NorthWestern Energy
4 residential tariffs on file in SD, ranging from $0.1130 to $0.1776 per kWh at 1,000 kWh a month.
$0.1130cheapest, all in
$0.1256average actually billed
2025most recent filing
The gap between this utility's cheapest and most expensive residential tariff is $775 a year for a household using 1,000 kWh a month. Tariffs are not always open to everyone — some require electric heating, a demand meter or program enrollment — so check eligibility with the utility before switching.
Residential tariffs
| Tariff | Structure | Filed | Fixed/mo | $/kWh @1,000 | Annual |
|---|---|---|---|---|---|
| Rate 14: Residential Space Heating and Cooling | Flat | 2025 | $4.00 | $0.1130 | $1,356.12 |
| Rate 15: Residential Dual Fuel and Controlled Service. | Flat | 2025 | $4.00 | $0.1130 | $1,356.12 |
| Rate 10: Residential Electric | Tiered | 2025 | $7.00 | $0.1776 | $2,130.74 |
| Rate 11: Residential Service with Space Heating | Tiered | 2025 | $7.00 | $0.1776 | $2,130.74 |
For reference, NorthWestern Energy collected an average of $0.1256 per kWh from residential customers in the most recent EIA survey, across all its tariffs and all usage levels. A single tariff priced at 1,000 kWh a month will differ from that blended figure.