GCMD, BCG: Engine choices today to shape shipping’s fuel pathways through 2050

With vessels operating for 25 to 30 years and only around 4% of the fleet renewed annually, newbuild decisions made over the coming decade will establish much of the engine capacity available in 2050, Global Centre for Maritime Decarbonisation said on Thursday (17 September). 

Yet having the capacity to consume a new fuel does not guarantee its uptake. Dual-fuel engines allow shipowners to switch between conventional fuels and the selected new fuel as economics and regulations evolve; continued fuel competitiveness is therefore critical to what vessels ultimately consume.

These are among the findings of Navigating the maritime fuel transition: How fuel economics, regulations, and fleet decisions shape the future bunkering landscape, based on a model jointly developed by the GCMD and Boston Consulting Group (BCG).

The model illustrates this dynamic in its base scenario. With the Tier-2 penalty under the IMO Net-Zero Framework held at USD 380/tCO2e through 2050, methanol dual-fuel engines account for around 10% of fleet engine capacity in 2050, but methanol represents just 2% of fleet energy consumption. With conventional fuels remaining more economical under this regulatory regime, methanol dual-fuel vessels continue to operate on fuels cheaper than methanol (Figure 1).

A global carbon price of USD 700/tCO2e materially changes the transition

The base scenario demonstrates how fuel economics can limit uptake even when vessels have the capacity to use new fuels. This picture changes if the IMO Tier-2 penalty rises to USD 700/tCO2e by 2050, at which point new fuels, including dropins, reach approximately 61% of fleet energy consumption (Figure 1).

By contrast, EU regulations alone will not drive a marked global shift, as they cover only around 20% of international shipping’s energy demand.

Overall cost of using e-methanol and e-ammonia is near parity

While a stronger global carbon price can accelerate the shift towards new fuels, the model does not point to a clear cost winner between e-methanol and e-ammonia.

E-ammonia’s production cost advantage is largely offset by higher logistics costs arising from its toxicity, including specialised crew training, larger exclusion zones, and more complex bunkering. As a result, the overall cost (Figure 2) of using e-ammonia and e-methanol is near parity through to 2050.

Professor Lynn Loo, CEO of GCMD, said: “Many vessels ordered over the coming decade will still be operating in 2050. Shipowners are therefore making long-lived engine choices before the relative economics of future fuels are clear. 

“Our modelling puts into perspective just how difficult closing the cost gap between new and conventional fuels will be. The carbon price required to close this gap is substantial. And achieving it will be particularly challenging in today’s geopolitical environment. Understanding the signposts that could change these economics will be critical to the decisions the industry makes today.”

Anand Veeraraghavan, Managing Director & Senior Partner at BCG, said: “The maritime fuel transition is being shaped as much by policy and cost uncertainty as by technology readiness. 

“Rather than offer a single prediction, our approach with GCMD maps how sensitive each fuel pathway’s competitive position is to a handful of critical variables — policy scenarios, key cost drivers, and potential restrictions. Our hope is that this gives shipowners, fuel suppliers, port operators, and infrastructure investors a practical tool to stress-test their own fuel strategies as conditions change.”

Photo credit: Global Centre for Maritime Decarbonisation
Published: 18 September, 2026