Which alternative fuels will actually help decarbonise the transportation sector by 2050?

On an urgent but arduous journey to decarbonise, the transport sector wrestles with the multiple challenges of growing passengers and increasing revenue, while also meeting increasingly tighter environmental targets. Additionally, government and public pressure is driving airlines, automotive manufacturers, shipping companies, and rail operators to use greener fuels and energy sources.

Here, Graham Upton, Head of Technology, Innovation & Chief Architect, Intelligent Industry, takes a deep dive into current developments in alternative fuels, and explains how transportation businesses can use them to offset carbon emissions while allowing mass sustainable travel. 

What are the key challenges in aviation?

Under the most glaring spotlight in transportation is the aviation industry – responsible for around 2-3% of global C0₂ emissions. According to the World Economic Forum, aviation demand will grow two-five times by 2050, putting even more pressure on bosses to decarbonise the sector.

Aside from electric Vertical Take-Off and Landing aircraft (e-VTOL) or hybrid-electric aircraft, one solution is to replace current fuel with sustainable aviation fuel (SAF) – renewable or waste-derived aviation fuel that meets sustainability criteria. There are two main categories of SAF: biofuels and synthetic electrofuels.

What are the differences between biofuels and electrofuels?

Biofuels originate from various biological sources, including waste materials and specific crops like corn and palm trees. Processing these materials involves breaking down complex plant structures into carbon-rich molecules, a key component of jet fuel.

Electrofuels, on the other hand, are synthesised from carbon dioxide and hydrogen made from electrolysis.

What’s the future of SAF in the aviation industry?

The International Civil Aviation Organisation’s CORSIA aims to cap aviation emissions at 2020 levels until 2035, with the industry targeting net zero carbon by 2050. SAF currently offers the best chance to meet these goals in the near term.

The Sustainable Aviation Fuel Grand Challenge, launched in 2021, aims to increase domestic consumption to 3 billion gallons by 2030 and 35 billion gallons by 2050, with a target of reducing lifecycle greenhouse gas emissions by at least 50%. Various manufacturing methods for SAF include Fischer-Tropsch, microbial, and hydro-processing, and SAF production facilities are expected to blend the fuel with Jet A1 at existing terminals for delivery to airports.

Currently, high production costs and limited supply mean SAF is up to five times more expensive than conventional jet fuel – a challenge stemming from the inefficiency of production processes, which are not yet widely implemented at commercial scale. Utility company Anglian Water has committed to providing biosolids – a product of its wastewater treatment process – to Firefly for an initial pilot SAF facility, who in turn will provide over 500 tonnes of the fuel to Wizz Air. Farm and food waste may not suffice to fully decarbonise all global sectors. Thus, there’s a need to ramp up the production of fuels from renewable electricity.

What are the benefits and drawbacks of SAF?

SAF can offer a significant carbon emission reduction between 65-85% compared to fossil kerosene, contingent on its life cycle and production methods. While SAF, like conventional jet fuel, emits nitric oxide (NOx), sulphur oxide (SOx), and other pollutants when burned, by utilising sustainable resources instead of fossil fuels, SAF ideally establishes a closed carbon cycle.

However, it’s worth nothing that current alternative fuel production processes may contribute to CO₂ emissions due to energy requirements or ecosystem impacts. Recent advancements demonstrate promising developments, like Virgin Atlantic’s trans-Atlantic flight using 100% SAF derived from BioForming® S2A technology. This technology produces BioForm® SAK, enabling creation of 100% sustainable fuel compatible with existing aircraft, infrastructure, and engines, eliminating the need for blending with conventional fuel.

Download Capgemini’s full study of aviation fuels, here.

What decarbonisation progress is being made in the shipping industry?

The shipping industry also struggles with a reliance on polluting fuels, currently responsible for 3% of global emissions. Heavy fuel oil remains the dominant choice due to its low cost – 30% cheaper than distillate fuels like marine diesel oil or marine gas oil.

Introducing cleaner alternatives like hydrogen, ammonia, and methanol presents a significant challenge as production requires enormous amounts of renewable energy to make them truly ‘green’.

According to a study by the International Chamber of Shipping, the industry will require up to 3,000 terawatt-hours (TWh) of renewable electricity a year, which almost equals the current global total of wind and solar electricity output (about 3,444 TWh).

When assessing how green a fuel really is, not only are the emissions created by burning it in the ship’s engine important but also the emissions from extracting, producing, transporting, and storing it – called “well-to-wake”.

In the same way an electric car is not zero-carbon if its power is generated using fossil fuels, nor is a ship using ammonia or methanol produced by burning natural gas. Among new technologies, battery systems, fuel cells, and wind-assisted propulsion offer potential for shipping applications.

Consideration of new global supply chain infrastructure is needed for their distribution, whilst other crucial steps include updating regulatory frameworks and developing new, green fuel-compatible ship engines.

