Your local utility company sends your household a bill for the
electricity and/or natural gas you use.
For electricity, you pay for the kilowatt-hours (kWh)
used in your home during the billing period. What is a kWh? It is
equal to 1,000 watts of electricity used for one hour. If you leave
ten 100-watt lightbulbs on for an hour, you’ve used one kWh
of electricity.
For natural gas, you pay for the therms you’ve
used during the billing period. What is a therm? It is the number
of cubic feet (cu. ft.) of natural gas used, multiplied by a therm
factor. The therm factor is based on the energy content
of the gas, which can vary. Some utilities simply assume an average
therm factor.