When the power goes out, a propane generator keeps the lights on and brings peace of mind. But how long can a generator run on propane before you need to refill the tank? It’s good information to know, especially if you’re preparing for storms, winter weather power outages or just want to be sure your home backup plan is ready to go.
At Moyer, we help homeowners like you across the region stay powered on with dependable propane service. Let’s take a closer look at how long your propane generator can run, and what you can do to make sure you’re prepared when you need to use it.
Exactly how long will your generator run on a full load of propane? Because generators come in all types and sizes, it depends. Here are the key factors to consider:
Generator Size and Electrical Load
The burn rate of your generator depends on how much power it needs to supply. A smaller generator, like an inverter generator, that can provide power to a few household appliances will burn far less propane than a whole-house standby generator that keeps everything running.
Here’s a general guide:
- A 5,000-watt generator running at half its capacity will use around 0.75 gallons of propane per hour.
- A larger, 20,000-watt standby generator running at full capacity would burn about 3 to 5 gallons of propane per hour.
Propane Tank Size
The size of the propane tank naturally plays a big role in generator runtime. Running at moderate load, you can expect the following runtimes:
- 20 lb tank (4.6 gallons): approximately 8-10 hours
- 100 lb tank (23.6 gallons): approximately 1-2 days
- 250-gallon tank: approximately 4-5 days
- 500-gallon tank: approximately 7-10+ days
- 1,000-gallon tank: up to 2 weeks or more
Depending on the capacity of your generator a larger tank will be the most efficient choice, with less need for refueling and longer runtimes.
Generator Maintenance
Keep up with your generator maintenance so it’s ready to go when you need it. It will also run more efficiently, burning less propane for the same amount of power. Regular maintenance includes oil changes, cleaning air filters and checking the spark plugs.
Environmental Conditions
Generator efficiency can be impacted by environmental conditions like cold temperatures or high altitudes. Propane will not burn as effectively in extreme cold, affecting power output and runtime.
How to Estimate Your Generator’s Runtime on Propane
Here’s how you can get a rough idea of how long your generator will run on a tank of propane.
Check Manufacturer Specifications
Every generator model is different. Your user manual should show the expected propane consumption in gallons per hour (GPH) at different loads, or level of use.
Calculate Gallons Per Hour
Once you know the consumption rate, divide your propane tank’s usable gallons by that number.
Let’s say you have a 500-gallon tank with about 400 gallons of propane. If your generator uses 2 GPH, take the total gallons (400) divided by 2 GPH for an estimated runtime of 200 hours (equal to a little over 8 days of continuous use).
Be Mindful of Load Capacity
Most people don’t run their generators at full load the entire time. Think about which appliances you really need during an outage to save propane. Running your generator at a 50% load instead of full load could help to double your runtime.
Tips to Extend Generator Runtime
How else can you make your propane last longer? Here’s what we recommend:
Keep Up With Generator Maintenance
We’ll say it again. Keeping up with routine generator care goes a long way. Make sure your generator is serviced regularly, especially before storm season. This includes:
- Cleaning air filters
- Checking spark plugs
- Changing oil
- Inspecting fuel lines
Stay on Top of Propane Deliveries
A generator is only as useful as its fuel supply. With our propane delivery service, you’ll never have to worry about running low. We offer reliable, timely deliveries so you’ll never have to worry.
Wise Load Management
Be strategic about your generator use. Focus on essentials like the refrigerator, sump pump, your heat source and a few lights.
For more insights about how a propane generator can help you keep your household running in an emergency, read Propane Generators as Reliable Backup Power.
Trust Moyer for Your Propane Needs
We deliver more than just propane—we deliver peace of mind.
We’ve been helping families stay safe and comfortable for decades. Here’s how we can help you:
- Reliable Propane Delivery: We offer automatic or will-call delivery with options for every budget.
- Proper Tank Sizing: Our experts will recommend the right tank size based on your needs.
- Professional Service: Maintenance and support from our experts.
Have questions about your propane supply or generator setup? Contact us online or call 215.799.2003 to speak with one of our experts.
FAQs
Can I convert a gas or diesel generator to run on propane?
Yes, most generators can be converted to run on propane. This is easily done using a tri-fuel or propane conversion kit. Before you do anything, check with the manufacturer or a qualified technician to make sure it’s safe for your generator model.
How should I store extra propane tanks for my generator?
Always store propane tanks outdoors in a well-ventilated area. Make sure they are stored away from direct sunlight and heat sources. Never store tanks indoors or in garages.
Is it more expensive to run a generator on propane than gas?
Propane tends to cost slightly more per gallon than gasoline, but it pays off because propane burns cleaner. Plus, propane is easier to store safely long-term.
What happens if my generator runs out of propane mid-use?
The generator will shut off when it runs out of fuel. This won’t damage the generator but you may still need a power source, in which case you’ll need to refill or swap out tanks. That’s why it’s important to monitor your tank levels and schedule timely refills.