Which method uses less energy? Well, it depends on how old your dishwasher is, what settings you use and how you wash dishes by hand. Studies are showing more and more that, when used to maximize energy-saving features, modern dishwashers can outperform handwashing.

Water use - Dishwashing by hand using two sinks full of water (washing + rinsing) uses around 15-20 litres per load.  It may be more for larger loads and the amount of water goes up considerably if you rinse dishes under running tap water instead of using a filled sink or bucket.  Modern dishwashers use around 10-45 litres of water per load, depending on their efficiency and the setting used.

Scrape, don’t rinse - Modern dishwashers do a great job of cleaning even heavily soiled dishes. Don’t be tempted to pre-rinse dishes before loading; simply scrape off any food and liquids and let the dishwasher do the rest.

Wash only full loads - The dishwasher uses the same amount of water whether it’s half-full or completely full. Putting dishes in the dishwasher throughout the day and running it once in the evening will use less water and energy than washing dishes by hand throughout the day. If you find that it takes a day or two to get a full load, use the rinse and hold feature common on most newer models. This will prevent buildup of dried-on food while saving time and water compared to pre-rinsing each item.

Use energy-saving options - Pay attention to the cycle options on your dishwasher and select the cycle that requires the least amount of energy for the job. Use the no-heat air-dry feature on your dishwasher if it has one. If you have an older dishwasher that doesn’t include this feature, you can turn off the dishwasher after the final rinse cycle is completed and open the door to allow drying.

Buying a new dishwasher - Look for the most water and energy efficient model that you can find (start by narrowing it down to the Energy Star models, then get the best one that you can afford).

In the office - At Omicron, we wash full loads in Energy Star compliant dishwashers.  Therefore our most efficient method is the dishwasher!  For best practice, skip the hand washing while in the office to save on water and energy usage.