HYDROGEN (H2) holds promise as a Green Energy source
Battery Cell and Fuel for Turbine
AIRBUS and Boeing positions plus two test flights
Aviation, particularly the airline sector, has adopted very strong goals for reducing CO2 emissions through an ICAO resolution called CORSIA. Much of the early mitigation action has focused on biofuels.
The below articles present some informative insights about HYDROGEN as an alternative fuel for the turbines and as a source for energy through batteries.
- The first listing elucidates the technical dimensions of this energy source, a long text fully included;
- then Airbus announces several of its hydrogen commercial aircraft;
- two articles about Boeing’s views on hydrogen—not clear what the final message
- finally, two reports of successful H powered flights.
It is being touted as a potential “holy grail” in the quest to decarbonize aviation. Hydrogen already successfully powers cars, so what does it take to transfer the technology to commercial flight? Let us take a look at how a hydrogen-fuelled passenger aircraft actually works.
The team behind the HY4 is developing a 19-seater regional hydrogen-powered plane. Photo: Getty Images
Yesterday, the world’s first commercial-grade all-hydrogen-powered flight successfully took off, flew, and landed back down in Bedfordshire, UK. Along with Airbus’ ambitious zero-emissions concept release earlier this week, this makes it an excellent time to dive a little deeper into what goes on behind the fuselage of these aircraft.
In its simplest explanation, a hydrogen aircraft is an aircraft that uses hydrogen fuel as a power source instead of traditional jet fuel. It can either be burned in a jet engine or used to power a fuel cell that generates electricity. The hydrogen needs to be stored in special pressurized tanks inside the fuselage, as opposed to other fuel, which is stored in the wings.
No emissions but water
Long-touted as a viable option for a sustainable fuel source, hydrogen has recently risen to the forefront as one of the most probable contenders as commercial aviation grapples with lowering its contribution to global emissions. Planes using hydrogen as a power source would only emit water while traveling at near the same speed as aircraft with engines running on traditional jet-fuel.
In 2008 Boeing flew its Fuel Cell Demonstrator for the first time. Photo: Adambro via Wikimedia Commons
A brief history of hydrogen flight
Of course, the basic technology is already available. In February 2008, Boeing flew the world’s first hydrogen-powered manned plane from an airfield near Madrid, Spain. The two-seat Dimona motor-glider was refitted with what is known as a proton exchange membrane. This fuel cell transforms the energy liberated during the chemical reaction of hydrogen and oxygen to electrical power.
In 2016, the experimental four-seater HY4 took off from Stuttgart Airport in Germany. At the time, André Thess, head of the DLR Institute of Engineering Thermodynamics, said that the goal was to improve the fuel cell power train further and use it on regional aircraft with up to 19 passengers.
The HY4 hydrogen aircraft took its maiden
flight in 2016. Photo: DLR, Felix Oprean via Wikimedia
250 miles before the end of the year
ZeroAvia, the start-up responsible for yesterday’s six-seater Piper Malibu all-hydrogen feat, intends to fly ranges of 250 to 300 miles by the end of the year. Of course, there is also Airbus’ new concept, which could potentially enter service by 2035. This includes a regional turboprop, a medium-haul narrowbody option, and an innovative wide fuselage model.
Storage is undoubtedly one of the key components to take into consideration when designing hydrogen planes. Hydrogen needs to be stored in pressurized tanks. In Airbus’ medium-range turbofan design, for example, it would be stored and distributed via tanks located behind the rear-pressure bulkhead.
In general, hydrogen planes could be aesthetically similar to modern jetliners, albeit with a slightly elongated fuselage or shorter cabin. Meanwhile, a radically redesigned plane, such as Airbus’ 200-passenger “blended wing-body” design would open up more options for storing the gas.
The blended wing concept provides for more storage options. Photo: Airbus
Concerns related to the safety of storing hydrogen on an aircraft are often raised by those who question the technology. However, in an article in Sustainable Energy News from 1997, German scientists concluded that hydrogen aircraft would be no more dangerous than conventionally powered ones.
In fact, in some respects, they could even be deemed safer. The researchers identified the main issue to lie with installing the necessary infrastructure at airports and refueling, rather than with the planes themselves.
Hydrogen fuel cells already exist in cars. The only problem is there is hardly anywhere to refuel them. Photo: Getty Images
Fuel cells vs. combustion
Then, of course, there are fuel cells needed to convert the hydrogen into energy. The technology already exists in hydrogen fuel-cell cars. Of course, hydrogen fueling stations are far and few between, so the broader introduction becomes somewhat of a chicken-and-the-egg situation.
