The Biggest Energy Guzzlers in Your Home

It’s no fun being slammed with a bigger than expected power bill. Various factors can affect the size of your electricity bill, so it can be hard to pinpoint the main energy guzzlers in your home.

But one simple thing to check is the energy efficiency of the appliances you use regularly. By pinpointing the ones using the most power, you’ll be able to make changes and knock your power bill down to size.

The most energy-draining appliances

Any appliance can waste electricity if not used efficiently, especially ones used regularly. And in the kitchen and laundry, appliances such as stoves, fridges, dishwashers, washing machines and dryers are all big power users.

However, by understanding how much electricity they consume, you can learn to use them more efficiently. Or, if the savings are great enough, consider replacing them with newer more energy efficient models.

But let’s start with an overview of normal energy usage in the home:

Normal electricity usage: what is the average household power usage?

Government statistics show that the average annual energy consumption per Kiwi household has been declining over the past 15 years. This is part of the reason the low-user tariff is being phased out.

→ Related article: End of the Low-User Electricity Tariff

Over the past year, to the end of August 2023, the average Kiwi home consumed approx 7000kWh per annum. At the current average kilowatt (kWh) price of 33.5c that works out to $2345 per year, or just over $195 per month.

Of course, larger households will consume more electricity, while smaller households will, as a rule, come in below average. And keep in mind that usage patterns naturally vary from one area to the other. For instance, consumption on the West Coast is typically lower because most houses are heated using fires, whereas in an area like Canterbury most houses are heated by electricity.

Energy-guzzlers in the kitchen

Oven

Ovens require a decent amount of power to heat up and cook food. For a medium-high heat, 2400kWh is a reasonable estimate. If you cook a meal for an hour, including preheat time, you might expect to spend around $0.80, depending on your $/kWh rate.

Pro tips

The cost of running an oven will increase if you open its door frequently to check food. An empty oven sitting at the right temperature for a long period is also a waste of power – so keep an eye on the preheat light. Check the door seal is in good condition, and that the oven fan is working properly, for both power efficiency and safety.

Also consider using a microwave oven when possible. As they cook much faster than regular ovens, microwaves use less energy for the same result. Take a jacket potato: it can take 45-50mins to bake in a regular oven, but will cook in 6-7mins in a microwave.

Fridge and freezer

A fridge/freezer upright combo will vary in its power consumption based on its size and efficiency. But an average 400L, 3-star energy rated fridge will use around 550kWh per year, and cost $184 to run. For more info on energy efficiency star ratings click here!

Pro tips

Check the seals regularly on both your fridge and freezer, any gaps could mean it’s burning extra power to keep cool. Make sure the unit is running properly, things like strange noises and lack of cold, despite being set low, could mean servicing or replacement is needed.

Fridges also waste power when they aren’t full enough. Big empty spaces need cooling for little purpose. Maybe your fridge is bigger than you need?

Dishwashers

They might not be running all the time like a fridge, but dishwashers get regular, daily use.

A 15-setting dishwasher with a four-star rating used every day will use 247kWh per year. This works out to 23c per load at average power prices, or $83 per year. A similar size machine with only a two-star rating will cost approx double that: 46c per load and $166 per year.

Based on the above usage, the running costs over five years are:

• Two-star dishwasher – $830
• Four-star dishwasher – $415

This is a total difference in running costs of $415

These numbers do give pause for thought, especially when standard kitchen appliances should last between eight and 12 years. Even a half-star difference between models has the potential to lead to considerable power savings over time. So it’s always a good idea to factor star ratings and long-term energy savings into your budget when shopping for appliances.

Pro tips

Make sure your dishwasher is full before you run it. If you have to run it half-full, use a half-load setting, if available. Clean the filter regularly using a brush and hot soapy water. And check the spray-arm holes aren’t clogged. Match the setting to the load. If you have an eco setting, try it for less-dirty dishes and save the default setting for nasty loads.

Energy-guzzlers in the laundry

Of the appliances in an average Kiwi home, washing machines and clothes dryers are often the most energy draining.

Washing machines

Choosing the right size washing machine for your needs is an important initial step to achieving energy savings. The number of washes you do each week, their size and whether you use hot or cold water will also be a factor. 

Before you buy, check the machine’s energy star rating, as this will give you a clear guide to its running costs.

