Hydrogen has been used for decades in a variety of different industrial processes. Oil refining relies on hydrogen to remove sulphur from fuels, it is used as a reducing and oxidising reagent in metallurgical processes, and it is a vital part of the production of two of the other future fuels we have discussed in this series – ammonia and methanol. And without hydrogen as a fuel, we would not have been able to send crews and cargo into space.

But there’s a problem. Almost all the hydrogen used today is so-called grey hydrogen and is produced using fossil fuels, typically natural gas, in a process known as steam reforming. Moving along the colour spectrum we have black or brown hydrogen, produced using coal. Blue hydrogen is hydrogen that has been produced in a process where the carbon generated during steam reforming is captured and stored, while green hydrogen production uses clean renewable energy to split water into hydrogen and oxygen in a process known as electrolysis.

Q: What is the current status of hydrogen as a marine fuel?
“Global hydrogen production was around 70 million tons in 2018. Currently, almost all hydrogen is produced at or very close to where it is needed, and directed to industrial processes, so it is not transported by ships in the same way as LNG, for example,” says Jussi Mäkitalo, Business Development Manager, Wärtsilä. “However, February this year saw the world’s first liquefied hydrogen cargo transported between Australia and Japan aboard the Suiso Frontier, which is a significant step forward. Unlike an LNG carrier, however, this vessel doesn’t use its cargo as fuel.”

Mathias Jansson, Director, Fuel Gas Supply Systems, Wärtsilä Marine Power continues: “From a regulatory perspective the biggest challenge is that there simply are no rules concerning the use of hydrogen as a fuel for shipping. The IGF Code provides high-level requirements for using low-flashpoint fuels like hydrogen in maritime applications but to date it has mostly been applied for projects involving LNG. There is work ongoing at the IMO to add hydrogen to the code but it is still at the very early stages, with draft proposals expected later this or next year at the earliest.”

“Progress is being made on the regulatory side, but slowly,” explains Kaj Portin, General Manager, Sustainable Fuels & Decarbonisation, Wärtsilä. “DNV has published a Handbook for Hydrogen-Fuelled Vessels, which covers the key aspects such as safety and risk mitigation, as well as engineering specifications for systems. As it stands today new hydrogen applications have to follow the Alternative Design approval process, which is a risk-based process for designs that cannot be approved with current regulations. There are several pilot projects in the pipeline that will provide benchmarks, but it’s still very early days. One worth mentioning is the partnership between Wärtsilä and the class society RINA to deliver a viable hydrogen fuel solution.”

Q: What are the main pros and cons of using hydrogen as a marine fuel, and how do the storage and supply technologies differ from traditional marine fuels?
Jussi Mäkitalo: “Compared to diesel operation the assumption is that CO2 tailpipe emissions are far lower or even non-existent when using hydrogen as a fuel; if we’re talking about green hydrogen the well-to-wake emissions are expected to be dramatically lower as well. On the downside, using hydrogen directly as a fuel as opposed to using it as a raw material to manufacture other renewable fuels requires a lot of space onboard.”

Kaj Portin: “Even as a liquid, hydrogen storage takes up significant space compared to marine gas oil. To get the same equivalent energy content requires a tank volume that is almost eight times more than that of marine gas oil. Land-based storage for liquid and compressed hydrogen already exists so there is technology that can eventually be adapted for use in maritime applications. Hydrogen is also very light compared to diesel, so if you are limited by weight rather than space onboard then it could make sense.

Mathias Jansson: “Hydrogen could be stored onboard either as liquid hydrogen, which gives you the biggest storage capacity in the smallest possible space, or possibly as compressed hydrogen in 200 or 700 bar pressurised tanks. Liquid storage, however, brings its own set of challenges due to the extremely low temperatures.

To keep hydrogen in liquid form it needs to be stored below -253 C, which is highly energy intensive and places huge demands on the storage and supply system in terms of insulation requirements. The extreme cold can lead to oxygen from the air condensing on the pipework, resulting in a risk of explosion. There will be boil-off to deal with as well, which means you will need an energy-intensive reliquefaction solution. Leakages are another important consideration because of the highly explosive nature of hydrogen. In principle it is possible to use a similar setup as with LNG but with a greater focus on insulation and preventing leakages.”

Q: What is the status of marine engine technology capable of burning hydrogen? What exists now, and what are the likely future developments?
Kaj Portin: “Prior to 2015 the specifications for our gas-fuelled engines allowed for fuel with a maximum hydrogen content of 3% and following this we have tested and developed our dual-fuel engine technology further, demonstrating that it can utilise fuel blends with a hydrogen volume of up to 25%.

“Moving on from this we learned a great deal more about the special requirements that hydrogen brings in terms of engine and material design and are confident that this volume could safely be increased. However, we have to take into consideration the fact that things get a lot more complex when the hydrogen content of a gas is above 25%. This changes the classification from IIA to IIC according to the IEC 60079 standard, which covers areas where flammable gas or vapour hazards may arise.

