Alternatives emerge for keeping drones airborne

Jon Lawson

The drone market, like the automotive sector is experiencing a growth in interest in alternative power sources. And like the auto sector, hybrid technology is seen by some as a stepping stone to fully electrified machines.  

Massachusetts-based ePropelled has just launched a new product line dubbed ‘Hybrid Ready’ which includes Starter/Generators (SGs), Intelligent Power Systems (also known as power management units or PMUs), Electronic Engine Starters (EES) and DC-DC converters. These can be specified to supply from 500 watts to 12kW, and the company hope it will prompt drone makers to try and optimise engine size by using the battery for assistance with range extension or to aid emergency landings. This means designers could use a smaller engine for those situations that demand full power, like taking off.

Nabeel Shirazee, company CTO noted, “ePropelled is the first vendor to introduce hybrid power assist capability. Our customers have told us that enhancing their aircraft capabilities is critical to the success of their programs. Hybrid Ready tells our industry that we are ready for business. ePropelled is one of the few vendors to provide both electric power and Power Systems for the commercial, security and defence markets. These applications usually have more demanding requirements that other sectors, especially their higher power requirements. We see a lot of synergy between all of our power products and there is a lot more to come.” 


When will fuel cells power drones?

There’s movement in this side of the market too. Technavio’s latest market report into just the military applications estimates that the market will grow by US$176.37 million and accelerate at a CAGR of almost 10% during 2021-2025, with 37% of this growth coming from North America during that time.

Boeing subsidiary Insitu is working on testing an all-electric, hydrogen-fuelled proton exchange membrane (PEM) fuel cell. In February, a Liquid Hydrogen (LH2) flight tank designed for the firm’s ScanEagle3 UAV successfully completed liquid hydrogen fill, pressure and vapour generation testing at Washington State University's Hydrogen Properties for Energy Research (HyPER) Lab. The tests verified operational metrics of the system in preparation for upcoming flights of ScanEagle3 equipped with a PEM fuel cell power system. The project is part of a larger effort to compare acoustic and thermal signatures of a small UAV powered with an IC engine versus an all-electric version. 

The company is aiming this squarely at the military market. Andrew Duggan, Managing Director at Insitu Pacific said, “For our global Defence customers, fuel-cell-powered UAVs in this Group 2 space represent a significant game changer in the battlespace. Operationally, fuel-cell-powered platforms provide the potential for longer endurance missions, increased power availability for payloads, as well as significant reductions in noise signature.”

If current ongoing tests go to plan, the first liquid hydrogen flight could take place in the late summer. 


• Read more about drone design here.


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