In short: Most St. Louis area homes are on Ameren Missouri, which averaged 12.6 cents per kWh for homes in 2024 and 148 outage minutes per customer, about two thirds of Missouri’s average (EIA). FEMA rates heat waves, ice storms and hail “very high” in St. Louis County, so backup power is about summer and winter alike.
This page covers the Missouri side of the St. Louis area: St. Louis, Chesterfield, St. Charles, O’Fallon and Wentzville. Statewide rules on net metering, licensing and incentives are in our Missouri energy guide. If you live across the river in Illinois, see the Metro East guide instead; Ameren Illinois is a different utility under different rules.
St. Louis at a glance
- Ameren Missouri (Union Electric Co.): about 12.6¢ per kWh for homes, averaged over 2024; 148 minutes without power per customer with major events, 94 without; 0.77 interruptions a year (EIA-861, 2024). It serves St. Louis, St. Louis County and most of St. Charles County.
- Cuivre River Electric Cooperative: serves parts of St. Charles County, including areas around O’Fallon and Wentzville; about 11.1¢ per kWh; 133 outage minutes and about 1.3 interruptions a year (EIA-861, 2024).
- Kirkwood Electric: the city of Kirkwood runs its own utility; about 14.4¢ per kWh; 167 outage minutes with major events, 134 without (EIA-861, 2024).
- Sun: about 4.2 kWh per square meter a day (NASA POWER, 2001 to 2020), or roughly 1,220 kWh a year per kW of panels by our estimate.
- Top hazards: St. Louis County is “very high” for cold waves, hail, heat waves, ice storms, lightning and winter weather, and “relatively high” for earthquakes, flooding, strong wind and tornadoes. The city of St. Louis is “very high” for heat waves; St. Charles County for strong wind (FEMA National Risk Index, December 2025).
- Public charging: 374 ports in St. Louis, 55 in Chesterfield and 35 in St. Charles (AFDC data, October 3, 2026).
The prices above are 2024 averages across all months. Missouri’s summer prices run higher; see the state guide for July 2026 figures.
Your utility and what it means
- Ameren Missouri: net metering follows Missouri law for systems under 100 kW. Each month, the solar power you send out offsets power you buy at the full rate; any surplus left at the end of the month is credited at a lower avoided-cost rate. Ameren’s old solar rebate has ended. We could not load Ameren’s website on October 3, 2026, so check its net metering page for the current credit rate, and ask Ameren about any EV charger or battery offers. Ameren had 8,041 homes with net-metered solar in 2024, and 555 of them had a battery (EIA). That is about 7%, close to three times the statewide share.
- Cuivre River Electric Cooperative: as a co-op it sets its own interconnection steps under Missouri’s net metering law, and Ameren programs do not apply. About 265 of its member homes had net-metered solar in 2024 (EIA). Ask the co-op before you sign a contract.
- Kirkwood Electric: a small city utility (44 net-metered homes in 2024, EIA). Ask the city about its application before you design a system.
Backup power in St. Louis
Ameren Missouri’s grid was fairly steady in 2024: under one interruption per customer and about two and a half hours without power in total. The risk is the bad day. FEMA rates heat waves “very high” in both the city and county of St. Louis, and ice storms “very high” in the county. A summer outage is a health risk for older people, babies and anyone on medical equipment, while an ice storm can keep whole neighborhoods dark for days. Hail, lightning and strong winds add spring and summer outages, and FEMA also rates earthquake losses “relatively high” in the city and county.
For short outages, a portable power station keeps phones, lights, Wi-Fi, fans and a CPAP machine going. A home battery switches on by itself and is quiet; paired with solar it recharges on sunny days. For a multi-day ice storm, a generator on natural gas or propane runs as long as the fuel lasts. Compare them in backup power options, then size yours with the generator sizing tool or the battery backup calculator.
Safety: the U.S. Consumer Product Safety Commission says to run a generator outdoors only, at least 20 feet from the house, with the exhaust pointed away from windows, doors and vents. Never run it in a garage, even with the door open. Install battery-backed carbon monoxide alarms. A licensed electrician should install the transfer switch or interlock; see generator installation.
Solar in St. Louis
At about 1,220 kWh a year per kW, St. Louis gets roughly the same sun as the rest of Missouri. At Ameren’s 2024 average of 12.6¢, each kW of panels would offset about $150 a year, and a 6 kW system about $920, if all of it replaces power you would have bought (estimates, not promises). Because Missouri credits only the monthly surplus at a lower rate, the best value comes from sizing the system to your own use, not oversizing it. Summer prices are higher, and that is when panels produce most.
