Recent tests undertaken by Mitsubishi Heavy Industries in Japan have demonstrated the feasibility of wireless electricity transmission.
An experiment last week in the Kobe Shipyard & Machinery Works in Japan managed to successful transmit 10kW of electricity in the air across a 500m distance.
This was a milestone for the wireless electricity technology, both in terms of the amount of power transmitted, as well as its distance. The experiment also proved that the advanced control system in charge of maintaining the beam could function correctly.
In order to transmit the power across this distance, Mitsubishi used a beam of microwave radiation.
Within this technology, electromagnetic energy is converted to microwave energy and then transmitted as a beam across a wide distance, before being collected by a receiver and re-converted to electricity. While this has high theoretical efficiency, it is limited by the size of the transmitters and receivers.
Mitsubishi believes this wireless electricity transmission technology has a large number of applications.
Within the next five years they plan to put the technology to use across a number of fields; including the transmission of power to remote, off-grid locations, as well as the wireless charging of electric vehicles.
Kenichi Amma, an engineering manager at Mitsubishi told Mainichi that: “The challenges we face now are how to downsize the devices and improve reliability. We believe we will be able to commercialize the technology at an early date as far as short-distance power transmission within a distance of one meter is concerned.”
Space-based solar power
One potential use of this wireless electricity transmission technology which Mitsubishi is interested in is its application in space-based solar power systems.
The company envisages a future which large arrays of solar panels are set up in geostationary orbit, collecting power to be beamed back to Earth via microwaves. Such a system could provide almost infinite amounts of clean energy, at much higher efficiencies than ground-based solar panels.
Japan has made the development of such a system a high priority, and this latest Mitsubishi research was conducted with collaboration with Japan Space Systems.
In order to be feasible however, the range of the power transmission will need to be massively increased to allow for the transmission of power from 36,000km above the Earth.