Are dishwashers bad for the environment?

  • Date: May 14, 2022

When it comes to eco-friendly credentials, dishwashers have a bad reputation. People assume that they are a lot worse for the environment than hand washing the dishes – but is this the case or is it a myth? If you, too, get a pang of guilt every time you use the dishwasher read on, you might even be surprised…

Do dishwashers use more water than washing by hand?

I don’t know about you, but I feel quite virtuous washing the dishes by hand – like I’m taking one for the team and doing my bit for the planet. Surely washing the dishes in the sink saves water?!

Well, dishwashers sound like they are using endless amounts of water, but they actually filter and reuse the same water for the duration of the cycle! Newer models are particularly good in this department. Energy Star certified, appliances deemed as energy efficient, can use as little as 3 gallons of water per cycle. Compare that to sink washing which can use up to a ridiculous 27 gallons per load, although I’m not sure the level of splashing about needed to use that amount of water.

The new technologies developed over the years in the dishwasher world have definitely paid dividends. Dishwashers produced in the early 1990’s used about 10 gallons per load. This is a significant step forward for the industry, especially important now due to consumers increasingly asking questions about the eco-friendliness of an appliance before purchase – it has become one of the main attributes searched for.

Do dishwashers use more energy?

The electricity that a dishwasher use is largely dependent on the make, model and age. You may be pleasantly surprised that an up-to-date dishwasher only uses between 1050 and 1500 watts, according to the Centre for Sustainable Energy (CSE). To put this in perspective, this is approximately the same as a hairdryer!

Most people perhaps forget the fact that washing dishes by hand uses energy – to heat the water – anyway. So, if you factor in the human energy too, and the energy it takes arguing about who is going to do the dishes, it is actually a close-run thing…

If the reason you are concerned about energy usage is the higher bills, you don’t need to worry too much. The average family expense to run the dishwasher can be as little as $35 (if used with full loads), although the price of the initial outlay needs to be factored in too – the best models can cost over $1000. Dishwasher tablets also tend to have a higher cost than wash-by-hand detergent.

Tips to make it even more eco-friendly

Don’t rinse!

Common practice amongst people who had the earlier models, pre-rinsing dishes before placing in the dishwasher is now not needed. It is estimated that pre-rinsing uses an incredible 6000 gallons of water per household every year! Dishwashers have sufficiently advanced to deal with increased soilage! And in fact, some models now have a turbidity sensor (also known as a soil sensor) – this measures the level of sediment in the water and alters the cycle to reflect how dirty the dishes are. Quite significant progress from the first models.  

Even the fanciest dishwashers don’t work miracles though, so any remaining food should be scraped into the compost bin (if compostable, of course) to avoid a clogged filter or contamination of newly-clean dishes. 

Ensure a full load

Less resources are wasted if you wait until you have a full load before turning the dishwasher on. If you are home alone for the weekend or have eaten out and not accrued many dirty dishes, it might be best just to do a quick wash by hand! Be sure to wash them in the right order though, cleanest first, so you don’t need to refill after a couple of especially messy plates.

Strategic placement!

Make sure that your dishwater works to its optimum level by placing dishes correctly – this will ensure that some dishes don’t need to have a second round of washing, and which will use more energy than necessary. Most importantly, make sure the most soiled surfaces are facing the spray and, although tempting, don’t overfill it – even spacing will ensure that no surfaces are missed. 

The bottom line

So, there you have it, dishwashers are actually better for the environment than washing the dishes by hand. Or at least, they can be; a lot depends on how wasteful you are when washing the dishes in the sink. Up-to-date dishwasher models are especially energy and water efficient. Avoid the water pre-rinse that many people insist on and wait till you have a full load before pressing ‘start’ – this will maximize how kind it is to the planet. Either way, dishwashers are not as bad as many people think – and this is a blessing for the laziest among us. So next time you hear the water gushing through the dishwasher you can relax, guilt-free.