Electricity rates in 57421 — Amherst, SD
Homes in ZIP 57421 pay about 15.3¢ per kWh (Northern Electric Coop, Inc., Jan–Aug 2026). The South Dakota average is 15.2¢ and the U.S. average 18.2¢ (Aug 2026).
What a month of electricity costs
Monthly cost at the average price of 15.3¢ per kWh. Real bills add or subtract fixed charges, tiers, time-of-use and fuel adjustments.
Where ZIP 57421 is
Outlined: ZIP code area · scroll or pinch to zoomUtilities serving 57421
| Utility | Home price | Avg. bill | Customers in SD |
|---|---|---|---|
| Northern Electric Coop, Inc. Cooperative | 15.3¢ Jan–Aug 2026 | $226 | 5,757 |
| NorthWestern Energy (SD) Investor Owned · serves Marshall County | 14.1¢ Jan–Aug 2026 | $113 | 51,467 |
| Otter Tail Power Co. Investor Owned · serves Marshall County | 11.5¢ Jan–Aug 2026 | $112 | 9,048 |
| Lake Region Electric Assn, Inc. (SD) Cooperative · serves Marshall County | 9.4¢ 2024 | $475 | 3,468 |
| Town of Langford (SD) Municipal · serves Marshall County | 16.1¢ 2024 | $213 | 190 |
Utilities are matched to this ZIP code by NREL’s ZIP–utility table and the EIA service-territory list for Marshall County; county matches may serve only part of the area. Prices are each utility’s average residential revenue per kWh.
South Dakota price trend
Hover or tap the chart for exact monthly values. Source: EIA-861M (monthly, latest months preliminary); forecast: EIA Short-Term Energy Outlook (October 2026) for the West North Central region, which includes Iowa, Kansas, Minnesota, Missouri, Nebraska, North Dakota, South Dakota.
Averages, not a quote. Prices here are what each utility’s residential customers paid on average (revenue ÷ kWh sold, fixed charges included), as reported to the U.S. Energy Information Administration. Your own rate depends on your plan, season and usage — check your bill or your utility’s tariff.
Questions about 57421
How much does electricity cost in 57421?
About 15.3¢ per kWh for homes (Northern Electric Coop, Inc., Jan–Aug 2026, EIA). At 900 kWh a month that is roughly $137.
Who is the electric utility for 57421?
Northern Electric Coop, Inc., with about 5,757 residential customers in South Dakota; 4 other utilities also serve parts of the area.
Is electricity in SD getting more expensive?
The South Dakota residential average was 15.2¢ per kWh in August 2026, up 9% from a year earlier; the U.S. average was 18.2¢.