Elyas Bakhtiari is a freelance writer currently working with long-running blog and green shopping site, Sustainablog. His guest post explores the difference between dishwashers & hand-washing and shares how going green can save you money.
If you haven’t really looked into energy efficient dishwashers, you may assume that no matter how efficient any given model is, it will still waste more water and energy than simply washing dishes by hand. Even the quickest dishwashers run for nearly half an hour, and taking a few minutes to fill a sink for some hand scrubbing intuitively seems less wasteful.
But that’s not the case, according to ENERGY STAR (a joint program of the U.S. Environmental Protection Agency and the U.S. Department of Energy). An ENERGY STAR dishwasher uses “less than half as much energy as washing dishes by hand and saves nearly 5,000 gallons of water a year.” To be more specific, the agencies estimate that lifetime water and energy costs of hand washing are around $754, compared to just $323 for an energy efficient dishwasher.
The vast majority of the energy used when washing dishes goes to heating the water, and energy efficient models have cut the amount used down to just a few gallons. ENERGY STAR qualified dishwashers are required to use no more than 5.8 gallons of water per cycle, and many newer models use significantly less than that.
Still, you might think that 5.8 gallons would more than fill up a sink for hand washing, and maybe if you’re very conscious about your water consumption, you could wash your dishes with just a couple of gallons. But that is far from the norm, according to a study out of the University if Bonn, Germany, (PDF) that measured the environmental effects of dishwashing.
After observing the manual dishwashing habits of 113 people, the researchers estimated that “the average consumption to clean 12 place settings of dishes was measured to 103 litres (27.2 gallons) of water, 2.5 kWh of energy and 79 minutes time.” So, for the average person, the energy efficient dishwasher seems like a no-brainer, right? Well, that depends in part on how you use it.
Most of the efficiency estimates are based on optimal use, which doesn’t include additional steps like pre-rinsing or heat drying, which can add to the total energy used. Rinsing alone can use up 20 gallons of water before the washing even begins. Most energy-efficient models recommend scraping food off of dishes before loading them. If you’re concerned about the overall environmental impact, and not just energy use, then the cleaning products you use also make a big difference.
Seventh Generation, for example, offers dishwasher gels and powders that are phosphate free and biodegradable, making them much greener than conventional detergents. The bottom line is that while energy efficient dishwashers can be more environmentally friendly than hand washing, both can be improved with a little extra effort. Check out other tips about how to make your dishwashing greener, no matter which method you currently use.