Each type of fuel has its pros and cons. Most of the small home generator models get fuel from an onboard gasoline tank and therefore have a short run duration. You could be adding fuel over a long period of time depending on the extent of your utility outage.
More expensive models can be hooked up to an external fuel source such as natural gas, propane or diesel. This results in extended run times with limited probability of getting an empty fuel tank during its performance.
Gasoline powered devices typcially cost less than other types of emergency home generators. But gasoline should not necessarily be your first choice because it has a very limited shelf life and will actually cause engine failure. Plus, when extended power outages occur the first commodity to be hoarded is gasoline.
Portable diesel generators are more efficiently quiet with the longest engine life, but generally are the most expensive. Diesel is the least flammable fuel source, but it too could be rationed in case of a major power outage.
Propane can be easily stored in large tanks and has practically unlimited shelf life. What’s more, natural gas is the only type of fuel normally available during wide spread outages.
There are multi-fuel devices that offer more options when one type of fuel is not available. Usually a simple adjustment option is needed to switch from one type of fuel to another. It might make sense for you to serious consider how to adapt your home generator system to operate on all three sources of fuel: natural gas, propane or gasoline.
You can buy an adapter kit that allows you to run your gasoline generator on propane (LP Gas), natural gas, or all three. Propane and natural gas are truly a backup fuel for a backup generator. Your engine will last longer, start better in cold weather and even start next year when you go to use it in an emergency. Propane and natural gas powered engines provide the same power as gasoline.
The main difference between using natural gas and propane for your emergency backup generator is that natural gas is provided through street lines while propane is stored in a tank on your property.
Generally speaking, propane and diesel fuels are the most reliably available sources for your residential emergency backup generator systems when you consider locations that are subject to potential earthquakes. On the other hand, natural gas is the fuel of choice for those locations within the central and eastern time zones.