Conventional vs. Inverter Generator – Key Differences

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In Brief: Conventional vs. Inverter Generator

Inverters generators are compact, fuel-efficient, less noise producing units offering clean electricity with parallel connection capability. But, they are highly priced and are not capable of producing very high power outputs as done by conventional generators.

There have been many types of generators available today in the market, but each of them is different from others.

Often, people confuse between an inverter generator unit and a conventional generator unit and think they are mostly the same.

They couldn’t be more mistaken, as an inverter and a generator are different from each other on various fronts.

In this article, we will discuss how an inverter generator is different from a conventional portable generator and help you decide which one best suits your needs.

Conventional vs. Inverter Generator

The most common and well-known generators are the conventional portable generators that basically run on fuel to produce electrical power and can be easily moved.

There are mainly three types of these generators based on the fuels they use, namely gasoline, propane, and diesel.

Some are hybrid units that use two or two fuels.

An inverter generator is a relatively new technology. It produces preliminary power similar to the conventional units using fuels.

But later, this power is processed further with the help of an alternator and an inverter to get final output power.

In this section, we will discuss some key differences between a conventional and an inverter generator, simultaneously explaining how one is better than the other.

1. Working principle

Both use different tech. Inverter generators are much more technical in nature. 

The critical difference between a conventional generator and an inverter unit is their working mechanism.

A generator unit produces AC output power while an inverter generator is a three-phase generator that provides AC power with the help of an alternator, and it is converted to DC power and then is inverted back again to AC for usage.

In conventional generator, the engine rotates the generator with the help of the mechanical energy obtained by the combustion of the fuels.

The alternator uses this energy and generates AC electric power based on the principle of electromagnetic induction.

When you start the inverter, fuels like natural gas, propane, and diesel are combusted and release energy.

This energy powers the motor attached to an alternator, which produces electricity, i.e., AC power.

This AC power is raw, high voltage, multiphase, and has a high level of Harmonic Distortions (HD), which cannot be used directly.

Hence, the inverter converts the AC power into Direct Current (DC power).

The inverter has a microprocessor that is programmed to invert back this DC power to AC power again.

2. Output power

Inverter Generators come with a limited range of outputs

Conventional portable generators usually run speed of 3,600 Rotations Per Minute (rpm) to generate 120 volts at a frequency of 60 Hertz.

They can produce a large amount of power up to 20-30k watts of power, depending on the size of the unit.

One of the most significant drawbacks of conventional portable generators is they cannot maintain a constant speed of 3,600 rpm.

Due to this, the output voltage and Hertz fluctuate, creating Harmonic Distortions (HD).

Most of the inverter models also run at 3600 rpm to produce 120 volts at 60 Hertz, but a constant speed of 3600 rpm is maintained while the output voltage can be adjusted according to the load connected.

This greater control over the electrical output makes inverter generators quite energy-efficient.

But the output power of an inverted unit is limited to 1,000-5,000 watts.

Because of this limited power output, inverter units cannot be used to whole house operations, power tools requiring high power, unlike conventional ones.

3. Output quality

Better with an inverter generator

Because of high HD and unstable electrical output, fuel-powered portable generators cannot produce “clean electricity.”

Clean electricity is a high-quality output that is very safe to connect to your electrical quality sensitive devices like phones, laptops, computers, and printers, kitchen appliances.

But the inverter units use a rectifier to convert the AC power to DC, and capacitors help to smoothen out this output to some extent.

Further, the DC power is inverted back to AC at a desired frequency and voltage.

This leads to high-quality output, i.e., the energy produced is clean, steady sine waves with low HD, which is safe for sensitive devices.

The inverter units are mostly preferred for their high-quality output, which is often on par with the quality of your electric supplier.

4. Fuel efficiency

Inverter generator wins hands down

Inverter generators are 20-40% more fuel-efficient than conventional generators.

This is because inverter generators can regulate the speed of the engine according to the load at hand.

