Microwaves don't absorb uniformly into materials. You can have a potentially deadly amount of energy, but if you can't actually interact with it then it's harml

Microwaves don't absorb uniformly into materials. You can have a potentially deadly amount of energy, but if you can't actually interact with it then it's harmless. The proposal for rectenna arrays was grids over farmland which could be used for cattle grazing with illeffects to the cattle - simply not enough EM can be absorbed by them for it to matter.