While you may have seen examples of “wireless” charging that involve putting a phone on a pad or the like, powering drones requires a charging system that can track and target them from further away. Long-range wireless power transmission can be achieved by a few different technological approaches, including focused electromagnetic fields (such as microwaves) and lasers.

For electronics geeks, there’s a detailed rundown of Dr. Aldhaher’s demo here.

Get Data Sheet, Fortune’s technology newsletter.

This is not entirely new technology. One company working on wireless drone power, Global Energy Transmission, this summer showcased a one-hour continuous flight by a large tethered drone, which they say was powered entirely wirelessly.

https://youtu.be/8mXIiBqs1pY

One form of long-range wireless power is actually close to market, though it doesn’t involve drones—the Cota wireless charger has a range of ten feet. In the further future, long-distance wireless power transmission could allow for farming solar power from orbit.

But in the nearer term, the implications of wireless power for aerial drones could be major. It’s already feasible to achieve long-term flight with large, winged drones powered by solar energy, suggesting that they could someday take over some functions from orbital satellites.

For more on drones, watch our video.

But the solar approach is unlikely to work for quadcopters, which are more power-hungry than winged drones, but are still hoped to someday take on endurance-dependent tasks such as infrastructure inspection and delivery. The ability to power or recharge a drone without replacing its battery or plugging it into a charger will mean those tasks can be accomplished more quickly, and with fewer human and material resources.

However, any implementation of this technology would require a good bit of infrastructure in the form of transmission towers, and there are some concerns about the health risks of higher-power electromagnetic fields for humans.