At a meeting I attended last week someone asked the question, “Is using a dishwasher more energy efficient then washing dishes by hand. She wondered if the dishwasher manufacturers weren’t the ones promoting the idea that built in dishwashers are the greenest way to handle our dirty dishes.
I wondered if that may be true. Over the years, I have read many articles on this debate and did not really take time to research the sources so I thought I would tackle this conundrum myself.
| Hand Washing | Dishwasher | Energy Star Dishwasher | |
| Water Usage | 2 gallons per minute | 6 gallons per cycle | 4 gallons per cycle |
| Energy | .30 kWh per 2 gallons | 1.59 kWh per load | 0.87 kWh per load |
Here are the stats I compiled from www.energystar.gov
All things being unequal, we must assume the same amount of dishes for the comparison to be accurate. A standard dishwasher holds an eight place setting and six serving pieces.
Can you hand wash and rinse a load of dishes with just 2 gallons of water? If so, then hands down, hand washing can be the greener choice. If so, perhaps you should contact the Guinness Book of records for your amazing dishwashing skills. In the interest of science, I attempted this feat. I used a double sink and filled bowl #1 with 1 gallon of warm soapy water for scrubbing. In bowl # 2, I prepared a 1 gallon jug filled with warm water to use for rinsing. On the counter piled a 4 piece place setting and 2 serving pieces. As my grandmother taught me, I started with the glassware, then silverware, onto plates but I was out of rinsing water. And frankly, the pieces that were done were not sufficiently rinsed to my liking. I then attempted the experiment again with four gallons of water. I kept the same 1 gallon for washing and now had three gallons to rinse. I was able to wash and rinse less than half of the amount of dishes a machine would with the same amount of water. It is hard to beat the machine.
According to the Energy Star website, using a dishwasher “can save you over 230 hours of personal time over the course of a year. That’s almost 10 days!” That’s what I’m talking about.
So the answer is….built in dishwashers win. If you have an Energy Star dishwasher and only run it when it has a full load then it is clear cut. If you have the dishwashing skills of a ninja then perhaps you can beat an older, average machine.
Let’s not forget the reduce and reuse part of the 3 R’s mantra. If we don’t dirty a dish it does not need to be washed so only use 1 glass or cup per day per person. Skip the separate salad plate and just use one plate per person at dinner. Skip the serving dishes all together and serve directly from the pot or pan you cooked in.
Greenest Choice: Energy Star dishwasher run only when there is a full load.
Happy washing!
