How Long Can You Run A Generator Continuously: portable, standby


When a big storm has ripped through your area and power goes out, the first thing that comes to mind is how long will it be out and if it is out for a long time how long can you run a generator for?

On average a 5500-7500 watt portable generator will run 9 – 11 hours at 50% load before running out of fuel. A 22 kW standby generator will run continuously for up to 150 hours or approximately 1 weeks time provided it is hooked directly to a fuel source, which at this point maintenance would be required.

In some instances, a generator may only be required for a few hours, but during prolonged power outages, a generator is going to be required for an extended period. 

Because of this, it is likely that many are now questioning how long you can run a generator and how long you should expect it to last. 

Portable Generator Fuel Type And Consumption

Understanding how long a generator can run continuously is going to be determined by the type of generator and the fuel that is consumed.

Gasoline Generator

The most popular tends to be a gasoline-fueled generator. A gas generator has a limited run time because it cannot be refueled when it is running and it is also dangerous to store gasoline in large amounts.

The size of the generator tank is going to influence the run time. For example, some larger 5000 watt generators can run for the day using 18 gallons of gas, whilst a smaller model will not run for as long.

One of the major problems with a gasoline generator is that it is rather costly so when required for long-lasting use you will require quite a lot of gas.

Despite this, there are many efficient models available that can run for a maximum of 10 hours per 1 to 2 gallons of gas.

Propane Generator

A propane-powered generator has a longer run time however, the energy produced by propane is lower in comparison to other types of fuel. A propane generator that is run correctly can last for between 150 to 200 hours.

Some units will allow you to connect two tanks so that you can alternate between them when one runs out using a stopcock valve.

It is also important to ensure that your generator is correctly maintained as this is going to enhance the continuity of the runtime.

Dual Fuel Generator

A dual fuel generator runs on two types of fuel at the same time, this is typically diesel and natural gas. You can either combine both fuels or use them alone.

To benefit from a long run time, it is worth investing in a well-made model. The ability to run the generator on two types of fuel provides greater flexibility as you can use the fuel that you have to hand.

Some dual fuel generators will run for approximately 5 to 10 hours on propane and 8 hours on gas.

Hybrid Generator

Hybrid generators run on fuel like traditional models but primarily operate via a battery that is powered by renewable energy sources. The fuel is required for a brief period to charge the battery.

Generators of this kind provide a highly efficient source of power. The combination of fuel and battery power ensures that you are provided with a continuous supply of power.

The runtime of these types of models will depend on the quality and chargeability of the battery. Ultimately, these models run for lengthier periods and consume less fuel.

Types of Generators

The type of generator can influence its run time and longevity. Portable generators require manual operation, whilst standby generators automatically function in the event of a power outage.

Portable Generator

Portable Generator

Portable models with larger tanks can serve you for a couple of days. Ultimately, the runtime of a gas-powered generator depends on the tank size and the unit’s efficiency. While some are capable of running for over 12 hours, others will run for a couple of hours.

Standby Generator

Standby generators are typically designed to run on propane. They have efficient motors and can endure long-term use. The exact runtime can differ depending on the manufacturer with some claiming that their unit can run for roughly 3 weeks continuously.

Although it is possible to run your generator for longer than this, you should avoid doing so as there is a risk of permanently damaging the unit and any appliances that are plugged into it.

Can any generators run for 24 hours non-stop?

Many portable generators can not run for 24 hours non-stop and this is because they typically have smaller tanks that cannot cope with an intense workload.

If you do intend to use your portable generator for extended periods you must ensure that it is given regular intervals breaks so you can check the fuel load and conduct any necessary maintenance.

As gasoline is highly flammable, it should not be left to run for 24 hours particularly if it is going to be left unattended.

Due to the flammability, ideally, your gasoline generator should only be used for the amount of time that it is required.

Many larger units are intended to be used as a backup power source because they can run for around 24 hours or longer. These units typically tend to be powered by natural gas or propane.

Factors on How Long Can You Run A Generator

Aside from the size of the tank, several other factors can influence the runtime of a generator. A generator that is subject to a great deal of stress is going to struggle to operate for a lengthy period and this can also lead to issues with overheating too.

Your generator needs a break and because of this, it is important to avoid running your generator for longer than the recommended time. The area that it is used to cover is also going to influence the runtime.

Using a small generator to power lots of appliances will cause it to run out of fuel sooner and this can also lead to possible overloading issues.

If you require a generator that is going to power multiple appliances to cover a large area ensure that you select the appropriately sized unit.

How Long Will A Generator Last?

The lifespan of your generator will differ depending on the type of generator, the load, and the overall build quality. Typically, a portable generator can serve users between 1000 to 2000 hours of total use.

For example, if your portable generator is run for 100 hours a year it is going to serve you 10 to 20 years of use. A reliable standby generator is likely to last for a total of 3000 hours.

For those who run their generator for around 100 hours annually, their generator is likely to last for a total of 30 years.

Many brands will cover their generators with a warranty although the length of this policy varies between manufacturers. This identifies the length of time that the brand guarantees the generator will work for.

It is preferable to opt for a generator that is covered by a warranty because this will help to tackle any problems regarding the functionality and doing so can enhance the life of the unit.

Also, ensure that your generator has been manufactured by a trustworthy company for greater assurance that it has been built to last.

Final Thoughts

The continuous runtime of a generator depends on a variety of factors. A generator that is running continuously must be monitored.

It is also important to conduct basic maintenance as failing to do so can damage the unit. While there are many heavy-duty units available, generators can only handle so much use.

Overloading a generator will not only damage the unit but any appliances that are plugged into it.

Most generators have an impressive runtime with portable models lasting for a maximum of 20 years and standby units lasting for around 30 years.

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