Industry's rendezvous with H2: How hydrogen can claim its place as a clean source of energy for sustainable mobility

Ready, set, H2

The European Union aims to be climate-neutral by 2050, which means net-zero greenhouse gas emissions for the 27 member countries. Recently, the Biden Administration set a goal of cutting US greenhouse gas emissions to 50% of 2005 levels by 2030.[1] And China has stated it expects to achieve net-zero greenhouse emissions by 2060.[2] A significant contributor to the success of these goals will be a wholesale restructuring of how the world’s transportation sector is powered: vehicles, planes, trains, and ships.

While many human activities contribute to global warming and pollution, the largest is transportation, which accounts for about 21% of all CO2 global emissions: 15% on the roads, 3% in the air, 2% on the seas, and 1% elsewhere.[3] Hydrogen fuel and fuel cells are possible replacements for fossil fuels as an energy source with either a low or zero carbon footprint. Their adoption will help achieve the transition to carbon neutrality.

The hydrogen molecule, specifically dihydrogen or H2, is seen (more than ever) as a viable and feasible means to generate usable energy complementary to other sustainable energy sources such as electric batteries and alternative fuel options such as biofuels.

And the enthusiasm for H2 today is much more than hype. As of early 2021, over 30 countries have released hydrogen roadmaps, and governments have committed funding.[4] The global hydrogen-powered transportation market is expected to reach $20 billion by 2025.[5] A growing number of countries are launching programs to produce "green" H2, including Germany, France, Japan, Canada, Australia, South Korea, the United States, and others.[6] And H2 is part of the EU’s plan to achieve carbon neutrality by 2050.

France is also investing heavily: 7.3 billion euros in H2 production over the next ten years, including distribution and storage infrastructure and heavy-duty use cases. An additional 1.5 billion euros will be dedicated to H2 in aviation. Germany is investing 9 billion euros to become a world leader in the production of hydrogen fuel. And in October 2020, the US Energy Department announced plans for a five-year, $100 million investment to develop environmentally sound hydrogen production and an H2 fuel cell for long-haul trucks.[7]

 H2: The basics

Hydrogen is the most abundant element on earth. It is colorless, odorless, but not directly available in nature. It's in water (H2O) and hydrocarbon molecules such as methane (CH4), ethane (C2H6), and propane (C3H8). H2 can be stored as a compressed gas, cryogenic liquid or chemical storage material.

H2 is well known and has been used for decades as a combustible energy source for industrial applications. In the nineteenth century, cities used H2 to light streetlamps and heat homes before transitioning to natural gas and electric power. H2 was used in World War Two to produce gasoline. And since the launch of the US Gemini Program in 1966, the space industry has relied on liquid hydrogen (LH2) to launch its rockets and fuel-cell technology to power manned flights to the moon.

The economics of fuel and the materials to produce energy for transportation is determined by several parameters, including energy density, safety, cost, weight, and volume. When we consider fuel economy as a metric – e.g., miles-per-gallon of gasoline – it’s essential to understand the calorific power per unit of weight—also known as the heating value. Specifically, the amount of heat that is released by weight for a type of fuel. For example, gasoline has an energy density of 45.8 MJ/kg, compared to H2 which has a density of 120-142 MJ/kg, about three times greater than gasoline. The higher the energy density of a fuel, the better because more more energy is available in the same unit of volume or weight.

In reality, producing H2 requires a lot of energy, and today about 90% of the world’s H2 is produced by coal and natural gas, which emit CO2. But in the not-too-distant future, H2 will be produced by low- or no-CO2 emitting sources such as solar and wind. While not fully adopted as a standard way of thinking about hydrogen production, the “colors” of hydrogen do provide some context into the different channels of production:

• At one end of the spectrum are black, brown, and grey H2 processes that use coal and natural gas and emit from 10 to 30 kg of CO2 for every 1 kg of H2 produced.
• In the middle of the spectrum is blue H2 that captures and stores the CO2 from natural gas, and turquoise H2 that uses biofuels, which emit from 2 to 7 kg of CO2 for every kg of H2 produced.
• At the other end of the spectrum are the future sustainable energy sources for producing H2: green for wind, solar, and renewables, pink for nuclear power, and yellow for the networked low-CO2-emissions electric grid. All these options use electrolysis, not combustion, to produce H2 and range from 1 to 5 kg of CO2 for every kg of H2 produced.

H2: Easier said than done

Hydrogen is a multi-purpose source of energy. However, it must be produced, stored, moved, and delivered in ways that make a hydrogen-based energy system both economically and environmentally viable. That includes considering the life cycle of the application of hydrogen that will contribute to the overall reduction of CO2 emissions in the transportation sector.

