VerdeGo Aero has started active testing of the hybrid-electric powertrain system it is developing with Continental Aerospace Technologies, VerdeGo CEO Eric Bartsch has revealed.
VerdeGo and Continental announced their collaboration last year at EAA AirVenture Oshkosh 2019. This week, Bartsch provided a status update during an Aviation Week UAM Virtual panel moderated by Aviation Week senior editor Guy Norris.
“Just some news for your audience today, I think this is the first venue we will have shared this in: We’re now running at production power the most powerful piston hybrid system in the world down in our Florida headquarters in Daytona Beach,” Bartsch said during the online panel on Aug. 13.
“We’ve entered the test and refinement phase of that to get towards a conformal design to enter production with, so we’re really excited about that. And that’s moved from hardware that was under development to hardware that’s being tested to prove it every day.”
Targeted at VTOL aircraft with maximum take-off weights of up to 7,500 pounds (3,400 kilograms), the powertrain combines VerdeGo’s Integrated Distributed Electric Propulsion concept with a Continental Jet A-fueled piston engine. The goal is to offer a hybrid-electric solution that is quieter, more fuel-efficient, more economical, and more scalable than hybrid systems using turbine generators.
According to Bartsch, while turbines have long been the “default” option for commercial aviation applications, they’re problematic in hybrid aircraft because they negate the primary benefits of electrification.
“We want electric aircraft so that they can be quieter and more efficient, burn less fuel, lower emissions,” he explained during the panel. “And then if you put a small turbine in the aircraft, it’s loud, it burns a lot of fuel, it’s expensive. You can do it, technically, but you just lost the reasons why you wanted the aircraft to be electric in the first place.”
Meanwhile, he said, VerdeGo believes that hybrid-electric powertrains represent a more promising near-term solution for urban air mobility and advanced air mobility aircraft than relying on batteries alone. That’s despite what Norris pointed out is a larger trend in the industry towards embracing fully electric designs — as exemplified by Bell’s decision to pursue a fully electric version of its Nexus air taxi, originally conceived as hybrid.
“Twenty years from now, there are going to be some amazing batteries on the market, but designing an aircraft around these future technologies right now is a very risky proposition,” Bartsch argued.
He suggested that hybrid-electric designs make sense even for short-distance urban air taxi missions, as they enable an operational flexibility that could be critical to the success of urban air mobility business models.
“In the short-range flying, hybridization isn’t there to get you more range, it’s to give you more operating flexibility, so that the aircraft has the ability to do not just one flight but maybe two, three, four, or five flights back-to-back,” he said. “It’s being able to do more flights and not take up time or space on the ground between them, and therefore have the kind of economics that we want to really deliver these services. . . .
“It’s not that batteries won’t play a role, but it’s a very difficult challenge to use a battery electric system to deliver that mission in a useful, certifiable, profitable way.”