Ferry and port operator Caledonian Maritime Assets Ltd has joined with community-owned wind farm company Point and Sandwick Trust and other companies to assess the feasibility of using local wind farms to produce hydrogen fuel for future ferries operating in the Western Isles and West Coast of Scotland.
Part-funded by the Scottish Government’s Low Carbon Infrastructure Transition Programme, the project explored the practical and economic feasibility of using new island wind farms to produce zero-carbon hydrogen fuel for future ferries that could use hydrogen fuel cells to operate on existing Caledonian MacBrayne (part of Caledonian Maritime Assets Ltd) routes.
The project team assessed the most practical locations and likely output and cost of island wind farms; how to overcome challenges associated with handling, transporting and storing the hydrogen on local piers; and the bunkering requirements of nine West Coast ferry routes.
Assessments found that the highest scoring route for a large ferry was the vessel operating on the long crossing from Stornoway to Ullapool, which would require 3,767 tonnes of hydrogen produced by 15 wind turbines. Estimates suggest this could save 21,815 tonnes of carbon dioxide equivalent per year, the equivalent of removing 4,742 cars off the road annually.
Meanwhile, the highest scoring route using a small ferry was on the short crossing from Barra to Eriskay, which would require 219 tonnes of hydrogen produced by a single 4.3-megawatt wind turbine generator. This could reduce carbon dioxide emissions by 676 tonnes every year – equal to taking 147 cars off the road in the same period.
“The richness of the Outer Hebrides renewable energy resource will allow the islands to make a significant contribution to the UK and Scotland’s green energy targets,” said Uisdean Robertson, councillor and chairman of Comhairle Nan Eilean Siar’s Transportation and Infrastructure Committee. “In addition to energy generation, however, it is essential that we look to new and innovative methodologies to decarbonise our transport infrastructure. The potential of fuelling Calmac ferries using hydrogen offers real potential and, as such, I welcome these studies and look forward to seeing the next stage of activity on the two West Coast routes progressing.”
Prices of hydrogen would range between £3.70 and £5.60 (US$4.50 and US$6.82 per kilogram), which equates to between £0.11 and £0.17 (US$0.13 and US$0.21) per kilowatt-hour. Current marine diesel fuel is £0.05 (US$0.06) per kilowatt-hour.
However, if hydrogen produced from renewable resources for marine transport was to be included in the UK government’s Renewable Transport Fuel Obligation mechanism, it was calculated that the price would fall to between £2.90 and £4.00 (US$3.53 and US$4.87) per kilogram, or £0.09 and £0.12 (US$0.11 and US$0.15) per kilowatt-hour.
Findings suggest that the price gap between using imported oil and local renewables is smaller than initially expected. However, to close the gap, the study found that Scotland needs to make further progress with designing and building more energy-efficient ships, and improve the economics of wind farm and hydrogen production.
“This is an exciting first step towards a future where zero-emission ferries are serving the Western Isles using hydrogen sourced from local and renewable wind power,” said Calum MacDonald, project manager at Point and Sandwick Trust. “We need to make our ferries zero-carbon to protect the planet, but at the same time, we need to use our local, renewable resources to fuel those ferries to protect and strengthen our communities. When we have the best renewable resources in Europe on these islands, it would be crazy to replace the import of marine oil with the import of hydrogen. By sourcing the power locally, we can create a virtuous and sustainable cycle that benefits both the nation and local communities.”
Project participants included engineering and technical services provider Wood; wind turbine supplier Siemens Gamesa Renewable Energy; hydrogen energy solutions manufacturer ITM Power; renewable energy company ENGIE; Ferguson Marine Engineering shipyard; and Johnston Carmichael, a firm of chartered accountants and business advisers specialising in renewable energy finance.