Record six hour flight for UAV powered by solid hydrogen-on-demand fuel cell

1 min read

A consortium of Singaporean institutions and private sector companies including have worked together to achieve a record six hour, 300km flight on the Skyblade 360 unmanned aerial vehicle (UAV) built in Singapore by ST Aerospace. This is the first time that a fuel cell has moved beyond the prototype stage and entered the standard product list of a UAV manufacturer.

The Skyblade 360 fuel cell system developed by HES Energy Systems and DSO National Laboratories is said to be lighter and more compact compared to the lithium batteries that typically power this aircraft: its 1L fuel cartridge holds 1000Wh of usable energy. Unlike a typical hydrogen fuel cell, the system doesn’t store its fuel as pressurised hydrogen gas, but stores it as a solid chemical material - making it easy for end-users to handle in the field.

Since its founding in 2009, HES has been developing advanced fuel cell systems and helps UAV manufacturers apply its technologies to improve the flight endurance of their electric powered aircraft. HES claims its system is able to store 7% of its weight as hydrogen and has a fuel utilisation rate of close to 90%. Several material options exist for hydrogen on demand, however most cannot meet performance targets due to the nature of their reactions and how much energy or reactants are needed to extract hydrogen, which then delivers net usable energy through a fuel cell.

HES said it took several years to achieve this performance. The company started with various approaches and technologies including the use of sodium borohydride. The system designs based on sodium borohydride were said to be expensive, complex, fragile, and came with many challenges for end-users. In 2013 HES pushed forward with a new material and a highly simplified system. This hydrogen on demand technology now targets operational costs of $10 per flight hour, making it more suitable for UAV manufacturers.