers in 2024; its 14.37¢ average was below the 15.37¢ statewide average for July 2026. Black Hills Electric Coop, Inc is a member-owned cooperative utility and served about 9,227 home customers in 2024; its 14.76¢ 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, Black Hills Electric Coop, Inc reported 102 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 Spearfish
- Winter weather (relatively 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.
- Wildfires (relatively moderate): Wildfire risk can mean planned shutoffs and smoke. A battery charged by solar gives quiet backup, and fueled generators need extra care on dry days and clear space around them.
- 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 Spearfish
By our rough estimate each kW of panels makes about 1,240 kWh a year in Spearfish (NASA sunshine data times 365 days times 0.80 for system losses). Valued at Black Hills Power, Inc.’s 2024 average of 14.37¢, that is about $178 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 6.99 and December the dimmest at 1.58, a 4.4-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. Spearfish has 11 public charging ports in the federal station list including 8 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 Spearfish: 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 Spearfish building or permitting department, or from Lawrence County if you live outside city limits, and often a utility interconnection approval. We have not verified a local permit page for Spearfish, 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: Rapid City energy guide and Box Elder, or the whole South Dakota energy guide.
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Spearfish energy FAQ
Who is my electric company in Spearfish?
Black Hills Power, Inc. and Black Hills Electric Coop, Inc both serve parts of Lawrence County. Which one serves you depends on your street, so check the top of your bill. Their 2024 home price averages differ (Black Hills Power, Inc. 14.37¢, Black Hills Electric Coop, Inc 14.76¢) so it matters for solar math.
How much power will solar make in Spearfish?
About 1,240 kWh a year per kW of panels by our estimate, so a 6 kW system would make roughly 7,440 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 Lawrence 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 Spearfish?
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.