A. O. Smith HPACO-45 1**+AXST-50S 1**: running cost
At 923 kWh/yr, the A. O. Smith HPACO-45 1**+AXST-50S 1**'s ENERGY STAR certification puts it cheaper than most models in its category to run against every other certified electric water heater.
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 205 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-50S 1**: State SHPCO-45 1**+SXST-50LBG 1** ($172/yr, 915 kWh/yr), then A. O. Smith HPACO-45 1**+AXST-50STTP 1** ($174/yr, 923 kWh/yr).
Within the A. O. Smith lineup
Ranked 17 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).
Cost over its typical lifespan
11 years is NAHB's typical service life for this category; at $174/year, the A. O. Smith HPACO-45 1**+AXST-50S 1** adds up to about $1,909 in electricity over that span.
Weighing a replacement
Efficient as certified electric water heaters go, $174/year is a reasonable baseline if you're comparing what else is on the market.
Compare current ENERGY STAR certified electric water heaters before buying.
If you're keeping it
A electric water heater like the A. O. Smith HPACO-45 1**+AXST-50S 1** is a real household expense whether or not it needs replacing yet; a protection plan is one way to budget for a repair rather than a full replacement.
Where this number comes from
Ranked 205 of 596, the A. O. Smith HPACO-45 1**+AXST-50S 1** sits in the middle of the electric water heater category, see the guide to why your state changes this number for the other half of the math. The 923 kWh/yr figure is ENERGY STAR's own certification, not a wattage estimate; exact dataset IDs are on the data sources page.