CII compliance: Effects of operational and technological measures on current levels and time development of calculated CII

From 2023, commercial ships must report their actual annual Carbon Intensity Indicator (CII), which will have to be verified against the required annual CII; the latter will become progressively stricter with time - a significant challenge for the maritime sector. The main objective of the present work is to investigate how various factors, influencing the value of CII, will affect its development, and therefore to identify the compliance challenges that existing ships may face. In this context, for a time horizon up to 2035, calculations have been performed and analyzed for two representative commercial ships, both built in 2011: (i) a handy bulker (28k DWT), and (ii) a supramax (56k DWT), with different performance characteristics. The effect of important factors on the current level of CII and its time development has been investigated. The present results indicate that compliance of both vessels is feasible, in meaningful and cost-effective ways. Nonetheless, a point of concern is associated with the high probability of a rating of “D”, for several consecutive years, higher than three, which is not favored by the present regulatory frame. Handling the problem may thus be a key issue for many ships, especially ones approaching the end of their service life; for them, investment for achieving an improved rating may not be justified. Beyond an horizon of one decade, solutions associated with the extensive use of low- and zero-carbon fuels, or with carbon capture, seem inevitable.