What is an Inverter Generator?

An inverter generator is a newer type of portable generator. Its design improves on conventional generators for many uses, from camping and tailgating to powering your home during a power outage.

An inverter generator typically uses less fuel, produces fewer emissions, and generally is much quieter than a conventional generator.

But what is an inverter generator, and how do they work? Read on to find out…

What is a portable generator?

Portable generators comprise five essential functional parts: internal combustion engine, alternator, starter, fuel tank, and outlets.

Portable generators run on fuel for the engine; the engine turns the alternator which produces the AC made available through the outlets that you plug appliances into. All wrapped up in a small enough package to be transported from one place to another.

How Do Inverter Generators work?

As we just saw, a traditional generator produces alternating current (AC) using an alternator attached to the engine and routes that power directly to its outlets.

An inverter generator produces AC similarly but converts it to direct current (DC) with a rectifier and then back to AC using an inverter.

Electronic switches in the inverter regulate and adapt the DC power input, converting it into AC power and smoothing out the power fluctuations and spikes in the current. The result is an inverter generator produces cleaner and smoother electricity, just the kind you need to avoid harm or malfunction of many electronic devices.

A Little History

While conventional portable generators have existed for about 100 years, Honda motors debuted the first portable inverter generator in 1987. The first model produced electricity with what’s known as a square waveform, which can cause problems. In 1988 they came out with a model that produced output with a pure sine wave, which is what you want. Electrical power in pure sine waveform is recommended for electronics and also works best for electrical motors, allowing them to run at peak efficiency.

Sizes of Inverter Generators

Depending on your needs and usage, the size of the inverter generator you should get will vary. Consider what you will use it for and under what conditions to determine which one will work best for you.

Recreational Inverter Generators

A recreational inverter generator is small and weighs no more than 60 pounds. They put out about 2000 watts. Let’s consider some potential applications for different power capabilities. 

One thousand watts is approximately enough to run a coffee maker. You can also run a low-power slow cooker and a small toaster oven. When considering off-grid energy options, you might have specific items you want to always keep on, such as a mini-fridge, which uses about 200 watts.

A small TV, about 25″, running continuously could take up about 150 watts. Additionally, you could rotate one or two other small appliances, such as a blender.

Mid Size Inverter Generator

A mid-size inverter generator may weigh 80 lbs or more. To improve its portability, it may come with wheels. These typically have wattages of between 2500 watts to 4500 watts.

This will give you enough power to run an RV air conditioner, a small refrigerator, and a few small appliances simultaneously.

Large Inverter Generators

These are the biggest and can weigh more than 250 lbs. At 220 volts, they can produce up to around 9000 watts of power. A large inverter generator can power entire homes with a transfer switch. Although you need to be careful not to overload the generator, say by running central AC, multiple refrigerators, and laundry machines simultaneously.

What’s the difference between an inverter generator and a regular generator?

There are a few critical differences between inverter generators and regular generators. As already noted, inverter generators produce cleaner power than traditional generators.

Inverter generators also tend to be much quieter than regular ones, making them ideal for use in camping or RVing situations where noise is an issue. This is partly because an inverter generator can throttle the engine speed down if less than maximum power is needed. Conventional generators must run their engines at a fixed high speed (usually 3,600 RPMs in the US market) to produce the required frequency that appliances are designed to use.

The ability to throttle down the engine means that inverter generators are more fuel efficient when the wattage demanded is relatively low, as is often the case. Using less fuel saves money, reduces environmental impact, and decreases fuel storage needs.

Tip: for more about reducing environmental impact and improved fuel storage, see “Propane vs. Gas Generator“

Finally, inverter generators are usually more expensive than regular generators, but they offer several advantages that may make them worth the investment.

Benefits of an inverter generator

Because of their advanced technological aspects, an inverter generator has many advantages. Here are some of them.

1. Quiet operation

Portable generators have a reputation for being loud. So engineers of inverter generators looked at the construction of portable generators and redesigned them to help make them quieter.

Some are quieter just because they have physically smaller engines. Some have technology specifically to dampen sounds and minimize noise.

The housing that they are built with is explicitly designed to dampen noise. And their ability to operate at lower engine speeds under light loads reduces overall volume.

Newer inverter generator models are so quiet that they can even be used at home. They average around 50-60 decibels, about the volume of a normal conversation.

