Jonathan Douglas-Smith, head of sales for aerospace at Intelligent Energy, discusses the readiness of the UK for fuel cell aircraft.

The aviation industry’s shift towards zero-emission solutions has been driven by heightened concerns about greenhouse gas emissions. With air travel demand rebounding since the pandemic, there’s a pressing need to address the industry’s significant contribution to global greenhouse gas emissions which is set to grow to 8-15% by 2050 based on forecasted air passenger traffic growth.

In response to this challenge, government and industry bodies have launched initiatives like the Jet Zero strategy and CAA Hydrogen Challenge to curb the UK’s growth of carbon emissions and achieve net-zero status in domestic aviation by 2040.

Substantial investments, such as the £113 million allocation for hydrogen and all-electric flight technologies to unlock guilt-free flying, highlight the commitment that’s being made to realise sustainable aviation solutions.

Other sectors continue to look at batteries as a sustainable solution. While considered for aviation, this technology has limitations – in terms of weight and energy density – which bring significant challenges. More energy and power required by a plane means more batteries, and more batteries mean the plane needs more and more power (more batteries) to support all the weight. So, the sector is turning to other technologies to replace kerosene combustion engines.

Intelligent Energy is the UK’s sole PEM fuel cell design and manufacturer that is well-positioned to address aviation’s sustainability challenges through its hydrogen fuel cells. As a major partner in the UK’s Aerospace Technology Institute (ATI) H2GEAR  project, we’ve developed the underlying fuel cell stack technology for use in aviation.

Why fuel cells?

For aircraft requiring substantial energy, such as regional-sized planes, fuel cells are a suitable alternative. Through collaborative efforts in the H2GEAR programme, we are now moving into the final phase of the programme where we are elevating the technology-readiness level of our products.

While still a work in progress, we are keen to showcase our lightweight stacked fuel cell technology at the Farnborough International Airshow so the aerospace industry can visualise how it can take advantage of fuel cells.

Fuel cells offer greater power density and energy efficiency compared to batteries. Hydrogen fuel cell systems can provide up to 3-5 times more energy per unit weight than batteries, making them the best zero-emission solution for CS-23 and smaller CS-25 aircraft carrying less than 100 passengers.

At Intelligent Energy, we’ve developed our fuel cell technology with a unique direct water injection cooling system that enables the effective control of fuel cell system temperatures. This means our fuel cell stack needs a smaller heat exchanger, which reduces weight and drag and enhances overall efficiency – particularly at higher speeds.

Hydrogen refuelling also secures notable benefits over battery charging. Batteries can take hours to charge, rely on rapid-charging technology and often require significant grid upgrades. But hydrogen refuelling comes with an efficiency that mirrors that traditionally associated with kerosene use, and with no mechanical parts inside the fuel cell stack, the greater time between service intervals also saves valuable time and money.

Most importantly, hydrogen fuel cells emit zero emissions from the tailpipe, contributing to sustainable aviation without the environmental impact associated with traditional fuels. Another alternative technology being considered in aviation is Sustainable Aviation Fuel (SAF), however, this is very expensive to produce, making it unpopular with airlines, and SAF still produces greenhouse gas emissions, albeit less so than fossil fuels. It is predicted that, in a best-case scenario, SAF would only reduce aviation CO2 emissions by 61% by 2050.

Hydrogen being burned in modified existing aero engines is being considered, which eliminates carbon dioxide emissions. While this would be an improvement to using fossil fuels, burning hydrogen still emits harmful nitrous oxides, which is a stronger greenhouse gas than CO2.

So, hydrogen fuel cells hold a strong position as we journey towards eco-friendly aviation, promising not only environmental advantages but also the ability to transport significant numbers of passengers across meaningful distances. These benefits are also supported by the aviation industry’s belief that fuel cell powered aircraft will be operationally safe.

Future outlook

It’s clear that hydrogen presents a practical solution for decarbonising aviation but scalability remains a key consideration. The general consensus is that fuel cells are highly effective for aircraft up to a certain size. Currently, fuel cells are robust for aircraft containing up to 50 seats, possibly extending to 100 seats, depending on technological advancements.

Regulatory standards and certification for new technology are still evolving however, there is significant investment ongoing into the hydrogen fuel-cell-powered aircraft ecosystem from public, private and regulatory entities to make fuel-cell-powered aircraft a reality as soon as possible, in order to support aviation’s journey to decarbonisation. There is an expectation that hydrogen fuel-cell-powered aircraft will gain traction and could become operational for regional travel within the decade.

At Intelligent Energy, we’re working closely with the regulators, who are writing the industry safety standards around hydrogen in aviation, to ensure alignment within our future products.

www.intelligent-energy.com