Recently I was asked the following question by someone who wants to install a 5000-watt generator to run their home in case of a power failure:
What is the best choice for fuel, propane, gasoline or diesel?
This reader is leaning towards getting a propane-powered generator. The choices are confusing, and a guide like this one can help the newcomer to the world of generators make the best choice.
I have been doing some research on the subject and here are some of the advantages and disadvantages of all three fuels for generators: gasoline, diesel, and propane.
|Propane:**See propane notes below.||
Propane produces 92,000Â BTUâ€™s per gallon, gasoline is capable of producing 114,000 BTUâ€™s per gallon, and diesel is capable of producing 129,500 BTUâ€™s per gallon. This means that it will take more propane per hour that either gasoline or diesel to run a generator.
How much propane will my generator burn per hour?
- It requires 2 horsepower to produce 1000 watts of energy per hour under load
- Under load each horsepower consumes 10000 BTU per hour
- Propane contains 92,000 BTU per gallon
- Propane weights 4.2 pounds per gallon
Using these factors how long can a 5000-watt generator run on a 500 gallon propane tank at 50 capacity.
- 10 horse power at 50% would use 5 HP to generate 2500 watts of electricity
- 5HP X 10,000 BTU would consume 50,000 BTU per hour
- 500 gallons X 92,000 = 46,000,000 BTU of energy in a full 500 gallon tank
- 46,000,000 BTU divided by 50,000 BTU = 920
- A 500-gallon tank that is full would run a 500-watt generator at Â½ capacity for 920 hours.
After comparing the various fuels, I would probably go with propane for a large generator in a fixed setting. I would want a minimum of a 1000 gallon tank. For small generators I would go with aÂ tri-fuel generator. Tri-fuel generators burn propane, gasoline and natural gas.
If you choose to purchase a large generator you need to weight the cost versus the benefits. Is running a generator worth the cost? Another consideration is how much fuel you are able to store. Propane tanks store indefinitely, which is another reason the propane generator is a good choice.
No matter what kind of generator you decide to purchase they all deliver the same benefits when the power goes out.
Updated July, 2020