I've worked on many products which had hoped to incorporate it, but ultimately didn't. It does work well for applications like you highlight which require very

I've worked on many products which had hoped to incorporate it, but ultimately didn't. It does work well for applications like you highlight which require very very low power levels for very intermittent use. Things like a desk calculator or a IR remote. As soon as you need any kind of "real" power for anything other than intermittent use it becomes a problem. You can only beam so much power without cooking everything in between, usually that amount of power is less than we need.