Part of the expense of running your dishwasher involves heating the water. To minimize those costs, don't run your dishwasher until it's full. Don't rinse dishes before you load the dishwasher; merely scrape them clean into the garbage or garbage disposal. And make sure you're water heater is set to 120°, so you're not using more natural gas then you really need to get clean dishes.

Skill Level: Basic
It's easy to save energy by using your dishwasher the smart way. This appliance uses about the same amount of energy and water per load, no matter how many dishes are inside, so wait until it's full to run it.
Cost Range: Free
Running your dishwasher as energy-efficiently as possible won't cost a thing.
Savings: $40 annually
Besides saving water and natural gas, you'll cut down on heat generation when you choose no-heat drying, which can be kinder on top-rack plastic dishes, too.