Extinguishing fires at 96 metres: French firefighters test spray drone on wind turbine

French emergency services have carried out a first practical test using a drone to combat fires in a wind turbine. The demonstration took place at the Breteuil wind farm, operated by Kallista Energy, where a specially equipped spray drone was deployed to show that firefighting operations at great heights can potentially be carried out faster, more precisely and with less risk using unmanned aircraft.

High-pressure spray drone

The experiment was initiated by the fire and rescue service of the Oise department (SDIS 60). The demonstration was attended by firefighters, drone operators and members of a specialised rescue unit trained for hazardous environments, as well as representatives from the municipality of Breteuil and staff from Kallista Energy.

For the test, responders used the Hercules 20 High-Dra, an industrial multirotor drone equipped with a high-pressure spraying system. The aircraft can deliver water or other liquids at pressures of up to 240 bar. During the demonstration flight, the drone reached a height of 96 metres, roughly comparable to the hub height of many modern onshore wind turbines.

Unlike conventional aerial firefighting drones that rely on onboard tanks, the Hercules 20 High-Dra operates with a hose connected to a water supply on the ground. This setup allows the drone to spray continuously without being limited by the payload capacity of a water reservoir. During the trial, the drone maintained stable operations in winds of around 30 km/h, with gusts reaching 50 km/h.

The Hercules 20 High-Dra is designed as a versatile industrial platform. Besides firefighting experiments, the drone can also be used for cleaning and maintenance tasks on large structures such as building façades, solar installations and wind turbine blades. The system features a heavy-lift multirotor configuration, a reinforced airframe designed to carry external equipment, and stabilisation software that helps maintain position while operating close to tall structures.

Unique challenges of turbine fires

Fires in wind turbines present a particularly complex scenario for emergency responders. The ignition source is often located inside the nacelle, where electrical systems, generators and lubricants are housed. These components are typically positioned dozens of metres above the ground, making direct access difficult and potentially dangerous.

Conventional firefighting equipment such as ladder trucks or aerial platforms often cannot reach these heights. Even when access is technically possible, deploying such equipment can take considerable time. In addition, wind turbines are frequently located in remote areas such as open farmland, coastal zones or offshore sites, further complicating emergency response.

Wind conditions also add complexity. Turbines are built in locations with consistent airflow, meaning firefighters may have to deal with strong winds that can intensify the fire or disperse water streams. Burning debris falling from the nacelle or rotor blades can also create hazards on the ground, requiring large safety perimeters.

A drone capable of approaching the nacelle directly could help responders assess the situation quickly and apply targeted suppression without exposing personnel to unnecessary risk.

Growing interest in firefighting drones

The French experiment reflects a broader international trend in which emergency services are exploring the use of drones for firefighting tasks. Various concepts are currently being tested worldwide, including drones that deploy fire extinguishers, drop fire suppression balls or deliver directed water streams to hard-to-reach locations such as high-rise buildings, industrial facilities or wildfire fronts.

In the Netherlands, researchers and developers are also working on novel approaches. One concept under development involves a drone equipped with an air-pressure cannon. Instead of spraying water, the system aims to extinguish flames by directing powerful bursts of compressed air at the fire source, effectively blowing the flames out. The concept is still experimental but illustrates how drones are increasingly being considered as tools for tackling complex firefighting scenarios.