Q&A – What is An Inverter Generator? We Answer your Questions

Most people don’t understand the difference between an inverter generator and a conventional portable gas generator, which isn’t a criticism, it’s just not common knowledge. It turns out that quite a few people want to find an answer to: What is an inverter generator? Most people don’t care until they want to buy a portable generator and they start seeing some generators categorized as an “inverter.” Naturally, you want to know that that refers to.

In this article we dive deep into the world of inverters and answer a wide range of related common questions. We understand it can be confusing to make sense of the technical aspects of generators. We also discuss :  Advantages and disadvantages of an inverter generator, how an inverter generator works, other applications for an inverter, and more.

We feel that education is important so we always do our best to keep our readers and informed.

What is an Inverter Generator?

An inverter generator is an advanced power source that efficiently produces stable electricity, making it an ideal choice for powering sensitive electronic devices. It differs from traditional gas generators, which directly produce alternating current (AC). Instead, inverter generators employ a more refined approach to power generation.

Inverter generators generate direct current (DC) power through a combustion engine. This DC power is then converted into AC power using advanced electronic circuitry called an “inverter.” The primary function of an inverter is to change DC into AC. To do this, a DC power source is directed to a switch that opens and closes to change the polarity of the current. Each side of the switch is connected to a field conductor, typically a copper coil, which generates an electric field around it.

The alternating electric fields created by the switch are supplied to transistors, which direct the current as a pulse to the final output at the desired frequency. The frequency is determined by the speed at which the current pulses or how many times the power is switched per second. For example, standard US power operates at 60Hz, meaning the transistor swaps polarity 60 times per second. This switching system employs Metal Oxide Semiconductor Field Effect Transistors (MOSFETs) in parallel mode to create the peaks and troughs of the sine wave.

The basic switching method produces a square sine wave, a rudimentary representation of a sine wave. However, this type of sine wave is not very efficient, and some equipment may not function properly on it. By adding more MOSFETs in parallel, multiple square waves are produced, creating a stepped square or modified sine wave. While not a true sine wave, it allows almost all AC equipment to operate normally, albeit not always as efficiently as a true sine wave. Larger capacity switch mode inverters use thyristors to handle higher currents.

The drawback of square and modified sine waves is the inability to control the harmonic distortion of the wave. In contrast, inverter generators produce “clean” electricity with minimal harmonic distortion, making it safe for sensitive devices such as laptops, smartphones, and medical equipment.

Inverter generators are also known for being “quiet” (53dB to 68 dB at full load) and producing clean electricity. They’re also smaller and more portable compared to conventional gas generators. Often overlooked is their ability to be connected in parallel, which doubles your power output. We discuss all of these factors in the next section.

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

Here’s a snapshot of the differences: What are the advantages of an inverter generator?

Advantages of Inverter Generators:

Disadvantages of Inverter Generators:

What’s Special About An Inverter Generator?

If you’re shopping for a portable generator it can be daunting initially because things get get technical once you start looking beyond the marketing language. Let’s be honest, most people just want to know the nuts and bolts, and how a gas generator or inverter generator are appropriate to my specific situation. Here’s a quick overview on what makes an inverter generator unique or special and why is an inverter a better solution for your needs. Consequently, when does it make more sense to save some money and buy a traditional gas generator?

Inverter generators are special for the following reasons:

