Propane Vs Gas Vs Diesel Generator: Which One Is More Energy Efficient?

Propane Vs Gas Vs Diesel Generator: Which One Is More Energy Efficient?

We should prepare for unforeseen events in our life, and a power failure is one of them.

You won’t have to be an Einstein to figure out what is the solution of sudden power failure problem is; of course, a generator.

But which generator should you buy?

Most of the generators nowadays are fuelled either by natural gas, gasoline, diesel or propane. So, obviously, you have to choose one of them.

But which one?

There are many criteria with which you could judge a generator, but the most important one is energy efficiency (according to me).


For, our natural resources, despite being extremely rich, are limited. And if we do not take necessary steps to preserve these limited resources, then the future of our next generation will be put into a jeopardy.

For this reason, being energy efficient in our daily lives is extremely important for the future of our children.

In addition, energy efficient generators will save you a lot of money and the prospect of saving a few bucks is always a good incentive to buy a specific product.

However, it is not my job to choose a generator for you. That’s why; I will provide you with all the details about diesel, propane and natural gas generators so that you could choose the best generator all by yourself.

Natural Gas Generators

Natural gas is regarded as one of the most effective fuel to power the generator and is being used widely all over the country.

Westinghouse WGen7500 Portable Generator with Remote Electric Start - 7500 Rated Watts & 9500 Peak Watts - Gas Powered - CARB Compliant - Transfer Switch Ready
  • 7500 Running Watts and 9500 Peak Watts; Remote Start With Included Key Fob, Electric and Recoil Start; Up to 11 Hours of Run Time on a 6.6 Gallon Fuel Tank With Fuel Gauge
  • Features Two GFCI (Ground Fault Circuit Interrupter) 5-20R 120V Household Duplex Receptacle and One L14-30R 120/240V Twist-Lock Receptacle; All Outlets Have Rubber Covers for Added Safety

Moreover, diesel is favoured to power the industrial generators due to its low price. In addition, it can be used to fuel both portable and emergency generators.


  • There is no need for storage; unlimited fuel supply
  • Burns clean
  • Engine noise level is quite low
  • In contrast to diesel, it has no issue with wet stacking.
  • Comes at a relatively low price


  • Natural disasters like earthquakes or cyclone could cause a disruption in supply
  • Fuel might not be available in remote areas
  • Energy efficiency isn’t its strongest suit
  • Not as durable as diesel generators
  • Can be dangerous due to its flammable nature.

Diesel generators

Diesel generators are commonly used in homes, offices, and industries as a backup power system. Moreover, by using a diesel generator, you won’t have to worry about the adverse effects of natural disasters, as you need not to rely on the remote fuel source. For, you can fuel the diesel generator from a local tank.   

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 Diesel generators are also used in ships to work as a power source. Here are some of its advantages and disadvantages-


  • Diesel generators are suitable for off-road application
  • Since it is the least flammable fuel, it is quite safe to use
  • Higher energy density
  • Durable and has a longer life expectancy


  • It is relatively expensive than other generators
  • Only 18-24 months shelf life (without additives)
  • Engine noise of diesel generators is higher than natural gas generators
  • Vulnerable to wet stacking or over fuelling if run with a lightweight load for a longer duration

Propane generators

Propane is primarily known for being used in smokers, but thanks to some of its distinctive feature, it has become increasingly popular as a fuel for powering generators.

DuroMax XP4850EH Dual Fuel Portable Generator, Green
  • Your purchase includes One DuroMax XP4850EH 4850 watt Dual Fuel Hybrid generator with Electric Start, One oil funnel, One spark plug wrench, tools set, wheels and handle kit, DC charging cables and owner’s manual
  • Portable Generator dimensions: 24” L x 17" W x 17" H. Product weight: 127 lbs

One of the best aspects of propane generators is that despite being a quality generator it is not heavy on the pocket and comes at a moderate price.

Without further ado, let me introduce you to some of its advantage and disadvantages-


  • Burns clean and environment-friendly
  • Boasts a long shelf life
  • Propane can be easily stored in both large tanks and small cylinders.
  • Liquid-cooled 1800 rpm engines boast an engine life that can reach 6000 hours.
  • Inexpensive


Because of the fuel's flammable nature, the pressurized cylinder could prove hazardous for your health.

Has a complex fuel system

It is not as durable as the diesel generators.

If the lines are broken, the fuel can become extremely dangerous.

So, What IS The Most Energy Efficient Generator?

Energy efficiency is measured by British standard British thermal unit (Btu). What is a BTU?

The amount of heat needed to raise the temperature of 1 pound water by 1 degree Fahrenheit is called BTU.  And FYI, whichever generator delivers more BTU per gallon is the most efficient generator.

Among the three different types of generators, natural gas generators are the least energy efficient with 38,209 BTU per gallon, while Propane generators come in the second place with 91,500 BTU per gallon. Diesel generators are the most energy efficient at 139,200 BTU per gallon.

Now that you know all the advantages and disadvantages of these generators, you can choose the best generator for yourself.

And Hey! If you have any question about generators or any suggestion to improve our article, please leave them in the comments section below.

Click Here to Leave a Comment Below 1 comments
michael griffin - January 10, 2019

I think propane fuel generator is very useful because its cheap more than other fuel generator and good for the environment.


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