While there is a path forward for producing environmentally responsible hydrogen fuel, there are several challenges that must be addressed before hydrogen becomes a competitive alternative to fossil fuels:

• Adapt vehicle propulsion to H2 fuels. There are several options for re-engineering vehicles to use H2 as a fuel. The first is redesigning the existing combustion engine to integrate fuel cells that drive electric motors. One option is a hybrid propulsive system for trains, planes, and cars. For example, burning H2 to power engines is very efficient and the primary approach in aviation.[8] However, the combustion chamber must be hydrogen-ready to avoid the risk of damage from cracking and corroding metal. Adopting hydrogen fuel-cell technology to challenge battery-powered electric vehicles (EVs) in the automotive sector requires designing an electric powertrain optimized for different classes and vehicles.
• Increase fuel cell efficiency and lifespan. H2 can generate electricity in fuel cells when combined with oxygen. It is similar to battery technology, where an electrochemical process produces electricity by converting chemical energy into electrical energy through an oxidation-reduction or redox reaction. Current fuel-cell technology, based primarily on proton-exchange membrane (PEM) technology, is well known but still expensive. The efficiency of the PEM process is around 30% to 40%, depending on the electrolysis technology. The polymer electrolyte membrane is perhaps the most expensive component as it uses costly and rare components, including platinum and rare-earth metals. Today, there are fuel cells on the market for all applications and all power requirements. For example, Ballard Power Systems produces heavy-duty modules that provide flexible solutions for transportation applications, including buses, trucks, and light rail in a range of 30 to 100 kW net power.[9] However, even with an efficient fuel cell, there is the challenge of building a network of charging stations to ensure customer adoption.
• Control H2 volatility. Transport technology is a vital component of the energy cost equation for any fuel. A hydrogen tank requires special attention because H2 molecules dilute quickly and can pass through plastic and weaken metal. H2 gas, when mixed with air or oxygen, becomes explosive at very low concentration levels. When hydrogen is compressed as a gas or liquid, it must be stored in high-pressure tanks for gas and at cryogenic temperatures in liquid form. All of these facts create substantial challenges for H2 when it comes to safety, especially for aviation. The choice of the storage tanks, the location, and the size will depend on many factors, including the specific application, the system's electrical architecture, the technology used, safety standards, and the level of autonomy sought. For aircraft, the only practical option is to use liquid H2 because it is lighter and requires significantly less space than gas. However, the boiling point of hydrogen is -253.8°C, so it must be cooled cryogenically below that temperature to remain a liquid. A key challenge will be the cooling process requires about 30% of the energy generated by the hydrogen fuel cell system, which may challenge the viability of H2 as an option for the long-haul class of aircraft.

H2: Almost all modes of transport

Hydrogen will play a role as a future fuel in transportation. The immediate short-term market opportunity for hydrogen is terrestrial, specifically railways, trucks, and buses. There are speculative niche markets in the passenger vehicle sector, such as taxi services and ridesharing, but lots of uncertainty in the consumer auto sales market. The aviation industry faces a longer time horizon – perhaps 2035 – as there are many problems to solve, including a reliable green hydrogen supply delivered at the right place, the right time, and an affordable price.

H2 in rail

The forecast is rosy for hydrogen trains. By 2030, trains running on hydrogen could make up one-tenth of those not already electrified. And by mid-century, the H2 train sector could be worth up to $48 billion, according to Morgan Stanley.[10]

The reality is that today’s diesel trains are already electric as a fossil-fuel generator drives an electric engine that turns the wheels. Moving to H2 fuel-cell “hydrail” trains means replacing the diesel engine and generator; the electric motor architecture stays relatively the same. So, the engineering challenges of hydrail trains are less complex than aircraft and revolve around the integration of fuel cells and fleet operations. It is also easier to build the refueling infrastructure across the railway system.

Several nations have hydrogen train initiatives in the works today. For example, Germany and France have invested in H2 trains for several regions provided by Alstom, an early hydrogen innovator.[11] In January 2020, South Korea announced it was planning to launch a prototype H2 fuel cell train.[12] And Japan announced that it would develop a rail vehicle powered by a hybrid system that combines fuel cells and lithium-ion batteries. The first test runs are scheduled for 2021, with plans to commercialize fuel-cell trains by 2024.[13] 

H2 in aviation

Synthetic fuels, and eventually biofuels, will likely be used for long-haul flights, while H2 will be favored for regional short-to-medium range flights. Here, hydrogen is seen either as an alternative to kerosene in a modified gas turbine or an electric generator to power an electric motor, offering close-to-zero greenhouse gas emissions. The global hydrogen aircraft market is forecast to reach $28 billion by 2030 and $174 billion by 2040.[14]

Still, the mainstream adoption of H2 in aviation will face hurdles because of the significant safety and technical challenges. To take advantage of LH2 to produce thrust means aircraft engine –both turboprop and turbofan – must be redesigned to include a process to “boil” gaseous hydrogen and modify it to fit the existing kerosene-based combustion chamber. These changes will make the engine more effective because the aircraft’s auxiliary air conditioning and onboard electrical generation can be directly powered by the fuel-cell system. And as stated earlier, the LH2 must also be stored in large, isolated, heavy tanks.

