Updated: Jul 11
Wireless power transfer is hard. Several teams have approached the problem in the long history of power transmission, with the vast majority of demonstrations since 1980. The challenge is actually getting the transmitted power on the receiver, as the radio frequency antennas want to spray the energy in all directions. For orbit to ground power transmission, you need a beam that is very narrow angle (called the solid angle) to put all the power on your receiver - our system needs 0.002 degrees of solid angle. We aren't there yet, but we are building bigger and better systems all the time. Last week we improved the performance of our phased array demonstration hardware significantly. How good is it? The chart below shows that we are already demonstrating proportionately greater distance and more energy moved than anyone, ever. If you have evidence you can do better, we'd love to talk to you.
The reference system performance values were extracted from the master's thesis of AJ Finnell "Wireless Power Transfer: Efficiency, Far Field, Directivity, And Phased Array Antennas" Purdue University, August 2021 and C. T. Rodenbeck et al., "Terrestrial Microwave Power Beaming," in IEEE Journal of Microwaves, vol. 2, no. 1, pp. 28-43, Jan. 2022, doi: 10.1109/JMW.2021.3130765.