We have partnered with Lockheed Martin since 2008 to integrate fuel cell technology into the Stalker UAS platform.
Our 450W propane-powered Defender Series fuel cell provides a sixfold increase in mission duration compared to battery-only systems. And propane is so efficient that the fuel cell can replace 90% of onboard batteries.
What started as a 350W product evolved last year into a 450W fuel cell that now enables Stalker to do VTOL and cruise operation without sacrificing the sixfold improvement over batteries.
Case Study: SOFC Set the Standard for Lightweight, Power-Dense UAS Fuel Systems
We could not be more excited about this latest achievement of a 39-hour flight, breaking all previous world records for UAS flight time. While most UAV platforms provide 2-12 hours of duration, Lockheed Martin has used this groundbreaking achievement to showcase Stalker’s ability to have a persistent mission for extended periods of time.
“Stalker flew three times farther than even the highest endurance capabilities of most Group 1, 2 and even 3 platforms,” said Michael Edison, Adaptive Energy CEO. “We look forward to the day when Lockheed Martin brings this type of endurance to market.”
How They Did It
A production Stalker VXE was modified with an external, wing-mounted fuel tank. The flight provided valuable insight for improvements to Stalker VXE aimed at scaling its mission capabilities for the future.
The unique power density of our fuel cell technology made this achievement possible.
“This flight demonstrates the utility of SOFC technology to continue operating with every incremental pound of fuel you can add to the system,” said Tom Westrich, Adaptive Energy CTO and head engineer. “Our Defender Series 450W fuel cell can deliver an extra three hours of flight time for every extra pound of fuel a platform can carry.”
Power density is significant for expeditionary uses because it means there are no missions to fly and come back to. Although the UAS carries extra weight for the fuel cell and fuel tank, if you find fuel in the field, that one pound of fuel onboard is an extra 20 charged batteries – or three days – out in the field.
“And you don’t have to rely on waiting for a resupply convoy or an airlift to provide that boost in mission duration,” Westrich said. “Our fuel cells’ power density makes energy independence more feasible.”