When people suggest possible uses for electric multicopter drones, it frequently seems like they're forgetting something – presently, most such aircraft can only fly for a maximum of around 25 minutes per battery charge. Horizon Energy Systems, however, is developing a quadcopter that should do a lot better. Known as the Hycopter, the fuel cell-powered drone is hoped to be capable of 4-hour flight times once completed.

In a clever design feature, the Hycopter stores 120 g (4.2 oz) of hydrogen gas at 350 bar (5,076 psi) in its existing structural tubing – no separate canister is required.

Although those refillable tubes are made of clear acrylic in the pictured display model, they'll be constructed from polymer-lined 5 mm-thick carbon fiber tubing in the functional prototype. According to Horizon, that amount of hydrogen should provide the same amount of energy as 3 kg (6.6 lb) of lithium batteries.

The gas is converted into electricity by a lightweight lithium polymer hybrid fuel cell. Altogether, the complete drone should weigh a total of 5 kg (11 lb), and be capable of carrying a payload of up to 1 kg (2.2 lb) – although when it's carrying that much of a load, its endurance will be more around the 2.5-hour mark. Additionally, the location of the payload can be adjusted, in order to keep the weight distributed evenly.

Taras Wankewycz, Horizon's Group Chief Executive Officer, tells us that the flying prototype is almost ready to go, and should be making its first flight later this year. In the meantime, the company is taking preorders for the Hycopter from interested parties. Final pricing has yet to be determined.

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