Honda inverter generators have a reputation for being especially quiet: check out the Honda EU2200i

2. Lower emissions

Inverter generators, in general, have lower emissions than conventional generators. Additionally, many have a CO safety shut-off valve. This means that the generator will shut off in an enclosed space if CO levels are dangerously high.

3. Good for power-sensitive equipment

Inverter generators have a harmonic distortion of 5 percent or less. Their ability to deliver clean power makes them ideal for sensitive electronics.

What is harmonic distortion?

Harmonic distortion measures how far an electrical wave’s shape deviates from being a pure sine wave. The higher the harmonic distortion, the greater the risk of problems with some devices you power.

For instance, running stereo or audio equipment would best be accomplished with an inverter generator. Otherwise, the sound quality could be affected — causing hum, pops, and clicks.

And you would want to choose a power source with the cleanest energy available for powering computers, laptops, or cell phones. In a computer, the high total harmonic distortion could even cause the computer to corrupt memory when a traditional generator powers it. 

4. Fuel efficient

By design, inverter generators adapt to the power output required. Instead of running at one set rate, the engine will change speed depending on the load demanded. So the machine won’t use any more fuel than is necessary. This helps to conserve fuel and also reduces emissions.

Many inverter generators have an eco-mode switch that makes the generator work even more aggressively at saving fuel. This comes at the expense of possibly stalling out if the engine is still cold and responding more slowly to changes in load.

5. Lightweight and Portable

Inverter generators are often made to be lighter and more portable than conventional generators. These models are constructed with advanced methods and designs, making them more compact. Which, when you’re transporting them, is a noticeable advantage.

This makes generators like the DuroMax XP2300iH ideal for camping, fishing, and other outdoor activities. Plus, when you are not using them, their smaller body size makes them easier to store.

Some generators can weigh as little as 30 lbs, which makes bringing them to a job site easy and hassle-free.

6. They Can Be Paired For Greater Output

Using a parallel kit, you can increase the power output by pairing the generator with another compatible one. So instead of replacing an inverter generator, if you need more power, you can upgrade it.

It is possible to pair conventional generators, but it’s highly technical and risky; with inverter generators, you can easily do it with a parallel kit. But the generators must be compatible with each other. Usually, you would use two of the same model.

7. Advanced technology

Many inverter generators have “smart” features that give helpful information. For example, it will show you how much fuel is left so you can plan ahead.

Also, you can see how much power it is putting out. This is helpful because it lets you determine if you can safely run more appliances. Finally, some will even tell you if it is time for maintenance so that you can preserve the life of the generator.

Cons of Inverter Generators

Knowing some disadvantages can help you plan and determine the best options when investing in an inverter generator.

1. Higher cost

Because of the advanced technology and design, inverter generators cost more than conventional generators for a given wattage output. Their ability to work at varying levels and meet output demands means that the components and mechanics are more sophisticated and expensive.

So the upfront cost of an inverter generator is higher than a traditional generator. However, because of its ability to adjust engine speed to match power usage, the resulting fuel efficiency will produce cost savings over time.

2. Lower power output

Conventional portable generators produce power ranging from 500 to 20,000 watts. The highest-wattage consumer-grade inverter generator currently available is the Duromax XP9000iH, which peaks at 9000 watts.

On average, an inverter generator will put out 1000 to 5000 watts of power. This limits their usage by themselves in many applications. However, as noted before, two generators can be used simultaneously and synced up to increase power output.

Which is better: an inverter or a generator?

Both machines are incredibly convenient and powerful. To determine which is better for you, look at the various needs and applications you will have for each one.

Inverter generators provide specialized power applications and solutions in situations that typically need lower wattages than conventional generators. However, the additional features of being quieter, lower weight, and using less fuel make an inverter generator an appealing choice for many people.

Generally, inverters use newer technology that could be more cost-effective over the long term. On the other hand, if you need a large power output, it may be that only a conventional generator will do the job. 

Is an Inverter Generator Worth It?

If you properly maintain an inverter generator, it will usually outlast a traditional portable generator. Its specialized features and engineering make it a better option in some situations than a conventional generator. Because of its fuel-efficient nature, portability, and high-quality power output, an inverter generator is often worth the higher price.

Inverters are also used for solar power. Check out our article “How Does A Solar Generator Work?” for more information.