1. Quiet operation: Inverter generators are designed to be significantly quieter than their gas generator counterparts. This reduced noise level is crucial, as it allows users to comfortably run their generator without causing disturbances to themselves or others nearby. The quiet operation is achieved through lower engine RPMs and the use of soundproofing materials. By providing a more peaceful power source, inverter generators are a desirable option for those who value a tranquil environment.
2. Clean electricity: Inverter generators produce a pure sine wave, which means they deliver clean and stable power. This attribute is essential for powering sensitive electronics, as it prevents damage to the devices and ensures optimal performance. Gas generators, on the other hand, can produce “dirty” electricity with fluctuations that can harm delicate equipment. By providing clean power, inverter generators cater to a wider range of applications and grant users peace of mind when powering their electronics.
3. Compact size and portability: Inverter generators are designed to be smaller and lighter than traditional gas generators. This portability is a game-changer for users who need a reliable power source on the go. The compact size makes it easier to transport and store the generator, making it an ideal choice for camping, tailgating, or other outdoor activities where space is a premium.
4. Energy efficiency: Inverter generators are known for their energy efficiency, as they can adapt their output according to the demand. This feature results in fuel savings and reduced emissions, contributing to a more environmentally friendly power source. By being energy-efficient, inverter generators offer users extended run-times and ultimately save them money on fuel costs.

There are situations where a gas generator may be more appropriate. For example, If you require a lot of power for heavy-duty applications, such as a construction site or remote work where you need a lot of power, and the generator needs to be lifted to the location, then yes, a gas generator is what you need. Also, if you want a portable generator that can run on alternative fuels like diesel, propane, or natural gas, a traditional gas generator will be a better choice.

Another reason which to buy a gas generator is because you don’t have enough money to buy an inverter generator. Sometimes you just need backup power and it doesn’t matter if it has low harmonic distortion and that it’s quiet. Sometimes people need the cheapest portable power they can afford. Simple.

We live in a world that assumes everyone is wealthy and that everyone should buy the “best” product but from my own experience, it’s important that people buy what they can afford, and that will determine the best choice for their situation.

Right now the economy is sinking. There’s a lot of uncertainty and people are losing their jobs. If you need power and you want to spend as little as possible then a traditional gas generator is the smartest decision you can make and as long as you won’t be running any sensitive electronics, then the gas generator will satisfy your needs.

How Does An Inverter Generator Work?

An inverter generator, a marvel of modern engineering, operates in a distinct manner compared to traditional gas generators. To begin with, the engine generates direct current (DC) power, which must be converted to alternating current (AC) power suitable for everyday devices. This conversion is facilitated by an inverter, which employs cutting-edge technology to create stable and clean electricity.

During the conversion process, the inverter employs high-frequency modulation to produce a raw AC waveform. This waveform is then rectified to DC power and subsequently re-inverted to create a precise sine wave. This fine-tuned sine wave is exceptionally clean, minimizing harmonic distortion and ensuring that sensitive electronics are powered safely and efficiently. Furthermore, the inverter generator can adjust engine speed according to the load, enhancing fuel efficiency and reducing noise levels.

What Size Inverter Generator Do I Need?

As for determining the ideal size of an inverter generator, several factors come into play. First, consider the combined wattage of the devices you plan to power simultaneously. Make a list of these appliances, and add up their respective running and starting watts. Starting watts, also known as surge or peak watts, account for the initial power draw when appliances with motors or compressors kick in. To ascertain your specific power requirements, utilize these figures as a benchmark.

Once you have a clear understanding of your power needs, select an inverter generator with a capacity that meets or slightly exceeds the total wattage. It is prudent to avoid running a generator at its maximum capacity continuously, as this could lead to premature wear and reduced performance. A buffer of approximately 20% above your calculated requirements is often recommended, ensuring that the generator operates comfortably within its capacity.

VIDEO | A Basic Explanation of what an inverter is

What is an open frame inverter generator?

An open frame inverter generator is an intriguing hybrid that combines the technology of an inverter generator with the design of a traditional gas generator. While sporting an open frame structure similar to conventional generators, these machines incorporate the inverter technology that produces cleaner and more stable power output. The result is a generator with increased power capacity and fuel efficiency, albeit typically with higher noise levels than enclosed inverter generators.

What’s better, a gas generator or an inverter generator?

The choice between a traditional generator and an inverter generator ultimately hinges on your specific requirements. Inverter generators boast cleaner power output, quieter operation, better fuel efficiency, and a more compact design. These advantages make them ideal for powering sensitive electronics, outdoor recreational activities, and residential use where noise restrictions are in place.

