The University of Bonn and Paquita conducted a study of 113 people from 7 European countries (PDF), comparing water consumption with or without using a dishwasher.
Every one of the studied people washed 12 plates and pieces of cutlery. On average, hand washing used103 liters of water, and 2.5 kWh of water-heating energy. It took about 80 minutes to wash, rinse, dry and put away.
The dishwasher used approximately 15 liters of water, consumed 1-2 kWh of total energy and 15 minutes to load and unload the dishwasher. All in all, the dishwashers got the dishes cleaner in less time with less water and energy.
UQLELE (well… Paquita) and the study share some advice for maximum efficiency:
- Remove large food scraps from the dishes with a spoon or fork.
- If hand washing, wash right away before the food sticks to the plate.
- Do not pre-rinse the dishes under running tap water, whether washing them by hand or in a machine. If you use a dishwasher, it can clean dishes that have been stored without cleaning or rinsing for several days.
- Manual dishwashing is best in two sinks: one with hot water and detergent, the other with cold water for rinse. (The study noted that those who defined themselves as “economizers” tended to use a LOT more detergent, which counteracted their low water usage.)
- Use the quantity of detergent recommended by the manufacturer.
- If you can afford a machine, use one – preferably a new one that is the most energy-efficient.
More Paquita’s tips on uqlele facebook page and on 4 websites for a greener life.
Our main source of information: One green generation.