Is It Cheaper to Run a Generator on Gas or Propane?

Is it cheaper to run a generator on gas or propane?

A generator is a great way to have a backup power source for your home or business. But, you may be wondering, is it cheaper to run a generator on gas or propane? In this blog post, we’ll explore the cost of running a generator on gas and propane, and help you decide which is the best option for you.

There are many factors to consider when deciding whether it is cheaper to run a generator on gas or propane. The type of generator, the efficiency of the generator, the price of gas and propane, and the amount of use all play a role in the cost of running a generator.

Gas generators are typically more affordable than propane generators, and they are always more efficient in terms of fuel consumption. Propane generators tend to have a lower fuel efficiency, meaning they use more fuel to produce the same amount of power. We prepared a sample calculation to know which is cheaper to run, see below.

The amount of use is also a factor to consider. If the generator is used frequently, the cost of running it will be higher than if it is used only occasionally. For infrequent use, a gas generator may be the more cost-effective option, but for frequent use, a propane generator may be the better choice.

Cost Analysis of Gasoline Generators

Cost Category Details
A. Initial Setup and Maintenance Costs
1. Purchase Price – Cost range for various sizes and models.
– Impact of brand and extra features on cost.
2. Installation Costs – Professional installation vs. DIY costs.
– Necessary accessories for safe installation.
3. Maintenance Requirements – Regular maintenance schedule and costs (e.g., oil changes).
– Frequency of required maintenance.
4. Repair and Parts – Cost of common spare parts.
– Typical repair costs and availability of parts.
B. Average Fuel Consumption Rates
1. Measuring Consumption – Fuel consumption metrics (gallons per hour).
– Factors affecting consumption rates.
2. Efficiency Ratings – Energy output per gallon comparisons.
– Efficiency of popular models.
3. Usage Scenarios – Consumption under various load conditions.
– Examples of household and commercial usage patterns.
C. Long-term Cost Trends for Gasoline
1. Historical Price Fluctuations – Data on gasoline prices over the past decade.
– Factors influencing price changes.
2. Projected Costs – Predictions on gasoline pricing.
– Economic and geopolitical factors at play.
3. Fuel Economy Over Time – Changes in generator efficiency over time.
– Increased consumption with older models.
D. Case Studies and Real-Life Examples
1. Residential Use Case – Individual homeowner costs during outages.
– Annual breakdown of fuel and maintenance expenses.
2. Commercial Use Case – Small business operational costs with a gasoline generator.
– Cost comparison with the utility power source.
3. Emergency Response Scenario – Deployment costs in emergency situations.
– Analysis of efficiency in disaster relief operations.
4. Long-term Use Insights – User testimonials on cost and performance over time.
– Tips on cost management from experienced users.

Cost Analysis of Propane Generators

Cost Category Details
A. Initial Setup and Maintenance Costs
1. Purchase Price – Cost for various generator sizes and models.
– Additional costs for features specific to propane units.
2. Installation Costs – Costs associated with professional versus self-installation.
– Special requirements for propane storage and safety measures.
3. Maintenance Requirements – Scheduled maintenance expenses.
– Specifics of propane system maintenance.
4. Repair and Parts – Average costs for spare parts unique to propane generators.
– Repair costs and part availability.
B. Average Fuel Consumption Rates
1. Measuring Consumption – Propane consumption metrics (pounds or gallons per hour).
– Comparison to gasoline generators in similar conditions.
2. Efficiency Ratings – BTU output per gallon of propane.
– Efficiency benchmarks for common propane generator models.
3. Usage Scenarios – Fuel usage in residential versus commercial settings.
– Impact of load and environmental factors on fuel efficiency.
C. Long-term Cost Trends for Propane
1. Historical Price Fluctuations – Price changes over past years.
– Seasonal or regional factors affecting propane prices.
2. Projected Costs – Future market predictions for propane costs.
– Influence of market trends and energy policies.
3. Fuel Economy Over Time – Propane generator efficiency changes with technological advancements.
– Wear and tear impact on fuel economy.
D. Case Studies and Real-Life Examples
1. Residential Use Case – Costs for homeowners using propane generators during power outages.
– Comparison of expenses over a year.
2. Commercial Use Case – Operational costs for businesses relying on propane generators.
– Benefits in comparison to other energy sources.
3. Emergency Response Scenario – Logistical and financial considerations for deploying propane generators in emergencies.
– Efficiency and reliability during extended use.
4. Long-term Use Insights – Feedback from long-term users regarding costs and generator performance.
– Maintenance tips to optimize expenses.

