Questions and Answers
How can governments help transition commercial aviation to zero-emission?
- Provide R&D project assistance using emission reduction metrics as the figure of merit.
- Streamline regulatory path for zero emission technologies, especially on the initial stages of experimentation.
- Once the vehicles are available, create operating incentives, perhaps similar to what exists already in California, USA (Low Carbon Fuel Standard Credit program that creates a robust market for carbon reduction in transport).
What sustainability requirements could be required as a part of COVID-19 assistance to airlines, especially after the Air France example?
- This is a perfect moment to incentivize low- and zero-emission technologies, beginning with the local, regional aircraft.
What will be the fuel of the future?
- Hydrogen-derived fuels, which include pure hydrogen and hydrogen-derived synthetic aviation fuels.
What do you see as the biggest roadblocks to a cleaner aviation path: governing bodies, technology, public perception, or something else? What are the top three hurdles to be cleared for success? Are they technical or social, like public fear of Hydrogen? How do you plan to overcome these?
- Montserrat Barriga: My personal opinion only: financial, technical, regulatory in this order. We should be able to overcome the psychological resistance if any.
- The biggest challenge is probably regulatory—the technology is already getting there, and the economics of hydrogen is getting to comparable to jet fuel within the next 3–5 years (already there for some segments).
Which roles do other stakeholders play such as oil & gas majors, electric utilities?
- Energy companies have a huge opportunity in leading the fuel infrastructure build-out for this $1.5T market.
What is the pathway for making e-fuels competitive with conventional jet fuel? What is the most promising path for cost competitiveness within this decade?
- Learning curve is already on track to break-even with jet fuel in the next 3 years for small aircraft, 5—7 years for large aircraft and large operators.
Can we raise the ambition and decarbonise completely by 2050?
- Yes we can, from the tech perspective, but fleet replacement will be the long haul, unless we see government programs that incentivize early fleet retirements.
How has COVID impacted the timeline for demand for sustainable aviation solutions?
- Accelerated it. See Air France restriction of sub-500NM flight, and many other government assistance programs for aviation industry that have green strings attached.
When will the infrastructure be ready for non-jet fuel as a source of energy, for example green vs grey H₂? What kind of infrastructure will need to be in place for the various solutions?
- Already in 3 years, we can see green H₂ infrastructure at the small and medium airports that will break even with jet fuel for small aircraft and small operators.
Which geographies will go first?
- We see great momentum in Europe in general, in particular in the UK, Norway, France, and Germany.
What is the role for carbon pricing to accelerate sustainable aviation?
- Very helpful for initial adoption. See California’s LCFS program.
- Audience: If aviation fuel was taxed to the same level as car fuel, low carbon aviation technology will become financially sustainable in the same way as the electric car industry is doing today. Currently airliners are operated at minimum cost per seat per mile and not minimum carbon emission, e.g. fuel tanking procedures. Taxing JET A fuel will finance the transition.
Under what conditions could the aviation industry progress under a “de-growth” model? Less energy consumed of course means there must be less travel and transport overall, less flying specifically, exchange of some flight for surface travel… How can aviation companies work with rail, shipping, etc. so that travel and transport is a more collaborative rather than competitive industry?
- We don’t think de-growth is the right answer. Technology to de-carbon is the right answer. Aviation is a great connector and uplifter of society—we must make it clean to let it continue doing its great service to humanity.
Do the panelists believe UAM or PAMeVTOLs provide a realistic urban transport mode, given the increasing urbanisation of our societies? With Earth’s population growing at a steady pace of around 80 million per year, have people behind this idea considered the numbers of flying vehicles that would be needed or required to support this growth in any given city?
- Great question. We believe that we need to focus first and foremost on the existing aviation segments, that actually produce emissions at an accelerated rate.
Barriga, are you and ERA engaged in specific bigger projects regarding sustainable aviation, for example EU Horizon 2020?
- Montserrat Barriga: Yes, projects like Artemisa, the development of SAF plant in an ultra-peripheral region, the Canary Islands. This is one example. Please read “Green and Sustainable Connectivity Report” on our website and write to me if you have any comments or questions.
How are we making sure that Zero Emission Aviation fits into the larger transition towards a Sustainable Energy Economy: sustainable energy production, storage, hydrogen production, technology and innovation.
