According to The California Energy Commission, microwave ovens use half the energy conventional ovens do, making the microwave a much more time efficient and energy efficient appliance for cooking smaller meals. You can save money and energy by adjusting your microwave's cooking power. In fact, you can still cook many of the foods you normally cook or defrost and not have to worry about overcooking food, just by lowering the cooking power on your microwave. By making this simple change, you can conserve energy and reduce the amount of energy expended by your microwave, which may make it last longer.
Use the keypad on your microwave to press the numbers that coincide with the amount of time you wish to cook your food for.
Locate the “Power” button on your microwave. This button is located on most microwaves among the other functions of the microwave, such as "defrost," "cook," "stop" and "start" buttons.
Press the “Power” button. Once you press the power button, a number will show up on the microwave display. Depending on what type of microwave you have, the number will differ; however, most microwaves display 100 percent as the default cooking power.
Delete the pre-set percentage by immediately pressing the corresponding numbers of the power percentage you want your microwave to cook at. If you want the microwave to cook at 50 percent of its power, press the numbers "5" and "0."
Press the “Start” button after you have entered the power percentage you want your microwave to cook at. The microwave will turn on and begin cooking your food.