What energy costs where you live

The fuel matters more than the appliance

Electricity runs from 12.35 cents a kilowatthour in Idaho to 52 in Hawaii^[1], against a national figure of 18.44¢. Two identical appliances in those two states differ in running cost by more than any two appliance types differ from each other within one state. Anyone comparing water heaters without naming a state is comparing on the smaller variable.

Comparing across fuels needs one more step, because the units are incommensurable. A kilowatthour carries 3,412 British thermal units^[2], a cubic foot of natural gas about 1,037^[3], and a gallon of propane 91,452^[2]. Divide price by energy content and all three land on dollars per million Btu, which is what the third column above shows. The result usually surprises people: electricity is very often the most expensive heat available, and propane is rarely the cheapest.

This is also the reason a heat pump changes the argument rather than merely improving it. Every other appliance on this site turns one unit of purchased energy into at most one unit of heat, so the dollars-per-million-Btu column is the whole story. A heat pump moves heat instead of making it and routinely delivers three units for one, which can make expensive electricity cheaper in practice than inexpensive gas. Fuel price alone does not settle it; fuel price divided by efficiency does.

What is published, and what is not

Electricity is published monthly for every state, so the figures here are one specific month rather than a rolling average, and the month is named on the methodology page. Natural gas is used at annual resolution deliberately: the monthly residential gas price swings by more than a factor of two across a year, not because gas gets more expensive in August but because the fixed monthly charge is spread over a tiny summer volume. Pricing a year of water heating off a summer month would roughly double the answer for no physical reason.

44 states and jurisdictions have a published annual residential gas price. 7 do not — Connecticut, Maine, Maryland, North Carolina, Oklahoma, Rhode Island, South Carolina — and those rows say so. Propane is published as a single national weekly series with no state breakdown, so every state shows the same $3 a gallon^[4], which is a real limitation rather than a coincidence. The national gas fallback, where it is needed, is $15 per thousand cubic feet^[5].

Questions people actually ask