Conference Papers 2024

Seminar
Day 1 (18 Sep 2024), Session 1, Maritime, 11:00 - 12:30

Status
Accepted, documents submitted

Submitted by / Abstract owner
Nathan Gray

Authors
Dr Nathan Gray, University College Cork (presenter)
Dr Richard O Shea, University College Cork
Dr David Wall, University College Cork
Dr Jukka Pekka Jalkanen, Finnish Meteorological Institute
Professor Jerry Murphy, University College Cork

Short abstract
This paper assesses the fuels, port infrastructure, and propulsion technologies that can be used to decarbonise shipping within an Irish context. Technical, environmental, and economic aspects are considered, and policy implications are provided.

Abstract
The maritime shipping sector is the foundation on which trade is built on, with shipping lanes acting as the arteries of the global economy. This is particularly true for island nations, such as Ireland, which are highly reliant on the shipping sector for the import and export of materials and products. However, the shipping sector is also a significant source of greenhouse gas (GHG) emissions and other environmental pollutants. Under business-as-usual conditions, the International Energy Agency (IEA) estimate that emissions from shipping will continue to steadily rise, whereas to be compliant with the Paris climate agreement, emissions must fall to near zero by 2050. Therefore, there is a need to identify and introduce measures that can lessen the environmental impact of shipping.

There are three main areas of the maritime value chain to focus on when it comes to decarbonisation: fuels, port infrastructure, and vessel propulsion technology. Within these three broad categories there are a range of potential pathways towards a decarbonised shipping sector. Alternative fuels can be made either from processing biomass or from using electricity to produce hydrogen, which can either be used directly as a fuel or combined with a source of CO2 to produce a synthetic electrofuel. The energy vectors that have been identified as most promising for use within the shipping sector are liquefied hydrogen, ammonia, liquefied methane, and methanol. As a dop-in replacement for fossil diesel, Fischer-Tropsch fuels can be used in existing shipping applications with little to no modification necessary. For short-sea shipping, there is emerging evidence that the use of battery electric vessels may be technically feasible, but their use in long-distance shipping is still questionable. Once the fuel has been produced, it must be suitably stored for distribution to receiving vessels. There are several options available for vessel refuelling, each with their own benefits and drawbacks. The main methods currently used for delivering marine fuels to vessels are “ship-to-ship”, “shore-to-ship”, or “truck-to-ship” refuelling. The final part of the marine fuel value chain is the vessel and propulsion system. The applicability of powertrain and fuel choice depends on the vessel segment and operational profile, with different fuels being better suited to different vessel types.

Therefore, the aim of this study is to identify the current state of the Irish shipping sector, and assess the fuels, port infrastructure, and propulsion technologies that can be used to decarbonise it. To understand the composition of the Irish shipping sector, an analysis was carried out of every shipping journey that had an Irish port as a destination or origin in 2019. This data was collected in conjunction with the Finnish Meteorological Institute, who have developed the Ship Traffic Emission Assessment Model (STEAM) model, which uses vessel Automatic Identification System (AIS) to provide ship emission inventories that reflect vessel routing and operation. The data set contains information regarding vessel type, size, and age that allows for a comprehensive understanding of vessels calling at Irish ports.

The vessel characteristics identified were compared with key performance metrics of the most promising alternative fuels and propulsion technologies. Other alternatives for reducing the environmental impact of shipping, such as slow steaming, operational improvements, and wind assistance were deemed to be outside the scope of this work and were therefore not considered further. To determine the suitability of these alternatives, they are assessed and discussed based on their technical, environmental, and economic performance. Finally, each alternative was discussed within the Irish context, with key strengths, weaknesses, and opportunities identified.

Preliminary results indicate that there is no single “silver bullet” solution that can be applied across all segments of the Irish shipping sector. Direct electrification in the form of battery electric ferries may be a feasible option to decarbonise small passenger ferries used to service remote island communities. For larger RoRo ferries, container ships, and bulk carriers the low energy density of battery technology presents significant technical challenges. For these vessels it is likely that an energy dense liquid or gaseous fuel is required, with methanol appearing to be the most promising. Due to the international nature of shipping coordination is needed with other nations, particularly the UK, France, and Spain, to ensure that Irish vessels and ports are compatible within the wider shipping network.

Programme committee
Freight and Logistics

Topic
Sustainable travel