Tue 14 July 2020 – A hydrogen-powered short-range commercial passenger aircraft could be flying within Europe by 2035, finds a major new study commissioned by the EU’s public-private Clean Sky 2 and Fuel Cells & Hydrogen Joint Undertakings. The published report concludes hydrogen propulsion has the potential to significantly reduce aviation’s climate impact. However, it will require significant aircraft R&D, further development of fuel cell technology and liquid hydrogen tanks, and also investment in fleet and hydrogen infrastructure alongside accompanying regulations and certification standards. The report lays out a number of policy actions and the framework needed for the transition, including a guiding roadmap, plus a big increase in in long-term research and innovation activities and funding. The report coincides with the launch by the European Commission of an ambitious strategy to include hydrogen in the EU’s overall energy mix as part of the bloc’s 2050 carbon neutrality goal.

Today, according to the ‘A hydrogen strategy for a carbon-neutral Europe’, hydrogen plays only a small part in the mix and is still largely produced from fossil fuels, notably from natural gas or from coal, resulting in the release of 70 to 100 million tonnes of CO2 annually in the EU. For hydrogen to contribute to climate neutrality, it will need to achieve a far larger scale and its production must become fully decarbonised, says the Commission. Renewable hydrogen – also called clean or green hydrogen – is produced through the electrolysis of water in an electrolyser powered by electricity stemming from renewable sources. The full life-cycle greenhouse gas emissions of the production of renewable hydrogen are close to zero.

In the first phase of the strategy, from 2020 up to 2024, the objective is to install at least 6 GW of renewable hydrogen electrolysers in the EU and the production of up to 1 million tonnes of renewable hydrogen. Some existing hydrogen production plants will need to be decarbonised by retrofitting them with carbon capture and storage (CCS) technologies. During the second phase, 2025-2030, hydrogen needs to become an intrinsic part of an integrated energy system with a strategic objective to install at least 40 GW of renewable hydrogen electrolysers by the end of the phase and production reaching 10 million tonnes.

In the third phase, from 2030 onwards and towards 2050, renewable hydrogen technologies, including hydrogen-derived synthetic fuels, are expected to reach maturity and deployed at large scale to reach hard-to-decarbonise sectors, such as aviation.

From now to 2030, investments in electrolysers could range between €24 and €42 billion, with a further €220-340 billion required to scale up and directly connect 80-120 GW of solar and wind energy production capacity to provide the necessary electricity to the electrolysers. In addition, huge investment will be required in CCS retrofitting; hydrogen transport, distribution and storage; and hydrogen refuelling stations for surface transport. To support these investments and kick off the whole hydrogen eco-system, the Commission has set up the European Clean Hydrogen Alliance, which will have a clear deliverable to identify and build up a clear pipeline of viable investment projects.

Because of the high costs involved in the switch to renewable hydrogen, the Commission is considering various demand side support policies and incentives at EU level, including the possibility of minimum shares or quotas in specific end-use sectors. The Renewable Energy Directive already provides support for renewable hydrogen and includes it explicitly as a means of meeting renewable targets in the transport sector. In the forthcoming revision of the EU ETS, the Commission says it may consider how the production of renewable and low-carbon hydrogen could be further incentivised.

The ETS Innovation Fund will pool together around €10 billion to support low-carbon technologies over the 2020-2030 period and will have the potential to facilitate first-of-a-kind demonstration of novel hydrogen-based technologies. The fund can substantially reduce the risks of large and complex projects, and therefore offers a unique opportunity to prepare such technologies for a wide-scale roll out, says the Commission. A first call for proposals under the fund was launched earlier this month.

It acknowledges that to kick-start hydrogen development, industry requires clarity and investors need certainty in the transition. The interest in clean hydrogen is growing globally, with the US and China investing heavily in research and industrial development, and an international hydrogen trade market is likely to develop. In this context, advises the Commission, the EU should actively promote new opportunities for cooperation with neighbouring countries and regions.

As part of its strategy of promoting research and innovation in hydrogen technologies, the Commission says it will launch in the third quarter of 2020 a 100 MW electrolyser and a Green Airports and Ports call for proposals as part of the European Green Deal call under the Horizon 2020 programme.

A similar strong increase in long-term research and innovation activities and funding is recommended in the ‘Hydrogen-powered aviation’ report, alongside other policy actions. These include an aviation roadmap to guide the transition, setting out clear ambitions, align standards, coordinate infrastructure build-up, overcome market failures and encourage first movers. A long-term policy framework will have to lay out the ‘rail guards’ for the sector, including how climate impact will be measured and how the roadmap will be implemented.

The technical challenges and unique characteristics of hydrogen as an on-board energy source make it best suited to commuter, regional, short-range and medium-range aircraft, says the report. In time, long-haul air travel is likely to be based on liquid hydrocarbon fuels.

Hydrogen planes would be similar in shape to traditional commercial planes but would need a slightly longer length. Smaller planes would likely use propellers, with hydrogen-powered fuel cells providing electric propulsion to turn the propellers. The report suggests hydrogen power could be feasible by 2035 to power a commercial passenger aircraft on a flight up to 3,000 kilometres and by 2040 a medium-range flight of up to 7,000 kilometres could be possible.

“That means you could connect all the big cities in Europe using hydrogen-powered planes, and by 2050 the ambitious scenario is that 40% of the European fleet would be powered by hydrogen,” said Dr Bart Biebuyck, Executive Director of the Fuel Cells and Hydrogen Joint Undertaking, a European public-private partnership to accelerate these technologies.

