Drones

H3 debuts all-in-one hydrogen powertrain pods for long-range flight

View 5 Images
H3 Dynamics is working its way from small drones up toward manned zero-emissions aircraft, with detachable self-contain hydrogen powertrain pods that can be retrofit to existing airframes or worked into new designs
H3 Dynamics
H3 Dynamics is working its way from small drones up toward manned zero-emissions aircraft, with detachable self-contain hydrogen powertrain pods that can be retrofit to existing airframes or worked into new designs
H3 Dynamics
H3's propulsion pods contain the entire hydrogen powertrain, including tanks, fuel cells, electric motors and propellers
H3 Dynamics
Concept design for a passenger plane running a bunch of detachable hydrogen propulsion pods along each wing
H3 Dynamics
Ground-based testing of a hydrogen propulsion pod
H3 Dynamics
H3's 25 kg test drone runs a propulsion pod on each wing
H3 Dynamics
View gallery - 5 images

France's H3 Dynamics has presented its self-contained hydrogen propulsion pods for retrofit or line fit to drones and airplanes. They deliver enormous range and endurance figures without heavy batteries, and they mirror the approach Airbus and others are taking with commercial airliners.

Batteries weigh aircraft down, they can heat up, and they take a long time to charge – but they're very simple, easy to use, and they store enough energy for many use cases. Hydrogen is a pain in the butt at every step of the way, but used in a fuel cell powertrain it carries so much more energy than lithium batteries for the weight it costs that you can keep your aircraft flying for ridiculous lengths of time.

To illustrate, back in 2020, we compared the world record endurance flights of multicopter drones running on pure battery power (1 hour, 51 minutes), a 16-liter gasoline-electric hybrid system (10 hours, 14 minutes), and a hideously ugly hydrogen fuel cell system fed by 6 liters of gas (12 hours, 7 minutes). If range and endurance are your priority, batteries don't come close to hydrogen.

H3's propulsion pods contain the entire hydrogen powertrain, including tanks, fuel cells, electric motors and propellers
H3 Dynamics

And while it's possible to stick the hydrogen tanks and fuel cells in the middle of an airframe, where the combustion powertrain or battery pack would normally live, there's a few reasons why you might not want to. Hydrogen weighs less than batteries, but takes up a lot of volume. You might want to dedicate that space to cargo, for starters. Or, if you're talking about a bigger airframe, passengers. If you're talking about passengers, there might be some psychological value in having the hydrogen stored well away from the cabin, and putting the whole system out on the wing probably helps with cooling and airflow as well.

Thus, Airbus is looking at self-contained end-to-end hydrogen propulsion systems for its future zero-emissions airliners. Fully swappable units that can be popped on and off for maintenance and whatnot without disrupting an aircraft's flight schedule.

And it's a similar concept here with H3 Dynamics. These guys have developed a lightweight, aerodynamic hydrogen propulsion nascelle containing a hydrogen tank, fuel cell system, electric motor and propeller; the whole powertrain. You can piggyback it on top of a fixed-wing fuselage, or you can stick multiple units out along the wings for distributed propulsion.

Right now, it's sized to be relevant to the commercial fixed-wing drone market; inspection, reconnaissance, scientific and emergency-zone aircraft. It's been tested on a 25-kg (55-lb) fixed-wing cargo drone using two pods, and H3 Dynamics estimates a whopping 350-km (217-mile) range running on gaseous hydrogen, or an outlandish 900 km (560 miles) using a more complex cryogenic liquid hydrogen fuel system closer to what Airbus is working on. Here's a video:

Next up is VTOL, which presents its own challenges. H3 has teamed up with Australian eVTOL drone company Carbonix to begin developing a VTOL hydrogen cargo and commercial drone based on a lift-and-cruise layout. To start with, H3 will start sticking some propulsion pods onto existing Carbonix aircraft, presumably just to handle long-range cruise flight while the existing battery system stays in place to handle the more unpredictable power demands of VTOL and hover phases.

As the partnership progresses, things will become more integrated, but we imagine some sort of battery will remain part of the design, capable of delivering the near-instant torque changes you need to stabilize a multicopter in a hover. Perhaps the fuel cells can divert some power off to charge up some much-smaller battery packs during flight. You can see the standard Carbonix Volanti airframe in the video below.

Then comes liquid hydrogen. The company has been working with the Institut Supérieur de l’Aéronautique et de l’Espace (ISAE-SUPAERO) in Toulouse on cryogenic liquid H2 systems since 2019, and the two groups have set themselves the goal of flying a hydrogen aircraft clean across the Atlantic Ocean within two years. For reference, the shortest Atlantic crossing is about 2,575 km (1,600 miles) between Senegal and Brazil – so it's a pretty epic challenge.

