Concord, CA: the heat pump payback math
This one's marginal in Concord: it only clears if you stay long enough. Against a like-for-like gas furnace and AC swap, going electric costs $1,000 more up front here (already netting out a $2,000 tax credit). Lower bills claw that back: about $97 saved annually, for a payback of roughly 10.4 years. It's a genuine toss-up here — Concord's numbers don't point clearly either way.
Concord's weather, in the numbers that matter
Degree days tell the story here: Concord racks up 2162 heating degree days each year (base 65°F), and summers are hot enough that cooling matters as much as heating, with 1129 cooling degree days on the cooling side. 33.1°F is the figure equipment gets sized against here — the 99th-percentile cold snap, not an average day — with a record low of 32°F on file. Worked through the model, that's a seasonal COP of 3.19 on the standard unit fit for this climate. Concord's winters don't get cold enough to need the cold-climate premium — a standard unit holds up fine. Source: NOAA station BUCHANAN FIELD AIRPORT, 3.2 miles from Concord — the closest one on record.
What it actually costs to run, year to year
A 2000-square-foot house here would pull roughly 1,716 heating kilowatt-hours annually on top of cooling, totalling about $879 a year on electricity. The gas furnace it replaces burns roughly 23 Mcf a year at 22.01 per Mcf here, for a running cost near $976 a year (electricity here runs 32.83¢/kWh). Looked at as a full purchase rather than an incremental one, payback here is roughly 114 years, leaving the 15-year total $448 ahead.
The other scenario: no gas furnace to begin with
Plenty of homes in Concord heat with electricity alone, no gas line involved. 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 $1,398 a year, which recovers the extra $5,500 spent going electric in roughly 3.9 years.
Concord against the rest of the country
Concord lands at position 2359 out of 3206 cities on heating severity (coldest is 1), and 236 out of 3206 by population size (biggest is 1). That's the mildest third of cities covered, where utility rates carry more of the answer than climate does.
Next step for 124,016 people in Concord
Concord, California is home to about 124,016 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 Concord, nothing is lost by holding off until the current equipment genuinely fails.
Ask a local HVAC contractor for a quote before committing either way.
More on how this number was built
The methodology guide walks through exactly how Concord's 3.19 seasonal COP and the rest of this page's numbers get built. Homes in Concord without gas service should read the electric-resistance comparison instead — the numbers there differ from the gas case above.