François le Scornet runs through the challenging but promising deployment of hydrogen-based solutions in the maritime sector.
The maritime sector encompasses many different activities as varied as fishing, cruise-boat tourism or ferry transport but shipping remains the most important segment when it comes to carbon emissions, with around 1 billion tons of CO2eq per year. This is 25% of all emissions from the global transportation sector and nearly 3% of global greenhouse gas emissions.
For this reason, challenging targets were set in 2018 by the International Maritime Organization (IMO), which calls for a 50% reduction in emissions by 2050, compared to 2008 levels. In Europe, emissions from ships are expected to be included in the EU Emissions Trading System from 2026 following a transition period. Key players are not insensitive to these policies and calls. Maersk, the largest shipping company in the world, announced in 2018 that it intends to be carbon-free by 2050, while another sector giant, CMA-CGM, also announced its commitment to invest in carbon-neutral shipping technology.
Hydrogen-based fuel represents medium-term option
Today, the shipping industry relies quasi exclusively on so-called carbon-dense “bunker fuels” and uses virtually no low-carbon fuels. Conservative when it comes to propulsion innovation, the industry is nevertheless investigating the deployment of alternative fuels, in particular biofuels and Liquefied Natural Gas (LNG), along with low-carbon synthetic fuel and hydrogen-based solutions.
Among these alternative fuels, LNG is currently seen as the most mature technology to lower emissions by replacing diesel. If LNG fits the required standards for NOx and SOx emissions, it still does not meet expected GHG emissions on the long term. For this reason, shipowners seriously consider the use of low-carbon hydrogen and green ammonia as medium to longterm alternative fuel solutions to LNG and to other alternative solutions. The development of on-board systems reforming hydrogen from LNG is also being investigated.
The most interesting option, when it comes to Greenhouse Gas Emissions, is the production of low-carbon hydrogen by water electrolysis using low-carbon electricity, either from renewable energy (green hydrogen), or from nuclear power (purple hydrogen). This hydrogen can be used directly in fuel cells to produce electricity, without having a carbon impact and pollutant emissions like NOx, SOx and particulate matter.
Green hydrogen can also be used to produce ammonia, which can fuel large ship engines. The need for autonomy is a strong requirement of the shipping sector and on-board H2 storage in heavy cryogenic tanks is a critical issue for large cargo ships, where space is very precious. With a density twice as high, ammonia is therefore a very interesting solution. Easy to liquefy, ammonia is already transported routinely worldwide in its liquid form and many believe that this technology is probably mature enough for deployment in a few years.
Many different use cases are investigated through demonstration projects
Europe has historically dominated demonstration projects with initiatives in the UK, Norway, France, Finland, Denmark and Belgium, to name a few. Of course, North America and Asia are also actively testing hydrogen applications in the maritime environment and several projects are under development.
Fuel Cell based solutions for relatively small boat propulsion have been tested successfully. Passenger boats have been demonstrated in many countries, from the lightweight catamaran to small river tourist transportation or water-taxi/bus as in the NavHybus demonstration in my hometown of Nantes (France). Fishing boats have also been equipped with hydrogen propulsion in projects like FILHyPyNE in France, for instance. Several small ferry boats are also currently demonstrated in the frame of projects likes HYBRIDShips and MF Ole Bull, the EU-funded HYSEAS III initiative. In Asia, Shell also announced in April 2021 that it intends to test a roll-on/roll-off cargo powered by a fuel cell.
Hybrid solutions using fuel cells and traditional propulsion on larger boats were also successfully launched. Projects like the EU project Maranda demonstrate that such propulsion can be useful for research organisations, offshore companies or logistics providers who need to switch to an “environmental mode” to align with regulation, for instance.
Green hydrogen can also support Auxiliary Power Units (APU) in order to supply in port operations and the so-called “Hotel Load” for communications, refrigeration, climate control or water desalination.
Port-specific heavy-duty equipment like yard tractors (for short-distance transportation of containers), RTG cranes (used to move containers from yard tractors to drayage trucks), and reach stackers (used to handle and pile containers) have been partly demonstrated in Finland (Demo2013) and in the United States (Project Portal) . In addition, other non-specific handling equipment like fuel cell powered forklifts and transportation solutions (shuttles, trucks etc.) are also extensively tested in ports.
Key challenges hindering the adoption of H2-based solutions
The first key challenges relate to the limited technological maturity for large shipping vessels. Today, many prototype demonstration projects have been launched but no pure hydrogen propulsion pilots involving very large shipping vessels have been successfully tested yet. Scaling up is critical to really have an impact on the sector as a whole. Albeit interesting for areas with a strong ecological focus (natural reserves, urban ports), switching to H2-based solutions for small boats would have a limited impact at sector level.
To make a real difference, the shipping industry needs to learn from these projects and scale up the solutions. To do so, the maritime sector must rely on technical standards, which have not emerged yet from the existing demonstration projects as there are no broadly accepted regulations for hydrogen vessel design and operations, for instance.
Costs also remain a challenge. The shipping sector obviously needs to have a commercial justification to ensure the viability of a hydrogen-based solutions. For specific minor segments like the harbour handling equipment, alternative solutions like batteries may be more cost-competitive for similar use cases and need to be assessed. It is trickier for vessel propulsion. In addition to higher capital expenditure for adapted vessels, ship owners also face uncertainties with regard to operational costs. With long system lifetimes, low fuel and maintenance costs are particularly critical to reach a credible cost of ownership for their vessels. For all these reasons, many observers anticipate that H2-based fuels will only become cost-competitive with alternative fuels in the 2030-2040 decade.
Hydrogen infrastructure must be reinforced with the proper supply logistics, adequate storage capabilities and refuelling stations in place in harbours to prevent a ‘chicken or egg’ dilemma. The speed of development for such required infrastructures is strongly influenced by the dialogue and the alignment of interest between public players, port management entities and ship owners. In addition, having a heavy footprint is a financial challenge for any installation in port environments.
To this end, the development of LNG infrastructure will definitely bring very interesting lessons learned for the deployment of hydrogen infrastructures as many of the challenges are potentially similar. Existing demonstration pilots for H2-fuelled boats also help structure a proper supply chain and appropriate port infrastructures.
Hydrogen applications for the maritime world are less mature than on-road applications and require additional development efforts in order to become more competitive with incumbent technologies. Lower costs and refuelling infrastructures development in particular remain critical challenges beyond technical maturity elements; and the use of fuel cells for auxiliary power and for port vehicles and handling equipment will be most probably adopted first. For vessel propulsion, hydrogen-based solutions will most probably be used initially for small boat propulsion in the next decade but from 2030, such systems may be more broadly adopted for larger ships.
Ambitious IMO targets, supporting regional and national regulations as well as strong public support from large public bodies like the EU, may drive faster adoption of hydrogen-based ecosystems in specific regions before it disseminates the most interesting initiatives globally. Let’s not wait, though: the lifetime of ships is high and the introduction of zero-emission vessels, including those using hydrogen-based solutions, must therefore start now.
About the author
François le Scornet carries 15 years of experience in the energy and power generation sector, mostly working in global strategy and market Intelligence roles at AREVA and GE Renewable Energy. Le Scornet created Carbonexit Consulting in 2017 to support industrial players and investors through market research, growth strategy development and commercial due diligence globally. He is also a visiting lecturer at INP-Polytech Grenoble and regularly supports the EU commission as an expert.