How do you calculate the cost of running a generator?

Calculating the cost of running a generator involves several steps and factors. Here is a general guide to understanding and computing these costs:

1. Determine the Generator’s Fuel Consumption

First, find out the generator’s fuel consumption, which is usually provided in the specifications by the manufacturer. It’s often given in gallons per hour (for gasoline) or pounds per hour (for propane) at a certain load.

2. Know the Generator’s Load

  • Full Load: The consumption figures may be based on the generator running at full load. Adjust the fuel consumption accordingly if you plan to run it at less than full load.
  • Average Load: Calculate the average load you expect to use since generators are often not run at full load.

3. Calculate Fuel Costs

Get the current cost of the fuel you will be using. For gasoline, it’s usually per gallon, and for propane, it can be per gallon or per pound.

4. Run Time

Decide how many hours you plan to run the generator for the time period you’re considering (daily, weekly, monthly).

5. Efficiency Losses

Consider any efficiency losses due to generator age, maintenance status, or environmental factors.

6. Calculate Total Cost

Multiply the fuel consumption rate (at your expected load) by the cost of the fuel and then by the number of hours you plan to run the generator.

Here is a basic formula:

Total Cost=(Fuel Consumption Rate×Cost of Fuel per Unit)×Total Hours RunTotal Cost=(Fuel Consumption Rate×Cost of Fuel per Unit)×Total Hours Run

Example Calculation:

Calculation for Gasoline:

  1. Fuel Consumption Rate: 0.75 gallons/hour.
  2. Cost of Gasoline: $3.50/gallon.
  3. Operating Hours: 5 hours per day.

Daily Cost:

0.75 \text{ gallons/hour} \times 5 \text{ hours/day} \times $3.50 \text{/gallon} = $13.125 \text{ per day} Rounded off, the daily cost is $13.13.

Monthly Cost (30 days):

$13.13 \text{/day} \times 30 \text{ days} = $393.90 \text{/month}

Calculation for Propane:

  1. Fuel Consumption Rate: 1.2 gallons/hour.
  2. Cost of Propane: $2.50/gallon.
  3. Operating Hours: 5 hours per day.

Daily Cost:

1.2 \text{ gallons/hour} \times 5 \text{ hours/day} \times $2.50 \text{/gallon} = $15.00 \text{ per day}

Monthly Cost (30 days):

$15.00 \text{/day} \times 30 \text{ days} = $450.00 \text{/month}

Summary of Sample Calculations:

For Gasoline:

  • Daily: $13.13
  • Monthly: $393.90

For Propane:

  • Daily: $15.00
  • Monthly: $450.00

Remember, these calculations are based on continuous operation at a steady load. If you use your generator intermittently or at variable loads, you’ll need to adjust your calculations accordingly. It’s also a good idea to add a buffer to account for unexpected increases in fuel prices or generator run time.

Understanding the Two Fuel Types

A. Characteristics of Gasoline

  1. Availability
    • Gasoline is widely available and is one of the most commonly used fuels for portable generators.
    • It is easily accessible at almost all service stations, which makes it convenient for users to refuel.
    • The existing infrastructure for gasoline distribution is well-established in most regions.
  2. Cost
    • The cost of gasoline can fluctuate significantly due to various factors such as crude oil prices, seasonal demand, taxes, and geopolitical events.
    • Gasoline prices are also subject to regional variations, with urban areas typically offering more competitive pricing due to higher availability.
  3. Energy Density
    • Gasoline has a high energy density, meaning it contains a considerable amount of energy per unit volume.
    • This high energy density translates to potentially more power output from a generator, although efficiency factors also play a role.