The financial barriers to decarbonisation are substantial. Although estimates vary, it could cost a monumental $2 trillion to fully decarbonise the shipping industry – a significant portion directed towards green hydrogen production, which is also essential for creating green methanol and ammonia.

Learn more about green hydrogen in Capgemini’s investigation into low-carbon energy solutions, here.

Are ship engines ready for alternative fuels?

Rather than replacing the world’s merchant shipping fleet (over 120,000 vessels) with new sustainable vessels, retrofitting existing ships to operate using green fuels like methanol or ammonia is an alternative option. However, this is expensive (tens of £ms) and is not economically viable for older vessels nearing the end of their life. Maersk’s green methanol vessel and MSC’s hydrogen-powered cruise ships  offer a glimpse of what can be achieved but this is an incremental change compared to what is needed to revolutionise the industry.

How could regulations increase alternative fuel uptake?

Studies by the International Energy Agency predict green ammonia will be the most widely used fuel by 2050.  Interestingly, shipping companies have ordered more methanol and methane-powered vessels.  The International Maritime Organisation (IMO) has issued safety regulations for methanol as a fuel but lack of similar regulations for ammonia and hydrogen has created doubt among shipowners.

A global supply chain for green fuels is needed at ports worldwide. Today they are sporadically distributed with approximately 120 ports capable of storing and delivering methanol (not necessarily green). According to the Green Methanol Institute, about 0.7 million tonnes of green methanol could be produced globally by the end of 2023. Production capacity is projected to reach 8 million tonnes annually by 2027, with the global shipping industry requiring 550 million tonnes by 2050 to replace oil.

What role will hydrogen play in decarbonising the automotive industry?

Hydrogen-powered cars using fuel cells face their own challenges. Hydrogen gas has low energy density, therefore to be efficient in cars, it needs high-pressure tanks for enough range, making refuelling difficult. Constructing a network of hydrogen stations, like EV charging points, for widespread adoption is both expensive and comes with negative public perception due to safety concerns.

Download our whitepaper to learn about specific engineering challenges in the hydrogen value chain.

So, what are the key alternative fuels for automotive?

While hydrogen fuel cell cars face challenges, the race for sustainable transportation offers a mix of promising contenders. Battery electric vehicles (BEVs) are at the forefront, boasting zero tailpipe emissions and improving range with each generation. However, charging times can be longer than refuelling gasoline vehicles, and charging infrastructure, especially fast chargers for long trips, still needs to be expanded. While BEV technology is less suitable for heavy-duty trucks and long-haul transportation, it’s readily available for passenger cars and urban commuting, and a growing number of compelling models are driving mass adoption.

Biofuels like bioethanol, biodiesel, and hydrotreated vegetable oil (HVO) offer a partially renewable option. They can be blended with gasoline or diesel, leveraging existing infrastructure, and some studies suggest they typically produce between 32% and 98% lower GHG emissions than fossil fuels.

Concerns remain about the sustainability of feedstocks, potential land-use change impacts, and overall actual lifecycle emissions. Biofuels are commercially available today, but widespread adoption is contingent on ensuring truly sustainable production practices.

Biomethane, derived from organic waste, offers a cleaner alternative to natural gas for internal combustion engines. It boasts lower greenhouse gas emissions and can be injected into existing natural gas infrastructure. However, production capacity is currently limited, and widespread use requires significant investment in biogas capture and purification facilities. Biomethane is a promising option in the medium to long term, but infrastructure development will be crucial.

How can Capgemini help you decarbonise?

We have deep expertise in the energy industry and its pursuit to decarbonise. Capgemini has worked with a leading aerospace manufacturer to evaluate the demand for medium-range planes by 2030 and to assess the feasibility of hydrogen aircraft, demonstrating potential market opportunities.

We also collaborated with Newcastle Marine Services, the University of Strathclyde, O.S. Energy, and MarRI-UK on decarbonising green energy by converting diesel boats to the emission-free novel hydrogen propulsion technology, Liquid-Organic Hydrogen Compounds (LOHCs). This involved capturing data on GPS, documenting the journey from port, and monitoring energy usage for up to two days at a time while servicing wind farms.

There are distinct similarities between the challenges in shipping, aerospace, and automotive in terms of costs of production, and distribution compared to their obvious benefits to the environment to hit global C0₂ emission reductions by 2050. Engineers are continuously arriving at new solutions to overcome these hurdles.

Capgemini can help you navigate alternative fuel options tailored to your vehicle type and industry. Our end-to-end approach means we’re your business and technology transformation partner right from strategy formulation – considering factors like policy evolution and infrastructure need – through to creating winning business cases, developing digital prototypes, and implementation of technology solutions at pace and scale.

Learn more about our experience with energy transition and utilities, here.

Or get in touch to start the journey today.

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