A new local entrant has emerged in the race for carbon-free air travel: Marina del Rey-based Hydroplane Ltd., which is developing a hydrogen fuel cell powertrain that can be swapped into existing general aviation aircraft.
Hydroplane announced last month that it won its second U.S. Air Force technology contract – worth $750,000 – to demonstrate its hydrogen fuel cell technology in aircraft both on the ground and in the air. At the same time, the company announced it recently closed a funding round that raised $2 million from unidentified angel investors.
Hydroplane’s fuel cell is in essence a hydrogen ion battery: hydrogen gas is split to create hydrogen ions that flow through the battery system to create about 200 kilowatts of energy to power the aircraft. The only emission is water.
“We are completely decarbonizing air travel,” said Anita Sengupta, Hydroplane’s founder and chief executive.
Sengupta is hoping to hold the first rigorous flight tests using the hydrogen fuel cell technology in Piper Aircraft Inc. general aviation planes sometime next year. The ultimate goal is to get Hydroplane’s hydrogen fuel cell technology certified for use in existing general aviation aircraft; the company is targeting the sizable mid-range flight market of 200 to 600 miles.
Sengupta is a propulsion systems engineer who spent 16 years working for NASA at the Jet Propulsion Laboratory in La Canada-Flintridge. She worked on several space missions, including the Mars science laboratory portion of the Mars Curiosity spacecraft, the Deep Space 1 craft that went on a flyby of an asteroid, and the Dawn spacecraft that orbited large asteroids Vesta and Ceres.
After a brief stint as senior vice president of systems engineering for downtown-based magnetic-levitation train developer Virgin Hyperloop, Sengupta decided to strike out on her own and launched Hydroplane in the spring of 2020, just as the pandemic hit.
She used her experience with ion propulsion at NASA and applied ion technology in an effort to develop a hydrogen fuel cell that could power an aircraft.
“The key to decarbonizing aircraft is energy storage,” Sengupta said. Because batteries and other energy-storage systems tend to be massive, using a large amount of storage is difficult on an aircraft, where every extra pound of weight decreases lift ability. As a result, there’s a strict limit on the amount of mass that can be used for energy storage.
“Conventional lithium-ion batteries only last about an hour in flying time, which means you can only fly about 100 miles or so. Hydrogen fuel cells have 10 times the energy storage for the same amount of mass, which allows you to fly for much longer times and therefore cover much longer distances.”
Sengupta said this extends the range to a maximum of about 600 miles, taking in the sweet spot of 200 to 500 miles for most general aviation travel.
Targeting mid-range market
Hydroplane is entering an increasingly crowded market for zero- or low-carbon-emission aircraft. Grabbing much of the headline attention in recent years has been the development of electric power train vertical takeoff and landing aircraft, led by Santa Cruz-based Joby Aviation. The aircraft that Joby has developed is designed for the local air taxi market and has a top range of 150 miles.
But efforts are growing to target the mid-range market of 250 to 600 miles, primarily through powertrain conversions of existing general aviation aircraft. (Larger commercial aircraft are for now out of reach, since the amount of energy required to lift them is too great for current zero- or low-carbon emission powertrain technologies.)
Two other local companies – both based in Hawthorne – are aiming for this market: Ampaire Inc., which is developing a hybrid gas-electric powertrain that can be swapped into Cessna Grand Caravan aircraft; and Universal Hydrogen Co., which last October raised $62 million in funding for testing of its hydrogen fuel cell retrofits to regional general aviation aircraft.
Earlier this month, Universal Hydrogen signed an agreement with Connect Airlines, a division of Bedford, Mass.-based Waltzing Matilda Aviation, to convert 75 regional general aviation airplanes to hydrogen powertrains, with purchase rights for an additional 25 conversions. Deliveries are set to start in 2025.
All this activity on the hydrogen fuel cell powertrain front represents the breaking down of the long-held belief that hydrogen fuel cells are too heavy for distance air travel, according to Darrell Swanson, a Newbury, U.K.-based advanced aviation mobility consultant who is familiar with Hydroplane.
“Hydrogen fuel cell technology was not developed for aircraft – it was developed for ground vehicles, where weight is not as important a factor,” Swanson said. “What Sungupta is doing is redesigning the hydrogen fuel cell for aerospace applications, giving it higher energy density for the same amount of mass.”
Differing approaches
Another key lynchpin of Hydroplane’s approach is its use of existing airplanes, as opposed to the designing of a completely new aircraft. Not only does this save time in the development process, it also offers an easier path for the technology to procure crucial flight certification from the Federal Aviation Administration.
“The air frame is already certified,” Swanson said. “That means less needs to get certified. For Joby and other (electric vertical takeoff and landing) companies, they have to get all the aircraft components certified, not just the power train. That takes a lot more time.”
In an attempt to make certification even easier, Hydroplane has pursued U.S. Air Force contracts, with the aim of getting the Air Force imprimatur on its technology. The first contract, for $150,000, came in 2020, right after the company was founded. It was awarded through the Air Force’s Agility Prime program, which invests in advanced air mobility technologies in the hopes they achieve military air worthiness.
Sengupta said that contract helped Hydroplane launch its research and development efforts.
The recent $750,000 Air Force contract Hydroplane announced last month allows the company, in partnership with the University of Houston, to demonstrate an engineering model hydrogen fuel cell-based powerplant in a ground and flight demonstration. Sengupta said she hopes the flight demonstration can occur next year.
She added that she thinks gaining military certification for Hydroplane’s technology will ease the path for FAA certification. She noted that Joby Aviation had taken a similar approach; that company announced in December 2020 that it received U.S. Air Force airworthiness certification and then in May, just 17 months later, announced its FAA certification.
But Swanson said that even with the military stamp of approval, getting Hydroplane’s technology certified by the FAA remains the company’s toughest obstacle in the near term.
“Once her (Sengupta’s) team gets that FAA certification – assuming they can get it – it should be fairly easy sailing,” Swanson said. “The demand for carbon-free air travel in this (mileage) range is most definitely there – more so than for the local air taxi market.”