“This has significant implications from a design perspective because it means the allowed voltages in components are lower and components such as pumps in the fuel supply system need to be hydrogen specific.”

Fredrik Östman, Product Manager, Lifecycle Upgrades, Wärtsilä Energy: “For energy production in land-based applications we are actively supporting our customers with proof-of-concept demonstrations for hydrogen blending. Our aim is to launch the first retrofit packages during 2023, and on the newbuild side we aim to have a pure hydrogen engine concept ready by 2025.”
Source: Wärtsilä

eFuels are synthetic fuels that are generated from water and CO2 in a synthesis process using renewable energy sources. eFuels can replace fossil fuels and be used in most applications currently involving internal combustion engines. When eFuels are burned, they only give off the CO2 that is captured from the atmosphere to generate them. This means that their use is climate-neutral.

The debate on efficiency does nothing to achieve the aims of climate policy

Producing eFuels is energy intensive. Roughly 60 % of the cost of producing synthetic fuels is spent on the renewable electricity needed to extract the hydrogen via electrolysis. For this reason, eFuels are produced in parts of the world where conditions are particularly favourable for generating electricity from renewable sources of energy. These are generally sparsely populated regions with an abundant supply of sun and wind – as in the case of the Haru Oni project, run by HIF Global in Patagonia. On average, a wind turbine built there generates roughly four times as many full load hours as a renewable energy plant in Germany. If eFuels are produced in these preferred regions outside Europe, they do not compete with other users of Germany’s still scant supply of renewable electricity. Instead, the world’s large, unused potential sources of renewable energy can be tapped and made available around the globe in the form of eFuels. Chile, for instance, claims to have 70 times more potential renewable energy sources than it needs to meet its own energy demands. The situation is similar in other regions of North and South America, Africa and Australia. The argument that is commonly repeated without reflection – that eFuels are too inefficient in comparison with the direct use of electricity – thus obscures the question that really needs to be asked: How can we replace fossil fuels as quickly as possible, at the lowest possible cost? From a global perspective, the world does not lack the means to produce renewable energy in the long term; it has the problem that climate-friendly technologies cannot be developed in time to end our dependence on the fossil-derived energy sources that cause climate change and pose a threat to our power supply.

eFuels are not the costly “champagne of the energy transition”

There has been extensive research into the fundamentals of eFuels. The technology can be transferred to an industrial scale. Today, our members already sell eFuels from suitable regions with production costs between one and two euros per litre. In the long term, the price will fall below 1 euro a litre. eFuel prices of 4 to 10 euros are a myth and relate to eFuels produced in the lab and pilot research facilities. One key component of the retail price consumers have to pay is the Energy Taxation. This is currently being revised at the European level. The Commission has proposed clear tax advantages for eFuels that make up for almost all additional expenses. Moreover, eFuels can be admixed with fossil-derived fuels; when only small quantities are added, the initially higher production costs will have little effect on the retail price. Economies of scale mean that the production cost will fall over the long term, as we have seen in the case of wind power, photovoltaics and batteries. At the final count, the citizens will thus always remain able to heat their homes or run their cars at today’s levels.

eFuels are not a niche solution

Production has begun on an industrial scale, and many investment decisions have been, or are being made. From as soon as 2023, eFuels will become available in large quantities. As part of the Green Deal, the EU plans to bring in a mandatory quota of 2.6 to 5.7 % green hydrogen and eFuels in the European transport sector by 2030, which works out as the equivalent of 14 to 30 billion litres of diesel.

Fraunhofer IEE has studied the potential for green hydrogen and synthetic fuels, determining that up to 88,000 TWh of climate-neutral synthetic fuels could be produced outside Europe. That equates to almost three times the energy demand of the global transport sector (33,603 TWh in 2019).

Combining climate protection and energy security with eFuels

Whether it is in the aviation, shipping, rail, road and off-road sectors, the chemical industry or steel production, eFuels are used in every shape and form, from hydrogen to motor fuels, ammonia or naphtha, to meet climate targets and fight climate change. This cannot be achieved – that much is clear – with eFuels alone: in certain contexts, other technologies are of course employed, such as all-electric solutions (battery electric vehicles) or heat pumps. The more technological paths we can go down, the faster we can cut CO2 emissions and the more options are available to users. Moreover, the ultimate aim is also to be as cost-efficient as possible, so as to save resources and keep production or mobility as affordable as possible. For that reason, we support an approach that is open to different technological solutions and want to create an environment that permits as much competition as possible and requires as few regulatory interventions as necessary to achieve the climate targets. Adding 5 % of eFuels to the European fuel mix could save 60 million tonnes of CO2. At the same time, 70 % of Russian crude oil imports could be replaced. There is no technology that has only advantages or disadvantages. One-sided forms of dependence are never good, as we in Germany are currently painfully finding out. eFuels will thus help protect the climate while also safeguarding and diversifying our energy supply in the long term.
Source: eFuel Alliance e.V.