Best Generators

How do generators work?

Generators work by converting mechanical energy into electrical power. They do this using two main parts. An internal combustion engine uses petrol, diesel or propane fuel, and powers an alternator, which produces an AC current that provides the electricity.

Why would I need a generator?

If you need back-up power at home, you can buy a generator for blackouts. This means you can switch on some lights and keep the fridge running even if the power lines are down.

The second main use of generators is as a portable power source while camping and caravanning. Inverter generators are handy as recreational or camping generators. They let you charge selected appliances and devices like your phone or laptop, even when you’re off grid.

You can also get generators for commercial and industrial use, but these are beyond the scope of this guide.

Camping and caravanning

If you’re packing a generator for a portable power source on your adventures, a portable inverter generator for camping is the best pick.

What is the difference between a generator and inverter generator?

A conventional generator or regular portable generator is also known as a single-phase generator. That’s because the alternator provides AC power that’s ready to use. This is the type of AC power that electricity companies provide to homes on-the-grid.

An inverter generator, on the other hand, is also known as a three-phase generator. It uses the alternator to produce AC power, but then converts this into DC power using a microprocessor, and then back into AC power. This has a number of advantages in a camping scenario, with relatively few downsides.

Home back-up power supply

These conventional generators can be either portable or stationary generators. When properly set up, either of these will be capable of providing emergency power for your home when you need it. (An inverter generator isn’t suitable for home use, however).

Portable generators for home use

You can plug an extension cord into selected home appliances, to connect them to the generator. You don’t need to connect the generator to the main electrical switchboard.

However, using a portable generator for home use is generally not considered an effective long-term solution. Portable generators used to power a home can cause up to 25% total harmonic distortion, when 6% THD is considered the acceptable limit for a smooth current.

For the power to be safe, you’ll also need to have a transfer switch installed by a licensed electrician.

A transfer switch ensures that the house won’t accidentally get electricity from both the generator and mains power at the same time, once the power comes back on. This overload of electricity damages appliances, and poses a fire or electrocution risk.

• An automatic transfer switch instantly connects the generator to your house when there’s a power outage, and disconnects it again when the electricity comes back on. Without it, the generator keeps feeding power to your house along with mains power. This causes an overload of electricity that can damage appliances, as well as bring a risk of fire and electrocution.
• A manual transfer switch does the same job, but you’ll have to remember to manually turn it on and off before and after a power outage.

Stationary or permanent generators

If you're asking the question, 'which generator is suitable for home use?' generators that are made to be permanent generators for home standby use are better for long-term use than portable generators. They are usually powered by natural gas - mains gas or LPG.

What size generator will I need?

A generator’s size is measured in kVA, which refers to the maximum amount of power it can provide.

What else to look for in a generator

Fuel capacity

If you’re out and about, you don’t want to be preoccupied with constantly refuelling your petrol generator. Check the tank capacity, and divide this by how much petrol is used per hour. This will tell you how many hours you can go until the petrol runs out.

Continuous running time

If the generator you want doesn’t have specs provided for petrol usage per hour, the continuous running time gives a rough indication of how long you can go before refueling.

Note that long running times, e.g. 9 hours for small inverter portable generators, are usually prescribed by manufacturers based on Eco mode. Eco mode may have special conditions, for example that you can only use it at a quarter of the maximum power load.

Portability

If you are taking your generator with you on-the-go (e.g. for camping or caravanning) portability is especially important. This is influenced by the weight, and any handles or a trolley to make it more ergonomically friendly.

Clean electricity

Some electronics, like personal electronics, are frequency sensitive. This means that if the power supply is not smooth, and fluctuates, they can be damaged as a result.

An inverter generator naturally cleans up the electricity with its 3-phase generator system. Pure sine waves make the current even safer for sensitive electronics. Power does not surge unexpectedly, and the inverter will match the wave of electricity as closely as possible. Look for pure sine wave technology, rather than modified sine waves, which aren't the same.

Safety features

These are really important in a generator, when you’re dealing with high voltages. At worst, lack of safety precautions can result in electric fires and electrocution.

Important features include a manual or automatic transfer switch, overload protection - disconnects the power if the combined wattage of electronics exceeds the maximum load; surge protection - protects electronics from voltage spikes, and waterproofing - which is especially important for home standby generators outside.

Price

Generators do not come cheap. However, due to the safety risks outlined above, this is not something you want to skimp out on, as it's not worth the danger to personal safety, or the cost of replacing expensive whitegoods if they get damaged.

An inverter generator that’s $400 would be considered affordable, but they are often pricier, and can be thousands of dollars. A home backup generator will start at around $2, 000 for a small, air cooled generator, up to $15, 000 for a large capacity water-cooled generator. This doesn’t include installation costs.

The bottom line

When buying a generator, ultimately you should balance convenience, capability and cost. The generator should be easy to use for the purpose you bought it for, capable of safely powering all your appliances and devices without risk, and worth its price for long-term use. If all these boxes are ticked, power on and read some reviews to find the right generator today.