Illinois · EIA utility 58957 · Energy supplier
Interstate Gas Supply, Inc. electricity rates in Illinois, 2025
Interstate Gas Supply, Inc.’s 22,865 residential customers paid an average of 12.73¢ per kWh in 2025, 28% below the Illinois average of 17.67¢. The typical home used 613 kWh a month, for an average bill of $78.
- 12.73¢avg ¢/kWh (2025)+1.35¢ (+11.9%) vs 2024
- $78Avg monthly billIllinois: $127
- 613 kWhAvg monthly useIllinois: 716 kWh
- 22,865Residential customersEnergy supplier
| Sector | Customers | Sales (MWh) | Revenue | ¢/kWh 2025 | ¢/kWh 2024 | Change |
|---|---|---|---|---|---|---|
| Residential | 22,865 | 168,180 | $21,410,000 | 12.73¢ | 11.38¢ | +1.35¢ (+11.9%) |
| Commercial | 6,248 | 1,379,579 | $114,418,000 | 8.29¢ | 7.45¢ | +0.85¢ (+11.4%) |
| Industrial | 0 | 0 | $0 | n/a | n/a | n/a |
| All sectors | 29,113 | 1,547,759 | $135,828,000 | 8.78¢ | 7.95¢ | +0.82¢ (+10.3%) |
How Interstate Gas Supply, Inc. compares
- Illinois residential average, 2025: 17.67¢ per kWh, 716 kWh a month, $127 average bill. U.S. average: 17.23¢, 874 kWh, $151.
- Among 39 energy suppliers in Illinois with at least 1,000 residential customers, Interstate Gas Supply, Inc. ranks 22 of 39 from lowest to highest average price.
- Latest monthly figure: Illinois homes paid 19.32¢ per kWh in August 2026 (preliminary), against 18.03¢ in August 2025. Summer months often run higher than the annual average.
- From 2024 to 2025 this average rose 11.9%; the state average rose 11.3%.
- Interstate Gas Supply, Inc. is a retail energy provider that sells electricity supply in a state with retail choice. Balancing authority: PJM.
Illinois energy suppliers with similar rates
| Provider | ¢/kWh | Avg bill | Customers |
|---|---|---|---|
| Reliant Energy Northeast LLC | 11.99¢ | $83 | 142,167 |
| CleanChoice Energy, Inc. | 12.31¢ | $67 | 29,609 |
| Viridian Energy PA LLC | 12.51¢ | $82 | 2,824 |
| SmartEnergy Holdings, LLC | 12.51¢ | $66 | 38,988 |
| Stream Energy Illinois, LLC | 12.89¢ | $75 | 2,415 |
| Energy Plus Holdings LLC | 13.13¢ | $78 | 5,466 |
| Energy Services Providers, Inc | 13.28¢ | $87 | 30,668 |
| Green Mountain Energy Company | 13.29¢ | $74 | 6,670 |
Sources
- U.S. Energy Information Administration, Annual Electric Power Industry Report, Form EIA-861, 2025 final data (f8612025.zip, file dated October 7, 2026): Sales to Ultimate Customers, Average Monthly Bill and Service Territory tables.
- EIA Form EIA-861, 2024 final data (f8612024.zip, file dated December 4, 2025), for the 2024 comparison.
- EIA Electric Power Monthly, Table 5.6.A (average price by state, August 2026 and August 2025; 2026 values are preliminary), file dated October 22, 2026.
Average price = residential revenue ÷ residential kWh sold, as reported to EIA. It includes fixed monthly charges, taxes passed through in revenue and seasonal tiers, averaged over the year. Your own rate depends on your tariff and usage.