Hello,
our room is filled with energy, heat and radiation, rectenna are certainly a viable solution soon, but looks like free energy https://energiestammtisch.hpage.com/49freieenergie2017.html Are there any more companies that build rectenna and how far are they?
https://www.google.com/search?q=darpa+rectenna&ie=utf-8&oe=utf-8&client=firefox-b-m (https://www.google.com/search?q=darpa+rectenna&ie=utf-8&oe=utf-8&client=firefox-b-m)
After several lab bugs and increasing the stable conversion efficiencies over 40% we can estimate the beginningof mass production 2030+ !
The barrier : pHz- switch ( atto-seconds) velocity and rectenna lifetime and the massproduction machinery for low production costs !
https://www.nature.com/articles/nature19821 (https://www.nature.com/articles/nature19821)
optical rectenna:"nantenna" https://www.google.com/search?q=nantenna&ie=utf-8&oe=utf-8&client=firefox-b-m (https://www.google.com/search?q=nantenna&ie=utf-8&oe=utf-8&client=firefox-b-m)
Problem : energy harvesting or Telecommunications ! https://rftonics.ksu.edu.sa/node/1164 (https://rftonics.ksu.edu.sa/node/1164)
Or increasing Telecommunications electro-magnetic field/smog re-capture !