Published by Marina Hoag under Energy Efficiency, Kitchen

Anticipating a lot of dirty plates after dinner today? Dishes covered in runnels of turkey, gravy, and stuffing? Sweet potato pie plates all sticky with marshmallow crust?

You may wonder if washing by hand might be the most environmentally friendly way to clean your dishes, but according to a German study, dishwashing by hand uses more energy and water than the average dishwashing machine.

But maybe your old dishwasher is below average. An older model may still be doing its job of washing and rinsing, but be secretly wasting a lot of energy in the water-heating process. 80% of the energy used in dishwashing goes to heat water, not to move it. How would you know?

Energy Star qualified dishwashers, which meet strict energy efficiency guidelines set by the US Department of Energy (DOE) and the Environmental Protection Agency (EPA), are at least 25% more energy-efficient than federal minimum standards dictate. The Energy Star program advises replacing any pre-1994 dinosaur of a dishwasher to save energy and $30 or more per year on your utility bill.

According to the Energy Star website, Asko and Bosch offer the most energy-efficient models:

Water efficiency is another side of the eco-friendly dishwasher. Efficient dishwashers should use less than five gallons of water per wash, while older models can gulp as much as 15 gallons.

Of course, short of upgrading your machine, there are also many practical, common-sense ways to make washing dishes more environmentally friendly.

One, use environmentally friendly dishwasher detergents to aid you in your “greenwashing” (the good kind, not the bad, mind-numbing kind). National Geographic’s Green Guide conducted a survey of 380 people who gave Seventh Generation brand the highest rating. Another brand not mentioned in the survey is Planet Automatic Dishwashing Detergent. Hopefully, we’ll have more options as demand grows for safer soaps.

Two, save water by washing full loads only, just as you do for laundry.

Three, don’t bother pre-rinsing your dishes. Older-generation dishwashers weren’t nearly as efficient as current models, and many of us hold onto old habits.

Four, use the air-dry option instead of the heat-dry feature.

Five, if your dishwasher has a water temperature setting, move it down to 120 degrees Fahrenheit.  You’ll still effectively kill bacteria while saving 84 kilowatts of electricity per year, according to Hotpoint.

If you’re in the market for a new dishwasher, you’ll want to mine the Web for further research.  In addition to the Energy Star site, help is available at sites such as Planet Green, Dishwasher Review, Consumer Reports, Consumer Search.

But in the meantime, take a moment to savor that wonderful post-prandial glow from all the Thanksgiving tryptophan you’ve ingested today.