1.A.3.d i (i) - International maritime navigation

Under NFR category 1.A.3.d i (i), emissions from international maritime navigation fuelling in and starting form German harbours are reported.

Primary fuel delivery data (primary activity data, PAD) for international maritime navigation is included in line 6 - 'International Deep-Sea Bunkers' of the National Energy Balances (NEB) (AGEB, 2023) ¹⁾ together with respective data for IMO-registered ships used in national maritime transport (see 1.A.3.d ii (a)), fishing (see NFR 1.A.4.c iii) and military navigation (see NFR 1.A.5.b iii).

The AD applied for international maritime navigation therefore represents the remains of primary fuel delivery data from NEB line 6 minus the modelled consumption data estimated for non-IMO ships in 1.A.3.d ii (a), 1.A.4.c iii and 1.A.5.b iii:

As a result, activity data can fluctuate strongly from year to year.

However, this effect can be explained with the fact that large ocean-going ships do not need to bunker fuels on every single harbour but can go on for weeks without any additional fuel uptake.

This can be further increased with increasing differences in fuel prices.

Table 1: Annual fuel consumption, in terajoules

source: own estimates based on underlying BSH model (Deichnik, K. (2023)) ²⁾

Consumption of heavy oil has been increasing since 1984 as a result of high petroleum prices, global increases in transports and increasing maritime use of diesel engines that can run on heavy oil. The emissions fluctuations that occurred in the navigation sector in 1992 and 1996 were caused by trade and oil crises.

Furthermore, after 2014, with ever stricter legislation espacially regarding fuel sulphur content, an ongoing shift from heavy fuel oil to maritime diesel oil can be observed.

For main pollutants and particulate matter, modelled emission factors are available from (Deichnik, K. (2023)).

Here, for sulphur dioxide and particulate matter, annual values are available representing the impact of fuel sulphur legislation. In addition, regarding SO₂, the increasing operation of so-called scrubbers in order to fullfil emission limits especially within SECA areas is reflected for heavy fuel oil.

Table 2: Annual country-specific emission factors, in kg/TJ

¹ estimated from f-BCs as provided in ³⁾: f-BC (HFO) = 0.12, f-BC (MDO/MGO) = 0.31 as provided in ⁴⁾, chapter: 1.A.3.d.i, 1.A.3.d.ii, 1.A.4.c.iii Navigation, Tables 3-1 & 3-2
² ratios PM_2.5 : PM₁₀ : TSP derived from the tier1 default EF as provided in ⁵⁾, chapter: 1.A.3.d.i, 1.A.3.d.ii, 1.A.4.c.iii Navigation, Tables 3-1 & 3-2

NFR 1.A.3.d i is not considered in the key category analysis.

Basically, with no significant technical improvements with respect to mitigation technologies, trends in emissions depend more or less directly the amounts of fuels bunkered in German harbours and the contributions of diesel oil/light heating oil and heavy fuel oil to the over-all fuel input.

Here, as the amounts of fuels allocated to international maritime navigation represent the remains of annual over-all inland fuel deliveries minus fuel consumption in domestic shipping, activity data and, hence, emissions, fluctuate strongly from year to year (see also information on activity data as stated above).

Therefore, especially emission trends for unregulated pollutants (such as NH₃, NO_x, NMVOC and CO, all HM and POPs) with only slight changes in the annual over-all IEFs applied, follow the trends in fuel consumption and the shares of diesel and heavy fuel oil:

In contrast, emission trends for SO_x and PM, both depending on the fuel's sulphur content, follow not only the trends in fuel consumption but do also reflect fuel-sulphur legislation:

Activity data have been recalculated widely due to the revision of the National Energy Balances (NEB) 2003 to 2021.

Table 3: Revised activity data 2003-2021, in terajoules

In contrast, all implied emission factors derived from the underlying BSH model ⁶⁾ remain unaltered.

Uncertainty estimates for activity data of mobile sources derive from research project FKZ 360 16 023: “Ermittlung der Unsicherheiten der mit den Modellen TREMOD und TREMOD-MM berechneten Luftschadstoffemissionen des landgebundenen Verkehrs in Deutschland” by Knörr et al. (2009) ⁷⁾.

Besides routine maintenance and further development of the BSH model, no improvements are planned.