Newcastle University

The Zephyr unmanned aerial vehicle (UAV) has just completed two weeks of non-stop flight powered only by energy from the sun.

Smashing all endurance records for an unpiloted vehicle, the Zephyr is the culmination of many years work by some of the world’s most talented engineers including a team from Newcastle University.

Led by Professor Barrie Mecrow and researcher John Bennett of Newcastle University's Centre for Advanced Electrical Drives, the team was responsible for developing the motors and electronics that drive the propellers on the aircraft.

Barrie Mecrow, professor of Electrical Power Engineering, explained: “The challenge was to design a very efficient but lightweight motor.

“In any system where you convert electricity into mechanical power, energy is lost, mainly through heat.  In this system, every watt of lost energy matters and so we had to develop new ideas to produce one of the lowest loss motors ever built.

“The work was particularly challenging because the plane operates up to 12 miles high, where temperatures can be below minus 60 degrees and conventional systems stop working.”

After 31 hours in the air, the Zephyr exceeded the official world record for a long-duration flight by a drone ... and then kept on going, unencumbered by the need to take on the liquid fuel that sustains traditional aircraft.

Clear skies at 60,000ft delivered copious amounts of sunshine to its amorphous silicon solar arrays, charging its lithium-sulphur batteries and keeping its two propellers turning.  At night, Zephyr lost some altitude but the energy stored in the batteries was more than sufficient to maintain the plane in the air.

Professor Mecrow added: “It has been an exciting and challenging project and is a real testament to the expertise we have here at Newcastle University that we have been involved in such a ground-breaking project.”

Pictured are Professor Barrie Mecrow, front, and John Bennett.