Check your roof with the solar potential tool, compare quotes in the solar savings calculator, and read solar installation and how net metering works. If you are building a new home in the city of St. Louis, a 2020 ordinance requires construction plans to show that solar could be added later.
Batteries in St. Louis
Under Missouri’s monthly netting, a battery adds little to bill savings on its own. Its main value here is backup through heat waves, ice storms and summer storms. Among Ameren Missouri’s solar homes, batteries are almost three times as common as across the state (EIA, 2024). A battery large enough for central air is expensive. Most people back up a few circuits instead: the fridge, lights, a gas furnace fan, Wi-Fi and medical devices. See home battery installation and home battery cost.
EV charging in St. Louis
The city of St. Louis has 374 public charging ports at 127 locations, Chesterfield 55 and St. Charles 35 (AFDC data, October 3, 2026). At home, about 30 kWh per 100 miles at Ameren’s 2024 average of 12.6¢ comes to roughly $3.80 per 100 miles, or about $450 for 12,000 miles a year (estimate). Try your own numbers in the EV charging cost calculator. A Level 2 charger needs a 240 V circuit installed by a licensed electrician, with a permit; read EV charger installation.
Drive on another fuel? See every alternative fuel station in St. Louis: hydrogen, propane, natural gas, E85 ethanol, biodiesel and renewable diesel.
Permits and inspections
- City of St. Louis: Building Division permits section. Solar needs a building permit plus an electrical permit pulled by a licensed electrical contractor; see the city’s Solar and the City of St. Louis page.
- St. Louis County: Transportation and Public Works handles unincorporated areas and the towns that contract with it for home inspections. It publishes a residential solar checklist and guide and residential electrical work rules. Other towns, Chesterfield included, may run their own permits, so ask your city first.
- St. Charles County: the Building and Code Enforcement Division issues residential building permits in unincorporated areas. The City of St. Charles Building Division covers the city; O’Fallon and Wentzville have their own building departments.
- Utility and HOA: Ameren, Cuivre River or Kirkwood must approve the connection before you switch on. Subdivisions with an HOA usually need written approval.
Cities we cover
- St. Louis
- Chesterfield
- St. Charles
- O’Fallon
- Wentzville
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St. Louis energy FAQ
Who is my electric utility in the St. Louis area?
For most homes on the Missouri side it is Ameren Missouri. Parts of St. Charles County, including areas around O’Fallon and Wentzville, are served by Cuivre River Electric Cooperative, and Kirkwood runs its own city utility. Your bill tells you for certain, and that utility must approve any solar or battery connection.
Are power outages common in St. Louis?
Not on ordinary days. Ameren Missouri customers averaged 0.77 interruptions and 148 minutes without power in 2024, against 224 minutes for Missouri as a whole (EIA). The concern is severe weather: FEMA rates heat waves and ice storms “very high” in St. Louis County, and those events can cause long outages.
Do I need a permit for solar panels in St. Louis?
Yes. In the city of St. Louis, solar needs a building permit and an electrical permit taken out by a licensed electrical contractor. St. Louis County publishes a residential solar checklist for the areas it inspects, and St. Charles County lists solar among projects needing a residential building permit.
Do Illinois solar incentives apply in St. Louis?
No. Illinois programs such as Illinois Shines and Ameren Illinois rebates apply only to homes in Illinois. Missouri homes on Ameren Missouri follow Missouri’s net metering law and have no active state solar incentive in 2026, so the savings come from your bill.
Is earthquake risk a reason for backup power in St. Louis?
It is one more reason. FEMA rates expected earthquake losses “relatively high” for both the city and county of St. Louis. A strong quake is rare but could cut power for days. A plan that covers several days, such as a generator with stored fuel or solar with a battery, also covers ice storms.
Sources
Utilities, prices, outages and net-metered homes: U.S. Energy Information Administration, EIA-861 data for 2024. Permits: City of St. Louis Building Division, St. Louis County Transportation and Public Works, St. Charles County and City of St. Charles pages, checked October 3, 2026. Ameren Missouri’s website could not be reached that day. Sun: NASA POWER, 2001 to 2020. Hazards: FEMA National Risk Index, December 2025. Charging: Alternative Fuels Data Center, October 3, 2026. Generator safety: CPSC.