In short: Brookfield has about 41,300 people and sits in Waukesha County. Wisconsin Electric Power Co and Oconomowoc Utilities serves different parts of Waukesha County, so your utility depends on your address; their 2024 home averages range from 13.75¢ to 19.23¢ per kWh (EIA). FEMA rates Waukesha County cold waves “relatively high”. Rooftop solar here makes roughly 1,120 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 Brookfield: its utility, outage records, sunshine, weather risks and charging. Statewide rules such as net metering, incentives and electrician licensing are in our Wisconsin energy guide and the wider area is covered in the Milwaukee guide.
Brookfield at a glance
- Place: Brookfield, Waukesha County, Wisconsin; about 41,268 residents (Census Bureau estimate, July 2024).
- Utility: Wisconsin Electric Power Co (investor-owned). Homes paid an average 19.23¢ per kWh in 2024 (EIA-861); the average customer lost 109 minutes of power on normal days and 296 counting major storms, with 0.7 interruptions a year (utility-wide, not just Brookfield).
- Utility: Oconomowoc Utilities (city-owned). Homes paid an average 13.75¢ per kWh in 2024 (EIA-861); the average customer lost 0 minutes of power on normal days and 6 counting major storms, with 0.0 interruptions a year (utility-wide, not just Brookfield).
- Sun: 3.84 kWh per square meter per day on average, from 1.29 in December to 6.25 in July (NASA POWER). Our rough estimate: about 1,120 kWh a year per kW of panels.
- Climate: about 630 cooling degree-days and 7,180 heating degree-days a year (base 65°F, NASA POWER), so heating is the big load.
- Top hazards in Waukesha County: cold waves “relatively high”, hail “relatively high” and tornadoes “relatively high” (FEMA National Risk Index; overall county risk rated “relatively moderate”).
- Public charging: 25 ports at 6 locations in Brookfield, 1 of them DC fast (AFDC, October 20, 2026).
Your utility and what it means
Wisconsin Electric Power Co is an investor-owned utility and served about 1,048,148 home customers in 2024; its 19.23¢ average was close to the 19.06¢ statewide average for July 2026. Oconomowoc Utilities is a city-owned utility and served about 9,972 home customers in 2024; its 13.75¢ average was below the 19.06¢ 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, Wisconsin Electric Power Co reported 109 minutes per customer without major storms in 2024, more than the statewide figure of 91 (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 Wisconsin guide and then ask your utility for its current interconnection steps before you sign anything.
Backup power in Brookfield
- Cold waves (relatively high): Cold waves raise demand and can cause both outages and frozen pipes. Keep at least one room warm with a battery-run heater circuit or a generator.
- Hail (relatively high): Hail is hard on rooftop solar; ask installers about impact-rated panels and your insurer about coverage.
- 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 Brookfield
By our rough estimate each kW of panels makes about 1,120 kWh a year in Brookfield (NASA sunshine data times 365 days times 0.80 for system losses). Valued at Wisconsin Electric Power Co’s 2024 average of 19.23¢, that is about $215 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 6.25 and December the dimmest at 1.29, a 4.8-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. Hail and storm exposure are worth raising with installers and your insurer.
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. Brookfield has 25 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 Brookfield: 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 Brookfield building or permitting department, or from Waukesha County if you live outside city limits, and often a utility interconnection approval. We have not verified a local permit page for Brookfield, so check the city and county websites or ask your electrician, who will know the process. Hire only a licensed electrician or installer; the Wisconsin guide lists the state licensing rules.
Nearby guides
More local guides: Milwaukee energy guide, Wauwatosa, West Allis, New Berlin and Menomonee Falls, or the whole Wisconsin energy guide.
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Brookfield energy FAQ
Who is my electric company in Brookfield?
Wisconsin Electric Power Co and Oconomowoc Utilities both serve parts of Waukesha County. Which one serves you depends on your street, so check the top of your bill. Their 2024 home price averages differ (Wisconsin Electric Power Co 19.23¢, Oconomowoc Utilities 13.75¢) so it matters for solar math.
How much power will solar make in Brookfield?
About 1,120 kWh a year per kW of panels by our estimate, so a 6 kW system would make roughly 6,720 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 cold waves in Waukesha 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 Brookfield?
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.