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Fuels and solutions with the potential to decarbonize shipping

In this article we focus on the impact of hydrogen strategies, targets, and activities, assessing advantages and disadvantages, and, lastly, make an alternative fuel forecast for the future of shipping.

Ambitious climate targets

The Paris Agreement targets a maximum 1.5 degrees Celsius global temperature increase. The urgency of the climate crisis is documented in the recent assessment report from the IPCC (AR6). The European Commission has responded by increasing EU targets for GHG emission reduction to 55 % by 2030 (“Fit for 55”). Contributions from all segments of transport, industry and the power sector are well received and in line with targeting a climate neutral Europe by 2050.

According to a recent press release from the International Chamber of Shipping, the industry has the ambition of delivering net zero by 2050, while, in 2018, IMO set the target of cutting GHG emissions by half by 2050. These prevailing stringent targets for GHG emission reductions in maritime transport point very clearly towards completely replacing all fossil fuels and focusing on sustainable fuels compatible with carbon neutrality.

From fossil fuels to alternative fuels

Given the long lifetime of vessels, typically 30 years, Møller-Holst explains that it is not advisable to invest in new builds that can only utilize fossil carbon alternative fuels like LNG, LPG and methanol. Replacing conventional maritime fuels with these intermediate fuels may eliminate local emissions such as PM, NOx, SOx, however, they are at best reducing GHG emissions by 15 %.

Steffen Møller-Holst, Vice President Marketing within Hydrogen Technologies at SINTEF.

In Møller-Holst’s view, the vast majority of the investments should therefore be made in future proof sustainable solutions and fuels, such as battery electric, clean hydrogen, ammonia, and synthetic fuels, as well as biofuels. For these fuels to be sustainable, the electricity and hydrogen production must be clean, meaning that it should originate from renewable sources or be deduced from fossil sources with a very high carbon capture and storage (CCS) rate exceeding 95%.

This leads us to the next question: Which alternative fuels are the most attractive for implementing in various vessels?

  • While pure battery-electric propulsion is well suited for smaller, low speed vessels operating on short connections, higher energy density fuels are required for larger ships and longer voyages. Compressed hydrogen is well suited for short sea applications, such as in car ferries and high-speed passenger boats where the voyage exceeds ½ to 1 hour. Furthermore, liquid hydrogen (LH2) exhibits 2-3 times higher energy density compared to compressed hydrogen, and 10 to 15 times that of batteries. Therefore, LH2 is well suited for longer voyages with a duration of up to 5 – 10 hours.
  • On the other hand, for longer missions and deep-sea shipping, fuels with even higher energy densities are required. Ammonia (NH3) has 30 to 50 % higher energy density compared to LH2 and is consequently being considered as a potential maritime fuel. Ammonia is, together with renewable based synthetic fuels such as e-LNG, e-methanol, and e-diesel probably the only viable solutions for these demanding maritime applications.

Tell us a bit about the pros and cons of implementing hydrogen?

  • Hydrogen has the highest energy density by weight of all fuels, more than 3 times higher than diesel. On the contrary, the energy density by volume of hydrogen is 3 times lower than diesel, leading to voluminous fuel tanks, which for some maritime applications is a significant drawback. The prime benefit of using hydrogen is related to the only emission upon usage being water. The GHG emission reductions of utilising hydrogen as a fuel are closely related to the energy source used for producing hydrogen. If the primary energy source is fossil, and CO2 is emitted to the atmosphere, hydrogen is less environmentally friendly than conventional fuels. Hence, hydrogen must be produced from renewable or fossil sources with carbon capture and storage (CCS) to make it a viable and sustainable maritime fuel.
  • Moreover, all fuels have to be handled safely and in accordance with their characteristics to be viable. Hydrogen is very flammable and, in the case of a leakage, ignites very easily. This leads to hydrogen specific regulations, codes and standards and corresponding precautions when designing hydrogen powered vessels. Double tubing and sensor systems are typically implemented to ensure safe operation. In case of leakage, the low density makes the hydrogen gas diffuse straight up, which for some open-air applications may be a benefit, while for others it could be a drawback, for instance when used in tunnels or parking garages.

EU and Norway have presented their hydrogen strategies. How do you think the new frameworks will affect production, infrastructure, financing, and not least trade?

