Issue 41 Unmanned Systems Technology December/January 2022 PteroDynamics X-P4 l Sense & avoid l 4Front Robotics Cricket l Autonomous transport l NWFC-1500 fuel cell l DroneX report l OceanScout I Composites I DSEI 2021 report

71 Northwest UAV NWFC-1500 fuel cell | Dossier “We don’t yet have robotic arms or other mass-automation systems, as high-end unmanned systems engineers don’t want to burn through thousands of power units,” Ratcliffe says. “But our architecture has been designed in such a way that automated machinery could build these fuel cells, and we know where we can add automation over time to be able to scale production in a safe and reliable way that doesn’t impact our quality control.” As NWUAV scales up its PEMFC output, it therefore anticipates using more and more automation, potentially growing closer to the kinds of automated fuel cell facilities that Toyota and Intelligent Energy are known for. The company’s existing test cells, as well as newer bespoke ones, will be used to validate its hydrogen power units at different stages of design and production. The company is now taking on launch customers, with aircraft being tailored to the NWFC-1500 (and vice versa). Critical usage data for future r&d is anticipated from them and initial flight tests, which are due to start in Q2 2022. “Architecturally, this system is designed to be flexible,” Ratcliffe notes. “The fuel cell has a voltage droop associated with the current we expect customers will want to run through it, but that isn’t guaranteed to match what the end-user’s aircraft will need. Some will want to drive off a common rail shared with a battery. “With that kind of requirement in mind then, we’re working internally on a new system that allows parallel hybridisation. It will take the variable voltage of the fuel cell and put it onto a bus rail it shares with a lithium-ion battery. “With that architecture, it can be controlled to recharge the battery, with the battery acting as a capacitor as in most PEMFC powertrains, or if a vehicle needs a temporary boost combining the wattage of both the fuel cell and the battery, it can be drawn out through the battery until the surge is no longer needed or until the latter’s energy store is depleted.” In the years ahead, NWUAV expects to perform extensive hydrogen-powered flight tests, as well as expanding the case for building an ecosystem around hydrogen production, mobility, and general r&d in the Beaver State, which might one day make Oregon as much a leader in hydrogen technologies as it is in UAVs. Unmanned Systems Technology | December/January 2022 NWFC-1500 Proton exchange membrane fuel cell Hydrogen gas Closed cathode Liquid-cooled Titanium housing 48 cells Size: 40.6 cm x 17.3 cm diameter Weight (without fuel tank): 4.3 kg Peak net power: 1500 W Cruising power: 500 W Operating voltage: 24 V Operating current: 50 A Energy efficiency at cruise: 53% Operating temperature range: -5 C to +45 C TBO: 500 hours Some key suppliers Bipolar plate materials: Borit Manufacturing Hydrogen tanks: HyPer Comp Air compressors: Eberspaecher Vairex Membrane electrode assemblies: WL Gore & Associates Additively manufactured parts: Northwest Rapid Manufacturing Specifications NWUAV is investing in comprehensive infrastructure for its fuel cell business, including hydrogen production as well as manufacturing and testing systems