- It’s all interconnected. We are setting up various partnerships as we speak. Aviation powered by hydrogen, with H₂ production and fueling infrastructure, will have dramatic impact on other industries, including ground transportation and energy.
Looking at the long term, is there concern over water conservation when producing hydrogen from electrolysis at a large scale? Would it be feasible to incorporate desalination powered by renewable energy in this process? Understandably, there are some challenges with efficiency in this regard.
- Water use is not a concern, as the amount of water used per average traveler is trivial compared to per-capita water use worldwide.
- Desalination can be used, and will require trivial amount of energy relative to the energy required for splitting water.
Is it conceivable that airlines could get more people flying if they think they could travel in a zero-emission aircraft? Could it not pull more customers to purchase tickets?
- Absolutely. We have seen Flight Shaming drive a negative 10% reduction in travel in some countries—logic tells us that reverse of that will drive at least 10% increase.
- We have seen studies that show that people will pay more for zero emission flights.
What are the differences in performance in some of the technologies we’re talking about here: battery versus Hydrogen, gaseous versus liquid H₂?
- Hydrogen-electric is 5–20x longer range, depending on H₂ storage type.
- Liquid H₂ has 5x advantage by weight over gaseous hydrogen.
What are the biggest research hurdles on the path to implementation?
- Energy density of energy supply. The answer is hydrogen or hydrogen-derived fuels.
- Power density.
When can we fly across the Atlantic on H₂ and when 100–200 PAX for over 500NM?
- Atlantic: 3–4 years (experimental).
- 100-200 PAX: 7–8 year (experimental).
What is the maximum range for a 50 seater with batteries? With hydrogen?
- Battery is limited by weight to 100–200 miles.
- Hydrogen is limited by volume to 1,000–2,000 miles.
What is the potential for retrofitting commercial fleets?
- This could be a primary initial market segment, allowing to scale much faster.
Why do we not see hydrogen-powered helicopters?
What is the route to commercialisation for your technology and specifically what opportunities do you see in the UK short haul sector?
- 10–20 seat aircraft in 3 years.
What is the life cycle impact of novel technologies?
- An order of magnitude reduction in lifecycle emissions.
Can you elaborate on hydrogen production pathways, like biomethane and traditional gas infrastructure?
- The most scalable way is electrolysis from renewable electricity.
Is this time of industry and general economic uncertainty a good time for small player innovation? Or is it a time that the primes are the ones to survive and eventually thrive?
- Now is absolutely best time for small companies that do not depend on ongoing revenues.
Which partnerships need to be built to de-risk the path to clean aviation?
- Certification and market access partnerships with established players at the right time.
What is the safety case for electric flight and how is it different from conventional propulsion?
- Fundamentally, electric power drive can be made more distributed with larger redundancy, which improves safety.
- Additionally, low-temperature, low-pressure electrified solutions have better safety characteristics.
What role should FAA and EASA play in “clean aviation” R&D schemes, compared to other government entities like NASA, CORAC, etc.?
- Make it easier to issue experimental licenses and conduct experiments for both small and larger aircraft.
What key investments does the UK need to make to cement its place in the future of sustainable aviation?
- Long-range, large-aircraft H₂ propulsion system development.
Do you see a trend towards smaller commuter aircraft flying regional connections while earlier enabling hybridization and related challenges like development, certification?
- We will have larger number of smaller aircraft, but the majority of the market, and thus impact of clean technologies, will be in the larger aircraft, which is currently over 90% of flights.
What is the breakpoint number of passengers where you must fly liquid and not gaseous hydrogen?
- Probably 20—40 passengers.
What should airlines do to accelerate or facilitate the transition to electric aviation?
- Airlines should engage with the technology companies to do early demonstrations on their routes.
Hydrogen fuels cells have been in existence for many years and never gained traction within the aviation industry….Why now?
- Tech has improved dramatically just in the last few years: efficiency of the production automotive fuel cells increased by 20–25% just in the last 3–4 years.
- Prices for fuel cells and hydrogen electrolyzers decreased by almost a half in the last 5 years as well.
I guess that Fuel cell hydrogen propulsion systems can only operate using propellers. As propeller airplanes normally operate at lower speeds than jet engines, will we need jet engines using hydrogen or SAF to still operate at today’s speed using jet engines?
- Actually a modern jet engine that powers today’s large jets is conceptually the same turbine that drives propellers in smaller planes—just rotating a fan instead.