Reaching the goals will rely on a number of factors, including the need to advance hydrogen storage technologies and new ways of transporting hydrogen to airports. Redesigns of aircraft interiors will be required to work out how to integrate all the necessary systems and tubing to run commercial planes on hydrogen.

“With integration, nothing has been done yet on a big plane,” said Biebuyck. “That would be a big challenge and we still need to prepare a lot of standards, codes and regulations. For example, what the aviation requirement for hydrogen tanks testing would be.”

As well as a storage system to safely hold liquid hydrogen, the other major components required are fuel cells to convert hydrogen to electricity, a device to control the power of the cells and then a motor to turn a propeller. However, progress has already been made in developing the underlying technology of hydrogen planes. In 2008, Boeing flew the world’s first hydrogen-powered plane – a single-seater – from an airfield near Madrid and in 2016 the first four-seater, built by German aeronautical research agency DLR, the University of ULM and a company called H2FLY, flew from Stuttgart Airport.

In Spain, an EU experimental plane project called HEAVEN is developing a powertrain to turn the propellers at high speed using electric power, along with similar liquid hydrogen storage systems to those that have been used in cars. The powertrain turns the hydrogen into torque to turn the propeller.

“This will be the first liquid hydrogen storage system for planes, which will be connected with a fuel cell and an electric motor, and then flown in a flight test,” said Dr Josef Kallo from the DLR and a member of the HEAVEN team. “The hydrogen storage, made by French firm Air Liquide, is built and will be finished this year. Next year will be the time for integration and then at the end of 2022, we will go into flight.”

For a 45-seater aircraft, a hydrogen-powered propeller plane will be capable of speeds of up to 600 kilometres per hour, according to Kallo, similar to the ATR 72 twin-engine turboprop short-haul regional airliner. While the focus is now on propellers, work is also underway to develop hydrogen-powered turbines, which are more efficient at higher speeds and relatively low noise, he said.

Most hydrogen today is produced by reforming methane from natural gas – a fossil fuel – which produces CO2. Green hydrogen, by contrast, is developed by using an electric current from a renewable source to convert water into oxygen and hydrogen. According to the study, latest estimates show hydrogen combustion could reduce climate impact in flight by 50 to 75%, and fuel-cell propulsion by 75 to 90%. This compares to around 30 to 60% for synthetic fuels (synfuels).

Compared to conventional aircraft, for a fuel cell-powered propulsion commuter or regional aircraft, the operational costs could increase by as little as $5-10 per passenger, found the study. This is before carbon costs and considering all direct infrastructure and CAPEX costs, but not indirect infrastructure costs like potential changes to airport layout, which remain highly uncertain. For short-range aircraft, a hybrid propulsion approach – hydrogen combustion and fuel cell – the costs increase per passenger by 20-30%. The next largest segment, medium-range aircraft, requires significantly extended fuselages for liquid hydrogen storage and would consume around 25% more energy than conventional aircraft, which would lead to a cost increase of 30-40%.

Considering the amount of climate impact avoided, says the report, this translates into costs per abated ton of CO2 equivalent to less than $60 for regional and commuter and $70-220 for short- and medium-range aircraft. This, it adds, compares favourably to $210-230 per ton CO2e for synfuel from direct air capture for short- to long-range aircraft.

Hydrogen is technically feasible but less suitable for evolutionary long-range aircraft designs from an economic perspective. The hydrogen tanks would increase airframe length and energy demand, resulting in 40-50% higher costs per passenger, and the study found synfuel is likely the more cost-effective decarbonisation solution. New aircraft designs, such as the blended wing body, could change that but is maybe at least 20 years away from entry into service.

If hydrogen-powered aircraft are deployed in segments where they are the most cost-efficient means of decarbonisation, they could account for 40% of all aircraft by 2050, with this share further increasing after 2050. With synfuel and/or sustainable biofuel powering the other 60%, aviation’s climate impact would then fall by the equivalent of about 2.7 gigatons of CO2e compared with 5.7 gigatons in a baseline scenario where only efficiency improvements are made, estimates the study.

“By 2050, we need to become a carbon-neutral society and the aviation sector needs to contribute,” said Biebuyck. “Of course, it is not only aviation that will have to adapt. We all need to work together but we cannot beat climate change without aviation being decarbonised.

“The hydrogen and fuel cell sector is ready to work hand in hand with the aviation industry to design, test and produce the required components and make zero-emission aviation an everyday reality.”

The report was presented at a virtual event (see below) that featured EU Transport Commissioner Adina Vălean and Patrick Child, Deputy Director-General of the Commission’s research and innovation directorate, as keynote speakers, along with other speakers from Airbus, Safran, DLR and the hydrogen industry.

“Hydrogen in aviation offers many opportunities for the transformation of our aviation sector,” said Vălean. “From production, to distribution, to new aircraft designs and large-scale use, it provides numerous opportunities for European companies to be at the forefront of our industrial revolution in the years to come.”

Added Child: “The excellent cooperation between the existing Joint Undertakings dedicated to hydrogen fuel cells and clean aviation illustrates the need for close synergies between the two sectors as we work together on the ambitious objectives of the post-Covid recovery and the European Green Deal.”

Hydrogen-powered aviation: preparing for take-off:

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