How Long Can a Generator Run? All You Wanted to Find Out

Find out how long a gasoline, diesel, or standby generator run non-stop in this article.
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Last updated: August 30, 2023
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A generator is an electromechanical device that converts kinetic energy into electrical alternating current. It is responsible for powering devices, but the generator itself can’t run endlessly. Eventually, users will have to power it. So, here’s a reasonable question of how long a generator can run. We’re going to consider different types of devices and answer this question comprehensively.

Spheres of Use

How Long Can a Generator Run? All You Wanted to Find OutAlternating current is widespread. Today, almost all household appliances and industrial mechanisms operate on it. In everyday life, they are used to provide autonomous power in the event of a power outage and receive it in places where there is no power line.

Industrial models are used to provide emergency autonomous power to hospitals, schools, kindergartens, as well as commercial and industrial facilities. Industrial generator sets are also used in the construction of new buildings.

Also, note that portable products are perfect solutions for traveling, camping, and hiking. Are you going to go hiking or want to discover nearby natural sightseeing? A compact portable device will be the best helper. Here, you can find a list of the best tailgating generators for your pastime.

Devices for industrial and household applications differ in power and operating hours. Below, you’ll find out how long you can run the generator continuously.

Types of Generators

The electrical industry produces three types of generators:

  1. Gas models. Devices are designed for short-term switching in case of failure in the supply of electric current by the centralized power supply network. Generators operate almost silently, and the exhaust of fuel combustion products is reduced to 0. That is why such models can be used in households.
  2. Gasoline devices. The power of such generators does not exceed 20 kW. They are used for emergency power supply of country houses and cottages, as well as for powering hand-held power tools, small machines, etc. Such products are powerful enough to support the lighting of the local area or car parking lots.
  3. Diesel products. The power of such models can reach 3 mW. Units can serve as a permanent source of electricity for country houses and cottages, feed powerful machines, and supply electricity to entire villages.

According to portability, all devices are divided into portable and standby ones.

Operating Time of Modern Portable Generators

Before we proceed to the issue of how long can you run a portable generator, note that operating hours will differ since the indicator is influenced by several factors:

  • fuel tank size;
  • maintenance;
  • engine size;
  • loads.

Depending on the specs of each particular model, its runtime ranges from 8 hours (for portal gasoline goods) up to 210 hours (for standby propane models). Yet, let’s get closer to details and discover the issue more precisely.

How Long Can a Gas Generator Run?

How Long Can a Generator Run? All You Wanted to Find OutLet’s start with considering the consideration of how long a generator can run on propane. The runtime of a portable propane device can reach 8-12 hours. Depending on ambient temperatures and load, the functioning period can increase or decrease. If compared to gasoline devices of this type, the gas generator runs more continuously if enough propane is supplied. However, note that products of this type require maintenance after every 100 hours of operation.

What Type of Gas to Use?

Propane-butane (gas in cylinders) and methane (main gas) are most common for industrial and household devices. Propane-butane is used in both summer and winter; they differ in the ratio of gases included in it.

If you need a gas-powered product, you can look through our compilation of the best propane generators. There, top models are provided.

Pros of Gas Products

  • long shelf life. A standard propane cylinder can easily last up to 12 years from the date of manufacture.
  • independence from centralized supplies. The supply of natural gas will be interrupted, the supply of gasoline will be irregular, and propane will still be available at points of sale.
  • propane is not contaminated. If it is stored in the original cylinder, then, after 12 years, it will still be of quality for the efficient operation of an electric generator.
  • gas burns, releasing very little carbon monoxide.
  • propane is less demanding according to storage conditions.

How Long Can a Gasoline Generator Run Non-Stop?

How Long Can a Generator Run? All You Wanted to Find OutDepending on the capacity of the fuel tank, the generator can operate without stopping for up to 13 hours at a flow rate of 0.5-0.8 l/h. Gasoline models mainly have power consumption in the range of 2-15 kW, which is considered low and medium. They are compact and economical but designed for short work (7-8 hours). Such units have a low time between failures (up to 4000 hours) and most often act as emergency power sources.

What Gasoline to Fill in a 4-stroke Generator?

AI-92 gasoline is used for feeding gasoline generators, while A-76 (AI-80) and AI-95 gasoline cannot be used. If you have a gasoline device, use clean gasoline without oil impurities (for 4-stroke engines). For gasoline engines with overhead valves (as a rule, the Latin letters OHV are indicated on the valve cover of such engines), the octane number of gasoline must be at least 92 (AI-92, AI-95).

How Often Should One Refuel Oil in Generators?

Gasoline generators require oil refueling every 50 hours of operation. It is allowed to use only high-quality fluid suitable for a particular model of equipment.

Pros of Gasoline Goods

  • an affordable price is the main advantage of gasoline generators. Such models are considered the most budgetary.
  • power is the second important point. That is, you need less fuel to get the required amount of energy. The pro is extremely relevant for those places where gasoline is much cheaper than propane.
  • better portability. They almost always have an internal reserve that allows the device to work more efficiently.