And finally there's manned flight. The company is working toward a larger, more powerful version of its propulsion pods that can be retrofit to a two-to-four-seat passenger plane, and it's hoping to get one airborne by the end of 2023. These could become a product you could retrofit to a lot of small planes, potentially even without removing the fossil fuel engines they've already got, so you might end up with double redundant powertrains and bonus range if you wanted it.

Concept design for a passenger plane running a bunch of detachable hydrogen propulsion pods along each wing
H3 Dynamics

So it's a bottom-up approach to arriving at manned flight, in contrast to the top-down strategy of companies like ZeroAvia, which have boldly jumped straight into the fearsome journey of developing zero-emissions hydrogen airliners. H3 is starting small, safe, and free from regulatory red tape by putting thousands of data-gathering hours on commercial drone airframes – and these will bring in some cash while it slowly scales up to start working with small planes and beyond.

It's pretty neat stuff, and we look forward to following H3's progress through the next steps.

Source: H3 Dynamics

View gallery - 5 images
  • Facebook
  • Twitter
  • Flipboard
  • LinkedIn
10 comments
STUDENT
Combining this with the Hydrofoil boats looks like a winner…
michael_dowling
I am surprise at the range possible from just compressed H2. This is a great advance if it actually pans out.
MartinLebel
Why incorporating the engine within the pod?
The electric engines are diverse but they just need the same juice…
FB36
Our world already always have countless people keep burning to death alive (after traffic accidents), because of using gasoline (which easily starts fires) as fuel!
(Diesel fuel, for example, does NOT easily starts fires (& that is why POTUS car is specifically chosen to be a diesel, for example)!)
Hydrogen, on the other hand, does NOT start fires but EXPLODES!!
Imagine a future world w/ all kinds of hydrogen vehicles, tanker trucks, gas stations everywhere!
Are we seriously thinking that there will be never any accidents/leaks/ruptures/mishandling to trigger massive explosions?
Not to mention, there is actually no need at all to use hydrogen as fuel!
All light/small vehicles are already becoming fully electric & all heavy/big land/sea/air vehicles just need us to start producing biodiesel/biofuel at large scales!
(From all possible industrial/agricultural/forestry waste/biomass & trash & sewage!)
Aermaco
Meaningful travel distance will require Hydrogen fuel.
Fb36 you really seem to be a relentless point person for marketing biofuel which is fine but you weaken you argument’s weight when you keep posting the incorrect description of H2 use safety. Diesel fuel does burn on the ground where people exist, while H2 escapes upward away from them and doesn't explode from an H2 storage tank. It burns like a candle as it escapes upward from the tank leak.
Graeme S
Fantastic step, a great leap for mankind, now if only we could stop humans polluting this planet there may be hope
ljaques
Michael, it's a fuel cell design, not "just compressed H2". Fuel cells will allow longer distance vehicles, and is the ideal aeronautic power of the future, IMO.
FB36, pure H2 leaks will catch fire but not truly explode. On YT, check for "Tank Safety: Hydrogen Tank Gunshot | Toyota" and "Vehicle Safety" by greenway energy.
vince
I can see these pods being very useful for current crop of battery electric planes in development. Since taking off and landing is what consumes the most battery power and also hovering, why not combine battery plus hydrogen and have the best of both worlds--use the hydrogen for taking off and landing and for when hovering is needed and battery power for horizontal cruising speed? Since the pods are fairly removed distance wise from the plane occupants it doesn't constitute a serious danger in the event of a crash. But having the hydrogen pods available for take off, landing and hovering could easily double or triple the range of pure battery drive electric planes. I would guess a hybrid system could probably have about 300 to 500 mile of range if they did the math right instead of 100 to 150 on batter power alone. And the hydrogen pods could even re-charge the batteries in flight (along with some solar panels as well) and have additional stored energy for emergencies.
jerryd
The problem with this is cost, space. It costs way too much to install, maintain and just where to put the H2 which is very bulky even as a liquid.
You certainly can't put enough in the engine pods for real range.
Vs we can now make cost effective drop in SAF/synfuels at no extra cost and the same or less impact than H2 at 20% of the cost.
And eventually metal/air batteries will handle it once they get over recharging them and swap them instead.
meofbillions
Very impressive engineering. As an engineer myself, I'm pleasantly surprised.