In Your Kitchen
Conserving energy is a big part of reducing your impact on the planet. Microwaves heat food much more efficiently than standard ovens and stove tops. They don't require preheating nor do they take as long to cook food. There have been concerns regarding the way microwaves heat food, but there has been no proof that they damage food.
There is concern, however, with respect to the temperature of the food. Because microwaves heat unevenly, you can easily burn your mouth. Heating baby bottles in the microwave is not recommended for this reason.
Other ways to conserve energy in the kitchen include using as small an oven as possible. The larger the oven, the more energy it takes to heat it to the proper temperature. Don't forget, ovens are made to keep heat inside, so you can turn off the oven before the timer goes off, and your food will continue to cook.
Glass and ceramic retain heat better than metal; switching will reduce the temperature as much as 25 degrees. When using the stove, make sure the burner fits the pan; an uncovered burner wastes heat. Always use a lid when heating items on the stove for the same reason.
Cooking plastic in the microwave may cause a chemical breakdown of the material and transfer of chemicals to food. Only use plastics for their intended method. Take-home Styrofoam should not be used to reheat any leftovers. If you really want to play it safe, do not use plastics in the microwave. Put your food on microwave-safe glass or ceramic dishes instead.