  • Based on energy system analyses, the EU launched, in 2020, a very progressive hydrogen strategy with ambitious targets, especially for hydrogen production. By 2024, the installed electrolyser capacity is targeted at 6 GW, increasing to 40 GW in 2030. It is, furthermore, estimated that the share of hydrogen in Europe’s energy mix is projected to grow from today’s 2 % up to 13-14 % in 2050.
  • A European-wide hydrogen pipeline network is foreseen totalling 11,600 km in 2030, connecting emerging hydrogen valleys. This hydrogen infrastructure is expected to grow to become a pan-European network, with a length of 39,700 km by 2040.
  • In addition, and in line with the strategy, the European Commission and member states have ear-marked funding and are pursuing joint investments in hydrogen through what they call financial engineering, combining for example regional funds with those from the European Investment Bank, ETS Innovation Fund and framework program funding. In December 2021, the Commission finalized the financial framework and launched the Clean Hydrogen Partnership, allocating one billion Euro to research, development, and the demonstration of hydrogen technologies until 2027.
  • The Norwegian H2-strategy, launched in June 2020, was purely descriptive, vague and did not contain targets. The Norwegian Government followed up with a somewhat more concrete, but still not very ambitious, Hydrogen Road Map in June 2021. The Norwegian Hydrogen Roadmap targets, by 2025:
    – Five hydrogen hubs for Maritime applications
    – One / two industrial projects including H2-production with global potential
    – Five to ten pilot projects for development and demonstration of new, more cost-efficient hydrogen solutions and hydrogen technologies

At the launch of this Roadmap, there were already more industry initiatives than the above-mentioned targets reflect. The recent increased political engagement and mobilization in the Norwegian funding agencies towards hydrogen have, however, substantially boosted the hydrogen funding level and activities in Norway lately. In December 2021, Enova provided more than one billion Norwegian kroner to three large hydrogen projects. A new funding scheme for hydrogen as fuel for maritime transport was launched by Enova in January 2022, facilitating the Roadmap target of establishing five hubs for maritime applications.

What is your forecast for the future in shipping with respect to alternative fuels and technologies?

  • For retrofitting existing vessels, fossil-based LNG may be a viable intermediate solution, if methane slip can be avoided. Moreover, Liquefied BioGas (LBG) and renewable based natural gas (e-LNG) are viable alternatives which may be taken into use in existing maritime propulsion systems, providing for substantial emission reductions at a relatively lower cost compared to investing in new vessels. Retrofitting older vessels with new fuels and propulsion systems, like hydrogen and fuel cells, is being considered. This may become an adequate and, in some cases attractive solution, particularly for complying with regulations in Emission Control Areas such as in UNESCO’s World Heritage Fjords and along Europe’s inland water ways.
  • In the surge towards sustainable shipping, some favour the fazing out of internal combustion engines (ICE), due to their efficiency limitations and inherent emissions. For some segments of maritime transport, fuel cells may preferably replace ICEs, but there are three main arguments supporting that ICE may still play a key role in shipping. Firstly, ICEs are very reliable and durable. Secondly, large maritime ICEs exhibit efficiency in the 50% range at cruise speed, which is close to what fuel cells can deliver. Last but not at least, ICEs can easily be adapted to convert sustainable fuels like e-methanol, biogas, and ammonia.

There are many forecasts regarding the future fuels of maritime transport, some of which are pointing at liquified natural gas (LNG). Considering the prevailing stringent emission targets, a vast majority of this LNG must be covered by synthetic e-LNG or Liquefied BioGas (LBG).

No silver bullet which fits all vessels and missions

Consequently, there are, as mentioned earlier in this interview, a need for a variety of fuels in maritime transport. It is crucial to underline that there is no silver bullet which fits all vessel types and shipping routes. Hydrogen is well suited for some, but hydrogen is too voluminous for larger vessels travelling intercontinental routes. For deep-sea shipping, ammonia and synthetic fuels, based on biobased carbon and renewable hydrogen seem to be the most promising solution, Møller-Holst concludes.

Many thanks to Steffen Møller-Holst for his time and participation in the above interview.

Article by Nikoline Astrup, YoungShip Oslo.

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