The Bells are best known for wringing absurd speed out of racing drones. Their Peregreen series has shattered and reclaimed the Guinness World Record for battery-powered RC (radio-controlled) drone speed multiple times – 247 mph on the first run in 2023, 300 mph (483 km/h) the following year, 363 mph (584 km/h) with the Peregreen 3 in Dubai, and 408 mph (657.59 km/h) with the Peregreen 4 in January 2026. Though that last record still officially stands, aerospace engineer Benjamin Biggs has bested it with his BlackBird drone, so the race is still very much on.

Luke Bell also holds the unofficial hover endurance record for a multirotor at 3 hours, 31 minutes, and 6 seconds, set with a purpose-built hyper-efficient drone running 101-cm (40-in) propellers and high-density semi-solid NMC (nickel-manganese-cobalt) lithium batteries.

But the Bells' solar drone is a different beast entirely. "A solar-powered drone that could fly for up to 12 hours in a day opens up a lot of possibilities," Luke told me via email. "It can take off and land anywhere and also never needs recharging. It could also fly for 100s of km per day. Compare this to what is currently on the market. Drone use is heavily limited by battery anxiety, but without a battery the use cases really open up. Specifically for things like agriculture, mining, surveillance, mapping, etc."

The team's first version had no batteries, no capacitors – it ran entirely on whatever the sun provided in real time. Built on an X-frame carbon fiber chassis with lightweight motors and 18 in (46 cm) propellers, it pulled power from 27 solar panels wired in series, producing around 150 watts on the ground. The concept worked, barely, until a wind gust ended the flight after three minutes.

For the second iteration, the Bells reworked the frame arms to reduce rotational inertia and trimmed roughly 70 g (2.5 oz) from the build, the equivalent to about 4 watts of saved power demand. They also switched to TPU (thermoplastic polyurethane - think flexible, 3D-printable rubber) sleeves over the carbon tubes to hold the panels in place more reliably.

But the real breakthrough came when they added a backup circuit using diodes and an auxiliary battery. Diodes act as one-way valves, blocking current from flowing back into the panels. When a cloud or wind gust pushes power demand above what the solar array can deliver, the battery bridges the gap automatically.

The final design runs 28 solar panels, arrayed across a carbon fiber frame. Under full sun, the array produces over 110 watts on the ground, comfortably above the roughly 70 watts the drone needs to hover. The surplus charges the auxiliary battery, ready to deploy whenever the sky doesn't cooperate.

"Wind is always a major issue with such a low wing-loading device," says Luke. "V3 will have a big focus on increasing wind resistance. How that will be done, I am still not sure. It's always a fine balance because it needs to be as light as possible."

Keeping a multirotor airborne indefinitely is a far harder problem than doing the same with a fixed-wing aircraft. The Airbus Zephyr S holds the absolute endurance record at 64 consecutive days aloft; BAE Systems' PHASA-35 reached 24 days. But even those industrial platforms plan missions of 200-300 days – not open-ended flights – because battery degradation, mechanical wear, and long winter nights all put a ceiling on how long any drone can stay up.

"I think indefinite flight is in theory possible," Luke says. "A simple way to try and achieve this would be to turn it into an eVTOL [electric vertical take-off and landing]. The panel will become a wing and reduce power to stay in the air to as low as 10% of hover power. This would mean the drone could fly on a small battery for a long time until the sun comes up again. Solar panel efficiency is also low at the moment, about 20-25% for the ones I use. If we can get that number higher, then the possibilities really explode for this kind of tech."