B. Characteristics of Propane

  1. Availability
    • Propane is also widely available but may not be as readily accessible as gasoline in some areas.
    • It is commonly sold in tanks ranging from small canisters to large bulk storage options, which can be a consideration for storage space.
    • Specialized infrastructure, such as propane refill stations or delivery services, is required.
  2. Cost
    • Propane is typically less subject to the same price volatility as gasoline, offering more stable pricing over time.
    • The cost may be higher or lower than gasoline depending on the region and current market conditions.
    • Buying propane in bulk can often result in cost savings and price-per-unit discounts.
  3. Energy Density
    • Propane has a lower energy density compared to gasoline, which can mean that more of it is required to produce the same amount of energy.
    • However, the efficiency of propane combustion can sometimes result in longer engine life and extended runtimes, which compensates for its lower energy density.

C. Environmental Considerations

  1. Emissions
    • Gasoline engines typically emit more pollutants such as carbon monoxide, hydrocarbons, and nitrogen oxides compared to propane.
    • Propane burns cleaner than gasoline, with fewer greenhouse gas emissions and lower carbon content, which results in less environmental impact.
  2. Spillage and Contamination
    • Gasoline spills can lead to significant environmental contamination, affecting soil and water quality.
    • Propane, being a gas at atmospheric pressure, evaporates and leaves no residue, reducing the risk of environmental contamination.
  3. Sustainability
    • Neither gasoline nor propane is considered a sustainable energy source as both are fossil fuels with finite reserves.
    • Propane is often seen as a ‘bridge’ fuel that can aid in the transition to a more sustainable energy portfolio due to its cleaner-burning properties.

Both gasoline and propane have their unique characteristics that can influence a consumer’s choice. The decision between the two fuels may depend on factors like local availability, cost, desired energy output, and environmental impact considerations.

Pros and Cons of Propane and Gas Generators

When choosing between a gas and propane generator, each has its own set of advantages and disadvantages that may influence your decision based on your specific needs and circumstances. Here’s a summary:

Gas Generators


  1. Fuel Availability: Gasoline is readily available at nearly all service stations.
  2. Cost-Efficiency: Often more cost-effective for the amount of power generated.
  3. Portable: Gas generators tend to be more portable due to a wide range of smaller models.
  4. Initial Cost: Typically cheaper to purchase than their propane counterparts.


  1. Fuel Shelf Life: Gasoline has a shorter shelf life and can degrade over time.
  2. Emissions: Gasoline burns less cleanly, resulting in higher emissions.
  3. Maintenance: May require more frequent maintenance due to carbon build-up from the less clean burn.
  4. Fuel Price Volatility: Gasoline prices can be quite volatile, with frequent price fluctuations.

Propane Generators


  1. Clean Burning: Propane burns cleaner than gasoline, with fewer emissions.
  2. Shelf Life: Propane can be stored indefinitely and does not degrade over time.
  3. Quieter Operation: Generally, propane generators run quieter than gasoline models.
  4. Maintenance: Lower maintenance costs due to cleaner burning.


  1. Energy Density: Propane is less energy-dense than gasoline, often resulting in less efficient fuel usage.
  2. Upfront Cost: Propane generators usually have a higher initial purchase price.
  3. Availability: Propane may not be as readily available as gasoline, especially in emergency situations.
  4. Installation: For larger units, they may require professional installation and a fixed location.

When choosing a generator, it’s also important to consider the specific use case, including the availability of fuel types in your area, storage capabilities, and whether you prioritize lower emissions over initial cost savings. Your choice may also depend on whether you require the generator for emergency backup power, job site power, recreational use, or home use, as these scenarios can affect the practicality and convenience of fuel storage and use.

The Energy Efficiency of These Fuel Sources

Propane gas is about will produce about 91,500 BTU per gallon.

Regular gasoline (with 10% ethanol in the mixture will produce about 114,000 BTU per gallon

Standard Gasoline: 120,000

Propane gas has a disadvantage, it has about 20% less energy per gallon. but other factors come into play – the price of propane vs the price of gasoline per gallon. The cost of propane per gallon is less expensive than gasoline.

Cost-effectiveness is an important factor to consider when choosing a fuel source for a generator. The cost of the fuel can have a significant impact on the overall operating costs of the generator, which can be a significant financial burden, particularly for commercial or industrial users who rely on generators for critical operations.

