Also, isn't heat (from a physics perspective) considered a by product, or mark of inefficiency? An incandescent lightbuld uses part of the energy input to make heat, which is inefficient. An LED light makes much less heat, and is much more efficient (as a measure of energy input vs light output).
Efficiency is not counted that way (excess heat vs work done) in semiconductor chips... These have high resistance and thus practically all energy passing through them is converted to heat. If a chip consumes 10w of energy, then it also produces ~10w of heat.