In addition, a new electrical distribution architecture is needed to generate electric power of up to 20 MW and a voltage increase from 230 V to 800 V. A significant part of the electricity produced will be used to cool the tank to -253° C. This will impact the aircraft's performance due to tank drift and weight and the fuel-cell system's overall effectiveness.

Finally, the adoption of aviation H2 requires the deployment of affordable technology at airports to encourage adoption by airlines. The need for infrastructure at airports led a consortium of organizations, including Paris Region, Choose Paris Region, Groupe ADP, Air France-KLM, and Airbus, to explore hydrogen opportunities at Paris airports.[15]

 H2 in automotive

The automotive sector’s big bet is on electrification using the battery-electric model, not hydrogen. The lack of appeal for H2 has been expressed loud and clear:

Herbert Diess, Volkswagen's chief executive, said, "You won't see any hydrogen usage in cars. The physics behind it are so unreasonable."[16] Mercedes shuttered an H2 project in 2020 and is no longer investing in passenger-car fuel cells.[17] Peterbilt, Kenworth, and Tesla plan to produce trucks that feature all-electric powertrains with battery packs to provide a longer range. In Europe, GM, Mercedes, and Volvo are investing in electric vehicles. In the US, FedEx set a goal of becoming carbon-neutral by 2040, requiring it to shift to all-electric delivery trucks.[18]

Still, there are proponents of hydrogen, and experimentation continues. The BMW i Hydrogen NEXT project will begin pilot production in 2022.[19] The X5 based model has plastic tanks that hold enough hydrogen to achieve the same range as a gasoline-powered model. Hydrogen is used to generate electricity to power a 369 hp electric motor. With that said, BMW does not expect any consumer offering until the “second half of this decade,” depending on demand.[20]

Still, electric vehicles have their own limitations, for instance, the restricted range of a typical EV battery and the time and effort to recharge. A recent study found that 20% of EV owners in California replaced their cars with gas-powered models because they lacked power or Level 2 charging at home.[21] Hydrogen also has an energy-to-weight ratio that is ten times greater than lithium-ion batteries. And depending on the battery capacity and other factors, hydrogen tanks can be refilled several times faster than fully charging an electric battery. Also, the recycling of EV batteries adds to the total cost of ownership.

There are several legitimate applications for H2 in the automotive sector. First, as a range extender for heavy-duty, light commercial vehicles (LCV’s) or long-range/long-haul trucks. Extending range is a significant development area as large diesel trucks account for 40% of the transport sector's greenhouse gas emissions and 5% of fossil-fuel CO2 emissions.[22]

For example, Stellantis is looking at LCV’s that have a large battery and an additional small low-power fuel cell to extend the range. The range extender would provide power to the battery but would not propel the vehicle if the battery is empty. This concept compares to full-power fuel cell systems that have large and powerful fuel cells and smaller batteries.[23]

Another scenario for H2 is the ridesharing sector, where mileage accrues across the fleet. For example, Toyota will supply two dozen zero-emission Mirai hydrogen fuel-cell cars to rideshare company Lyft.[24] Finally, H2 could also be used for last-mile deliveries in light trucks serving urban centers as there is no pollution or noise. In addition, construction machines, mining trucks, heavy equipment, and pallet truck are candidates for hydrogen fuel-cell technology.

Regardless of the niche application, the nagging issue of refueling infrastructure is a central and costly challenge that needs to be addressed for H2 to become a viable fuel alternative for all transportation sectors in the future.

 H2: Innovating takes stamina

Improving efficiency and massively reducing cost will be crucial for hydrogen's future over the next five to ten years. It will take pioneering engineering to solve reliability, safety, and security challenges for H2 storage and transportation. While hydrogen will not replace the alternatives, it will play a role in the green mix of energy sources as a direct fuel, a complement to batteries, and synthetic and biofuel production.

We are in the early stages of the H2 journey to optimize production, storage systems, and end uses to reduce pollution and carbon emissions at a competitive cost and safely transport goods and people.

