How to choose the right generator – the ultimate guide

Do you want to buy a generator but you have no idea where to start? With so many options it can seem very confusing. How do you choose the right generator for your needs?

Do I need an inverter generator? 3 phase generator? How many kVA?

Have no fear!

This helpful guide is the best place to start and will give you a simple overview of the most important things to consider when purchasing a generator.

Now let’s get cracking!

Part I – Generator types

It’s useful to put generators into a few categories:

inverter generator, trade generator and diesel generator

Recreational – These generators are the lightest, quietest and most efficient models around. They are designed to be super portable and convenient. They are popular for recreational activities such as camping and caravanning. But many people use them for outdoor events, commercial and backup purposes too. These range from 1 - 6kVA in size.

Trade/Backup – These models are bigger, heavier and louder than recreational types. They are also available in a much greater range of sizes. They typically have an open, roll frame design. They are available with a wide variety of features including inverter models, different start options and petrol or diesel powered units. These range from about 2.5 – 16 kVA.

Stationary – These are large units for heavy commercial/backup usage. They are diesel powered and available in single, 2 phase and 3 phase options. They are designed to run for extended periods of time and provide as much power as is required, even for large scale industrial or agricultural operations. Smaller stationary models are also popular for home and business backup. These start at about 6kVA.


Inverter – Inverter generators create the cleanest power available, known as pure sine wave power because of the stability of the current wave. They are the best for powering sensitive equipment such as computers. They are often lighter, quieter and more efficient than conventional (non-inverter) generators. Recreational generators are nearly always inverters, and trade/backup style inverters are also available.

An Automatic Voltage Regulator prevents spikes in voltage and is another way of protecting your appliances. They are used on trade/backup and stationary generators.

3 phase – 3 phase power is used to power some buildings as well as larger equipment. These are used for commercial and backup purposes. Stationary generators are often 3 phase. If you want to power your home or worksite and you aren’t sure whether you need 3 phase power, it is best to consult an electrician (this is recommended if you want to power a building in any case).

Petrol powered – All inverters and many trade/backup generators are petrol powered. They are generally cheaper, lighter and quieter as well as being available in a much larger range of models.

Diesel powered – Available in trade/backup models and all stationary units. Diesel engines are more efficient and reliable, so are best suited for long operation.


Specialty generators: 

          Tractor pack – PTO driven generators that are popular on farm sites. Powered by tractors they are a convenient solution.

          Welder generators – A generator combine with a welding unit in a single frame. It can be used for either purpose.

Part II – How to size a generator
Part III – Generator features


We hope this guide will be useful in helping you to choose the right generator for your needs. It gives you an introduction to the all of the key concepts. We look in more depth at certain topics in other articles and videos so please have a look at those too.