Charles Mix Electric Assn, Inc
Cooperative electric utility · South Dakota · #1,944 of 3,199 U.S. utilities by customers · EIA utility #3315
Charles Mix Electric Assn, Inc is a cooperative electric utility serving 2,661 customers in South Dakota. In 2025 it sold 66.0 gigawatt-hours of electricity for $9.07M in revenue, an average realized rate of 13.74¢ per kWh across all customer classes and — per kWh for residential customers. Its reported service territory covers 4 counties.
Customers, sales and rates by customer class (2025)
| Class | Customers | Sales (GWh) | Revenue | Avg realized rate | Share of sales |
|---|---|---|---|---|---|
| Total | 2,661 | 66.0 | $9.07M | 13.74¢ |
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 (— kWh/month).
This utility files the EIA-861S short form, which reports totals only - no breakdown by customer class is published for it.
Five-year trend
| Year | Customers | Sales (GWh) | Revenue | Residential rate |
|---|---|---|---|---|
| 2021 | 2,606 | 67.1 | $8.45M | — |
| 2022 | 2,627 | 69.5 | $8.71M | — |
| 2023 | 2,641 | 69.1 | $8.84M | — |
| 2024 | 2,660 | 64.9 | $8.48M | — |
| 2025 | 2,661 | 66.0 | $9.07M | — |
Meters & rooftop solar (2025)
Smart (AMI) meters: 0.0% of 2,660 meters
Counties served
Bon Homme, SDBrule, SDCharles Mix, SDDouglas, SD
Other large utilities in South Dakota
- Black Hills Power, Inc. - 85,804 customers, residential 15.07¢
- NorthWestern Energy - (SD) - 65,396 customers, residential 13.35¢
- Sioux Valley SW Elec Coop - 30,059 customers, residential 13.87¢
- Southeastern Electric Coop Inc - (SD) - 24,428 customers, residential 12.98¢
- West River Electric Assn Inc - 21,332 customers, residential 15.16¢
- Watertown Municipal Utilities - 14,497 customers, residential 9.29¢
- City of Brookings - (SD) - 12,568 customers, residential 10.69¢
- Black Hills Electric Coop, Inc - 11,478 customers, residential 14.79¢
All South Dakota utilities and rates
Source: U.S. Energy Information Administration, Form EIA-861 2025 (filed by the utility; figures as published). Utility #3315 in the EIA frame.