Heat pump savings calculator · San Francisco Peninsula
Gas furnace or heat pump: what will your bills look like?
Enter your home and we compare your yearly PG&E bills today with a heat pump, using NREL building-stock models for homes like yours and current PG&E rates. Add your solar system and battery to see how much of the heat pump runs on your own power. No phone call, no home visit.
- Real rates. PG&E E-TOU-C, E-ELEC and G-1 gas, including the rate plan that opens up once you own a heat pump.
- Honest numbers. A range, not a single promise. If your home has no air conditioning today, we show the cost of the cooling you gain separately.
- Your solar, your bills. Enter your system size or the monthly generation from your inverter app.
How the numbers are made
Homes like yours. NREL ResStock 2025 models thousands of Peninsula homes by climate zone, age, size, heating and cooling. We take the homes that match yours and show the middle and the typical range.
Current PG&E rates. Electricity on E-TOU-C or E-ELEC with baseline allowances, gas on G-1 with baseline tiers, applied hour by hour and month by month. A heat pump qualifies you for E-ELEC, which also lowers the price of the rest of your electricity in winter.
Not a bill forecast. Your thermostat, insulation and family habits change the result. Enter your own kWh and therms to scale the model to your home. Rates are from PG&E tariff sheets dated 2026; we update them when PG&E does.
Questions people ask
Will a heat pump cost more to run than my gas furnace?
In most Peninsula homes, no. A modern heat pump delivers about three to four units of heat per unit of electricity. On the E-ELEC rate plan that works out cheaper per unit of heat than gas at today’s G-1 prices, and it also lowers the winter price of everything else in your home. On the standard E-TOU-C plan the two are close, which is why the calculator tells you which plan to pick.
I have solar. Does that change things?
Yes, and not always the way people expect. Heating happens mostly at night and in the morning, when panels produce little, so a battery matters more than the panels for heating. Cooling happens when the sun is out, so a heat pump’s air conditioning runs mostly on your own power. Enter your system to see your numbers.
What about keeping the furnace as a backup (dual fuel)?
You can pair a heat pump with your existing or a new gas furnace and let a thermostat pick the cheaper fuel by time of day. On the Peninsula it rarely gets cold enough for the furnace to be cheaper, so the bill difference is small either way; the calculator shows it. A dual-fuel system does not qualify for the $1,500 WestLight heat pump rebate.
Where do the CO₂ numbers come from?
From the same NREL models, using average California grid emissions. A heat pump cuts a gas-heated home’s emissions roughly in half today, and more every year as the grid gets cleaner.
