A. O. Smith HPACO-45 1**+AXST-50STTP 1**: running cost
ENERGY STAR certifies the A. O. Smith HPACO-45 1**+AXST-50STTP 1** at 923 kWh/yr, cheaper than most models in its category to run for its category.
That $174 is priced at 18.8¢/kWh, the average of all 51 state rates this site tracks. Your own state's rate is one click away.
Efficient, or not, for a electric water heater
Against the category average of 1,105 kWh/yr, this model uses 16.5% less, ranking 206 of 596 electric water heaters tracked here for running cost. That average is drawn from all 596 electric water heaters ENERGY STAR currently certifies, not an outside number, a $34/year gap from this model at the national rate. Full sourcing is in the sourcing notes.
Right next to it on the list
A rank or two either side of the A. O. Smith HPACO-45 1**+AXST-50STTP 1**: A. O. Smith HPACO-45 1**+AXST-50S 1** ($174/yr, 923 kWh/yr), then A. O. Smith HPACO-45 1**+AXST-50T 1** ($174/yr, 923 kWh/yr).
Same brand, different models
Ranked 18 of A. O. Smith's 61 certified electric water heaters, this sits between the HPS10-50H45DV 2** ($156/yr, the brand's cheapest) and the HPV10-80H01DV 2** ($311/yr, its priciest).
A. O. Smith HPACO-45 1**+AXST-50STTP 1** over 11 years
11 years is NAHB's typical service life for this category; at $174/year, the A. O. Smith HPACO-45 1**+AXST-50STTP 1** adds up to about $1,909 in electricity over that span.
Is it worth replacing?
Efficient as certified electric water heaters go, $174/year is a reasonable baseline if you're comparing what else is on the market.
Worth comparing a few current certified models before deciding.
If you're keeping it
Whether or not the A. O. Smith HPACO-45 1**+AXST-50STTP 1** ever needs replacing, a repair is the more common failure for a electric water heater, one a protection plan budgets for ahead of time.
Where this number comes from
Nothing here is estimated from a nameplate wattage; the 923 kWh/yr is ENERGY STAR's own certified figure for this model. The full Electric Water Heater category page shows all 596 electric water heaters ranked by cost; the state-rate guide covers the half of this number that isn't the appliance.