Homemade solar multirotor flies past five hours in endurance milestone
A homemade solar-powered multirotor has stayed airborne for 5 hours, 2 minutes and 21 seconds, setting an unofficial endurance mark for an electric drone of its type. The result points to a new path for vertical takeoff aircraft, which usually trade flexibility for short flight times and heavy dependence on batteries.
The team behind the aircraft is better known for building record-chasing high-speed drones, but this project targets the opposite problem. Instead of maximum velocity, it focuses on extreme efficiency. The aim is to keep a multirotor in the air using sunlight as the primary energy source while preserving the takeoff-and-landing freedom that fixed-wing aircraft cannot match. That could widen the appeal of drones in agriculture, mining, surveillance and mapping, where battery limits still constrain coverage and time on station.
An early version flew with no battery and no capacitor buffer, drawing power directly from sunlight in real time. It used an X-frame carbon-fiber chassis, lightweight motors, 18-inch propellers and 27 solar panels wired in series. The aircraft generated about 150 watts on the ground, enough to prove the concept but not enough to ride through disturbances. A gust of wind ended that first serious attempt after only a few minutes. The next iteration cut rotational inertia in the frame arms, removed about 70 grams of weight and adopted TPU sleeves to secure the panels more reliably to the carbon tubes.
The key advance came with the addition of a backup circuit using diodes and an auxiliary battery. The diodes prevent current from flowing back into the panels, while the battery automatically fills in when clouds reduce solar output or gusts push power demand above available supply. The latest design carries 28 solar panels across a carbon-fiber frame. In full sun, the array produces more than 110 watts on the ground. The drone needs roughly 70 watts to hover. The excess charges the backup battery for use when conditions worsen. Wind remains the main challenge because the aircraft is so light, and the next version is expected to focus heavily on improving resistance without erasing the gains in efficiency.
The flight does not prove unlimited endurance, but it does show how far solar-assisted multirotors can be pushed. Fixed-wing solar aircraft still dominate long-duration missions because they need far less power to stay aloft. Multirotors face a harder physics problem since hovering constantly consumes energy. Even so, the latest result suggests a hybrid path is emerging. A future design that shifts into wing-borne flight, in eVTOL fashion, could cut cruise power dramatically and stretch operations far beyond current battery-only limits. For industries that need persistent aerial coverage with flexible launch and landing, that would be a meaningful shift in what small electric drones can do.