How Long Will A Generator Run On 20lb Of Propane?

Heather Robbins
by Heather Robbins
Running a generator can be a lifesaver in outages if you have enough propane. It varies based on the generator, but a 20lb tank of propane can last up to 5 hours. Whether it be the electrical load or your generator, let’s explore the factors in how long a 20lb tank of propane should last.
  • Over the last twenty years, the USA has experienced extreme weather conditions much more frequently than in the past. As a result, more and more people are considering how they can secure a backup power source to use in case of an emergency. This is where generators come into play. However, is 20 pounds of propane enough to run your generator? How long will this last you?

    Most propane generators will run at least 5 hours on a 20-pound propane tank. Several variables will affect the run time. The size of the generator and the load placed on the generator can increase or decrease the run time. Most home-style generators will use between two and three pounds of propane an hour.

    Investing in a generator is vital when it comes to weathering through extreme storms that result in power outages. Choosing a propane-fueled generator as opposed to a gasoline-fueled generator will help aid in cleaner burning and save you on costs. This article will explain how to factor in how long a propane tank will last you when running your generator.

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Choosing A Propane Generator

With news of the rain and snowstorms, icy conditions, destructive hurricanes, and even wildfires, which result in the power to entire areas being cut off for extended periods, it’s no surprise that people want to plan ahead. A major power outage can cause significant problems for homeowners and businesses. One possible solution is to invest in a generator that can run on 20 pounds of propane.

Propane is stored, under pressure, in liquid form. When it reaches boiling point, it produces a vapor, which is what is drawn off as it rises, to be used as fuel by an engine. When considering and comparing the running times for gasoline and propane, it’s essential to keep in mind that they can only provide an estimate: several factors can influence consumption, so all the figures given below are estimates.

How Long Can A Generator Operate On 20 Pounds Of Propane?

Believe it or not, propane doesn’t deteriorate over time. That is often an influential factor when people select an emergency backup power supply. So, in return, propane may not be needed for quite some time. The Consumer Reports site estimates that the typical operating time with a 20-pound tank is around 5 hours (with a variety of loads). Obviously, when the load is higher, the running time will decrease.

However, most generators can run on either 20- or 30-pound tanks. In this case, a 20-pound tank will operate for about 4.75 hours at half load. If you use a 30-pound tank, this will run about 7 hours at half load as well. But, again, the higher the load, the less time it will run.

How Long Will a Generator Run On 5 Gallons Of Propane?

As always, the answer depends on the load. Specific models can use around 5 gallons in an 8-hour window. Other models, such as Honda generators, are more economical in terms of running costs, consuming only 2.5 gallons of gas per 24 hours.

How Long Will A 22kw Generator Run On 500 Gallons Of Propane?

The answer will depend on what you’re using the generator to power. A 22kw generator can be expected to consume approximately 2-3 gallons of fuel per hour.

A 500-gallon tank can only be filled with 400 gallons of gas to leave space for the expansion and contraction, which occurs as the ambient temperature fluctuates. With 168 hours in a week, multiplied by 3 (gallons), a full tank would last you around 6 ½ days.

Propane Generator Fuel Consumption

Propane-powered generators typically require 2 to 3 gallons an hour to operate. This means that a 500-gallon tank will provide power to your home, 24 hours per day, for at least a week. Obviously, a 1,000-gallon tank could keep you going for two weeks if you run it for 24 hours.

How Efficient Are Propane Generators?

Propane generators are a practical option as an alternate power source. However, you should be aware that they produce fewer BTUs than gasoline models. Suppose you’re looking beyond simple power output and thinking of the broader environmental impact. In that case, propane is much cleaner when it burns, so it produces a smaller and less damaging carbon footprint than gasoline or diesel.

Propane Tank Sizes

To decide which size of tank is best for you, it’s a good idea to understand the range of options available. A 20-pound tank won’t give you enough power to heat an entire home, but one advantage is that you can buy and store several spare tanks. They’re also easy to refill, as and when required, at a specialist gas retailer.

Many people find that a 20-pound propane tank is the most useful and convenient for residential uses. It is ideal for connecting to a gas grill, a fireplace, and small appliances which don’t require a heavy-duty energy source.

What Size of Propane Tank For A ‘Whole House’ Generator?

The answer to this question really depends on how big your generator is and much time it will spend in operation. In a typical home, we would suggest a 120-gallon tank, which would be adequate to carry you through a short outage of your main power supply.

If you have space, a 500-gallon or even a 1000-gallon tank will give you peace of mind, knowing that it will keep you going even during an extended outage of up to 10 days. If you decide to go with this option, locating the tank below ground will avoid it taking up space in the outdoor area around your home.

Check out this guide for more information on ‘whole house’ generators: How Much Does A Whole House Generator Cost?

What Size Propane Tank for A 22kw Generator?

It’s recommended that a 22kw generator requires a tank that holds at least 500 gallons. The size you need depends on what you use it for and how often, but as a general rule, the bigger, the better. If you have space, go for a 1000 gallon so you will be well prepared in case of emergency.

Is It Cheaper To Run A Generator On Propane Or Gas?

Propane is generally cheaper than diesel or gasoline, but it is less energy-dense. This means that, when you compare overall running costs over an extended emergency period, a generator that works with gas or diesel will work out cheaper than if it uses propane.

Propane vs. Natural Gas Generator

The advantage of a natural gas generator is that it will operate as long as needed. The natural gas line will maintain the constant pressure required for it to operate. Even during a power outage, the line will have enough pressure to keep working and supply your home with the energy you need to stay comfortable.

A natural gas generator will automatically switch itself on and keep running until your default power source is restored. A propane-powered generator will operate until the gas supply runs out. The majority of propane tanks, whether above or below ground, will hold 500 to 1,000 gallons.

How Often Should You Operate Your Generator?

While proper storage can help prevent problems, it’s still advisable to switch on your generator every four weeks or so and keep it running for a few minutes. This will allow the oil to circulate through the engine, keeping components lubricated and ensuring they don’t freeze up.

When you exercise your generator each month, remember to add a load to the generator as it runs. You can damage the alternator on the generator running it for long periods with no load. Plug in an electric heater or some other appliance to protect the alternator on the generator.

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Wrapping It Up

To return to our original question, while a generator will run for between 5 and 8 hours with a 20-pound tank, you may want to ensure you are even more prepared if you were to face an extreme power outage. To do this, you have two practical options: purchasing an adequate supply of 20-pound tanks for emergency use or having a full-sized storage tank with a capacity of 500 or 1000 gallons.

Given the increasing likelihood of interruptions to the power grid and the amount of time required to restore service, it makes perfect sense to consider how you’ll keep your family safe and comfortable. Preparing now will help you to meet whatever power outages you face, with minimum inconvenience.

Remember, you have an option to store your propane tank underground. While the thought of having a gigantic 1,000-pound propane tank in your yard is unsettling, it can be buried so that you can keep your yard pleasing to the eyes. However, you may want to hire help to store it underground properly.

Related Guides

Does A Whole House Generator Add Value To Your Home?How To Purge A Propane TankHow To Read A Propane Tank Gauge

Heather Robbins
Heather Robbins

Heather is a passionate writer who loves anything DIY. Growing up, she learned everything from home repairs to design, and wants to share her tips with you. When she's not writing, she's usually hiking or searching for her next DIY project.

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