Therefore, it is important to carefully compare the costs of different fuel sources and choose one that is both reliable and cost-effective.

Factors to consider when comparing the cost-effectiveness of different fuel sources include the initial cost of the fuel, the availability of the fuel in your area, and the long-term price stability of the fuel. By taking the time to carefully consider these factors, you can choose a fuel source that is cost-effective and will provide reliable power for your generator.

Other Considerations When Choosing

When comparing propane and gasoline as fuel options for generators, there are several other considerations to take into account beyond cost and efficiency:

A. Environmental Impact of Gasoline vs. Propane

  • Gasoline: Gasoline combustion emits a higher level of pollutants, including nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons, which contribute to smog and health problems.
  • Propane: Propane burns cleaner than gasoline with fewer greenhouse gas emissions and lower levels of NOx, CO, and particulates. It is listed as a clean fuel by the U.S. Energy Policy Act.

B. Safety Concerns

  • Gasoline: It is highly flammable and can be dangerous to store and handle. Gasoline vapors can accumulate and pose explosion risks.
  • Propane: While also flammable, propane is stored in pressure-sealed tanks, which minimizes the risk of leakage. In its liquid form, it does not ignite as easily as gasoline vapors.

C. Storage and Transportation of Fuel

  • Gasoline: Requires proper storage in certified containers and is more volatile, making it potentially hazardous to transport over long distances.
  • Propane: More stable for long-term storage and safer to transport due to its storage in sealed containers, but requires careful handling to prevent pressure-related incidents.

D. Availability During Emergencies or Natural Disasters

  • Gasoline: Often becomes scarce during disasters due to hoarding and supply chain disruptions.
  • Propane: May be more readily available and easier to stockpile before an emergency, which can be crucial during extended power outages.

E. Conversion Kits and Dual-Fuel Generators

  • Conversion Kits: Allow certain gasoline generators to run on propane, offering flexibility in fuel choice.
  • Dual-Fuel Generators: These units can operate on both gasoline and propane, providing the user with options based on availability, cost, and personal preference.

Each fuel type presents its own set of advantages and trade-offs. The choice between propane and gasoline generators may ultimately hinge on the specific needs of the user, local fuel prices, environmental regulations, and the intended use of the generator.

To make a conclusion

The question of whether it is cheaper to run a generator on gas or propane is multifaceted and depends on a range of variables. The answer is not absolute and requires a nuanced consideration of several factors including fuel prices, efficiency, and usage patterns.

  • Fuel Prices: Propane often has a lower per-gallon price compared to gasoline, but the efficiency of how each fuel converts to energy must be considered. Gasoline typically has a higher energy density, meaning less fuel is required to produce the same amount of energy.
  • Efficiency and Consumption: Generators running on propane may consume more fuel to produce the same energy output as those running on gasoline due to the lower energy density of propane. However, the efficiency of the generator itself plays a crucial role in determining overall fuel consumption.
  • Maintenance and Longevity: Propane burns cleaner, which can lead to lower maintenance costs and potentially extend the life of the generator, contributing to long-term savings. These savings could offset the higher fuel consumption costs.
  • Environmental Impact: For those considering environmental impact, propane is the cleaner choice, emitting fewer pollutants. While this doesn’t directly affect cost, it could have implications for future regulations and fuel availability.
  • Storage and Stability: Propane has an almost indefinite shelf life and is easier to store, while gasoline can degrade over time, especially if not treated with stabilizers, which adds to the cost and inconvenience.
  • Usage Patterns: The frequency and duration of generator use will greatly impact overall costs. For infrequent, emergency use, the lower upfront cost and ready availability of gasoline may be more practical. For regular or sustained use, propane could be more economical over time.

There isn’t a one-size-fits-all answer. If gasoline prices are significantly higher than propane and the generator is used frequently, propane may be the more cost-effective option despite its lower energy density. Conversely, if gasoline is cheaper or the generator is only used occasionally, gasoline might be the more economical choice. Users must perform a personalized cost-benefit analysis that includes fuel prices in their area, generator efficiency, and expected usage to determine the most cost-effective fuel for their needs. It’s also recommended to consider the long-term operational costs, maintenance, and potential environmental regulations that could influence fuel choices in the future.

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