Scotland’s ambitious plan for a “green” ferry has been left in tatters after it emerged the new vessel will actually emit more carbon dioxide than the ship it is replacing.
The Glen Sannox and Glen Rosa were originally touted as “world-leading” when plans were submitted for them to run on liquefied natural gas (LNG) instead of diesel.
However, the building process has been plagued with complications, including a lack of expertise and parts, which led to Ferguson Marine going bankrupt and the yard being brought into public ownership.
The cost of the vessels also ballooned from £97 million to over £400 million, with delays pushing back the delivery by more than five years, reports the Scottish Daily Express.
The Glen Sannox is now expected to begin passenger service in January.
A previous report highlighted how the LNG-powered ferries would produce more CO2 than anticipated due to methane leaks, as well as the environmental impact of transporting the fuel from Qatar via diesel trucks from Kent.
According to the BBC, an emissions analysis conducted by CalMac found that the Glen Sannox will emit 10,391 equivalent tonnes of CO2 annually, compared to just 7,732 tonnes for the 31-year-old MV Caledonian Isles, which currently operates on the same route.
The new ferry’s bigger car capacity necessitates bigger engines, which also emit methane.
Initially, ferry bosses claimed that the LNG engines would cut CO2 emissions by 25% compared to a similar-sized vessel running on conventional marine gas oil. However, the latest findings cast doubt on this claim.
Professor Tristan Smith, from University College London’s Energy Institute, explained that when the environmental cost of importing LNG from Qatar is taken into account, running the ship on diesel might actually be the more sustainable option.
He said: “In a best-case scenario, there’s a negligible benefit to using LNG, and at worst, there would be a deterioration.”
The Glen Sannox is equipped with dual engines, meaning it can also run on regular diesel. While air pollutants like NOx and SOx should be reduced, in terms of greenhouse gas emissions, the difference between the two vessels is minimal.
Taking into account methane emissions, the advantage of using LNG is less than 9%, and the larger engine size and increased fuel consumption make the new ferry’s carbon footprint approximately 35% larger than that of the Caledonian Isles.
Scottish Tory Shadow Energy and Net Zero Secretary, Douglas Lumsden, criticised the government for what he called “eco-friendly spin”.
He added: “Betrayed islanders have been waiting years for this lifeline ferry, only to discover it will pump out more carbon than its 31-year-old predecessor. Meanwhile, hundreds of millions of taxpayers’ money have been squandered.
“This is why Scots are fed up with the SNP. In the real world, this kind of failure would cost people their jobs, yet no minister has been held accountable for this national scandal.
“It’s no wonder the SNP is failing to meet its own net-zero targets when they’re responsible for a ferry that will emit over 10,000 tonnes of CO2 a year. They must urgently explain how they will mitigate these harmful emissions.”