You are likely to hear about the startup Emrod in the coming years, and for good reason: the firm has just demonstrated with Airbus and the European space agency ESA a technology to deliver electricity without the lesser cable, via electromagnetic waves.
The technology developed by Emrod promises for the first time to make this type of approach viable. Until then, projects for the production and delivery of electricity from space required the construction of antennas several kilometers in diameter to transmit only a few gigawatts (with a lot of losses).
Soon “wireless” electricity everywhere on Earth?
Building such antennas would in itself be a real challenge on Earth, not to mention building them in orbit… The antennas used by Emrod’s prototypes are only 1.92 m in diameter, which allows launches in conventional rockets. In its demonstration with ESA, the prototype Emrod transmitter transmitted electricity without any cables for 36 meters, between an Airbus hangar and the Oktoberfest.
The system thus made it possible to supply a model city, a hydrogen generator and a fridge for the festival. 36 meters is still a short distance, but the startup has already demonstrated with New Zealand energy supplier Powerco transmission over 200 meters. The technology can be adapted to longer distances, and the firm believes that it is ready for commercial exploitation over even greater distances.
In fact, all Emrod technology needs is an unobstructed view between the transmitter and the receiver or relays. This could make the transmission of electricity by satellite finally viable. A startup manager explains:
“So far all research has treated wireless power transmission as telecommunications […] but with this type of far field system you have lobe formation [électromagnétiques, ndlr] on each side of the beam, which immediately causes you to lose between 15% and 20% of the energy. To make matters worse the beam tends to diverge, which requires a gigantic antenna to collect the energy – so the cost-benefit ratio has always until now made this type of approach unfeasible”.
Conversely, Emrod’s technology does not use the concept of “far field”. But from “near field”:
“When we talk about distant field or near field, we should not necessarily think that the two approaches are differentiated by distance. It is indeed more about where the beam is focused and at what stages you re-capture it. Our technology uses a phase array type antenna to create a more precise beam that is somewhat the equivalent of copper in a virtual wire – it is very precise and has no lobes to cause loss”
The beam is then recaptured in precise zones, called Fresnel zones. Thanks to this approach, efficiency is around 95%. But the firm thinks it can eventually reach 99%. Emrod’s ultimate goal is to launch its own satellite constellation and thus create a new global energy distribution network. A sort of Starlink constellation for power delivery – especially if it’s green.
Indeed, the solar panels on the day side of the planet could thus finally supply, for example, homes plunged into darkness, on the opposite side of the Earth. An alternative to storing this energy in various types of batteries or water reservoirs.