Shipping emissions in a Nordic port: Assessment of mitigation strategies

- Oceangoing vessels are the main contributors to emissions from the port.
- Around 50% of emissions from oceangoing vessels occur at berth.
- Low sulphur (<0.1%) fuel involves 90% and 10% reduction in SO2 and PM10 emissions.
- Onshore power is an effective measure to reduce emissions from shipping.

We use a bottom-up approach to develop a comprehensive emissions inventory for the Port of Oslo for current and future scenarios, including compliance with environmental legislation. We estimate the emission of air pollutants (NOx, PM10, SO2) and greenhouse gases (GHGs; CO2, CH4, N2O) from shipping and land activities in the port. The inventory shows that oceangoing vessels are the main contributor, providing 63-78% of the total NOx, PM10, SO2 and CO2e emissions. The main contributors among oceangoing vessels are international ferries, cruises and container vessels, and the main contributors to emissions among harbour vessels are domestic ferries. We estimate the emissions from oceangoing vessels for different operational modes, obtaining the highest values at berth followed by emissions during vessel manoeuvres. We evaluate a 2020 scenario that takes account of (i) the expected increase in maritime traffic; (ii) compliance with a new regulation regarding sulphur content in ship fuel (<0.1%); and (iii) implementation of various mitigation measures. These measures include implementation of onshore power, and its combination with a speed reduction zone in the port, and the increase use of liquid natural gas (LNG). The results show that compliance with regulation provides a reduction of 90% and 10% in SO2 and PM10 emissions, respectively. Onshore power in combination with a speed reduction zone provides reductions of up to 15% in NOx and CO2 emissions by 2020 compared with 2013, and further reductions of up to 23% (NOx) and 17% (CO2e) if we extend the use of LNG among domestic ferries.