The fuel cell is the system’s power plant. Hydrogen drawn from the onboard tanks is combined with oxygen. During the oxidation, hydrogen atoms react with oxygen atoms to form water. During this process, electrons are released. They then move through an external circuit as an electrical current. Water and heat are the only by-products.
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This technology is incredibly quiet. Imagine those electric cars or mopeds you do not hear approaching. It would make for a very pleasant and noise-free plane-ride for passengers, not to mention the improved quality of life for those living in the near vicinity of an airport.
This is different from hydrogen-powered engines that use combustion. These are simply a modified version of a traditional internal combustion engine that uses conventional fuel sources. While the smaller aircraft taking flight thus far have used fuel cells, Airbus proposes installing combustion engines in its turboprop ZEROe.
Airbus is proposing to use combustion in its regional turboprop hydrogen ZEROe concept. Photo: Airbus
R&I need to be accelerated
The Hydrogen Powered Aviation Report, released in May this year, concluded that “hydrogen propulsion has significant, so far underestimated potential to reduce the climate impact of aviation and contribute to decarbonization objectives.” However, it also adds that research and innovation must be immediately accelerated for the aviation industry to begin to make the transition.
The latest developments and presentations are undoubtedly exciting news. However, merely transitioning to hydrogen planes will not be a panacea for decarbonizing aviation. While zero-emission flights are a necessary goal and will contribute significantly to our transition towards a carbon-neutral society, unfortunately, most of today’s hydrogen is produced from methane, a natural gas. This process produces carbon dioxide in and of itself. The energy sector also has a lot of work to do.
What is your take on hydrogen planes? Do you think they should be redesigned to better accommodate storage options? Fuel cell or combustion engine? Let us know in the comments.
Journalist – With a Masters in International Relations, Linnea has combined her love for current affairs with her passion for travel to become a key member of the Simple Flying team. With eight years’ experience in publishing and citations in publications such as CNN, Linnea brings a deep understanding of politics and future aviation tech to her stories. Based in Amsterdam, Netherlands.
Airbus has revealed three concepts for the world’s first zero-emission commercial aircraft which could enter service by 2035. All of these concepts rely on hydrogen as a primary power source—an option which Airbus believes holds exceptional promise as a clean aviation fuel and is likely to be a solution for aerospace and many other industries to meet their climate-neutral targets.
Boeing’s top product developer doubts hydrogen-powered airliners will be viable in the near future due to technical and regulatory hurdles and remaining technological uncertainty.
Speaking to reporters on 22 September, Boeing’s Sinnett describes hydrogen power as having “unique promise”. He made his comments while also discussing Boeing’s ecoDemonstrator programme, which recently partnered with Etihad Airways to test noise-reducing and efficiency-boosting technologies using a 787.
As part of its ecoDemonstator programme, Boeing and Etihad Airways recently pressed this new 787 into test duty, evaluating various technologies aimed at reducing aircraft noise and improving efficiency.
But, Sinnett says, hydrogen-fuel production and storage challenges will take significant time to work through. Additionally, for hydrogen propulsion to become reality soon, government regulators must work at a pace matching technological development – also no sure bet.
“I don’t think it’s something that’s right around the corner,” Sinnett says.
Boeing‘s ecoDemonstrator program has been designed to accelerate innovation, by taking promising technologies out of the lab and testing them in the air; to improve sustainability for airlines, passengers and the environment.
The 2020 program was conducted in partnership with Etihad Airways, on one of their new Boeing 787-10 Dreamliner airplanes, expanding a strategic sustainability alliance that the two companies formed in the fall of 2019. Other key partners included NASA and Safran Landing Systems.
Flight testing on the four projects was conducted over eight days at Boeing’s facility in Glasgow, Montana and featured two transcontinental flights between Seattle, Washington and North Charleston, South Carolina.
A hydrogen fuel-cell plane that’s capable of carrying passengers completed its maiden flight this week, in another step forward for low and zero-emission flight.
ZeroAvia’s six-seater Piper M-class aircraft — which has been retrofitted with the device that combines hydrogen and oxygen to produce electricity — undertook a taxi, take-off, full pattern circuit and landing on Thursday.
California-based electric aviation company Ampaire flew its second hybrid-electric technology demonstrator for the first time last week. Ampaire’s “Electric EEL” is a converted Cessna 337 Skymaster powered by tail-mounted 310-horsepower Continental IO-550 and a 200kW—limited to 120 kW—electric motor in the nose. In partnership with Mokulele Airlines and climate change solutions company Elemental Excelerator, Ampaire plans to use the prototype to conduct a series of flight trials in Hawaii later this year.
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