When it comes to washing dishes, you might guess that it is more environmentally friendly to wash by hand than by machine. But that's actually not the case.

A study by German researchers at the University of Bonn showed that most modern dishwashers actually use as little as half the energy, a sixth of the water, and less soap than even the most conservative hand-washing techniques.

Green Dishwashers

Get the most out of the energy and water used to run your dishwasher by washing full loads. If your machine has an energy-efficient setting, use it. If your dishwasher doesn't come with that option, you can simply shut the machine off after the final rinse and let it drip dry, with the door open. If you are in the market for a new dishwasher, be sure to choose an Energy Star model that uses less energy and water than comparable models.

Hand Washing

If you need to wash dishes by hand, use as little water as possible. Don't leave the tap water running. If you have a double basin sink, fill each basin halfway or less — one with soapy water to wash and one with clean water to rinse. If you only have one basin in your sink, just give your dishes a quick burst of water each time you need a rinse.

When choosing soaps and detergents, whether for the sink or the dish-washer, look for all-natural brands, like Seventh Generation or Ecover. Natural soaps are cheaper and more widely available than ever before, and they are far less damaging to the eco-system.