 As of April 2021, Capgemini Engineering has over thirty active H2 research and innovation projects in the works in France, Germany, and Spain. Together these projects are focused on solving hard problems and gearing up for the adoption of hydrogen in specific vertical domains. Here are six examples of Capgemini Engineering projects:

• A model to integrate fuel-cell auxiliary systems in the powertrain of electric/hybrid vehicles. The project explores the dynamic modeling and validation of fuel cells in the powertrain, integrating auxiliary systems such as compressors and humidifiers, and strategies to combat the problem of cold start and catalyst poisoning.
• Developing methods to facilitate the design of systems integrating hydrogen storage by optimizing the performance of storage equipment, reducing manufacturing and operating costs, and ensuring the most reliable storage systems for hydrogen.
• Designing a racing catamaran powered by clean energy. The prototype will participate in the 2021 Solar & Energy Boat Challenge organized by the Yacht Club of Monaco. It will differ from the competition by its integrated design approach and incremental technological innovations.
• Exploring ways to optimize the design of liquefied natural gas (LNG) transport tanks using a fully phenomenon-coupled calculation mode to improve LNG tank designs. We analyze fatigue simulation and multi-physics simulation, thermodynamics, and fluid mechanics to optimize LNG tank design to maximize the life and security of the tanks.
• Study and develop new intelligent, functional materials to build innovative solutions for different industrial sectors such as energy, aeronautics, and healthcare. This project aims to develop materials and systems for the capture, storage, and recovery of CO2.

H2: The ground truth

As companies in the aerospace, automotive, rail, and industrial sectors progress on their journey toward a green, hydrogen-based, carbon-neutral future, they will face many challenges. Chief among them is managing cost through all phases of development, from production to distribution and storage. It will be essential to adapt existing and developing new vehicles and infrastructure to integrate H2 as an energy source.

 In closing, here are five hydrogen takeaways to bring value to the transportation sector:

1. Localize production and storage. The industry will most likely evolve into a regional model that includes ready access to renewable energy sources and refineries to produce synthetic fuel relatively close to end users. For production, distribution, and storage, the only practical way of using H2 to tackle CO2 challenges is to use green (wind and solar) or pink (nuclear) H2, both of which are expensive to produce, distribute, and store. That means production sites need to be close to both the renewable energy source and the end customers of multimodal mobilities. To extend the local footprint and optimize logistics, the reuse of natural gas pipelines is one transportation option but will not be a simple retrofit for hydrogen.
2. Establish partnerships with key stakeholders across the value chain. Think outside the box and be open to building new relationships. Consider partnerships between energy providers, vehicle OEMs, fuel-cell providers, and vehicle OEMs. Energy providers might team up with other energy providers, where one provides the green electricity, another produces the H2, and a third makes the synthetic fuel. Examples of value chain relationships between H2 stakeholders and vehicle makers include Alstom Transport and SNAM, Plug Power and Renault, Air Liquide and Toyota, Total and Engie for the Masshylia project in France, Plastic Omnium and Elringklinger, and IVECO and Nikola.
3. Focus on captive fleets and a high-use ratio in the transport sector. This includes aviation, rail, buses, trucks, and taxi fleets. In the early years of the transition to a hydrogen-based fuel economy, H2-powered personal cars will probably not be viable as the infrastructure will take decades to build.
4. Diversify the ways to produce clean H2. By 2050, cumulative investments in renewable hydrogen could be 180-479 billion euros[25]. However, renewables will only make sense when they can be produced cost-effectively, which means we’re not going to get rid of fossil fuels anytime soon. Ideally, we will see a bridge between the old and the new, as fossil-fuel-based blue hydrogen alternatives incorporate carbon capture and storage in the production process.
5. Resolve the high cost and low efficiency of fuel cell technology. Current fuel-cell technology, primarily based on proton-exchange membrane technology, is well known but still expensive due to the use of rare components. Also, its 60% effectiveness is affected by environmental factors such as temperature, unstable power demand, and vibration. Other fuel cell technologies (AFC, PAFC, SOFC, MCFC) will need to be considered for greater efficiency

For more information & contributors to the article:

• Marianne BOUST is director of Energy Transition from Capgemini Invent
• Jean-Luc CHABAUDIE is research and innovation director, driving Capgemini’s ecosystem and new business development in H2 across the transportation sector 
• Arnold COPPIETERS is the H2 and industrial solutions senior architect in Capgemini’s Technology Engineering Center in Toulouse, France
• Alan JEAN-MARIE is a program manager for Future of Energy research and innovation, leading H2 projects in France
• Pierre Yves LE MORVAN is technology and innovation director in Capgemini’s Technology Engineering Center in Toulouse, France
• Walid NEGM is the chief research and innovation officer for Capgemini Engineering
• Nicolas D'ORAZIO is director of Capgemini’s Technology Engineering Center in Toulouse, France

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