Running cost comes down to wattage, hours and your rate. In Missouri the rate is 13.68 cents per kWh, which is 25.8 percent below the national average. Here is what that means for a electric water heater.
A electric water heater drawing 4,000 W costs $0.55 per hour in Missouri. Run 3 hours a day that is $1.64 daily, $49.25 a month and $599 a year, which is $208 less than the same appliance at the US average rate.
Cost by hours used per day in Missouri
| Hours/day | Energy | Per day | Per month |
|---|---|---|---|
| 1 h | 4.00 kWh | $0.55 | $16.42 |
| 2 h | 8.00 kWh | $1.09 | $32.83 |
| 4 h | 16.00 kWh | $2.19 | $65.66 |
| 6 h | 24.00 kWh | $3.28 | $98.50 |
| 8 h | 32.00 kWh | $4.38 | $131 |
| 12 h | 48.00 kWh | $6.57 | $197 |
| 24 h | 96.00 kWh | $13.13 | $394 |
Cost by wattage at 13.68 cents
| Rated power | Per hour | Per day | Per month |
|---|---|---|---|
| 3,000 W | $0.41 | $1.23 | $36.94 |
| 3,800 W | $0.52 | $1.56 | $46.79 |
| 4,500 W | $0.62 | $1.85 | $55.40 |
| 5,000 W | $0.68 | $2.05 | $61.56 |
| 5,500 W | $0.75 | $2.26 | $67.72 |
Find the row matching the nameplate on your own unit. Within a single appliance category the spread is often wider than the difference between categories, so the label is worth reading.
Water heating in Missouri
Incoming groundwater temperature sets how hard the element works, and it is colder in winter everywhere. In Missouri the seasonal swing is smaller, which keeps water heating cost relatively steady through the year. A heat pump water heater cuts consumption to roughly a third and works particularly well in a warm garage.
Why Missouri pays what it does
Missouri is a regulated market, so your utility is the only supplier and the rate is set through the state commission rather than by competition. Pricing tends to be steadier than in deregulated states, and there is no switching decision available. The levers are all on your side of the meter.
At 13.68 cents, Missouri ranks 7 of 51 from cheapest to most expensive. The Midwest regional average is 16.55 cents. Roughly half of any residential bill is transmission and distribution rather than generation, which is why rates keep climbing even when fuel prices fall.
How this compares across the country
The same electric water heater on the same schedule, in the cheapest and dearest states:
| State | Rate | Per month | Per year |
|---|---|---|---|
| Idaho | 12.35¢ | $44.46 | $541 |
| Utah | 12.96¢ | $46.66 | $568 |
| Missouri | 13.68¢ | $49.25 | $599 |
| California | 33.25¢ | $120 | $1,456 |
| Hawaii | 52.00¢ | $187 | $2,278 |
Lowering the number in Missouri
- Set the thermostat to 120 degrees. Many ship at 140. Every 10 degrees cuts standby loss by around 4 percent.
- Insulate the first six feet of hot and cold pipe. Cheap, and it stops heat walking out through the plumbing.
- Fix dripping hot taps. A hot tap dripping once a second heats water that goes straight down the drain.
- Flush sediment annually. Sediment insulates the lower element from the water, so it runs longer.
- Consider a heat pump water heater. Roughly a third of the energy for the same hot water.
Offsetting it with solar in Missouri
This load uses about 12.00 kWh a day. Covering that would take roughly 9 standard 400 W panels at typical sun hours, an array of about 3.60 kW. Because it offsets electricity worth 13.68 cents rather than the national 18.44 cents, the same array is worth less here than the national payback figures suggest.
Water heating is the single best use of surplus solar, because the tank is a battery that stores heat instead of electrons. Diverter controllers exist specifically for this. Full sizing, including battery and inverter requirements, is on the solar sizing page for this appliance.
Questions people actually ask
[hed_faq]How much does it cost to run a electric water heater in Missouri?About $0.55 per hour and $49.25 a month at 3 hours a day, using the Missouri average rate of 13.68 cents per kWh.
How many watts does a electric water heater use?Around 4,000 W while running, with a range of roughly 3,000 to 5,500 W depending on model and setting.
Is that expensive for Missouri?Missouri electricity runs 25.8 percent below the national average, so this appliance costs $208 less per year here than it would at the US average rate.
Can I lower this without replacing the appliance?Usually yes. Run time is the variable you control, and the hours table above shows exactly what each hour costs. Since Missouri is regulated, shopping for a supplier is not an option, so usage is the lever.[/hed_faq]