Emissions and environmental impact

93. The shipping industry as a whole faces significant challenges moving towards net zero. Emissions from Scottish domestic ferries, including council and private operators, have been calculated at 1.7% of transport emissions and therefore less than 1% of total emissions; these shares are predicted to rise as other sectors decarbonise. The Scottish Government is committed to reducing emissions of the CHFS and NIFS fleets in line with wider Government targets. This will be achieved by encouraging efficient design and by adopting modern technologies to build on ongoing work to modernise the fleet.

Total Emissions

94. Modernisation of the fleet will ultimately lead to lower total emissions by adopting, and encouraging, the use of modern technologies and efficient design to make the strongest possible contribution to the climate change targets set out in NTS. However, it should be recognised that adding additional vessels to the fleet – to provide improved resilience – and increasing the number of sailings on some routes – to improve capacity – are likely to increase the total emissions of the fleet pending the introduction of alternative fuels. However, as we work to reduce the average age of the fleet to 15 years old by the end of the decade, this will see modern, more efficient vessels enter the fleet; during the overall life of the Plan to 2045, we aim to introduce alternative, zero/low emission propulsion options when these become technically viable and commercially available.

Emerging Technologies

95. The Scottish Government is committed to encouraging the efficient use of assets throughout the network to work towards net zero targets.
96. For ferries, there are currently limited options available for low/zero carbon alternative to fossil fuels, especially for the larger vessels on the longer routes. If ferries are to make a more significant contribution towards carbon reduction, and ultimately achieve zero carbon, then emerging alternatives such as all-electric and, potentially in the longer-term, vessels powered by green hydrogen, ammonia or methanol will need to be developed.
97. Battery technology is the most readily available low-carbon option (assuming greening of the electricity supply) and CMAL’s Small Vessel Replacement Programme (SVRP) is exploring the option of all-electric ferries.
98. The SVRP focuses on building low emissions vessels, in line with Scottish Government climate change commitments and will utilise the latest proven battery and onshore charging technologies. Moving forward, the future vessel investment programme set out in this draft Plan will build on the work undertaken as part of the SVRP and take cognisance of the lessons learnt when applying the same ambition to the major vessels fleet.
99. There is potential for the use of all-electric ferries to be expanded onto other shorter routes with smaller vessels, potentially those described above as “medium vessels”, but for the longer routes, with larger and heavier vessels, and higher energy requirements, other options will need to be explored.
100. The Scottish Government has supported the various phases of the HySeas project, which is developing a concept design for a hydrogen fuelled vessel that could operate in Scotland. Although further advancement of the technology is required until the fuel can be economically viable for use on the networks, new vessels should be designed to accommodate future technologies. For example, vessels currently being designed and built by CMAL are considering the option of mid-life retrofits to allow any future technology solutions, including hydrogen, to be utilised.

Improved Design

101. Where zero emission technology is not currently feasible new vessels can take advantage of the latest technology and design concepts to maximise efficiency and reduce emission
102. Alongside work on alternative fuels, Caledonian Maritime Assets Ltd (CMAL) is appraising design improvements to new vessels which can reduce fuel consumption. There are opportunities to design vessels that require less energy and can make use of existing lower emission propulsion options.

Shore Power

103. Action is also being taken to improve fuel efficiency, through the introduction of overnight charging of vessels from electric shorepower – an initiative also taken forward by Serco NorthLink and Orkney Islands Council (with Scottish Government funding) for the MV Hamnavoe berthing overnight at Stromness.
104. Of the major vessel fleet, the majority of vessels currently use auxiliary generators run by the engines to provide internal power for heating, lighting and the ships safety systems. With the appropriate on-board equipment and on-shore power supply, vessels can directly connect with a shore side power source transferring the load to the shore side with minimal interruption to onboard facilities and services. Whilst berthed, this results in:

• Reduced direct emissions;
• Reduced noise pollution;
• Provides better onboard comfort while in port;
• Provides green profile for ship owners and customers;
• Reduces lifecycle cost by fewer fuel consumption and maintenance costs.

105. The use of shorepower requires both vessel and shoreside infrastructure and adequate local electric supply on-shore. To reduce emissions overall, shore supply needs to be from renewable sources – or at least from electricity production with lower emissions than Marine Gas Oil (MGO).
106. Scotland is in the fortunate position to be able to capitalise upon the renewable energy supplies that are currently available. However, collaboration with the energy sector will be critical to ensure that energy supply will continue to meet demand.
107. The long-term decarbonisation of the fleet by 2045 relies on one or more emerging technologies reaching technical and commercial maturity in the coming years – a challenge faced by the whole maritime transport sector. The Scottish government will continue to monitor developments and opportunities to harness the benefits of alternative fuel to lower emissions and contribute towards meeting net zero targets.
108. More information on plans to progressively remove emissions from our ferries by 2045 will be set out as part of the wider Islands Connectivity Plan and in the next Scottish Government Climate Change Plan in 2023.