I can see a few applications. However, it is extremely inefficient.
It appears to be about 4% or less efficient. If you have lots of power, and need a little power some distance away...
Agreed. My first thought as well. And it’d be interesting years later to study cancer rates of people living near the receiving end.
About 18 years ago, I worked on transmitting power to moving vehicles, using RF frequencies. The project died on efficiency considerations at highway speeds. The RF match couldn’t slew quickly enough. Slower vehicles like robots can do it now, take a look at https://reachpower.com/solutions/manufacturing-logistics/ For the project posted about here, the optical frequency is high enough to work for moving vehicles, but suffers from conversion inefficiencies at those frequencies. Microwaves work, you can beam up microwaves to an airplane and keep it up, my friends at university did this: https://en.wikipedia.org/wiki/Stationary_High_Altitude_Relay_Platform It is still too inefficient for commercial use, and not friendly to birds flying through the beam.