Encouraging developments on green fuels and propulsion technologies

Recent developments and reports show that good progress is made regarding  technologies and fuels that help the maritime industry on its trajectory towards net-zero GHG emissions. One example relates to advancements on the use of ammonia and methanol as sustainable maritime fuels, the other example relates to wind propulsion technology. Both are further described below.

The “Getting to Net-Zero Coalition”, which defines itself as an “alliance of more than 200 organisations (including over 180 private companies) within the maritime, energy, infrastructure, and finance sectors (…) committed to getting commercially viable zero-emission vessels powered by zero-emission fuels into operation by 2030”^[1], has published a report^[2] on the state of play of ammonia and methanol as sustainable maritime fuels. The report finds that in principle, both fuels are ready for use in the shipping sector. According to the report, there are around 60 methanol- capable vessels already in circulation and more than 300 additional ones on order. Ammonia has not yet reached the same degree of maturity, but the report explains that first ammonia-powered vessels have been successfully piloted and bunkering trials are underway at major ports, including Rotterdam.

However, both fuels still face remaining challenges for their commercial scale-up. The report finds that for methanol, the challenge consists of enhancing the availability of “green molecules” (e.g. renewably sourced hydrogen and carbon atoms derived from biogas)) that form the basis of the production of the green fuel. Consequently, green methanol at the moment only represents a small share of the total amount of methanol used in shipping. As regards ammonia, the report identifies the challenge of rolling out bunkering infrastructure in key ports. There are debates as to whether dedicated ammonia bunkering vessels are needed from an early adoption phase; also, some ports appear to be adverse to the risk of hosting ammonia bunkering infrastructure.

Moreover, an article^[3] by leading German weekly news magazine “Focus” describes the potential of wind-assisted propulsion. Gavin Allwright, secretary general of the International WindShip Association^[4] is quoted as saying that in the next five years about 15% of the global fleet could be equipped with wind assistance systems. By 2050 this proportion could reach 50%. The growth in wind propulsion technology is generated by technological progress on the one hand and legislative as well as political developments on the other hand. The article explains that the EU’s Emission Trading System (ETS)^[5], which now also applies to international maritime transport  and the FuelEU Maritime Regulation^[6], which sets increasingly strict carbon emission limits for marine fuels,  will contribute to ship operators opting for wind technology as it helps achieve compliance with the emission and fuel standards. The process is likely to be even accelerated once the IMO adopts its Net-Zero Framework in October. The article concludes that wind propulsion assistance systems can be used on nearly all types of vessels. So far, only very large container vessels have refrained from it, mainly due to technical challenges like the need for large space on deck as well as challenges for cranes to load and unload container vessels that would have sails.^[7] But shipping company Hapag-Lloyd reportedly has plans to also use the technology for its container vessels.

^[1] Global Maritime Forum: https://globalmaritimeforum.org/getting-to-zero-coalition/

^[2]https://downloads.ctfassets.net/gk3lrimlph5v/42oVCMYa8EuGXsvd46hlH6/e7a183fa7adb94749676607ad72a2a8c/Getting_to_Zero_Coalition-From_pilots_to_practice__Methanol_and_ammonia_as_shipping_fuels.pdf

^[3] Focus, 14 August 2025: https://www.focus.de/earth/weniger-emissionen-im-schiffsverkehr-mit-segelschiffen_2a6dc3c1-733c-4145-84d4-9ef545e4447e.html

^[4] https://www.wind-ship.org/

^[5] Governed by EU ETS Directive: https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A02023L0959-20230516

^[6] https://eur-lex.europa.eu/eli/reg/2023/1805/oj/eng

^[7] Dassault Systems Blog: The return of wind assisted propulsion at sea: https://blog.3ds.com/industries/marine-offshore/the-return-of-wind-assisted-propulsion-at-sea/