Is Scotland’s ‘Green’ Ferry Really Greener? Here’s What You Need to Know
When the MV Glen Sannox, the UK’s first dual-fuel ferry, was unveiled in 2017, it was hailed as a major step toward achieving Scotland’s climate goals. But has the promised “green” innovation fallen short? Recent emissions analysis suggests its environmental impact may be far worse than anticipated, sparking concerns about the ferry’s true ecological footprint.
If you’re wondering whether the ‘green ferry’ lives up to its name — the data might shock you.
The Environmental Reality of the MV Glen Sannox
Despite its innovative design, the MV Glen Sannox emits over 10,391 equivalent tonnes of CO2 annually, significantly more than the 7,732 tonnes emitted by its predecessor, the 31-year-old MV Caledonian Isles. Surprisingly, this makes its carbon footprint about 35% larger. What went wrong with this ‘green’ innovation? The answers lie in both its design and the challenges of implementing new fuel technologies.
Methane Slip and Bigger Engines
One major issue is methane slip. The Glen Sannox runs on liquified natural gas (LNG), a fuel once thought to be more climate-friendly. However, LNG largely consists of methane—a greenhouse gas 28 times more potent than CO2. Unburned methane escapes through the ship’s funnels during operation, contributing significantly to its global warming potential.
Add to that the ferry’s larger engines, necessitated by increased car capacity (127 cars compared to 90 on the older ferry), and it becomes clear that the ferry’s increased size comes with an environmental cost.
No Local LNG Supply
The ferry’s reliance on LNG poses another issue—logistical emissions. With no LNG supply available in Scotland, the fuel has to be transported 445 miles from Kent using diesel road tankers. This process alone adds 140 tonnes of CO2 emissions annually to its footprint.
Experts Weigh In
Critics argue that LNG fails to deliver on its promise in terms of greenhouse gas reduction. According to Professor Tristan Smith of University College London’s Energy Institute, “At best, LNG offers a negligible climate benefit. At worst, it exacerbates the situation.”
Even CalMac, the ferry operator, concedes that real-world methane emissions may be higher than initial estimates due to factors like methane slip during fuel-switching and unideal running conditions.
Is Diesel a Better Option?
Ironically, the analysis suggests that sticking to diesel fuel might be less harmful to the environment under the current circumstances. The MV Glen Sannox can run on Marine Gas Oil (MGO), a low-sulfur diesel. Though far from perfect, diesel avoids the significant methane slip associated with LNG.
Lessons for Scotland’s Ferry Future
While the MV Glen Sannox has fallen short of its green aspirations, there are lessons that could shape Scotland’s shipping future:
- All-Electric Ferries: Advances in battery technology make all-electric ferries a viable option for up to 90% of Scotland’s ferry routes if paired with renewable energy.
- Catamaran Designs: Catamarans, like the Alfred, offer far greater fuel efficiency due to their lightweight and optimized designs.
- Invest in Biogas: Building local bio-methane production facilities would provide a carbon-neutral fuel alternative, though this would require substantial infrastructure investment.
- Retrofit Future Builds: New ferries can be designed with flexibility for future fuels like ammonia, which offers better long-term sustainability prospects.
Why This Matters Now
With over-budget and delayed delivery, the MV Glen Sannox has already attracted controversy. But its environmental shortcomings spotlight an even larger issue—how to balance modern engineering challenges with genuine climate goals. Scotland must address these gaps now to ensure a greener ferry fleet for the future.
Do you think LNG still has a place in Scotland’s “green” future? Share this article and voice your thoughts!