What is an Inverter Generator?

What is an Inverter Generator?

Ultimate Inverter Generator Guide

Just what is an inverter generator? You may have heard people talk about them and how much better they are than regular generators.

An inverter generator is a device that inverts electricity in order to provide cleaner, safer power for your sensitive electronics. It is more compact, quiet, and energy efficient than a traditional generator, but usually comes with a higher price tag.

If you're wondering whether the hype is true, we'll break down in more detail how inverter generators work, as well as how to choose and use them properly.

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How Does an Inverter Generator Work?

An inverter generator works by converting AC electric current into DC electric current and then inverting it back to AC to create a cleaner wave of electricity. If you're not sure what the difference between AC and DC power is, please check out our article about electrical phases. Also, read up on the basics of how generators work.

Westinghouse inverter generators

A typical non-inverter generator produces what is called "dirty" power, which is basically power with voltage spikes that can harm sensitive electronic equipment. It has a high total harmonic distortion (THD), which represents the variance from the standard 60-herz frequency.
This means that if you were to plug your computer into a regular open-frame generator, the power fluctuations could cause computer memory loss or operating errors.

An inverter generator "cleans" up that power by inverting the electrical wave in a way that allows for a consistent flow of electricity without the ripples and irregularities of dirty power. It has a clean THD of less than 6%. You would need an electrical engineering course to understand all the complexities of how this works. Just know that an inverter generator improves the quality of electricity and allows you to plug in a computer or smart phone without fear of damage.

laptop computer

What is the Difference Between a Generator and an Inverter?

As mentioned, the primary difference between a generator and an inverter is an inverter's ability to clean up electrical power for sensitive electronics.

Fuel Efficiency

The second major difference is an inverter generator's higher fuel efficiency. It can adjust the speed of its engine depending on how much power it is being asked to provide. For example, if you only want to power one lamp, the engine will run more slowly and produce less current. If you add a second lamp, the engine will ramp up to meet the additional demand.

This is different from a traditional generator, which only runs at one speed no matter the power demand. Of course, the result is that inverters save more energy because they're not constantly running at full power.

Honda inverter generator


Inverter generators have a limited wattage range-the largest-output inverters produce only around 7,000 watts of electricity. This is vastly less than some traditional portable generators that can produce upwards of 17,000 watts.

For this reason, inverter generators typically aren't used in emergency backup settings, unless you only need to power a few small items. More often, inverters are used in recreational applications such as camping, tailgating, picnicking, etc.

How to Size an Inverter Generator

Inverter generators are much more compact than traditional generators. Their internal design and construction is more efficient, and they can get by with a smaller fuel tank. Many units weigh less than 40 pounds, making them easy for people of all ages to move around, which is another reason why they're so popular for outdoor activities.

Using the chart below, you can quickly see the differences in use and wattage. Choose between 1,000, 2,000, and 3,000 watts.

Do You Need a Compact, Small or Medium Inverter Generator?

You can also use our generator wattage calculator to figure out your power needs. Just choose which appliances you want to power, and the calculator will automatically recommend a range of generators.

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Noise Level

Inverter generators are also designed to be much quieter than traditional generators. We tested how loud one inverter generator was compared to a traditional open-frame generator.

The decibel meter registered as high as 76 dB for the regular generator and only around 66 dB for the inverter. This quiet operation is perfect for campgrounds where, in addition to wanting to get a good night's sleep, there may be official noise restrictions.

Parallel Capability

What inverter generators lack in power, they make up for in their ability to parallel with other inverter generators. Yes, you can combine two inverter generators with a parallel cable to get double the power. This then allows you to power larger items, like the A/C in a mobile home. This doesn't work on all models, however, and many have a specific companion unit that you must use.

How to Choose an Inverter Generator

Before choosing the right inverter generator, you need to determine two things:

  1. What are you planning to use it for?
  2. How much power will you need?

If you're looking to backup a large chunk of your house during a storm, an inverter isn't going to get the job done. For that, you either need a larger, emergency portable generator or a home standby generator. If, however, you're only looking to power a few basic items, than a larger inverter generator might cut it.

Inverter generators are best used for recreational activities, however. If you run frequent tailgating parties or love camping, then an inverter will be a great convenience for you.

Westinghouse inverter for tailgating

Once you've settled on your application, determine how many watts you'll need. Our portable generator wattage calculator can help with that. The more items you want to power at one time, the larger unit you will need.

How to Use an Inverter Generator

Inverters can be used in the same way as traditional portable generators in theory. In practice, there are differences because of their lower wattage.

How to Connect an Inverter Generator to Your House

You can connect an inverter generator to your house using extension cords, a convenience cord, a through-the-wall kit, or a manual transfer switch. In fact, there is no difference between hooking up an inverter generator and hooking up a regular portable generator to your house.

That being said, most people won't hook up an inverter to their house because it will only power a few items. In some cases, though, people have used a manual transfer switch to connect an inverter generator to their furnace system circuit to get emergency heat during the winter.

Can Inverter Generators Be Used Indoors?

No! The number one generator safety rule is NEVER RUN IT INDOORS. Inverter generators may look small and harmless, but they have a combustion engine inside that releases exhaust gases that could poison and kill you.

There are no exceptions to this rule. You CANNOT use an inverter generator in a detached garage, shed, open garage, under a deck, or anywhere within 15 feet of your house. People have died doing this and there is no acceptable workaround.

Is an Inverter Generator Worth It?

Inverter generators are a convenient, fuel efficient way to power your sensitive electronics during an outage. Many people find that the higher upfront costs are made up for by the fuel savings, quiet operation, and portability offered by inverter generators.

If you get frequent power outages and are looking for heavy backup power, go with a larger portable generator or home standby generator. If you are looking for the convenience of backup power for trips, minor power outages, or outdoor activites, you can't beat the performance of an inverter generator, and it will be well worth it.

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Alberto, the Portable Generator Expert
Portable Generator Expert
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