Where heat pumps pay off in Hawaii
In a typical Hawaii house heated with propane, a heat pump saves the most near Hawaii National Park ($1,007 a year) and the least near Hilo (Hilo Intl Airport 87) ($0). Typical savings under $100 a year on a $10 heating bill. Pays for itself within 10 years in 0% of its ZIP codes with a hired installer, 5% if you install it yourself.
Same typical house everywhere: 1,800 sq ft, built 1970 to 1989, heating costs only, 12 places in Hawaii. How
Hawaii at a glance
Gas heat
Pays for itself within 10 years in 5% of its ZIP codes with a hired installer, 5% if you install it yourself. Typical heating bill today $10.
Oil heat
Pays for itself within 10 years in 5% of its ZIP codes with a hired installer, 5% if you install it yourself. Typical heating bill today $10.
Propane heat
Pays for itself within 10 years in 0% of its ZIP codes with a hired installer, 5% if you install it yourself. Typical heating bill today $10.
Electric baseboard heat
Pays for itself within 10 years in 5% of its ZIP codes with a hired installer, 10% if you install it yourself. Typical heating bill today $20.
Model your own house
These open the home model at the place with the typical house filled in and propane as today's heat. Change anything to match yours.
Every place in Hawaii, propane heat
| Place | Heating today | Saves a year | Pays back (contractor) | Pays back (DIY) | Heat from the heat pump |
|---|---|---|---|---|---|
| Hawaii National Park | $3,908 | $1,007 | 11.6 years | 8.0 years | 100% |
| Hilo (Hilo 5 S) | $66 | $4 | over 30 years | over 30 years | 73% |
| Wheeler Army Airfield | $26 | $2 | over 30 years | over 30 years | 68% |
| Hoolehua | $14 | $1 | over 30 years | over 30 years | 70% |
| Kahului | $13 | $1 | over 30 years | over 30 years | 65% |
| Kekaha | $6 | $0 | over 30 years | over 30 years | 53% |
| Hanamaulu | $6 | $0 | over 30 years | over 30 years | 62% |
| Kailua | $1 | $0 | over 30 years | over 30 years | 41% |
| Jbphh | $1 | $0 | over 30 years | over 30 years | 22% |
| Ewa Beach | $11 | $0 | over 30 years | over 30 years | 59% |
| Kailua Kona | $0 | $0 | never | never | 0% |
| Hilo (Hilo Intl Airport 87) | $7 | $0 | over 30 years | over 30 years | 32% |
Contractor installed unless marked DIY. Place names are the nearest ZIP code city to each weather station. Download all places.
How these numbers are made
Every place on the map is the area closest to one of 1,983 weather stations. For each one we ran the HeatPushers home model (the same code you can use for your own house) with the past year of hourly weather at that station (2025-10-28 to 2026-10-28) and the state's average electricity and fuel prices from the EIA (the US average where the EIA has no figure for the state).
- The house: 1,800 sq ft, 2 stories, built 1970 to 1989 (wall insulation R-14, attic R-16), 3 bedrooms, thermostat at 70°F. The heat pump heats the whole house.
- Heat today: gas furnace (80% efficient); oil boiler (85% efficient); propane furnace (92% efficient); electric baseboard (100% efficient). Furnace houses have ducts inside the heated space; boiler and baseboard houses have no ducts, so only ductless heat pumps count there.
- The heat pump: out of 772 models sold online, the one with the lowest 10-year cost (price, installation and energy), in the number of units that costs least. The old heat stays and takes over in the hours it is cheaper to run.
- Installation: a contractor at $2,500 per indoor unit, or yourself: $350 of tools once and $300 of materials per indoor unit.
- Payback: what it costs up front divided by what it saves a year. Under 10 years means it pays for itself within the lifetime we assume.
- Heating only. Cooling is left out. A heat pump also cools: against old central AC that saves a bit more; in a house without AC, using it in summer costs extra.
- Not included: rebates and tax credits, electrical upgrades, new ductwork, heat-pump electricity rates and financing.
- Shares of ZIP codes: each place counts by how many US ZIP codes are closest to its station, so cities count more than empty desert.
Your house is not this house. Size, insulation, prices and what you already own change the answer, often a lot. Use "Model your own house here" on the map, or start at the home model. More: full method and how we know.