Propane conversions

Knowing which energy to choose for your home appliances can be a daunting task given that each source of energy is measured differently. Electricity output is measured in kilowatts per hour, natural gas in cubic feet and propane in gallons. One gallon of propane amounts to 27kWh of electricity and 36.39 cubic feet.

What does this mean? Not much, since it says nothing about how efficient each energy source is for similar appliances. In this regard, it is useful to use British Thermal Units
(or BTUs) to see how much energy an appliance requires and, ultimately, costs.

Using BTUs to convert energy units into dollars

BTUs are convenient to establish the power needed for an appliance and the price you will pay using electricity, natural gas or propane. For example, a 12,000 BTU/hr Air Conditioner will require 3.5kW of electricity, 11.6 cubic feet of natural gas or 0.13 gallons of propane to run for an hour. In dollars, for December 2011 average prices, this amounts to the following:

Energy

Electricity

Natural Gas

Propane

Price/Unit

11.40 cents/kWh

$9.84/1000cf

$2.856/gallon

Total cost

40 cents

11 cents

37 cents

As you can see, propane is cheaper than electricity but not natural gas. This is why it is particularly popular in areas that are not linked to the natural gas pipelines network in the United States.

Propane conversion table

Last, the table below illustrates the BTU output of a unit of electricity, natural gas and propane.

Into

Propane (gal)

Electricity (kWh)

Natural Gas (cubicft)

BTU

From

       

Propane (1gal)

1

27

36,39

91500

Electricity (1kWh)

0,037

1

3,41

3413

Natural Gas (1cubic ft)

 0,027

0,29

1

1030