An inverter unit can produce the same amount of output electricity as conventional one without running the engine at 3600 rpm all the time.

Thus, an inverter generator needs less fuel to run for the same amount of time as conventional ones leading to its high fuel efficiency.

5. Noise

Lower in inverter generator

Conventional generators produce lots of sound of more than 65 dBA when they are functioning.

This is a significant inconvenience for you and your neighbors, especially if you are running the generator unit at night.

The generator’s inability to maintain a constant speed of 3600 rpm contributes to this.

An inverter unit has an inbuilt sound blocking enclosures, mufflers, etc., which produces less noise around 50 to 65 dBA.

This range is much lesser than the noise produced by conventional ones and almost equal to an office noise, normal conversation, or the sound from inside of a running car.

Further, an engine running at a slow and steady speed as of an inverter generator produces less noise.
Due to low sound, inverter units are very comfortable to run indoors or outdoors at any time.

6. Portability

Easy with an inverter as they are usually lightweight

Conventional generators are usually bulkier and heavier, weighing over 100 pounds as they are not fuel-efficient and have larger fuel tanks.

But the large fuel tank enables the conventional generators to produce high output power.

Most inverter generators weigh only around 40-60 pounds and have smaller fuel tanks and are highly portable.

But you should keep in mind that compact models usually produce less power. As the size increases, the generator unit can generate more power.

Though generator units are bit heavy than inverter units, they are still portable, and most of them come with wheels for easy transportation.

Because of these reasons, conventional units are an excellent fit to use at home with high power requirements.

The portable inverter units are a good fit for camping trips or outdoor recreational activities where you don’t need much energy than you usually do at home.

7. Parallel capability

Inverter generators have parallel connection capability

Inverter units make up for their low output power by their parallel connection capability. You can pair one inverter with others to get more power output.

This way, you can use two small inverters to produce power equal to one large inverter unit.

For this, the inverters need to be of the same model and build.

This parallel connection comes handy when your home power requirements increased, or your existing generator power output is not up to the mark.

Conventional units don’t offer parallel connections as they are already able to deliver more power.

8. Initial cost

Conventional ones are usually much cheaper for the same output. 

The conventional portable generators are cheaper to purchase than inverter units. They are affordable with high power delivery capability.

The sound attenuating, clean power output and fuel-efficient features of the inverter units are the reasons behind the increased cost.

9. Maintenance

Low maintenance for inverter

Inverter units are easier to maintain than portable generators models.

This is because inverters use less fuel, leaving lesser residue for longer running time.
Plus, inverters also don’t need regular replacements of parts like the carburetor, fuel lines, or gaskets.

10. Safety of appliances

Inverters are safer due to clean power

The clean power produced by inverts is more reliable and safe to use with sensitive electronic devices such as laptops and computers.

The unprocessed power produced by conventional generators might lead to malfunction or damage to such devices.

11. Environmental friendliness

With higher fuel efficiency, inverters are more environment-friendly.

Comparatively, inverter generators are environmentally friendly as they have an engine that can run at regulated speeds and consume less fuel, unlike a conventional generator that runs at one speed using large amounts of fuels.

Main brands for Inverter Generators

Some of the leading brands for inverter generators are Generac, Briggs & Stratton, Energizer, Winco, Westinghouse, DuroMax, DuroStar, ATIMA, Caterpillar (CAT), Champion Power Equipment, Firman Power Equipment, Sportsman, Powerhorse, Earthquake, Powermate, Predator, Ford Generators, Honda Power Equipment, Hyundai, and Yamaha.

Summary

Inverters are compact, fuel-efficient, less noise producing units offering clean electricity with parallel connection capability.

But, they are highly priced and are not capable of producing very high power output. On the other hand, conventional generators are low cost, bulkier, top power offering units.

It’s hard to say which is better than the other as both of them have a different set of benefits and limitations.

About Steven

Steven is an engineering graduate with amazing zeal and enthusiasm. He is fascinated by solar power and has set up a small solar plant at his rooftop.

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