And there can be big differences between models. For example, a 2-star machine can use up to four times the electricity as a five-star machine for the same wash: around 2kWh, instead of 0.5kWh. At 33.5c per kWh, that’s roughly 67c per wash, compared to 17c per wash.

Pro tips

Using a cold wash option is preferable, while loading the machine fully each time will save on the extra cost of putting on another load. Washing on a hot cycle can use up to ten times as much energy as a cold wash.

Check spin speed, machines with a spin speed of 1000rpm or higher will remove a good amount of water, cutting down on drying times. Check for auto-sensing or load-size selection, so you’re not using more water and energy than needed.

Dryers

Clothes dryers use a lot of electricity. A super-efficient 10-star 9kg dryer will consume around 2kWh (67c) per load. While a similar 2.5 star machine can use up to 7kWh ($2.35). 

However, by using your dryer sensibly, and choosing to dry clothes outside on the clothesline, you could save $100 or more over a year.

Pro tips

As when buying a washing machine, look for a model with an auto-sensing feature if you use your dryer regularly, to prevent over-drying. While heat pump dryers are the most energy efficient, they are also the most expensive machines.

→ Related article: Most Energy-Efficient Clothes Dryers

Energy-guzzlers in the lounge and bedroom

Home entertainment gadgets and heat pumps also use energy, but they aren’t the home’s biggest energy guzzlers.

Heat Pumps

Although the initial outlay for a heat pump can be expensive, they are the most economical way to heat a home. As the figures below show, even used six hours per day, for four months of the year, their annual running costs are low.

However, as with all appliances, the heat pump’s star rating has a big effect on its running costs:

Based on unit with a heat output of 4kW

Pro tips

• Timer – can be used to warm the room just before you get home, and set to switch off the heat pump when you don’t need it
• Thermostat – set it above 18°C to combat damp and mould, and below 21°C to save power
• Don’t crank up your heat pump to full blast to heat a room quickly. Give it time to bring the room up to temperature
• Heating mode – should be used. Auto mode has the potential to waste energy, constantly switching between hot and cold
• Very cold weather – set the fan to “auto”, as “low” and “quiet” won’t deliver full blast
• Filter – every few weeks clean the filter with a vacuum cleaner and/or warm water

Televisions

Over the years, televisions have steadily grown bigger and slimmer. They are far removed from the energy guzzling plasmas of just a decade ago.

For our comparison, we looked at the running costs for a 50” model, and the numbers involved are very small, ranging from just over 3c per hour for a two-star energy rated TV, to around 1.5c per hour for a six-star screen and 1c per hour for a highly efficient seven-star rated TV.

Pro tips

Despite being cheap to run, there are still savings to be had. Of course, switch off your TV when it’s not in use. Brighter screens tend to use more energy, so check yours is set to a recommended or a lower brightness. And enable ‘automatic power down’ or ‘eco solution’ mode, to turn off your TV automatically when nobody’s watching.

Computers and laptops

Like modern TVs, laptops use very little power. A laptop is designed to be used with its own internal battery, so is very frugal, using between 0.025kWh and 0.060kWh. That’s just between 0.83c and 2.1c per hour to run.

However, if you’re running a big, powerful desktop model or gaming rig, they can use considerably more electricity, between 0.4kWh (13c per hour) and 0.7kWh, (23c per hour) depending on your set-up.

Pro tips

Although, individually, laptops and regular computers don’t use much power, if lots of computers are in use, and they are plugged into screens and other hardware, electricity usage can add up. So when not in use, make sure you switch off computers, printers, etc. 

Compare Power Companies

If you’ve reached the end of this story, it’s clear that you’re interested in finding a better power deal. And a great way to start is by checking out Canstar’s latest Star Ratings awards. Based on the satisfaction ratings of real-life Kiwi electricity consumers, they rate NZ power companies for customer satisfaction and value for money. See the table below for some of the results, or click on the button below for the full results of our survey.

Canstar Blue’s latest review of NZ power companies compares them on customer satisfaction. The table below is an abridged version of our full results, available here.

Compare Power Companies

About the author of this page

This report was written by Canstar’s Editor, Bruce Pitchers. Bruce has three decades’ experience as a journalist and has worked for major media companies in the UK and Australasia, including ACP, Bauer Media Group, Fairfax, Pacific Magazines, News Corp and TVNZ. Prior to Canstar, he worked as a freelancer, including for The Australian Financial Review, the NZ Financial Markets Authority, and for real estate companies on both sides of the Tasman.