Conventional Generator vs Inverter Generator

Deregulation of energy has seen major changes in the market requirements for power generation industry. Today's generator designs must be cost effective, highly reliable, and very efficient. There are two technologies available today in generators: conventional generators and inverter generators. As a first-time-generator-buyer, understanding the differences between the two technologies before making any purchase can help you choose wisely.

Is there any functional difference between an inverter and a generator?

The difference between inverter and generator in how each operatesexplains the significant dissimilarity between conventional generators and inverter generators. A generator produces electrical power, while an inverter draws power from a fixed DC source and uses a microprocessor to invert DC to AC. Inverter generators are a marriage between these two concepts. Below is more about generators and inverter generators.

Conventional generators

Conventional generators have been around the longest and are the most widely used today. These generators run on gasoline, diesel, or propane. The fuel powers a motor attached to an alternator that generates electricity. The motor runs at a speed of 3600 rpm to produce 120 volt AC / 60 Hertz. The fluctuation of the motor's speed affects the cycles per second or Hertz of the output. This means that, if possible, the rpm should be maintained constant throughout the generation of power to avoid variation in the power output.

In old-fashioned generators, you can also find silenced generators that are enclosed in an acoustic cabinet to reduce the level of noise. However, the noise level is still higher than that of inverter generators by far.

Inverter generators

Inverter generators are relatively a recent invention. An inverter generator is composed of an engine, an alternator, a rectifier and an inverter. The fuel runs the engine's motor that is attached to an alternator to produce high-frequency 3-phase AC, which has to be rectified to be picked by the built-in inverter that has a DC input. The DC power is then picked by the inverter and converted to a steady AC power that can be used in various electric appliances.

Between an inverter generator and a conventional generator, which is which..?

Your choice may boil down to what you are powering. There are many other important considerations that you should look at, including your budget. Conventional generators significantly differ from inverter generators in terms of size and weight, quality of energy, run time, noise level, power, and price. Let's look at these dissimilarities:


Here is a quick outline of the differences between conventional generators and I-generators:

#1 Size and weight

Inverter generators are generally small and light. They are pretty portable and stow away. You can easily transport an inverter generator in your car.

Conventional generators are quite bulky and heavy. To relocate them, you will need a big metal frame and wheels. While they can technically be moved, conventional generators lack convenience factor that you find in inverter generators.

Among the three, a silenced generator is probably the bulkiest to handle due to the acoustic cabinet that encloses it.

#2 Fuel efficiency and run time

The run time of a generator is determined by the size of the fuel tank. Conventional designs are big and thus can accommodate a sizeable fuel tank. This means that they have relatively long run times. Inverter generators are compact and lightweight, meaning they can't accommodate big fuel tank and thus have shorter run times.

Inverter generators use a technology that allows them to automatically adjust the engine speed to produce only the power needed. They make a better use of fuel, which can go up to 40 percent. Inverter generators are actually about 20 percent more efficient than conventional counterparts. High efficiency also means that inverters produce lower exhaust emissions. Conventional generators run at 3600rpm regardless of the load.

#3 Noise

Inverter generators are designed with quiet engines, in-built special mufflers, and sound-dampening technology that reduce noise to very low levels. The ability of inverter models to regulate the power produced using microprocessors make it possible for the engine to throttle back when the need arise, saving fuel and significantly reducing noise. I-generators run as low as people conversing.

A conventional generator's engine at a constant speed, which means the engine throttle up when the load is heavy, making it very noisy. Old-fashioned models can make noise as high as that a chainsaw. Silenced produce lower noise range or decibels due to the acoustic enclosure that dampens the sound.

#4 Maximum power output

You can get a conventional or silenced generator with a power rating ranging from 500 watts up to 50,000 watts and higher. They are the best option when a large amount of power is needed.

I-generators are less powerful, which means that their maximum output possibilities are more limited. The models available have a rating of 1000 to 4000 watt. So don't count on an I-generator to power your welder.

#5 Quality of power produced

The engine of an inverter generator is connected to an efficient alternator, a device that produces AC electricity. The rectifier picks the AC power and converts it to DC power. The capacitors smooth it out before it is inverted back into clean AC power. I-generators can produce steady and reliable clean AC power regardless of the engine speed.

With conventional generators, the alternator's output is directly connected to the load, without processing. This means that the quality of the power produced is pretty low compared to their I-counterparts.

Many electronic products today use some forms of microprocessors. Examples include phones, computers, printers, DVD players, kitchen appliances, TVs among others. These microprocessors are easily affected by the quality of power they use. This gives an inverter generator an upper hand when it comes to products that require clean power.

#6 Price

An I-generator can be two to eight times more costly than a conventional unit. The high tech used in the 3-phase system and microprocessor controlled rectifiers and inverters make the price to be higher than that of their conventional counterpart. Conventional generators are not only cheaper but are also less costly to repair.

So what should you buy?

Understanding the difference between inverter and generator will help you settle on the better option. Inverter generators come with many advantages: convenience, fuel-efficiency, small design, much quieter operation, and controlled power output. Conventional generators have only two advantages: higher power output and lower price. I-generators are, therefore, a better plan for your off-grid power needs.


This PDF provide a closer look at inverter generators.

This Honda web page provides rich information on the technology used in inverter generators.

This PDF by Tech Doctor provides information on inverter vs. generator.