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

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

Unexpected events are something we should be prepared for in our lives, such as a power outage. 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 factors that you can use to judge a generator’s efficiency, but I believe the most important is energy efficiency.


Our natural resources are very limited, even though they are extremely rich. If we don’t take the necessary steps to protect these precious resources, our future generations will be in peril. It is vital to be energy efficient in every day life for our children’s future. Additionally, you can save a lot of money by using energy efficient generators. The prospect of saving some bucks is always an incentive to purchase a 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 sources to power generators, and can be used for both industrial and portable appliances. Diesel also has a number of advantages that make it an attractive option for powering these devices; namely its low cost which makes it accessible even in cases where other fuels are scarce or unavailable. Additionally, diesel offers compatibility with many different types of engines without any special additives needed during conversion.


  • 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.

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.

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.