Decarbonisation Technology February 2026 Issue

100.0%

80.0% 90.0%

Base target

ZNZ uptake 10% short versus base case - base case transitional fuels ZNZ uptake 10% short versus base case - transitional fuels strongly encouraged ZNZ uptake 10% short versus base case - transitional fuels discouraged ZNZ uptake 50% short versus base case - base case transitional fuels

70.0%

60.0%

50.0% 40.0%

30.0%

20.0% 10.0% 0.0%

ZNZ uptake 50% short versus base case - transitional fuels strongly encouraged

ZNZ uptake 50% short versus base case - no transtional fuels

2035 2034 2033 2032 2031 2030 2029

2028

2040 2039 2038 2037 2036

Figure 4 GFI attained on a global average basis for different scenarios in case of ZNZ supply shortages (g CO 2 e/MJ)

between discouraging and encouraging scenarios becomes of the order of 11% ZNZ uptake. Note the inflection point in the curve for strongly encouraged transitional fuels in 2039. This is the point where essentially all straight fuel oil use would be replaced by transitional fuels, and any further GFI reduction can only be achieved through greater uptake of ZNZ. At that point, transitional fuels start being phased out in favour of ZNZs in order to meet the Base Target. Figure 3 illustrates the evolving fuel mix for this case. Another way to look at the effects of transitional fuels is to look at the GFI attained on a global average basis, in case ZNZ uptake falls short, versus what would be needed in the base case scenario. These results are shown in Figure 4 . The lower group of curves shows the GFI attained on a global average basis if the supply of ZNZs were to fall short by 10% versus what we calculated for the base case transitional fuel scenario. The orange line indicates that in 2040, under the base scenario, the GFI attained would be around 38g CO 2e/MJ, versus the Base Target of 32.7g CO 2 e/MJ. Under a discouraging scenario, GFI attained would be around 41g CO 2 e/MJ, while under the strongly encouraging scenario, the Base Target could still be met. The upper three curves show the GFI attained in the case of a severe shortage of ZNZs. For 2039, the difference in GFI attained between a strongly encouraged transitional fuel scenario and no transitional fuels is slightly more than 11g CO 2 e/MJ. For a total marine fuel market of

250 million tons/yr, this would represent more than 110 million tons CO 2 e/yr, which is more than the total GHG emissions of Belgium in 2023 (106 million tons) ( Wikipedia ). Are shortages in the ZNZ fuel supply versus what is needed to reach the NZF Base Targets likely to occur? Unfortunately, the answer is yes. Just having an ambitious target in a regulation is not enough to attract the major investments needed to rapidly increase ZNZ production. As the NZF regulations are not fully defined yet (the reward mechanism is still to be decided, and the default fuel GHG footprint data has not yet defined), large uncertainties remain about the business case for ZNZ fuels. This will likely lead to delays in investment decisions for vessels capable of using these ZNZs and in production facilities for the fuel. Several recent reports have highlighted the slower-than-hoped-for development of e-fuel; for example, DNV’s latest Maritime Outlook ( DNV, 2025 ) refers to the headwinds for hydrogen-based fuel production. Rystad Energy’s in-house ZNZ supply outlook ( Rystad Energy Clean Shipping Solution, 2025 ) forecasts a ZNZ supply of around 35 million tons FOE by 2035, or less than half the estimated 75 million tons required to meet the 2035 IMO Base Target in the base case scenario. Evolving fuel technology Fuel and engine technologies continue to evolve, aiming to improve performance from an energy efficiency, environmental impact, and economic