Sun Prairie Utilities
Municipal electric utility · Wisconsin · #767 of 3,199 U.S. utilities by customers · EIA utility #18312
Sun Prairie Utilities is a municipal electric utility serving 18,906 customers in Wisconsin. In 2025 it sold 304 gigawatt-hours of electricity for $33.21M in revenue, an average realized rate of 10.94¢ per kWh across all customer classes and 12.11¢ per kWh for residential customers. Its reported service territory covers 1 counties. EIA records its activities as: distribution.
Customers, sales and rates by customer class (2025)
| Class | Customers | Sales (GWh) | Revenue | Avg realized rate | Share of sales |
|---|---|---|---|---|---|
| Residential | 17,082 | 125 | $15.18M | 12.11¢ | |
| Commercial | 1,820 | 149 | $15.63M | 10.49¢ | |
| Industrial | 4 | 29.2 | $2.40M | 8.22¢ | |
| Total | 18,906 | 304 | $33.21M | 10.94¢ |
Average realized rate = revenue divided by sales as reported on EIA Form 861. It blends fixed charges, demand charges and riders into one per-kWh figure; it is not the utility's tariff rate. Estimated residential bill assumes the average residential customer's actual 2025 usage (611 kWh/month).
Five-year trend
| Year | Customers | Sales (GWh) | Revenue | Residential rate |
|---|---|---|---|---|
| 2021 | 17,190 | 295 | $29.66M | 11.40¢ |
| 2022 | 17,383 | 294 | $32.24M | 12.35¢ |
| 2023 | 18,263 | 292 | $30.56M | 11.84¢ |
| 2024 | 18,498 | 290 | $31.26M | 12.13¢ |
| 2025 | 18,906 | 304 | $33.21M | 12.11¢ |
Reliability (2025)
Average outage time (SAIDI): 11 minutes per customer per year
Average outages (SAIFI): 0.14 per customer
Average restoration time (CAIDI): 75 minutes
As reported for Wisconsin under the IEEE standard, with major event days included where the standard reports them. Lower is better; see the reliability rankings.
Energy supply (2025)
Net generation: 0.0 GWh
Wholesale power purchased: 311 GWh
Winter peak demand: 50 MW
Energy losses: 2.3% of energy handled
Meters & rooftop solar (2025)
Smart (AMI) meters: 99.9% of 18,784 meters
Customer-sited generation (net metering): 352 installations, 4.0 MW of capacity
Counties served
Dane, WI
Other large utilities in Wisconsin
- Wisconsin Electric Power Co - 1,179,163 customers, residential 20.53¢
- Wisconsin Power & Light Co - 505,706 customers, residential 18.47¢
- Wisconsin Public Service Corp - 472,199 customers, residential 17.20¢
- Northern States Power Co - 273,992 customers, residential 15.55¢
- Madison Gas & Electric Co - 168,439 customers, residential 21.11¢
- Adams-Columbia Electric Coop - 39,826 customers, residential 18.98¢
- Polk-Burnett Electric Coop - 22,408 customers, residential 15.96¢
- Riverland Energy Cooperative - 20,219 customers, residential 16.19¢
All Wisconsin utilities and rates
Source: U.S. Energy Information Administration, Form EIA-861 2025 (filed by the utility; figures as published). Utility #18312 in the EIA frame.