There’s no question that dishwashers are efficient users of water – they’re more water-efficient than washing by hand – but how do they fare in terms of energy efficiency? And will the energy star rating give you a simple answer to that question?
Well, it’s complicated. And unfortunately energy star ratings aren’t always a helpful way to find an energy-efficient dishwasher. (See below to find out why.)
So what’s an environmentally or budget-conscious consumer to do?
Energy star ratings aren’t always a helpful way to find an energy-efficient dishwasher
“When you’re shopping for a new dishwasher, don’t just look at the energy star rating – it’ll only give you part of the picture,” says CHOICE dishwasher expert Denis Gallagher.
“But don’t buy solely on performance either if energy efficiency is important to you.”
We’ll talk you through the ins and outs of energy efficiency. Plus, exclusively for CHOICE members, we’ll tell you which dishwashers are the most energy-efficient, and which energy-efficient dishwashers perform the best (hint: they’re quite different lists).
On an Energy Rating Label, you’ll find two numbers: the energy star rating, and the energy consumption.
Energy star rating
Image: Energyrating.gov.au.
This helps you compare how energy-efficient an appliance is compared to others about the same size.
The more stars, the more energy-efficient the dishwasher is in comparison with other models that are around the same size and capacity.
To compare apples with apples, you should only use the energy star rating to compare similar-sized dishwashers.
A dishwasher with a five-star rating will use less electricity than a similar-sized one that has a three-star rating.
In our detailed dishwasher reviews, we score each model on its energy efficiency – the amount of energy used per place setting. The less energy a dishwasher uses, the better it scores.
Energy consumption
Image: Energyrating.gov.au.
This is an estimate of how much electricity the appliance uses each year.
For dishwashers, it’s calculated based on using the dishwasher seven times a week, plus the energy it uses in standby mode.
If you only run your dishwasher a few times a week, you’ll use less electricity than what’s on the label.
Sounds confusing?
We’ve done the maths so you don’t have to: our detailed dishwasher reviews include running costs over 10 years for each model, so you can see which ones are the cheapest to run.
How we calculate dishwasher running costs
The 10-year running costs are an estimate of how much the dishwasher will cost over 10 years for electricity and water if you wash a full load on a normal cycle. It’s based on electricity costs of 40c per kWh and water costs of $2 per 1000L
Why you shouldn’t buy on energy star ratings alone
When you’re buying a new appliance, you might think you should just look for the one with the highest energy star rating.
Unfortunately it’s not quite that simple.
Most energy star ratings are based on the dishwasher’s ‘eco’ mode. That’s because it’s the most energy-efficient program, which helps manufacturers get the highest star rating for each model.
However, most people use the default mode on their dishwashers (also known as normal or auto mode), so they may not get the same levels of energy efficiency.
We test dishwashers using the default, normal or auto mode, so our results are based on real-world use.
CHOICE tip: If you take a look at the energy star rating sticker, it’ll tell you which program and settings were used to calculate the results.
Here’s the bad news: if you want stellar performance, you’ll probably need to give up on your dreams of energy efficiency.
Dishwashers that do a good job of drying your dishes tend to use more electricity.
The hot water in the dishwasher heats up the crockery, which helps it dry. More heat means better drying, but it also means more energy used.
An energy-efficient dishwasher won’t necessarily give you the best performance – and a dishwasher that delivers the best performance probably won’t be especially energy-efficient.
If you want stellar performance, you’ll probably need to give up on your dreams of energy efficiency
Your best bet is to try to find the sweet spot between energy efficiency and performance.
When we test dishwashers, we assess both performance and energy efficiency, plus running costs, water use, energy use and more so you can find the best dishwasher for your needs.
We independently test and review dozens of new dishwashers each year in our onsite labs, and our experts know exactly what to look for to help you find the best product.
Our detailed dishwasher testing data is available exclusively for CHOICE members. If you’re not yet a member, join CHOICE to get instant access to all of our expert, independent reviews, from fridges and freezers, toasters and TVs, kettles and cots, and more.
Or log in to unlock this article and find out which energy-efficient dishwashers are our experts’ top picks.
Alice Richard is a Content creator and marketer. Alice writes on a range of topics, from health insurance to heaters and BBQs to bargain-hunting, always with the aim to help consumers find the best products to buy, and which to avoid.
Alice can take vast amounts of data from CHOICE product tests and turn it into content that is easily digestible and fun for readers.
Alice has a Bachelor of Arts from the University of Queensland.
Alice Richard is a Content creator and marketer. Alice writes on a range of topics, from health insurance to heaters and BBQs to bargain-hunting, always with the aim to help consumers find the best products to buy, and which to avoid.
Alice can take vast amounts of data from CHOICE product tests and turn it into content that is easily digestible and fun for readers.
Alice has a Bachelor of Arts from the University of Queensland.
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