Drone as lightning rod: successful trial in Japan

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Researchers in Japan have succeeded for the first time in triggering and redirecting lightning using a drone. The successful experiment could lead to a new type of lightning protection and, in the best-case scenario, even harness electrical energy from lightning, according to the Japanese telecommunications company NTT, whose research department carried out the experiment.

During the experiment in the mountainous region of Hamada City in Shimane Prefecture in western Japan, the researchers succeeded in flying the specially developed drone into a thundercloud and triggering a targeted lightning strike. At the heart of this is a specially developed lightning protection cage that protects the drone from the effects of a direct lightning strike. This metallic cage conducts the current around the drone's sensitive electronic components and distributes the lightning current radially, neutralizing the resulting strong magnetic fields.

Part of the cage melted

However, part of the cage melted during the impact. Reinforcements should ensure that it can now withstand lightning strikes of 150,000 amperes – This is significantly more than a natural lightning strike. Thanks to the cage, commercially available drones could also be used.

In future, drones could play a role as lightning conductors at outdoor events, in cities and to protect telecommunications systems and wind farms. Current protective measures are mainly based on passive lightning conductors, which have a limited protection area and cannot be installed everywhere. In Japan alone, lightning damage costs between 100 and 200 billion yen (around 610 million to 1.22 billion euros) every year.

Connected to the ground by wire

In order to actively trigger lightning, the researchers developed a method in which a conductive wire connects the drone to the ground. A high-voltage switch installed on the ground generates a rapid change in the electrical field around the drone when it is closed, which facilitates the lightning strike.

The practical test took place on December 13, 2024. As a thundercloud approached and the measured electric field strength on the ground increased, the team launched a drone equipped with the protective cage to an altitude of 300 meters. After activating the switch, a voltage of over 2000 volts was measured between the wire and the ground just before the lightning struck.

Plans for the future

NTT plans to further develop the technology to improve the success rate of drone-based lightning triggering. Future research will focus on the precise prediction of lightning positions and a deeper understanding of lightning mechanisms. In the long term, the company aims not only to trigger and control lightning, but also to harness its energy.

(mki)