On the other hand, traditional generators tend to have a higher power output and can be more cost-effective, making them suitable for larger power needs, such as construction sites and emergency backup power for an entire home. It’s essential to weigh your priorities and requirements before deciding which type of generator is best suited for you.

What is an inverter generator used for?

Inverter generators are versatile and can be used in a variety of applications. They’re particularly popular for recreational activities, such as camping, tailgating, and RV trips, due to their quiet operation and portability. Additionally, their clean power output makes them ideal for powering sensitive electronics like laptops, smartphones, and medical equipment. Inverter generators can also be employed as backup power sources during power outages or for off-grid living, providing stable electricity to households with moderate energy demands.

Are inverter generators pure sine wave? Yes, inverter generators produce a pure sine wave output, which is crucial for powering sensitive electronics. A pure sine wave mimics the clean and stable electricity provided by the utility grid, minimizing harmonic distortion and ensuring the safe operation of devices. This is a standout feature of inverter generators and a key reason why many users prefer them over traditional gas generators when it comes to powering delicate electronics.

Are inverter generators quieter than gas generators?

Yes, inverter generators are generally quieter than traditional gas generators. The primary reason for their lower noise levels is their ability to adjust engine speed based on power demand, which results in less noise during lower loads. Moreover, inverter generators often have additional sound-dampening features, such as enclosed casings and noise-reducing materials, further contributing to their quieter operation.

Are Honda inverter generators worth the money?

What makes them better? Honda inverter generators are highly regarded for their reliability, build quality, and performance. While they may command a premium price, many users find them worth the investment due to their longevity, fuel efficiency, and quiet operation. Honda’s reputation for producing dependable engines and well-designed products often places their inverter generators among the top choices for consumers looking for a trustworthy power source.

A lot of people wonder why Honda generators cost so much but think about it this way, Honda has been developing gas powered vehicles and power equipment for decades. They have some of the best technology money can buy and it’s their proprietary technology you can’t get anywhere else.

For example, Honda makes the quietest inverter generators on the market. You won’t find quieter portable generators. Most people want quiet generators so this is a valuable feature that people are willing to pay for. Besides that, Honda makes some of the most reliable engines in the world and their generators have Honda engines. Of course it will cost you more to get a Honda engine.

Honda cars are known for their reliability and it’s the reason why their cars are so popular. When you buy a Honda inverter generator you get all of benefits from their years they’ve invested in making exceptional gas powered machines.

Can you add an inverter to a generator?

Yes and no. Technically, you can add an inverter to a traditional generator to create a makeshift inverter generator, but it’s not something you can just buy and screw it on to your gas generator. This is not something that people do. If you want an inverter generator then you would simply buy an inverter generator. Even if you did manage to do it, you wouldn’t get the same level of performance as a purpose-built inverter generator.

Would you buy a gas powered SUV and convert it to an electric SUV? Yes, people do things like this but they are experts and know what they are doing. People who heavily modify power equipment are generally engineers or people trying to invent something new. Unless you fit into that category, I will say that you can’t simply add an inverter to a gas generator to convert it into an inverter generator. That is not an available option.

What is the largest inverter generator?

The Genmax GM9000 and Duromax XP9000iH are the largest portable inverter generators you can buy in 2023, offering a substantial 9,000 watts of starting power and 7,600 watts of running power. Running these two behemoths in parallel would result in an impressive 18,000 watts of starting power and 15,200 watts of running power. This configuration would cater to large power needs, such as powering an entire home during an outage or providing electricity for high-demand activities. Keep in mind that such a setup would be significantly less portable and potentially louder than smaller inverter generators.

Can you parallel two different brand inverter generators?

