Rock Energy Cooperative and solar
Rock Energy Cooperative is an electric cooperative serving about 16,830 homes in Illinois, Wisconsin. Here's what its rates and export rules mean for solar: for a typical customer, solar is a close call.
- Average price (2026 est.)
- 15.6¢17% below Illinois average
- Typical bill
- $134860 kWh a month
- Exports credited
- ~58%Reduced export credit
- Typical payback
- 15.3 yrs6.2 kW, cash
Export rules for Rock Energy Cooperative customers
Reduced export credit (Illinois rule).
For ComEd and Ameren customers who connected on or after Jan 1, 2025, solar exports only offset the energy supply part of the bill (about 8-12 cents/kWh), not delivery charges. To compensate, the state pays an upfront $300 per kW rebate for solar with a smart inverter, and Illinois Shines pays for solar renewable energy credits.
Solar for a typical Rock Energy Cooperative home
| System | 6.2 kW (80% of 860 kWh/month) |
|---|---|
| Cost | $21,480 |
| First-year savings | $1,268 |
| Payback | 15.3 years |
| 25-year net | $19,747 |
Uses the utility's average price.
Solar adoption
- Homes with solar (2025)
- 148
- Share of customers
- 0.9%
- Residential solar capacity
- 1 MW
- Residential customers
- 16,830
EIA-861, 2025.
Questions about Rock Energy Cooperative and solar
Does Rock Energy Cooperative have net metering?
Rock Energy Cooperative follows Illinois's rules: For ComEd and Ameren customers who connected on or after Jan 1, 2025, solar exports only offset the energy supply part of the bill (about 8-12 cents/kWh), not delivery charges. To compensate, the state pays an upfront $300 per kW rebate for solar with a smart inverter, and Illinois Shines pays for solar renewable energy credits.
How much does electricity cost with Rock Energy Cooperative?
Residential customers paid an average of 14.6¢ per kWh in 2025 (EIA), about 15.6¢ adjusted to 2026. The typical home uses 860 kWh a month, a bill of about $134.
Is solar worth it with Rock Energy Cooperative?
For a typical customer, solar is a close call: a 6.2 kW system costing about $21,480 pays back in about 15.3 years, with $19,747 net over 25 years.
How many Rock Energy Cooperative customers have solar?
About 148 homes had net-metered solar at the end of 2025, roughly 0.9% of residential customers (EIA-861).
Legal name: Rock Energy Cooperative (EIA ID 16196). Data: EIA-861 2025 and monthly data through 2026, state policy research October 2026.