How does fuel-cell hydrogen flight—as with ZeroAvia—compare to direct hydrogen flight via hydrogen IC engine or hydrogen jet. How does it compare to biofuel-driven flight?
- Fuel cells powering electric motors will always be more efficient than combustion.
- Maintenance costs will be lower due to lower temperatures, pressures and lower number of rotating parts.
- Biofuels are not scalable to anywhere close to 100% of aviation demand, so comparison is less meaningful.
Many new entrants are betting on all-electric, battery powered aircraft for commuter aircraft, Heart for example. And the established airframers, and McKinsey, state that synthetic fuels are the only viable solution for long distance aviation. Is there really a place for fuel cell based aircraft?
- The majority of the market is actually in neither of these segments.
- The majority of the market is in mid-size aircraft (A320 / B737) flying mid-distances (300–1000 miles).
- Fuel cells are perfect for that.
- Even in the smaller aircraft, hydrogen-electric is the only way to deliver reasonable range and economics.
- Synthetic fuels are drop-in fuels for the conventional engines, but while considered carbon neutral, they still emit SOx, NOx, microparticles and contrails similar to conventional fuel.
How will the airports—specially the medium ones—be able to cope with the logistics of refueling different kinds of aircraft requiring hydrogen, batteries, synthetic fuels and kerosene?
- Montserrat Barriga: Very good question. Ensure eligible funding for investments. True this is a classic challenge for medium and small regional airports that lack the economies of scale with reduced passenger numbers. It has been for safety and it will be for green investments: energy efficiency, electrical ground power to aircraft on stand.
How do you decarbonise air travel by building an expensive, state-of-the-art, energy, resources materials and technology–intensive flying pod with a payload of 250kg, that is 2–3 people including the pilot?
- Great question. You don’t.
Currently less than 5% of hydrogen produced is ‘green’ H₂ and all this is spoken for. How do you plan to increase the production of green H₂ to fuel their next generation aircraft in the 2030s?
- Electrolysis technology exists and is already approaching the right cost levels. That’s what will help scale green production. It will also help integrate more and more renewable energy into our energy mix, as hydrogen fuel provides natural storage.
We are only talking about civil aviation. What is the interest of customers on the military side instead? Any military zero–emission interest?
- Yes, but it’s less about emissions, more about quiet flight with in-field fuel generation (from solar, etc.), and low heat signatures.
Could cargo like Amazon or UPS be the initial uses of these electric or H₂ airplanes: less risk to passengers, and fulfilling CSR goals?
McKinsey just published a study for European commission. Suggests it will take until 2035. Your views? This would place the sector outside the scope of VC capital, relegate to government and big institutions, strategics?
- McKinsey study focused on long-term perspective, and in fact mentioned in the study that shorter term solutions are becoming available, like ‘evolutionary’ design of commuter planes with gas H₂ storage from ZeroAvia, but are out of scope for the report.
- These shorter term commercial solutions and markets provide first revenues and necessary technology maturation roadmap to enable longer-term deliveries.
- This is a $1.5T industry today, becoming $3–5T in 2050. Technological solution to the sustainability problem will be worth hundreds of billions of dollars. Yes, the timeline to that is a bit longer, so the VCs normally funding the new PokemonGo need not apply. Rather, the impact-driven capital providers with the view towards solving humanity’s biggest problems are the right types of investors to support this revolution.
Besides the technology challenges for battery and hydrogen fuel cells, what infrastructure and scalable challenges do you think need to be addressed? What do you think is the role of the governments and industry to address these?
- Audience: this is a powerful question. If you are going to have large scale Hydrogen use, you need production. However, I don’t believe a large scale centralized hydrogen production is the way to go. We need distributed production.
- Governments should incentivise the distributed hydrogen production not only for aviation but for other uses like heating or local energy storage, as it is already planning in some regions.
Is anyone seeing significant developments in the area of conformable, non-cylindrical, H₂ tanks that could be packaged efficiently inside an aircraft wing?
- Michael Tate (Infinite Composites): Type 5 tanks are a solution for less bulky storage vessels: www.infinitecomposites.com/composite-pressure-vessel-resources
- For larger aircraft and longer distances, liquid hydrogen will be the technology of choice. Low internal pressure in such tanks will allow conforming shapes. Additionally, they will require lower volume, compared to gas tanks. The downside is higher complexity and cost.
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