How Long Can a Diesel Generator Work Continuously?

How Long Can a Generator Run? All You Wanted to Find OutThis kind of good is not of great popularity on the modern market. Consumers give preference to gas or gasoline products, or even dual-fuel models. This is due to the fact that diesel generators produce too much noise over operation. Extra noisiness is the main disadvantage of diesel goods.

However, as for runtime, this group has the best results. Among portable devices, this type of good demonstrates the best performance in terms of an uninterrupted runtime.

For example, do you know how long a Generac 22kw generator can run continuously? Imagine that the model is able to run non-stop for 32.4 hours at half load. Over this period, the device consumes 12 gallons of diesel.

Some portable models of diesel generators can demonstrate even more pleasant performance. Thus, compact goods with smaller fuel tanks can run up to 10 hours.

Pros of Diesel Devices

  • A wide choice of rated power. Customers can find household products for 2-3 kW, as well as industrial units that produce up to 3000 kW.
  • The efficiency of modern units reaches 70–80%; for other types of devices, this figure is still unattainable.
  • Diesel generators are characterized by lower fuel consumption. To generate 1 kWh of electricity, 250-290 grams of fuel will be required.
  • Practice has shown that the average motor resource of the units before overhaul is 20-30 thousand hours, and for some models, this figure is even higher.
  • It is believed that diesel generators are more fireproof, but this is not an entirely objective assessment, any internal combustion engine is potentially dangerous.
  • Devices are allowed for installation in various conditions, including outdoors.

To summarize the indicators of portable models, it should be noted that gas models are in great demand on the modern market. They provide an optimal ratio of runtime, fuel consumption, and power supply. Gasoline goods lose to other types of generators in terms of performance. An average level of non-stop operating hours is lower if compared to gas or diesel devices. Yet, diesel models overtake all other types of products in terms of runtime, but their main disadvantage is noisiness.

To pick the best portable generator, read our reviews, where you’ll find a list of the most popular models.

Runtime of Standby Models

How Long Can a Generator Run? All You Wanted to Find OutNow, let’s switch to the analysis of standby options. While portable generators are ideal for traveling, a standby device will be an excellent solution for your household. Such models are powerful enough to feed the house and nearby premises with electricity.

Note that according to the specs of most devices, it is recommended to limit their runtime to 500 hours of continuous operation. Manufacturers recommend switching off the generator once per three weeks to let the engine cool down. After periodic maintenance, the product is ready for non-stop performance.

Now, let’s have a closer look at how long a whole house generator can run.

Diesel Product Runtime

Diesel models have a fuel tank and can run as long as the fuel is supplied. The average runtime of such goods ranges between 48 to 72 hours.

Let’s see an example and analyze how long a Generac generator can run non-stop. Two standby goods produced by the Generac brand differ in running wattage and fuel tank but have the same engine size. With a fuel tank of 32 gallons and a running wattage of 15000W, the device will run for 39 hours uninterruptedly at half load. With an increase of the tank size to 132 gallons and a running wattage to 50000W, performance time will rise to 65 hours.

Gas Device Performance

Let’s switch to gas generators. Here, two kinds of machines are distinguished according to the fuel type. Standby gas models can be fed by natural gas or liquid gas. Depending on the fuel types, runtime and specs differ.

Natural Gas Supply

Here’s the explanation of how long a natural gas generator can run continuously. The thing is that such machines are fed by gas from a utility station. It means that it is not required to pour liquid into a tank; in general, a fuel tank is not needed at all.

When feeding natural gas from the station, generators can run indefinitely until gas is supplied. According to specs, average indicators reach 100-165 ft3/hr of non-stop operation at the half load.

Liquid Propane Feed

In this case, the generator construction requires a tank. Its working hours will be limited to the tank size. This kind of product can run for 90-185 ft3/hr without breaks.

Note that dual models are offered on the modern market. Gas generators can be fed by both liquid propane and natural gas.

Useful Tips to Ensure Long and Smooth Generator Operation

  • Although some generators are promised to run for an indefinite period, still, each machine requires periodic maintenance. Do not neglect it and provide professional care to your device.
  • Remember that each engine requires cooling from time to time. Even natural gas generators need to be unplugged. Thus, let the heart of your generator cool down after a continuous performance.
  • Fuel tanks have limits. Do not overfill them and keep the liquid used within permissible limits.
  • Gasoline, diesel, and gas fumes are flammable substances. Never pour them close to open fire.
  • Install units on flat surfaces, especially if you use portable models for hiking in forests. Make sure that the device is reliably installed.

Today, generators are used everywhere, not only in heavy industry or construction but also in the domestic sector. The installation of such devices can be used as a backup or permanent power supply. The modern market offers a wide assortment of options to please the demands of all customers. Now, you know how long the generator can run non-stop depending on the fueled liquid. Taking into account the obtained information, you’ll easily pick an appropriate model according to your tastes and needs.

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