“We have developed a new design for an aluminium catamaran powered by jet engines. They can run on liquid fuels such as HVO, as well as natural gas, biogas and, not least, hydrogen,” says Christer Bruzelius, Project Manager for the development of the new vessels in the Horizon series.
On board the ferry M/S Visby, he and Johan Gråberg, Environmental and Quality Manager, welcome a group from the Biogas Solutions Research Center (BSRC), a national centre of excellence for biogas at Linköping University.
Gas-powered ferry
The visit includes a guided tour of the bridge and the engine room, where the four-stroke engines are running at full capacity and are mainly fuelled by natural gas. Diesel operation is also possible on this ferry. Diesel is used to ignite the gas engines, but also when there is a shortage of natural gas.
“After Russia’s invasion of Ukraine, we felt the effects of the shortage of natural gas. We did not want to use Russian gas, but we were given no guarantees and therefore ran on diesel for large parts of 2022,” explains Johan Gråberg.
EU regulations
New regulations under FuelEU Maritime impose stricter requirements for reducing emissions of carbon dioxide, methane and nitrogen oxides. Based on baseline emissions measured in carbon dioxide equivalents per megajoule of fuel energy, emissions must be reduced by two per cent during the period 2025 to 2030.
“After that, the requirement increases to a six per cent reduction, then 15 per cent after 2035, and by 2050 the reduction is set at 80 per cent. The government has proposed that traffic to and from Gotland should be exempt. However, we have said that we want to be part of this transition from the very beginning,” says Johan Gråberg.
High demand for biogas
The company is now preparing for a future in which many different types of fuel will be available. However, they see the greatest advantages in hydrogen, or a combination of hydrogen and biogas. Modern vessels of the future will be largely about technological development, access to fuels and the infrastructure needed to deliver the fuel to the ships.
“Demand for biogas is high. Many will be interested in fossil-free operation and production. We conclude that biogas will remain relevant for the coming decades. However, as demand increases, a shortage situation will arise. We need a vessel that can operate on as many fuels as possible,” says Christer Bruzelius.
How far has the process progressed?
“Together with a shipyard in Australia, we have developed the conceptual design of a new ferry, a catamaran. We are working with several subcontractors, including Siemens Energy, which manufactures the gas turbines for the vessels. There are not many shipyards in the world that can build aluminium catamarans of this size with this type of gas turbine. Traditional RoPax vessels made of steel and powered by piston engines are a completely different matter.”
During the visit, the BSRC group raised several issues, including the need for electricity generation to produce the amount of hydrogen required for the ferries.
Electricity demand
“If all three vessels serving the Gotland route were to run on hydrogen, around 1 TWh of electricity per year would be required. That is roughly equivalent to Gotland’s total annual electricity consumption, so it represents a very large share. This is why we are keen for the planned offshore wind farms in the Baltic Sea to go ahead. We also do not rule out electricity from nuclear power. However, we believe that the fastest way to increase production today is through wind and solar power.”
At the same time, Destination Gotland is running a number of different projects to reduce emissions, for example by introducing new hull coatings that reduce friction and by improving operational efficiency at sea.
“We reduced fuel consumption per nautical mile by six to seven per cent over the past year,” says Johan Gråberg.
We are only part of the system and
must take shared responsibility
They are also working to reduce food waste from the vessels, while ensuring that all food waste is sent for biogas production. The company is also engaged in initiatives on shore, including cooperation with restaurateurs on Gotland. Used frying oil from restaurants on the ferries and in Visby is collected and transported to Brogas’s facility for biogas production.
Investments
The parent company behind Destination Gotland, Gotlandsbolaget, is now also a co-owner of the biogas production on the island through its investment in the company Energiskiftet, which includes the biogas plant in Bro.
“We understand that we are only one part of the system, and that we must take shared responsibility,” says Johan Gråberg.
