In short: Marshalltown has about 27,900 people and sits in Marshall County. Interstate Power and Light Co, Midland Power Coop and Consumers Energy Coop serves different parts of Marshall County, so your utility depends on your address; their 2024 home averages range from 13.6¢ to 17.9¢ per kWh (EIA). FEMA rates Marshall County drought “relatively high”. Rooftop solar here makes roughly 1,170 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 Marshalltown: its utility, outage records, sunshine, weather risks and charging. Statewide rules such as net metering, incentives and electrician licensing are in our Iowa energy guide.
Marshalltown at a glance
- Place: Marshalltown, Marshall County, Iowa; about 27,886 residents (Census Bureau estimate, July 2024).
- Utility: Interstate Power and Light Co (investor-owned). Homes paid an average 17.9¢ per kWh in 2024 (EIA-861); the average customer lost 99 minutes of power on normal days and 116 counting major storms, with 1.0 interruptions a year (utility-wide, not just Marshalltown).
- Utility: Midland Power Coop (member-owned cooperative). Homes paid an average 13.6¢ per kWh in 2024 (EIA-861); the average customer lost 105 minutes of power on normal days and 123 counting major storms, with 1.3 interruptions a year (utility-wide, not just Marshalltown).
- Utility: Consumers Energy Coop (member-owned cooperative). Homes paid an average 15.0¢ per kWh in 2024 (EIA-861); the average customer lost 96 minutes of power on normal days and 493 counting major storms, with 1.0 interruptions a year (utility-wide, not just Marshalltown).
- Sun: 4.02 kWh per square meter per day on average, from 1.55 in December to 6.34 in July (NASA POWER). Our rough estimate: about 1,170 kWh a year per kW of panels.
- Climate: about 880 cooling degree-days and 6,670 heating degree-days a year (base 65°F, NASA POWER), so heating is the big load.
- Top hazards in Marshall County: drought “relatively high”, strong winds “relatively high” and winter weather “relatively moderate” (FEMA National Risk Index; overall county risk rated “relatively low”).
- Public charging: 14 ports at 7 locations in Marshalltown, 4 of them DC fast (AFDC, October 20, 2026).
Your utility and what it means
Interstate Power and Light Co is an investor-owned utility and served about 417,153 home customers in 2024; its 17.9¢ average was above the 15.99¢ statewide average for July 2026. Midland Power Coop is a member-owned cooperative utility and served about 11,939 home customers in 2024; its 13.6¢ average was below the 15.99¢ statewide average for July 2026. Consumers Energy Coop is a member-owned cooperative utility and served about 6,922 home customers in 2024; its 15.0¢ average was below the 15.99¢ 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, Midland Power Coop reported 105 minutes per customer without major storms in 2024, more than the statewide figure of 90 (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 Iowa guide and then ask your utility for its current interconnection steps before you sign anything.
Backup power in Marshalltown
- Drought (relatively high): Drought raises fire and heat risk and strains wells. If you rely on a well pump, include it in your backup plan.
- Strong winds (relatively high): High winds knock out lines on ordinary days. A battery or portable power station handles the common short outages; add a generator for multi-day repairs.
- 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 Marshalltown
By our rough estimate each kW of panels makes about 1,170 kWh a year in Marshalltown (NASA sunshine data times 365 days times 0.80 for system losses). Valued at Interstate Power and Light Co’s 2024 average of 17.9¢, that is about $209 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 6.34 and December the dimmest at 1.55, 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. 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. Marshalltown has 14 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 Marshalltown: 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 Marshalltown building or permitting department, or from Marshall County if you live outside city limits, and often a utility interconnection approval. We have not verified a local permit page for Marshalltown, so check the city and county websites or ask your electrician, who will know the process. Hire only a licensed electrician or installer; the Iowa guide lists the state licensing rules.
Nearby guides
More local guides: Ames, Cedar Falls, Ankeny and Waterloo, or the whole Iowa energy guide.
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Marshalltown energy FAQ
Who is my electric company in Marshalltown?
Interstate Power and Light Co, Midland Power Coop and Consumers Energy Coop all serve parts of Marshall County. Which one serves you depends on your street, so check the top of your bill. Their 2024 home price averages differ (Interstate Power and Light Co 17.9¢, Midland Power Coop 13.6¢, Consumers Energy Coop 15.0¢) so it matters for solar math.
How much power will solar make in Marshalltown?
About 1,170 kWh a year per kW of panels by our estimate, so a 6 kW system would make roughly 7,020 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 strong winds in Marshall 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 Marshalltown?
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.