CostToRunIt

Water Heating · West

Cost to run a well pump in Hawaii

At Hawaii’s average residential rate of 52.00¢ per kWh, a well pump drawing 750W for 2 hours a day costs about $11.87 a month. Change the numbers below to match how you actually use yours.

Quick answer

Per hour$0.1950.375 kWh
Per day$0.390.75 kWh
Per month$11.8722.8 kWh
Per year$142274 kWh

Based on 750W at a 50% duty cycle (this equipment cycles on and off rather than drawing full power continuously) and 52.00¢/kWh, the Hawaii average for May 2026.

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Why the cost differs in Hawaii

Hawaii has the 51st cheapest residential electricity of the 51 US states and territories we track, at 52.00¢ per kWh against a national average of 18.44¢. That is +182.0% compared with the national figure. Hawaii is the most expensive electricity market in the United States by a wide margin, and the cause is geographic rather than regulatory: no pipeline or transmission line reaches the islands, so most generation burns imported petroleum priced on world markets. Each island runs its own grid with no mainland backup. Cooling demand is steady year-round, and there is essentially no heating load.

For this appliance specifically, the difference works out to an extra $91.87 a year over what the same well pump would cost at the national average rate. Run the identical appliance in Hawaii and it would cost $142 a year; in Idaho it would cost $33.81. That spread of $109 is entirely down to location.

That works out to roughly 2.6% of a typical Hawaii household's annual electricity bill - modest individually, though appliances in this range add up.

Because Hawaii is among the most expensive states for electricity, efficiency upgrades pay back faster here than almost anywhere. A more efficient well pump that saves a given number of kilowatt-hours saves noticeably more money in Hawaii than the same upgrade would in a cheap-power state.

Retail service in Hawaii is regulated, so most households pay a tariff set through state rate cases rather than a shopped rate. The state average is a reasonable proxy, though your utility's specific tariff still varies.

Annual cost of this well pump at different rates
LocationRatePer monthPer year
Hawaii this page 52.00¢ $11.87 $142
US average 18.44¢ $4.21 $50.48
Idaho cheapest state 12.35¢ $2.82 $33.81
Hawaii most expensive 52.00¢ $11.87 $142

Hawaii electricity rate trend

Rates in Hawaii have moved from 40.96¢ to 52.00¢ per kWh over the last twelve months of published data. Nationally, residential rates rose about 6.2% year over year.

2025-06 to 2026-05 · cents per kWh

About running a well pump

Cost scales with water usage rather than time, since the pump only runs on demand. A leaking fixture or running toilet raises pump cost invisibly, and a failing pressure tank causes rapid cycling that wears the motor and wastes energy.

What actually changes the cost

  • Nameplate wattage is not running cost. This well pump draws about 750W when active, but cycles roughly 50% of the time it is switched on, so effective consumption is near 375W.
  • Models vary widely, from about 500W to 1500W. Check the nameplate on your own unit rather than assuming an average, because the spread is more than 2x.
  • If your utility offers time-of-use pricing, shifting this load off-peak can cut its cost substantially without using any less energy.

How we worked this out

The arithmetic is simple and we would rather show it than hide it. Divide watts by 1,000 to get kilowatts, multiply by hours of use and by the duty cycle to get kilowatt-hours, then multiply by your rate:

750W ÷ 1000 × 2h × 50% = 0.750 kWh/day × 52.00¢ = $0.390 per day

One honest caveat: Hawaii’s figure is a state average published by the EIA. Your own utility’s tariff, any time-of-use pricing, fixed monthly service charges and local taxes all shift the real number. Put your actual per-kWh rate into the calculator above for a figure that reflects your bill.

Questions about well pump running costs

How many watts does a well pump use?

A typical well pump draws about 750 watts while running, with most models falling between 500W and 1500W. Check the nameplate label or manual for your specific unit - the range is wide enough that averages can mislead.

How much electricity does a well pump use per day?

At around 2 hours of use a day and a 50% duty cycle, that works out to roughly 0.75 kWh per day, or about 23 kWh a month. Your actual figure depends on your usage and model.

Why does the cost differ so much between states?

Residential electricity rates across the US range from about 12.35 cents per kWh in North Dakota to 46.62 cents in Hawaii - nearly a fourfold difference. The same well pump, used identically, therefore costs almost four times as much to run in the most expensive state as in the cheapest.

Is it cheaper to run a well pump at night?

Only if you are on a time-of-use or variable tariff. On a flat rate, the time of day makes no difference to cost. If you are on time-of-use pricing, off-peak hours are typically materially cheaper, and shifting this load can reduce its cost without reducing usage.