At home portable generators can run on different types of fuel (natural gas, propane, diesel, gasoline). Some models even run on more than one of the aforementioned fuel types, although the dual fuel types of generators are considerably more expensive. The choice of fuel type will depend on how and under what circumstances the generator will be used and how the generator can be maintained. Remote locations require the most dependable units since it could take days for a serviceman to come to make repairs.

An advantage of the diesel fuel generator is that it is more fuel-efficient than the other sources. A gallon of fuel will last from two to three times longer than a gallon of gasoline would. Under the same load a diesel generator might run clear through the night when a gasoline generator may have to be refueled at least once if not twice. Since gasoline generators must be cooled down to refuel, it might be a very good reason to go with the diesel generator on that point alone.

Diesel generators do not require frequent maintenance and are designed to function for long hours continuously. The engines are cooled by water and durable (meaning they are heavier, but designed to last two to three times longer), plus they are more dependable than other kinds of generators.

Diesel portable generators use direct injection, therefore they don't use spark plugs and this means they're less likely to ignite fires. Diesel is the least flammable fuel so it is much safer to store and has the longest storage life of all the fuels. It is available at several gas stations and can be carried and stored in fuel cans or can be delivered by a fuel company to your location.

The disadvantages of diesel fuel generators are that they are noisy and smokey, plus they are hard to start in cold weather and require heaters. In some places, the price of diesel fuel may exceed the cost of gasoline.

Diesel portable generators have the same safety concerns that other generators have. Do not operate in a wet environment or while standing in a puddle; do not operate indoors or in an enclosed area; use sufficiently rated electrical cords and do not overload the generator.

Home diesel generators range from $1000 to up to $9000 for a 15kw model. Larger industrial diesel generators are available in sizes that go up to 2000kw.