Southgate, MI: the heat pump payback math
Southgate is a place where a heat pump genuinely costs more to operate than the alternative. Swap a failed furnace and AC for a heat pump rather than buying like-for-like, and the extra cost here runs $3,500 after a $2,000 federal tax credit. Unfortunately the electric bill outweighs the gas bill it replaces by about $300 a year here, so the extra spend stays unrecovered. That's Southgate's own climate and rates talking, not a hedge or a caveat.
Southgate's weather, in the numbers that matter
5000 heating degree days pile up here every year, so Southgate has a cold winter that leans hard on heating equipment; the cooling side runs to 928 cooling degree days, where summers add a moderate cooling load. Sizing runs off the design temperature, not the average day: 1.9°F here (record low -2.9°F), which works out to a seasonal COP of 2.75 for the cold-climate class of unit this climate calls for. A cold-climate unit is the right call in Southgate — below 25°F design temperature, a standard heat pump leans hard on electric-resistance backup, which erases most of the savings. Source: NOAA station DETROIT METRO WAYNE COUNTY AI, 6.7 miles from Southgate — the closest one on record.
Southgate's running-cost comparison, in dollars
Modelled on a typical 2000-square-foot house, the heat pump draws about 4,604 kWh a year to keep it warm, plus cooling, for a combined electric bill near $1,118 a year. That compares with roughly 52 Mcf a year of gas at Southgate's 10.92 per-Mcf rate — about $818 a year — against a local electricity rate of 20.72¢/kWh. Looked at as a full purchase rather than an incremental one, payback here is longer than the 15-year equipment life, leaving the 15-year total $8,000 behind.
Electric resistance heat in Southgate, compared
Not every home in Southgate has gas service. Swap the comparison to resistance heat instead of gas, and Southgate's answer improves. The saving here runs about $1,755 a year, which recovers the extra $8,000 spent going electric in roughly 4.6 years.
Where Southgate ranks in this dataset
Southgate lands at position 697 out of 3206 cities on heating severity (coldest is 1), and 1381 out of 3206 by population size (biggest is 1). That's the coldest third of the dataset, where climate does most of the work behind this figure.
What to do with this number in Southgate
Southgate, Michigan is home to about 29,081 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 Southgate, nothing is lost by holding off until the current equipment genuinely fails.
Get quotes from local HVAC contractors before deciding.
More on how this number was built
The methodology guide walks through exactly how Southgate's 2.75 seasonal COP and the rest of this page's numbers get built. At a 1.9°F design temperature, Southgate sits in cold-climate territory; the guide to that class of unit explains why.