Running a 1,500-watt space heater 8 hours a day in South Dakota costs about $53.22 a month — $0.22 an hour on full power at South Dakota's average 14.58¢/kWh.
At 14.58¢/kWh — South Dakota average, Jan–Aug 2026 (EIA). That is 20% below the U.S. average of 18.19¢.
| Period | kWh | Cost |
|---|---|---|
| Per hour of use | 1.5 | $0.22 |
| Per day | 12 | $1.75 |
| Per month | 365 | $53.22 |
| Per season (8 mo) | 2,920 | $426 |
Normal mean temperature (NOAA, population-weighted). Highlighted months average below 60°F.
| Heat source | $ per million Btu | This much heat |
|---|---|---|
| Gas furnace, 95% AFUE | $10.02 | $12.48 |
| Gas furnace, 80% AFUE | $11.90 | $14.82 |
| Heat pump (ENERGY STAR avg) | $17.27 | $21.52 |
| Propane furnace, 95% AFUE | $21.52 | $26.81 |
| Space heater / baseboard | $42.73 | $53.22 |
In South Dakota resistance heat costs 4.3× as much as gas heat from a 95% furnace. A space heater only saves money when it lets you turn the whole-house thermostat down several degrees and heat just the room you're in. A heat pump delivers the same heat for about $21.52 a month.
| Heater | Per hour | 8 h/day, month | 24 h/day, month | Season (8 mo, 8 h) |
|---|---|---|---|---|
| 750 W | $0.11 | $26.61 | $79.83 | $213 |
| 900 W | $0.13 | $31.93 | $95.80 | $255 |
| 1,500 W | $0.22 | $53.22 | $159.67 | $426 |
1.5 kW × 8 h = 12 kWh a day; × 30.42 days = 365 kWh a month; × 14.58¢ (South Dakota average, Jan–Aug 2026, EIA) = $53.22.
Because resistance heat costs 4.3× as much as gas heat in South Dakota, a space heater saves money only if it lets you turn the whole-house thermostat down and heat just the room you're in. If your home heats with electric baseboards or furnace strips, a space heater costs the same per Btu — the saving comes only from heating fewer rooms.
The average South Dakota home used 1,005 kWh a month in 2025 (EIA); this heater adds 36% to that while it runs.
The full method, material data and tips are on the main space heater cost calculator page.