A small ferry for Orkney has been designed as part of a programme that aims to place Scotland at the forefront of emission-free hydrogen technology. But will it occur?
In recent years, “ferries” has become somewhat of a nasty term in Scotland. Regularly reported news topics include an increasingly unreliable fleet, as well as major cost overruns and delays in the construction of new boats.
Simultaneously, a heterogeneous coalition of Scottish and European organizations, commercial enterprises, and academics have been quietly collaborating on a significantly more positive view of the future.
Since a decade ago, the feasibility of moving people and cars across lochs and oceans using hydrogen, a fuel whose only byproducts are oxygen and water so pure that it may be consumed, has been examined.
The Shapinsay crossing ferry
The most recent iteration of the project, HySeas III, aims to construct a tiny, double-ended vessel to transport passengers and cars on a 25-minute journey between Kirkwall and Shapinsay in Orkney.
Orkney was selected for a purpose. Just north of the Scottish mainland, the island settlement is a pioneer in the hydrogen economy.
The National Grid cannot consistently accommodate the islands’ excess wind and tidal energy.
Instead of shutting down the wind turbines, they are used for electrolysis, which separates water molecules into oxygen and hydrogen.
This “green hydrogen” can then be utilized to produce power using a device known as a hydrogen fuel cell.
Already, a small fleet of city vans, buildings, and ships docked in Kirkwall’s harbor are powered by fuel cells. For a society that relies so heavily on boats for transportation, ferries are a natural next step.
Does it appear straightforward? Not nearly that straightforward.
Challenges and alternatives
Initially, there have been technological obstacles and decisions to make.
Hydrogen can be combined with other fuels and used directly in an internal combustion engine, producing significantly less carbon monoxide. However, this process also generates nitrogen and sulphur oxides, sometimes known as NOx and SOx.
Instead, the HySeas project opted for the far more environmentally friendly fuel cell method, which uses hydrogen to generate electricity to power electric motors.
The technological obstacles have been mostly surmounted. About the size of a closet, a marine-certified hydrogen fuel cell can generate 200 kilowatts of power. Output may be ramped up like construction blocks; three would be required for the Orkney boat.
In addition to fuel cells, the ferry would require 7.5 tonnes of batteries to operate as a buffer, smoothing out the power supply to the motors and giving extra power when necessary, while also assuring the ferry could reach port in the event the fuel cells failed.
Regulations, or rather the lack thereof, have posed a greater problem. When the rulebook has not kept pace with technology, the team has frequently battled to obtain regulatory approval.
Despite these obstacles, a crew training program has been approved. The prototype design was approved by maritime regulators DNV last week, marking a significant milestone.
The Hindenberg dread
Hydrogen has already established itself in the history of transportation.
The Zepellin LZ1 was the first modern airship to take flight in 1900, three years before the Wright brothers and their winged aircraft.
For decades, hydrogen-filled airships provided a cost-effective way of air transport, but that ended on May 6, 1937, when the Hindenberg exploded upon landing in New Jersey, creating a tremendous conflagration.
The 35 fatalities, coupled with the far more fatal accident of the R101 airship seven years earlier, shattered public confidence in airship transport, necessitating a conversion to the safer but more expensive helium gas.
Hydrogen is extremely flammable, but so are many other fuels, including gasoline. In Aberdeen, hydrogen is already utilized to fuel buses.
Prof. Martin Smith of St. Andrews University notes that until the 1970s, millions of households were piped with coal gas, which contains 50% hydrogen, rather than natural gas.
“Your grandmother, great grandmother, and great-great grandmother will have used hydrogen as a fuel,” he continues.
It has been around for a very long time and is not the terrifying new fuel that it is frequently touted as.
To satisfy authorities, the designers want to store the hydrogen in pressurized carbon fibre tanks on the wheelhouse deck of the ferry.
Risks associated with a leak or, in the worst-case situation, an explosion have been meticulously modeled, and the level of pressurization has been determined to minimise the possibility for harm.
Using the lightest element on Earth as a fuel has one safety advantage: if a leak occurs, the gasoline just floats away.
A few years ago, it appeared that the proposed Orkney ferry could be the world’s first hydrogen-powered ferry, however, like with the race to the South Pole in the early 20th century, this distinction will almost certainly belong to Norway.
In 2019, the major design partner for HySeas III, the Ferguson Marine shipyard in Port Glasgow, went bankrupt and was nationalized, impacting project finance and generating a mound of paperwork.
The Scottish government’s ferries agency, CMAL, assumed responsibility for design and began the project from scratch.
In the meantime, the Norwegian ferry company Norled has taken delivery of the 82-meter-long vessel Hydra, which is expected to become the first hydrogen-powered ferry in the world later this year.
The fuel cells of Hydra have been installed, however it is now powered by batteries due to a lack of locally manufactured hydrogen. They are now finalizing the importation logistics from Germany.
Even if it is not the first hydrogen-powered ferry in the world, the Orkney ferry would be a model of sustainability, with locally-produced hydrogen powering a ship without the emissions that occur from carrying gasoline over vast distances.
Other potential fuels
When plotting a road to a zero-emission future for ships, hydrogen is not the only option.
Battery-powered ferries are becoming increasingly widespread, particularly in Scandinavia.
Seven replacement small vessels for the west coast ferry company CalMac are expected to be battery-powered in Scotland.
However, at this time it is believed that electric boats are best suited for shorter excursions or routes where charging time is not a major concern.
The marine sector is also considering ammonia and methanol as potential fuels for the longest voyages because they are easier to store.
In lieu of a “one-size-fits-all” solution, multiple technologies may be required to chart a path toward a greener future.
Cost is also a factor. Saving the planet is not inexpensive.
The price of electrolysis-produced green hydrogen is tied to the cost of renewable electricity, which is currently more expensive than nonrenewable power.
Currently, sustainable hydrogen costs about twice as much as diesel, but as additional wind energy and electrolysis comes online, some believe that it may someday be less expensive than fossil fuels.
Another difficulty is producing enough of it. The west coast of Scotland lacks Orkney’s hydrogen infrastructure, which would cost millions of pounds to implement.
Prof. Smith argues that employment growth would also have wider economic advantages. Using wind power to produce hydrogen, he claims, is a cost-effective method of storing renewable energy.
“Skye cannot house a battery the size of Ben Nevis. As a compressed gas, storing renewable energy is significantly easier.”
The planned prototype ferry for Orkney, combined with the refueling infrastructure, would cost approximately £25 million, more than double the cost of a conventional vessel of comparable size.
Will it be created? This essentially hinges on whether or not lawmakers in Holyrood and Orkney believe the cost is worthwhile.
Prof. Smith is not an impartial source, but he has strong opinions regarding what should occur next.
“We’ve invested a great deal of time and effort on this, and we’ve watched people in other parts of the world catch up,” he explains.
“In order to be a world leader in hydrogen technology, we must demonstrate leadership and complete this task.”
Such a vessel would do little to alleviate the strains on Scotland’s overburdened ferry system in the near future, but the technology provides a peek of what may be possible in the years to come.