Best practice report on compliance monitoring of ships with respect to current and future IMO regulation

Report, 2021

Since 2015, new rules from the International Maritime Organization (IMO) and legislation from EU and the US allows ships to run with maximum fuel sulfur content (FSC) of 0.1 % m/m on northern European and US waters, respectively, or use appropriate abatement technique. In addition, since
2020, there is a global cap of 0.5 % for the FSC. From 2021, northern Europe is a NOx emission control area, requiring at least 80 % emission reduction (Tier III) for all ships built from this year and onward, compared to ships built between 2000 and 2010 (Tier I). There is also a discussion within
IMO how to control particle emission of black carbon (BC). This report focuses on best practice in remote compliance monitoring of FSC without stepping on board of the ship. Similar measurements for NOx are also shown, with a discussion whether these can be used for compliance monitoring.
Some examples of remote measurements of BC are provided. Remote measurement methods for compliance monitoring of FSC in ships have been developed during the last 10 years within national and European projects (EnviSum and Compmon) and furthermore implemented in national
monitoring in Belgium, Denmark, Germany the Netherlands and Sweden. The measurement methods are generally based on sniffer systems measuring the exhaust gas concentrations of SO2, NOx and particulate matter (BC), respectively, against CO2. There are systems with varying sensitivity that are
operated at different distances from the ships (50 m to 2 km) and from different platforms, i.e. fixed, shipborne and airborne (manned and unmanned). There are also optical systems measuring the ratio of SO2 against NO2, as an indicator of the FSC, primarily used from manned aircraft. The focus in
this report is on standard sniffer systems, based on generally available equipment for air quality monitoring. Such systems have been used extensively during the last 5 years for operational compliance monitoring from both fixed and airborne platforms. A summary of FSC measurement
results for multiple operators and platforms shows that the noncompliance level has decreased significantly over the last 5 years at different parts of Europe, i.e. from 5-13 % in 2015 to below 1 % in 2020. The highest noncompliance levels were found at the SECA border in the English channel
and in the middle of the Baltic sea. The measurement data, interpreted with ship modelling data from the Finnish Meteorological Institute, indicates that remote compliance monitoring of NOx should work reasonably well for ships operating at high loads (above 40 % load). For slow steaming ships
the measurements are associated with larger uncertainties and care should be taken in the interpretation of then results here and further ship emission modelling is needed to assess this. The remote measurements of BC work well to identify high emitters and groups of polluting ships. However, the BC emissions have a strong load dependence are intermittent by nature and it is therefore difficult to make short term measurements. See https://cshipp.eu