Parallel capabilities can vary between inverter generator brands and models. While it’s theoretically possible to parallel two different brand inverter generators, it’s not generally recommended. Manufacturers typically design parallel kits specifically for their own generator models, ensuring compatibility and safety. Mixing brands might result in uneven power distribution, damage to the generators, or even safety hazards. It’s best to follow the manufacturer’s guidelines and only parallel generators of the same brand and compatible models.

What is a dual fuel inverter generator?

A dual fuel inverter generator is a versatile power source that can operate on two different types of fuel, such as gasoline and propane. This capability offers users greater flexibility in terms of fuel availability and storage. Dual fuel generators provide the same advantages as traditional inverter generators, such as cleaner power output and quieter operation, while offering the added benefit of fuel choice.

What is the cost of an inverter generator vs. a traditional gas generator?

Inverter generators tend to be more expensive than traditional gas generators, primarily due to the advanced technology and electronics involved. While prices can vary widely based on factors such as brand, power output, and features, you can generally expect to pay a premium of 2x to 4x more for an inverter generator compared to a similarly sized traditional gas generator. Despite the higher upfront cost, inverter generators often offer advantages like quieter operation, fuel efficiency, and cleaner power that many users find worth the investment.

For example:

For $950 you can buy a traditional 7500W dual-fuel gas generator like the Westinghouse WGen7500DF, with 7500 running watts and 9500 starting watts

or, to get the inverter generator equivalent, you can buy the Genmax GM9000iEDC which has 7000W of running power and 9000W of starting power. The price is $2500.

The difference is around $1550 between the two different generators, with roughly the same power output. Obviously these are not exactly the same but it gives you an idea of what the difference in cost is between an inverter and a gas generator.

Do I need an inverter generator for my RV?

Whether you need an inverter generator for your RV depends on your power needs and priorities. Inverter generators are recommended for RVs because they produce cleaner, more stable power suitable for sensitive electronics, such as laptops and smartphones. Additionally, inverter generators are usually more compact and quieter than traditional gas generators, making them a more convenient and neighbor-friendly option at campgrounds. However, if your power requirements are more basic and noise isn’t a significant concern, a traditional gas generator may suffice for your RV.

History of Inverter Generators

I doubt anybody will be surprised to learn that the company that started the inverter generator revolution is the leading brand making inverter generators. Yes, I’m talking about Honda. It all makes sense once you realize how this market segment began.

In the annals of generator history, the advent of inverter generators marked a significant milestone. Honda, a pioneer in this field, introduced the world to the first generator with an inverter circuit, the EX300, in 1987. This groundbreaking technology provided the basis for today’s inverter generators, enabling stable frequency and improved generation efficiency through a 3-phase multi-pole high-speed generation system. Despite its limitations, the EX300 set the stage for future advancements in the realm of inverter generators.

The term “inverter” can be misleading, as it implies an inversion function, which is not the case. In actuality, an inverter is an engineering solution designed to convert electricity, typically from a low-level direct current (DC) to a high-level alternating current (AC). Historical precedence has unfortunately attached the term “inverter” to a function more accurately described as conversion.

Inverters have a long history, dating back to the 19th century when Westinghouse created rotary converters to convert DC to AC. Inverters are now a ubiquitous technology used in a wide array of industries and applications, such as air conditioners and solar systems. At the most fundamental level, inverters convert electricity by switching the direction of a DC input back and forth rapidly, thus producing an AC output. Additional filters and electronics are used to create a clean, repeating sine wave that can be safely used in various applications.

In 1996, Honda made further advancements with the release of the sine-wave generating EX500. Through the use of custom integrated circuits (ICs), the EX500 produced a sine-wave equivalent to mains power, a significant improvement over the EX300. As microprocessor technology advanced, Honda incorporated it into their portable generators, leading to the release of the EU9i, EU24i, and EU28is in 1998. These models featured CPU data processing control, providing high-quality electricity output capable of powering sensitive electronic devices such as personal computers.

