A majority of home generators can run on two different fuels such as natural gas and propane.
Changing over from one type of fuel to the other is as simple as making a small adjustment on the generator.
When natural gas is already being used in the home its a logical choice to connect a standby generator to the gas line.
For an average sized home with up to a 4 ton central air conditioner the generator should be rated between 15kW and 17kW.
This results in a fuel source that is always available and eliminates the need for refueling. The same can be said for homes which are powered by onsite propane.
While the large propane tanks would require periodic refilling by a local propane distributor, this option is still more convenient than being forced to refuel during long power outages.
Propane also has other advantages including an extended shelf life and availability during power outages.
One consideration for selecting natural gas to power a generator is that some generators require gas pressure at levels higher than what some utilities commonly deliver.
Without the proper pressure level, a generator could deliver sub-par performance or not work at all.
Higher pressure levels can be reached by either adding a separate gas meter for the generator or to switch out the existing gas meter for one that works at higher pressure levels.
If a new meter is installed it will come with a regulator so that lower gas pressure can be delivered to stoves, water heaters, and other appliances.
Propane can be used to back up a natural gas powered generator in the event of an interruption in the delivery of natural gas due to weather related or other disasters.
In this situation a bi-fuel generator could easily be switched over the backup fuel source and power would continue to be delivered to the home.
A third fuel option is diesel power, normally the most efficient and maintenance free option for generators.
Diesel powered generators are usually the most expensive type of generator, however, which is why they are more commonly used for commercial applications.
Diesel fuel can also become unavailable in the event of a power outage, which should be considered before opting for this fuel source.