In short: Derby has about 26,600 people and sits in Sedgwick County. Evergy Kansas South, Inc serves the county, averaging 14.25¢ per kWh for homes in 2024 (EIA). FEMA rates Sedgwick County ice storms “very high”. Rooftop solar here makes roughly 1,350 kWh a year per kW of panels by our estimate, which is good for solar.
This page covers what is local to Derby: its utility, outage records, sunshine, weather risks and charging. Statewide rules such as net metering, incentives and electrician licensing are in our Kansas energy guide and the wider area is covered in the Wichita guide.
Derby at a glance
- Place: Derby, Sedgwick County, Kansas; about 26,604 residents (Census Bureau estimate, July 2024).
- Utility: Evergy Kansas South, Inc (investor-owned). Homes paid an average 14.25¢ per kWh in 2024 (EIA-861); the average customer lost 87 minutes of power on normal days and 206 counting major storms, with 0.9 interruptions a year (utility-wide, not just Derby).
- Sun: 4.62 kWh per square meter per day on average, from 2.23 in December to 6.95 in June (NASA POWER). Our rough estimate: about 1,350 kWh a year per kW of panels.
- Climate: about 1,860 cooling degree-days and 4,320 heating degree-days a year (base 65°F, NASA POWER), so heating and cooling both matter.
- Top hazards in Sedgwick County: ice storms “very high”, cold waves “very high” and tornadoes “very high” (FEMA National Risk Index; overall county risk rated “relatively high”).
- Public charging: 2 ports at 1 locations in Derby, none of them DC fast (AFDC, October 20, 2026).
Your utility and what it means
Evergy Kansas South, Inc is an investor-owned utility and served about 302,508 home customers in 2024; its 14.25¢ average was below the 15.27¢ 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, Evergy Kansas South, Inc reported 87 minutes per customer without major storms in 2024, less than the statewide figure of 104 (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 Kansas guide and then ask your utility for its current interconnection steps before you sign anything.
Backup power in Derby
- Ice storms (very high): Ice storms bring down lines for days. A standby generator with a transfer switch, or a battery sized for the fridge, furnace blower and well pump, matters more than a small power station.
- Cold waves (very 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.
- 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 Derby
By our rough estimate each kW of panels makes about 1,350 kWh a year in Derby (NASA sunshine data times 365 days times 0.80 for system losses). Valued at Evergy Kansas South, Inc’s 2024 average of 14.25¢, that is about $192 a year per kW if all of it offsets your own use (an estimate, not a promise). Production swings with the seasons: June is the sunniest month at 6.95 and December the dimmest at 2.23, a 3.1-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. Derby has 2 public charging ports in the federal station list (none of them 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 Derby: 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 Derby building or permitting department, or from Sedgwick County if you live outside city limits, and often a utility interconnection approval. We have not verified a local permit page for Derby, so check the city and county websites or ask your electrician, who will know the process. Hire only a licensed electrician or installer; the Kansas guide lists the state licensing rules.
Nearby guides
More local guides: Wichita energy guide, or the whole Kansas energy guide.
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Derby energy FAQ
Who is my electric company in Derby?
Federal data lists Evergy Kansas South, Inc as the main utility serving Sedgwick 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 Derby?
About 1,350 kWh a year per kW of panels by our estimate, so a 6 kW system would make roughly 8,100 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 ice storms in Sedgwick 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.
Do I need a permit for solar or a generator in Derby?
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.