Microwave technology challenges fuel: is the future of flight wireless?

In 2050, your transcontinental flight could be powered not by kerosene, but by invisible microwave beams. This technology, which seems like something out of a science fiction novel, is emerging as a serious proposal to revolutionize aviation. How exactly does this aircraft microwave technology work? Is it really doable? All you have to do is poke around a bit and see what it's all about.

The working principle: wireless energy for aircraft

Instead of storing all the energy needed for flight on board the plane, why not transmit it wirelessly from the ground? Using powerful microwave beams, energy would be sent from large antennas on the ground directly to the aircraft in flight. This is the crux of the idea, which is based on already existing technologies: for example phased antenna arrays, commonly used in radar. These arrays can concentrate energy into a narrow, steerable beam, capable of following the plane as it travels.

To make this vision a reality, however, engineers would have to overcome formidable challenges. Ground broadcast antennas would have to be huge, with diameters of hundreds of meters. They would be as big as football stadiums dotted along airline routes. Furthermore, the same aircraft should be equipped with a receiving antenna (called a “rectenna”) integrated into its structure, capable of converting microwaves into electricity to power the engines. A rectenna that should be incredibly efficient and light, without compromising the aerodynamics of the aircraft.

Microwave technology, let's think for a second

A typical airliner requires about 30 megawatts of power at takeoff. Transmitting this amount of energy through the air safely and efficiently is a huge challenge. The power density on the aircraft's receiver is expected to be extremely high, requiring cutting-edge power conversion technologies. This would lead to obvious safety concerns: how to protect passengers from microwave radiation? And what would happen to the birds flying through the energy beam?

To put it mildly, the implementation of microwave technology would require a complete rethink of aviation infrastructure. Hundreds, if not thousands, of transmission stations would be needed along air routes, including floating platforms for transoceanic flights. The regulatory challenges, then, would be equally significant. Current radio transmission regulations would have to be completely revised to allow the use of such powerful microwave beams.

Comparison with other sustainable aviation solutions

Despite the challenges, aviation microwave technology could offer significant advantages over other proposals to decarbonize the sector:

1. Battery electric planes: currently, batteries have too low an energy density for long-range commercial flights.
2. Hydrogen: presents safety challenges and requires substantial changes to aircraft and airport infrastructure.
3. Synthetic fuels and biofuels: they may be more expensive and do not completely eliminate climate impacts.

Microwave technology, while more radical, could offer a zero-emissions solution without compromising the performance of current aircraft.

Conclusion: it is still early for microwave technology, but congratulations on your courage

Microwave technology to power airplanes is undoubtedly a bold idea. It may never become a reality, or it may require decades of development before it is viable. I put it among the radical solutions. However, whether or not it becomes a viable solution, exploring such innovative ideas is essential to leading us towards a truly sustainable aviation future. Perhaps, one day, looking out the window of an airplane, instead of seeing wings full of fuel, we will see the almost imperceptible glow of a microwave beam carrying us to our destination, in a completely new and clean way. Or maybe not.