During test flights, Asia’s first fully solar-powered quadcopter UAS has flown higher than 30 feet in the air.

Developed as a student project under the Innovation & Design Programme (iDP) at the National University of Singapore (NUS) Faculty of Engineering, the UAS uses solar power with no battery or other energy storage on board.

The solar-powered UAS is constructed using lightweight carbon fiber material, weighs just under six pounds, and can take-off and land vertically without a runway. It is fitted with 148 individually characterized silicon solar cells and supported by a frame equipped with four rotors.

According to NUS, rotary winged aircraft are “significantly less efficient” at generating lift compared to their fixed wing counterparts, so while there have been some examples of solar airplanes in recent years, a “viable 100 per cent solar rotary aircraft” that can take-off and land vertically remains a major engineering challenge to date.

“Our aircraft is extremely lightweight for its size, and it can fly as long as there is sunlight, even for hours,” explains Associate Professor Aaron Danner from the Department of Electrical and Computer Engineering at NUS Faculty of Engineering, who supervised the project.

“Unlike conventional quadcopter drones, our aircraft does not rely on on-board batteries and hence it is not limited by flight time. Its ability to land on any flat surface and fly out of the ground effect in a controlled way also makes it suitable for practical implementation.”

​The UAS can be controlled using a remote control, but it can also be programmed to fly autonomously using a GPS system incorporated into the aircraft. NUS says that the UAS has a potential use as a ‘flying solar panel’ to provide emergency solar power to disaster areas, as well as for photography, small package delivery, surveillance and inspection.

When there is no sunlight, or when charging needs to take place during flight to enable operation when it is cloudy or dark, batteries can be used to power the UAS. For specific applications, other hardware such as cameras can be included.

Over the last six years, eight NUS student teams have made successive design improvements and worked towards a fully-solar powered aircraft under the supervision of Associate Prof Danner, who also holds a joint appointment at the Solar Energy Research Institute of Singapore at NUS. The first solar-assisted quadcopter UAS developed by students in 2012 could only achieve 45 percent of flight power from solar cells and the rest from on-board batteries. 

The latest team made further refinements to the earlier prototypes of the quadcopter UAS, and eventually achieved a fully solar-powered flight with their latest prototype.

The team members graduated from NUS in July 2018 and were jointly supervised by Mr Brian Shohei Teo from the iDP programme for this project.

“To be able to make something fly under control for a long time is a very complex engineering problem,” Mr Teo says. “Our students have attained flight in its purest form, powered by natural sunlight. This is an amazing achievement.”

To further improve the aircraft’s efficiency, the team will continue to work on fine tuning it. The team is hopeful that these enhancements will help bring the technology closer to commercialization.

Video footage of the project can be seen below:

Below: A team from the National University of Singapore (NUS) Faculty of Engineering has developed Asia’s first fully solar-powered quadcopter drone. The aircraft has flown above 10 metres in test flights and achieved controllable flight without the use of batteries. From left: Mr Yeo Jun Han, Mr Brian Shohei Teo, Mr Kuan Jun Ren, Mr Goh Chong Swee, and Associate Professor Aaron Danner. Photo: National University of Singapore