States › South Dakota › Day County
Electric utilities serving Day County, South Dakota
Utilities that list the county in their Form EIA-861 service territory for 2024, with each one's average price, bill and outage minutes.
Day County, South Dakota, appears in the Form EIA-861 service territory of 7 utilities for 2024; NorthWestern Energy, Otter Tail Power Co and Montana-Dakota Utilities Co are the largest by residential customers statewide.
Their average residential prices ran from 10.93¢ to 14.59¢ per kilowatthour, with a median of 11.93¢, against a South Dakota average of 12.86¢ and a US average of 16.48¢. Each price is the utility's figure for all of its South Dakota customers, not for this county alone.
WAPA: Western Area Power Administration lists the county too but reported no residential sales in South Dakota under its own name.
The median SAIDI they reported was 105.4 minutes per customer including major event days; the median among all South Dakota utilities reporting was 73.7.
The Census Bureau estimates the county's population at 5,484. EIA does not publish customers by county, so which utility serves a given address has to be confirmed with the utility or the state utility commission.
Average price is revenue divided by sales for the sector and year; it is not a tariff rate. Reliability figures are as reported by utilities to EIA on Form 861 and may use different calculation methods. Figures are for each utility's whole South Dakota operation; EIA publishes nothing at county level.
Utilities and their 2024 figures
| Utility | Ownership | Residential customers | ¢ per kWh | Monthly bill | SAIDI, all events | SAIDI, no major events |
|---|---|---|---|---|---|---|
| NorthWestern Energy | Investor-owned | 51,467 | 12.56¢ | $113.36 | 76.0 | 66.5 |
| Otter Tail Power Co | Investor-owned | 9,048 | 10.93¢ | $111.78 | 134.7 | 70.8 |
| Montana-Dakota Utilities Co | Investor-owned | 6,367 | 14.59¢ | $121.53 | 154.0 | 148.0 |
| Northern Electric Coop, Inc | Cooperative | 5,757 | 11.29¢ | $225.58 | 49.8 | 49.8 |
| Lake Region Electric Assn, Inc short form | Cooperative | 3,468 | — | — | — | — |
| Codington-Clark Elec Coop, Inc short form | Cooperative | 3,457 | — | — | — | — |
| WAPA: Western Area Power Administration | Federal | — | — | — | — | — |
Ordered by residential customers in South Dakota. Short-form filers are small utilities that report only totals to EIA, so no residential price is available; their all-sector revenue per kWh was Lake Region Electric Assn, Inc 9.37¢, Codington-Clark Elec Coop, Inc 9.84¢. A utility with no customers shown reported its retail sales elsewhere or delivers power that other companies bill for.
Against the state and the country
| Measure, 2024 | Utilities listing Day County | South Dakota | United States |
|---|---|---|---|
| Average residential price per kWh | 11.93¢ median | 12.86¢ | 16.48¢ |
| Average monthly residential bill | $117.45 median | $127.81 | $142.26 |
| SAIDI, all events (minutes) | 105.4 median | 73.7 median | 184.5 median |
| SAIDI, without major event days | 68.7 median | 65.1 median | 99.8 median |
| Utilities counted | 7 | 20 | 1,413 |
Outage minutes reported
SAIDI for 2024 across each utility's whole system, including major event days (paler bars: only the figure without major event days was reported). Not a measure of outages in Day County itself.
Population: 5,484 (U.S. Census Bureau, Vintage 2025 estimate). Statewide, residential sales came to 5,529 kWh per resident in 2024.
Other South Dakota counties
- Clark County 6
- Clay County 4
- Codington County 7
- Corson County 4
- Custer County 3
- Davison County 4
- Deuel County 7
- Dewey County 2
- Douglas County 5
- Edmunds County 4
- Fall River County 4
- Faulk County 5
All 66 counties and every South Dakota utility
Questions and answers
Who provides electricity in Day County?
NorthWestern Energy, Otter Tail Power Co, Montana-Dakota Utilities Co, Northern Electric Coop, Inc, Lake Region Electric Assn, Inc and Codington-Clark Elec Coop, Inc and 1 more list the county in their Form EIA-861 service territory for 2024. Territories overlap, and a utility may cover only a corner of the county.
What is the electricity price in Day County?
EIA has no county-level prices. The utilities serving the county reported average residential prices of 10.93¢ to 14.59¢ per kilowatthour across their South Dakota customers in 2024; the state average was 12.86¢.
How reliable is power in Day County?
Reliability is reported per utility, not per county. The utilities listed reported a median of 105.4 minutes of interruption per customer in 2024 including major event days and 68.7 minutes excluding them.
Provenance
Source: U.S. Energy Information Administration, Form EIA-861 for 2024, final release: service territory file (counties by utility), sales to ultimate customers, reliability and short form files. State and US averages: Form EIA-861M workbook. Population: U.S. Census Bureau. Public domain. To confirm the utility at an address, ask the utility or the state utility commission.