Today, inverters are employed in countless applications beyond generators, from air conditioning systems to solar energy installations. For instance, in solar systems, inverters convert the DC electricity generated by solar panels into the AC electricity utilized by the electrical grid. As the world transitions towards an electrical grid with more inverter-based resources, advanced inverters that can respond to changes in frequency and other grid disruptions are essential for maintaining stability.

In essence, the evolution of inverter generators can be likened to the journey of a fledgling caterpillar, undergoing a metamorphosis into a vibrant butterfly. This transformation, driven by the changing needs of a technologically advancing society, has led to the inverter generators of today, which deliver efficient, clean power to the ever-expanding range of electronics that have become integral to our daily lives.

What is Total Harmonic Distortion (THD)?

Just like sound, alternating current moves in waves and both of these wave types can become distorted. We are familiar with sound wave distortion because we can hear it when the amplifier becomes overloaded or there is interference with the signal. Electric sine waves experience the same distortion, only we cannot see or hear it. It does, however, affect the way electric equipment functions.

Harmonic distortion can cause electric motors to be less efficient and overheat. HD is most detrimental when it comes to electronic equipment. Electronic equipment that uses a microprocessor are affected by HD in that it changes the way they perform and it generates excessive heat.

Repeated exposure to HD will damage the circuitry of this type of equipment. Eventually causing them to fail. Microprocessors are common in many household devices from computers, phones, and TVs to many kitchen and other household appliances. It is, therefore, becoming increasingly important to ensure that we use “clean” power with low HD.

All AC power will experience some degree of distortion. Engineers measure the amount of harmonic distortion over a continuous sine wave as Total Harmonic Distortion (THD). A THD of less than 3% is considered to be clean power. Even grid power can sometimes exceed the 3% threshold but this happens very seldom because grid power uses large generating capacity. A portable generator does not have the same capacity and the THD can fluctuate greatly as the load demand changes. As a result, standard gas generators will cause damage to electronic equipment over time.

Modern inverters use Insulated Gate Bipolar Transistor (IGBT) technology to create a near-perfect sine wave. The sine wave produced by IGBTs is far superior to MOSFET inverters as they create many more points or steps. In addition to this, pulse width modulation is used to control the sine wave and limit the THD. The result is a clean pure sine wave, suitable for use with the most sophisticated electronic equipment. Capacitors are also used to compensate for changes in DC voltage, thereby maintaining a stable output voltage.

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The Role of the Governor

Standard gas generators have been around for a long time and use very basic technology. A gas engine is used to run an alternator that produces AC power. A governor controls the amount of fuel supplied to the engine to keep it running at a constant speed (usually 3600 RPM). As the load is increased, more power is needed to keep the alternator running at the same speed. The governor will open to supply more fuel as more power is needed, very much like pressing down on the accelerator pedal of a car to keep the speed constant when you approach a hill.

A governor is not 100% accurate and there will be changes in alternator speed causing both the voltage and frequency of the current to change. Many modern generators use an Automatic Voltage Regulator (AVR) to keep the voltage relatively stable. They cannot, however, control the frequency changes and generators are therefore prone to high levels of harmonic distortion. For example, it’s common for gas generators to have THD levels over 18%.

By using a double conversion system, an inverter generator is able to correct this and the inverter produces a very clean sine wave with low THD.

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Video | Inverter vs Portable Generator | Explained by Yamaha

Even though this video promotes Yamaha products it still provides some useful information that helps you understand what an inverter generator is.

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Inverter vs Generator : What’s the Difference?

If you’re interested in learning about the major differences between inverter generators and conventional generators then you should go and read our comprehensive article on the subject: Inverter vs Generator : What’s the difference between an inverter generator and a conventional generator. It will clear up any remaining questions you have about choosing the right generator.

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Finding the Best Inverter Generator

If you think that an inverter generator is the best option for you, your next step is to find the best inverter generator to meet your needs. In this section, we’ll be reviewing three models that offer the latest technology for a very reasonable price.

