The most basic type of cooking uses an open flame as the heat source, with the heat transferred into the pan through “conduction.” Modern propane or gas stoves use the same principle. Traditional electric stoves use the same principle, except the the heat source is created by running electric current to heat a highly resistive coil.
Electric induction stoves use an entirely different principle — they create a variable magnetic field vi an embedded coil and energy is then transferred to a ferrous cooking pot via this “inductive field.” This method is much more efficient than even the best “improved charcoal cookstoves” — recent measurements have shown a measured “boiling water” efficiency greater than 80%. This method only works when the pots are magnetic — cast iron, hard steel and stainless steel with a special magnetic plate included will work, but the system will not work with aluminum or standard stainless pots. If a magnet will stick to the bottom of the pan or pot, it will work with an induction cookstove.
This technology has been used in industrial applications for many years, and the first induction stoves for cooking applications appeared ten years ago or so, although they were very expensive. In the past few years, however, the cost of this technology has dropped dramatically, and a single burner induction cookstove now costs less than $50 in single quantity at a retail store, with wholesale purchases less than half that cost.