Rock Energy Cooperative
Cooperative electric utility · Illinois · #779 of 3,199 U.S. utilities by customers · EIA utility #16196
Rock Energy Cooperative is a cooperative electric utility serving 18,357 customers in Illinois, Wisconsin. In 2025 it sold 534 gigawatt-hours of electricity for $55.07M in revenue, an average realized rate of 10.32¢ per kWh across all customer classes and 14.58¢ per kWh for residential customers. Its reported service territory covers 8 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 | 16,830 | 174 | $25.33M | 14.58¢ | |
| Commercial | 1,429 | 142 | $16.46M | 11.56¢ | |
| Industrial | 98 | 218 | $13.29M | 6.11¢ | |
| Total | 18,357 | 534 | $55.07M | 10.32¢ |
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 (860 kWh/month).
Operations by state
| State | Customers | Sales (GWh) | Residential rate |
|---|---|---|---|
| Illinois | 10,462 | 217 | 14.86¢ |
| Wisconsin | 7,895 | 317 | 14.31¢ |
Five-year trend
| Year | Customers | Sales (GWh) | Revenue | Residential rate |
|---|---|---|---|---|
| 2021 | 17,931 | 547 | $48.22M | 12.88¢ |
| 2022 | 18,081 | 538 | $55.23M | 13.97¢ |
| 2023 | 18,151 | 524 | $53.72M | 14.37¢ |
| 2024 | 18,168 | 524 | $55.08M | 14.72¢ |
| 2025 | 18,357 | 534 | $55.07M | 14.58¢ |
Reliability (2025)
Average outage time (SAIDI): 16 minutes per customer per year
Average outages (SAIFI): 0.40 per customer
Average restoration time (CAIDI): 40 minutes
As reported for Illinois 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: — GWh
Wholesale power purchased: 559 GWh
Winter peak demand: 86 MW
Energy losses: 4.4% of energy handled
Meters & rooftop solar (2025)
Smart (AMI) meters: 0.0% of 19,767 meters
Customer-sited generation (net metering): 148 installations, 1.1 MW of capacity
Counties served
Boone, ILDane, WIGreen, WIMcHenry, ILRock, WIStephenson, ILWalworth, WIWinnebago, IL
Other large utilities in Illinois
- Commonwealth Edison Co - 3,261,563 customers, residential 17.71¢
- Ameren Illinois Company - 663,709 customers, residential 16.70¢
- MC Squared Energy Services, LLC - 293,923 customers, residential 8.14¢
- Homefield Energy - 160,102 customers, residential 10.64¢
- Energy Services Providers, Inc - 90,477 customers, residential 13.01¢
- Just Energy Solutions Inc. - 80,538 customers, residential 11.33¢
- City of Springfield - (IL) - 70,871 customers, residential 13.09¢
- Residents Energy, LLC - 69,834 customers, residential 17.34¢
All Illinois utilities and rates
Source: U.S. Energy Information Administration, Form EIA-861 2025 (filed by the utility; figures as published). Utility #16196 in the EIA frame.