Do you really need an inverter generator?

We hope you now have an answer to the question : What is an inverter generator? But, now you need to figure out if you truly need an inverter generator?

The advantage of parallel function for home users is that you can use one small generator for when you want a portable unit to take with you for camping or yachting trips. If you want more power to back up your home during power outages, there’s no need to buy a large generator that costs more and is more difficult to move around. You can simply add another small generator and run the two in parallel. If you want to use the generator for multiple functions, this will save you money and be more convenient.

For contractors, a parallel inverter generator can be very beneficial. You may want something small and portable for a site where you don’t much power. If you have more than one team working on different sites, you’re going to need more than one generator. When you need extra power for larger jobs, you can simply use more than one generator together to provide a higher watt output. This versatility makes it more affordable to use more than one generator and allows for expansion as your business grows.

In the end, whether it’s for domestic or commercial use, a parallel inverter generator gives you the advantage of versatility. You can use them for multiple purposes and you have the adaptability to allow for your changing needs.

What does the future hold for inverter technology?

There was a time, not too long ago, when inverter portable generators were a luxury few could afford. The landscape was entirely different before 2021 – a turning point reminiscent of the Cambrian explosion. Suddenly, not only were new Chinese brands entering the market, but established companies were also offering high-quality inverter generators at far more accessible prices.

For years, the inverter generator market was under the sway of revered brands like Yamaha and Honda, with their premium pricing. Honda’s EU7000iS, for instance, cost a staggering $6,000. These top-tier models were on par with Yamaha’s offerings and were reserved for those with deep pockets. The transformation of the market since then has been astounding.

Make no mistake, Honda’s inverter generators remain top-notch, boasting features that few can match. Their 5500W EU7000iS still retails for around $5,000. However, with alternatives like the Genmax GM9000iE – a 7500W inverter generator – priced at a mere $2,200, the industry landscape has shifted dramatically. One can only imagine the dismay of Honda executives as they witness this unfolding.

Today, a decent 2200W inverter generator can be acquired for about $400, compared to Honda’s $1,200 counterpart. Although the quality differs, the cheaper option isn’t three times inferior or louder than its pricier rival. The upshot is that clean, quiet portable power is now accessible to all, fueling exponential market growth.

What I find truly fascinating is the rapid evolution towards portable power stations and solar generators. As inverter prices have plummeted since 2021, there’s been an astonishing surge in the development of battery generators. Now, in 2023, power stations boasting 3600W of rated power and 7200W of starting power are available, with expandable options reaching up to 25,000W – enough to power an entire home.

While I won’t delve into the nitty-gritty of battery generators here, you can explore our comprehensive guide on portable power stations. Just know that this rapidly evolving market is fundamentally changing how we perceive portable power.

Gasoline engines are steadily being replaced by solar and electric alternatives, and the transition is accelerating. Soon, gas generators will be obsolete as solar generator prices continue to drop and their capabilities expand. Currently, power stations cost between 2x and 4x more than inverter generators, which mirrors the price ratio between inverter and traditional gas generators.

Personally, I’m an avid fan of solar and battery-powered equipment. Many remain skeptical of battery-based systems, but it turns out they can outperform gasoline-powered alternatives. The myriad benefits of clean technology often go unnoticed as people cling to outdated beliefs. What truly concerns me is the rapid pace of change that we’re struggling to keep up with.

We started by asking, “What is an inverter generator and how do they work?” I’m heartened to know that curiosity remains alive and well. Humans have an innate drive to innovate and improve their surroundings. While inverter generators were groundbreaking in their time, the next generation of portable power stations will leave you in awe of battery technology’s potential. The demand for backup power isn’t going anywhere; in fact, it’s only growing as prices become more reasonable.

Ultimately, every person on Earth requires power. The question you must ask yourself is: What type of power do you rely on for backup electricity, and how does it work?