France-based Xsun and H3 Dynamics announced a collaboration to develop a solar, hydrogen and battery powered autonomous aerial system with integrated power management and able to navigate at low altitudes.

H3 Dynamics, a hydrogen aviation specialist, and XSun, a developer of unmanned aerial systems (UAS), both based in France, announced a partnership targeting solar-hydrogen-electric UAS for low-altitude flights.

Combining solar power with hybrid electric fuel cell systems can enable improved fuel efficiencies, extending flight durations, while saving space and weight, the companies said in a statement.

A new power management system that would optimize onboard energy production and use was also highlighted in the statement. “While the sun is available, ultra-thin wing-integrated solar PV cells contribute power to the overall power system, batteries provide peak power during take-off, and a miniaturized hydrogen fuel cell system provides the main cruise power,” the companies said.

They also described an onboard “micro-grid system” that could enable endurance for heavier aircraft, such as electric vertical takeoff and landing (VTOL), horizontal vertical takeoff and landing (HTOL) and short takeoff and landing (STOL) aircraft. No further details about the solar PV, fuel cell, or battery technlogy were provided.

Xsun, which launched several years ago a lightweight, fully electric, solar-powered drone, said that as part of its ‘next-generation' system line-up, it will be offering a “full solution ecosystem” to XSun clients in Europe, the United States, Australia and the Gulf region. This includes a solar hydrogen UAS and a mobile hydrogen refueling system, which can be deployed on-site at the point of operations.

The earlier XSun design was a tandem solar wing drone with a weight of 29kg and a payload capacity of 4kg. Its 400W solar arrays reportedly provided 12 hours of flight duration, covering distances of 600 km.

H3 Dynamics is an aerospace and defense platform provider that noted it has developed hydrogen-electric fuel cell systems for the past 15 years, both small-size air-cooled miniature systems and larger liquid-cooled systems, achieving the best power-to-weight benchmarks and fuel efficiencies in the world.

Source:https://www.pv-magazine.com/2025/06/24/h3-dynamics-xsun-partner-on-solar-hydrogen-electric-unmanned-aerial-systems/