Otter Tail Power Co
Investor Owned electric utility · Minnesota · #192 of 3,199 U.S. utilities by customers · EIA utility #14232
Otter Tail Power Co is a investor owned electric utility serving 134,544 customers in Minnesota, North Dakota, South Dakota. In 2025 it sold 5,918 gigawatt-hours of electricity for $481.63M in revenue, an average realized rate of 8.14¢ per kWh across all customer classes and 11.19¢ per kWh for residential customers. Its reported service territory covers 75 counties. EIA records its activities as: generation, transmission, buying transmission, distribution, wholesale marketing.
Customers, sales and rates by customer class (2025)
| Class | Customers | Sales (GWh) | Revenue | Avg realized rate | Share of sales |
|---|---|---|---|---|---|
| Residential | 104,750 | 1,254 | $140.32M | 11.19¢ | |
| Commercial | 29,781 | 3,436 | $269.35M | 7.84¢ | |
| Industrial | 13 | 1,228 | $71.95M | 5.86¢ | |
| Total | 134,544 | 5,918 | $481.63M | 8.14¢ |
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 (998 kWh/month).
Operations by state
| State | Customers | Sales (GWh) | Residential rate |
|---|---|---|---|
| Minnesota | 63,450 | 2,799 | 11.27¢ |
| North Dakota | 59,067 | 2,555 | 11.07¢ |
| South Dakota | 12,027 | 564 | 11.42¢ |
Five-year trend
| Year | Customers | Sales (GWh) | Revenue | Residential rate |
|---|---|---|---|---|
| 2021 | 133,943 | 4,790 | $414.76M | 11.05¢ |
| 2022 | 134,122 | 5,592 | $470.61M | 10.99¢ |
| 2023 | 134,339 | 5,772 | $452.92M | 10.76¢ |
| 2024 | 134,397 | 5,681 | $450.72M | 11.32¢ |
| 2025 | 134,544 | 5,918 | $481.63M | 11.19¢ |
Reliability (2025)
Average outage time (SAIDI): 557 minutes per customer per year
Average outages (SAIFI): 1.74 per customer
Average restoration time (CAIDI): 320 minutes
As reported for Minnesota 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: 3,683 GWh
Wholesale power purchased: 2,835 GWh
Winter peak demand: 1,004 MW
Energy losses: 1.3% of energy handled
Meters & rooftop solar (2025)
Smart (AMI) meters: 99.4% of 174,291 meters
Customer-sited generation (net metering): 160 installations, 4.1 MW of capacity
Counties served
Barnes, NDBecker, MNBeltrami, MNBenson, NDBig Stone, MNBottineau, NDBrookings, SDBurleigh, NDCass, MNCass, NDCavalier, NDChippewa, MNClay, MNClearwater, MNCodington, SDDay, SDDeuel, SDDickey, NDDouglas, MNEddy, NDFoster, NDGrand Forks, NDGrant, MNGrant, SDGriggs, NDHamlin, SDKandiyohi, MNKidder, NDKingsbury, SDKittson, MNLaMoure, NDLac Qui Parle, MNLake, SDLincoln, MNLogan, NDLyon, MNMahnomen, MNMarshall, MNMarshall, SDMcHenry, NDMcLean, NDMoody, SDMountrail, NDNelson, NDNorman, MNOtter Tail, MNPembina, NDPennington, MNPierce, NDPolk, MNPope, MNRamsey, NDRansom, NDRed Lake, MNRedwood, MNRenville, NDRichland, NDRoberts, SDRolette, NDRoseau, MN + 15 more counties
Other large utilities in Minnesota
- Northern States Power Co - Minnesota - 1,594,256 customers, residential 16.50¢
- ALLETE, Inc. - 153,192 customers, residential 15.86¢
- Connexus Energy - 148,716 customers, residential 14.11¢
- Dakota Electric Association - 117,913 customers, residential 15.63¢
- East Central Energy - 68,154 customers, residential 17.60¢
- Rochester Public Utilities - 60,963 customers, residential 18.58¢
- Wright-Hennepin Coop Elec Assn - 57,130 customers, residential 15.00¢
- Lake Country Power - 51,603 customers, residential 18.34¢
All Minnesota utilities and rates
Source: U.S. Energy Information Administration, Form EIA-861 2025 (filed by the utility; figures as published). Utility #14232 in the EIA frame.