[DB]

If you have to transmit a watt for something that needs 10mW that isn't unreasonable even though is is only 1% efficient.

A nice use would be to keep a rarely used car or truck charged. So when you do need it isn't dead and you don't have to remember to drive it every few weeks.

[Wonder Warthog]

"A nice use would be to keep a rarely used car or truck charged."

Plug a small solar charger into the dashboard. Unless the vehicle is stored in complete darkness, it'll get "some" charge.