MeterMath

Heat pump Illinois

Heat pump vs gas heating cost in Illinois

$5 a year more to heat a typical Illinois home with a heat pump than with a gas furnace.

A typical home here burns about 540 therms of gas a year for heat, about $918 at the national average of $1.70/therm. A heat pump would use about 4,804 kWh instead, $923 at 19.22¢/kWh. Electricity would have to fall to 19.1¢/kWh, or gas rise in price, before the heat pump became the cheaper way to heat.

Prices updated October 2026 from EIA, AAA and BLS data.

How you heat now
therms/yr
 
$/therm
 
¢/kWh
 
Efficiency, upfront cost and rebates
%
Older furnaces 78 to 80, new 90 to 97.
 
$
Heat pumps also replace your AC.
$
State, utility or HEAR rebates.

How Illinois compares

Ranked by yearly saving against gas, Illinois is 33rd of 51. At U.S. average figures a heat pump saves $27 a year. Illinois has the 35th cheapest residential electricity of the 50 states and DC, near the middle, at 19.22¢/kWh, 5% above the U.S. average of 18.31¢.

With an estimated 6,000 heating degree days a year, winters here are moderate, and the calculator uses a seasonal COP of 2.8.

Against propane the heat pump saves $564 a year, against heating oil it saves $1,325 a year, and against electric baseboard heat it saves $1,662 a year.

Heating nowNow, per yearHeat pumpDifference
Natural gas furnace$918$923−$5
Propane furnace$1,487$923$564
Oil furnace$2,248$923$1,325
Electric baseboard$2,586$923$1,662

Four of its five neighbors do better against gas: Indiana, Iowa, Kentucky and Missouri, led by Kentucky at $182 a year saved.

StateElectricitySaving vs gas a year
Kentucky13.81¢$182
Missouri16.09¢$116
Indiana16.73¢$107
Iowa15.99¢$24
Illinois19.22¢−$5
Wisconsin19.06¢−$180

More for Illinois

What these numbers assume

  • A heating load estimated from about 6,000 heating degree days a year: 540 therms of gas, 590 gallons of propane, 414 gallons of oil or 13,453 kWh of baseboard heat.
  • Natural gas at $1.70/therm, the U.S. city average for September 2026. Gas prices vary a lot by state and utility, so enter the price per therm from your bill.
  • Propane at $2.52 and heating oil at $5.43 a gallon, EIA forecasts for winter 2026–27.
  • Furnaces 85% efficient (oil 80%), and a heat pump with a seasonal COP of 2.8.
  • No federal tax credit: Section 25C ended for equipment placed in service after December 31, 2025.

Change any of them in the calculator above to match your own bills. The formulas are on the main heat pump calculator.

Sources

  • Electricity price: EIA Electric Power Monthly, Table 5.6.A (July 2026 data).
  • Natural gas: BLS U.S. city average, September 2026.
  • Propane and heating oil: EIA Short-Term Energy Outlook winter forecast, October 2026.
  • Heating degree days: MeterMath rounded estimate for the state.
  • Tax credit status: Public Law 119-21.