Few other methods of heating can achieve those heights. Blowing hot air, for instance, only gets you about 10,000 watts per square meter. Conduction (like using a frying pan) can get very hot, but it's not as fast, and there are problems creating a uniform crust. Keener and Farkas thought of using radiant energy, like the kind that comes from the sun. They settled on infrared, which doesn't penetrate food as far as microwaves, but shares some similarities.