Feasibility of IMO Annex VI Tier III implementation using selective catalytic reduction
Reading the tea leaves in IMO’s NOx decision
Two weeks ago the International Maritime Organization (IMO) convened the 66th session of its Marine Environment Protection Committee (MEPC-66). Among a host of issues, perhaps the most contentious was finalizing the implementation date for NOx (nitrogen oxide) Tier III requirements in Emission Control Areas (ECA). Here’s a short summary of the outcome on that topic, and what it means for vessels, NOx emissions, and future implementation.
Tier III NOx emissions limits were originally set to take effect in 2016 in ECAs with NOx restrictions in place (applying to new-build ships and engines). Despite MEPC’s finding [.pdf] that the requirements were technically feasible (a finding in which we concurred), at MEPC-65 the Russian Federation submitted a request to have the implementation date pushed back to 2021, citing inadequate technology availability and cost concerns. That started an international [.pdf] debate over the readiness of technology and industry to meet the 2016 implementation date generally pitting North American, European, and East Asian nations whose manufacturers [.pdf] had invested heavily to develop Tier III–compliant technologies [.pdf] against other countries with less developed industry.
At the meeting earlier this month, a compromise agreement was reached:
- The 2016 implementation date would stand for larger vessels operating in existing ECAs. This means that the NOx emissions limits will apply to vessels built or significantly rebuilt after 2016 while they operate within the North American and Caribbean ECAs.
- New large recreational vessels smaller than 500 gross tonnes (“superyachts”) would not need to be Tier III compliant in ECAs if they are built before January 1, 2021. This five year exemption was adopted in response to arguments that new, optimized selective catalytic reduction (SCR) systems would need to be developed for superyachts due to the difficulty of installing existing systems given size constraints.
- Implementation dates for new NOx ECAs will be set by the applicant nations, but in those cases mandatory requirements cannot be imposed on new ships built before the adoption of the ECA.
This is where it gets tricky. Under IMO’s original language, all new NOx ECAs, regardless of when they came into effect, would retroactively apply to all vessels built in 2016 or later. This would mean that any vessel intending to transit in a future ECA would need to be built to those standards now, or to be retrofitted later. For example, for a new Baltic Sea NOx ECA coming into effect in 2020, all vessels built after 2016 would have had to comply with NOx restrictions even though those restrictions did not apply within the new ECA’s waters when those vessels were built. This apparent disconnect was pointed out during discussion at MEPC.
In answer to that concern, it was proposed and later adopted that the date of applicability for new-build ships would depend on the date of adoption of the NOx ECA, rather than being pegged to 2016. Take, for example, the same hypothetical 2020 Baltic Sea ECA. If the application for that ECA was made two years before it went into force, or in 2018, only vessels built or significantly rebuilt in or after 2018 could be required to meet Tier III NOx emission restrictions while operating in those waters. And nothing would require the ECA to cover those vessels built or rebuilt between the application date and the date it entered into force; nations could stipulate a later effective date.
This compromise has pros and cons. On the one hand, the benefits of implementing the North American and Caribbean ECAs NOx restrictions in 2016 will be retained, and the technologies that industry has been developing will begin to be deployed. On the other hand, there is less certainty in the application of technology to new ships since the requirement now depends on the adoption of new NOx ECAs. There are also some potential loopholes; for example, a commercial marine vessel designed for global use and built between January 2016 and December 2017 would need to activate NOx emission control technology in the North American ECA but not when operating in the hypothetical Baltic ECA described above.
Ultimately, the compromise may make it easier to adopt new NOx ECAs in areas where the 2016 implementation date could be seen as requiring widespread retrofits of existing vessels. It will be key, as the industry moves forward, to continue to provide accurate and current information on the progression of technology, so that countries and regions may adopt NOx control areas based on the best available information.