What to Look For
Even for conscientious consumers, getting an eco-friendly oven likely isn't at the top of your priority list. An oven is only used intermittently, and seldom are all of its functions employed simultaneously. Compare that to say, your fridge, which is always on, all the time—cooling the entirety of its interior. That said, there are some things you can do to make sure your oven is as environmentally sound as possible.
For starters, if you're just looking at gas or conventional electric models, it's somewhat hazy territory. Gas isn't a terribly efficient energy source, both in terms of converting the gas to energy and transferring heat to your cookware. While electric models can transfer heat more efficiently, the heating elements take more time and energy to reach their maximum temperatures, compared to gas.
By far, the most eco-friendly type of range is induction. This technology uses magnetism to directly heat your cookware, which is not only quick, but also cheaper in its energy consumption. The downside, however, is it will only work with steel, some stainless steels, and cast-iron cookware.