The cheapest way to heat a home in California at today's average prices is natural gas ($24.02 per million BTU of heat), then heat pump ($37.23). A heat pump costs 55% more to run than a gas furnace.
How we compare: fuel price ÷ (energy content × efficiency). Assumptions — heating oil 138,500 BTU/gal at 85%, propane 91,500 BTU/gal at 90%, natural gas 1,037,000 BTU per Mcf at 90%, electric resistance 100%, heat pump seasonal COP 2.5 (lower in very cold weather). Gas and electricity use last winter's average price; oil and propane the latest weekly survey. Delivery fees, tank rental and fixed charges vary and are not included.
Natural gas price in California
Residential natural gas, $ per McfMonthly · summer prices per Mcf run higher because fixed charges are spread over less gas
Average price paid by homes, including delivery charges. Source: EIA Natural Gas Monthly.
Not at average prices: a heat pump (seasonal COP 2.5) costs $37.23 per million BTU of heat, 55% more than a 90% gas furnace at $24.02. A higher-efficiency heat pump or a lower electricity rate can change this.
What is the cheapest way to heat a home in California?
At current average prices: natural gas $24.02, heat pump $37.23, electric resistance $93.07 per million BTU of delivered heat (cheapest first).