How do you wash your dishes? Everyone does it differently, so there’s no clear winner in the energy efficiency stakes when it comes to choosing between hand washing or using a dishwasher. Read on to discover some of the key variables involved, along with some tips to help you save energy whichever method you use.
In this guide:
How much energy does a dishwasher use?
How to choose an energy-efficient dishwasher
Dishwasher versus hand-washing: cost
Dishwasher versus hand washing: how to hand-wash more efficiently
Dishwasher versus hand washing: how to use your dishwasher more efficiently
The verdict: are dishwashers worth it?
Beyond using an energy-efficient dishwasher, how can I save energy at home?
Being a major appliance, dishwashers can take up a large percentage of your electricity bill. The Energy Saving Trust works out the average annual running costs to be between £37 and £48 (this is less for slimline dishwashers – around £23-£37). The most efficient models on the market – rated A+++, have annual running costs around £7 less than the lowest rated dishwashers of equivalent size.
According to the Energy Saving Trust’s At Home With Water report, hand washing dishes makes up 4% of the average household’s water use, while using a dishwasher only accounts for 1% of our water bills.
The amount of water used by a dishwasher will depend on its age and efficiency rating. For example, a dishwasher manufactured before 2000 would use an average of 25 litres per cycle, while a new one would use 10 litres per cycle on an Eco setting. This difference is due to modern dishwashers reusing water in a cycle, rather than consistently piping in hot water.
But how does water use vary when looking at a dishwasher versus hand washing? A modern dishwasher uses 11 to 13 litres of water per cycle on average, while washing by hand can use up to nine times that amount if you rinse everything under a running tap.
Of course, people’s different dishwashing habits can make this exact amount difficult to predict. If you pre-rinse your dishes before popping them in the dishwasher, for example, then you’ll use significantly more water.
Electricity use will also vary depending on the age and efficiency rating of your appliance. According to the Centre for Sustainable Energy (CSE), modern dishwashers have an average power rating of 1,050 to 1,500 watts. You can see the exact kWh on the appliance’s energy rating. Overall, a dishwasher isn’t a very energy-intensive appliance, particularly if you only run it once per day.
There’s wide variation in the efficiency of dishwashers. Whether you’re purchasing your first dishwasher or upgrading an older model, look for appliances with an A+++ rating for maximum efficiency. These are designed to use less electricity and water.
Energy-efficient dishwashers are cold-fill only, which means they take in cold water from your main supply and use an interior heating instrument. Older models will take in hot water from your supply, which uses more energy.
It’s also important to think about size when choosing an energy-efficient dishwasher. Full-sized dishwashers will be more water and energy-efficient, with higher energy ratings to match. However, the efficiency is based on filling the machine to its capacity every time you run it. If you live alone or in a smaller household, a compact dishwasher will likely be the most efficient choice.
As with water and energy use, the cost of washing your dishes will depend on your habits. Generally, your dishwasher will save you money if you only run it once it’s fully loaded. A single dishwasher cycle costs the same amount as leaving the hot water tap on for between six and nine minutes.
There is, of course, the added expense of purchasing a new dishwasher to factor in. New models can cost anywhere from £170 to £1,400 on average – a huge variation.
Whether you’re washing your dishes by hand out of preference or necessity, there’s a way to do it more efficiently. Here are a few tips to use less water when you’re doing the washing up.
Fill up a bowl or half of a split sink with hot water and dish soap, and a second bowl or half-sink with clean hot water.
The water should be as hot as you can stand to touch, to properly clean and sterilise your dishes.
Pre-soak dishes in a bowl of hot water to soften and loosen any dried-on bits. This will make you expend less water and energy when the time comes to scrub them clean.
Rather than washing dishes under a constantly running tap, keep them in the bowl of warm water for cleaning.
Use the second bowl of clean water for rinsing, instead of rinsing them separately under a running tap.
Dry your washed dishes with a cloth towel rather than expending paper towels or let them air dry on the counter.
If you follow these tips, you’ll use roughly the same amount of water as the dishwasher!
No matter its age or efficiency rating, there are always ways to use your dishwasher more effectively. Here are a few tips.
Don’t pre-wash your dishes
There’s no need with most modern dishwashers to clean your dishes in any way before you put them into the machine. Rather than rinsing them, simply scrape off uneaten food into your food waste bin.
Use the economy or eco setting
All modern dishwashers include an energy-efficient setting. These use less power by heating the water slowly over a longer cycle, which can reduce energy consumption by up to 20%.
Don’t run your dishwasher until it’s full
When you wash a half-empty load of dishes, you’ll be wasting half of the machine’s water and energy. According to the ‘At Home with Water’ report, only 77% of us follow this rule.
Yes, if you’re using a modern dishwasher properly. Energy-efficient dishwashers are designed to save water, particularly if you run them on the Eco setting, fill them to capacity and don’t pre-rinse your dishes.
If you struggle to fill your dishwasher or have an older, less efficient design, it may be better to hand wash your dishes. However, be sure to use separate bowls for washing and rinsing to reduce the time spent running the tap.
There are a whole host of ways you can save energy at home, down to the type of fridge or freezer you have. Staying with the water theme, though, washing the dishes makes up about 5% of your household water use, but washing clothing is a similar energy-intensive activity.
We’ve already recommended not running the dishwasher until it’s at capacity. The same advice applies to the washing machine. Wash your laundry in full loads, and at low temperatures for more savings. It’s also worth upgrading to a newer model if yours is outdated. Choosing a washing machine with an A+++ rating over an A+ one could knock up to £65 a year off your energy bills.
Using a lower temperature setting on your washing machine is another way to save energy. Save the hottest water setting for when you really need it. Generally, 30 degrees Celsius is sufficient for everyday clothing, but those with stubborn stains will need a higher setting.
After a wash, air-dry your garments when possible. Drying clothes on a washing line outdoors or a drying rack indoors is completely free of cost, and it’s the clear eco-friendly choice. When you do need a tumble dryer, use one with a built-in sensor that tells you when your clothing is dry. And as with dishwashers and washing machines, choose a model with a higher energy rating to save the most money.
Last updated: 27 November 2020