Heat Pump Payback in South Milwaukee, WI
Will a heat pump pay off in South Milwaukee, WI?
Here in South Milwaukee, the honest answer is that a heat pump raises your annual running cost. $5,500 is what South Milwaukee would pay extra to go electric rather than replace the furnace and AC with the same again. The heat pump would cost about $298 more a year to run than the furnace it replaces, a premium with no payback. That's South Milwaukee's own climate and rates talking, not a hedge or a caveat.
Compare against another city
South Milwaukee is one of 3206 cities covered here, each run through the same model. Search another below.
South Milwaukee's weather, in the numbers that matter
5229 heating degree days pile up here every year, so South Milwaukee has a cold winter that leans hard on heating equipment; the cooling side runs to 806 cooling degree days, where summers add a moderate cooling load. The 99% winter design temperature here, the cold snap equipment must be sized for, not the seasonal average, is -2.9°F, and the coldest daily reading in the 2024 station record was -5.1°F. That puts the seasonal coefficient of performance at 2.63 for the recommended cold-climate unit. South Milwaukee needs the cold-climate class of unit: past a 25°F design temperature a standard heat pump falls back on resistance backup often enough to eat the savings. These numbers come from General Mitchell Internationa, the closest NOAA station, 3.6 miles out.
What it actually costs to run, year to year
Electricity use for heating alone comes out to about 5,034 kWh a year on the 2000-square-foot reference house; folding in cooling puts the electric bill near $1,080 a year. South Milwaukee's gas rate of $10.74 per Mcf, applied to the 54 Mcf a year the furnace burns, puts the current furnace-and-AC running cost near $782 a year, against 18.87¢ per kWh for electricity. Because the heat pump costs more to run here, the gap only widens with time: $9,965 behind after 15 years compared with replacing the furnace and AC like-for-like.
What would change South Milwaukee's answer
For the verdict in South Milwaukee to flip, electricity would need to drop to about 12.5¢/kWh from 18.87¢, or gas climb past $16.21 per Mcf from $10.74. A utility offering a lower heat pump rate can change this. Until then, no quote price makes a heat pump pay back against gas in South Milwaukee; the case for one here rests on comfort, cooling, or replacing electric heat instead.
The other scenario: no gas furnace to begin with
Not every home in South Milwaukee has gas service. Against electric-resistance heat, baseboard or an electric furnace, both 100% efficient but still just resistance, the case for switching gets stronger here. The saving here runs about $1,616 a year, which recovers the extra $10,000 spent going electric in roughly 6.2 years.
How South Milwaukee compares nationally
Ranked against the other 3206 cities covered, South Milwaukee comes in at 544 for heating severity, 1 would be the coldest place in the dataset, and 1902 by population, where 1 is largest. That's the coldest third of the dataset, where climate does most of the work behind this figure.
Next step if you live in South Milwaukee
South Milwaukee, Wisconsin is home to about 20,233 people, and the figures above are the same ones a local HVAC contractor uses to size and quote a system, this site doesn't guess where a real quote would land, it just tells you whether it's worth asking for one. In South Milwaukee, nothing is lost by holding off until the current equipment genuinely fails.
Get quotes from local HVAC contractors before deciding.
Where South Milwaukee's figure comes from
Every constant behind this page, the 2.63 seasonal COP, the degree-day corrections, the equipment costs, is documented in the methodology guide. South Milwaukee's -2.9°F design temperature is below the 25°F line, which is why a cold-climate unit is the right call here, see what that changes in the cold-climate unit guide.