After building the most powerful electric ferry in the world, Søby Værft shipyard is keen to use its experience to build more electric and hybrid ferries
Søby Værft shipyard aims to continue building green and electric ferries after building e-ferry Ellen, the most powerful electric ferry in the world.
The Denmark-headquartered shipyard dates from 1931 and offers repairs as well as shipbuilding, with ship repair the largest part of its business. As its chief technical officer Henrik Frederiksen tells Passenger Ship Technology, “This is because we do not always have newbuildings contracted, some years we do and some we don’t, although last year we delivered five newbuildings.”
Indeed, last year was a stand-out year as not only was all-electric ferry Ellen delivered by the shipyard but also electric-hybrid ferry Kanalen. The other three newbuildings were fishing boats for Norway. Overall, the shipyard has built 10 ferries and repaired many others over the years.
Speaking about the impact of Ellen for the yard, Mr Frederiksen says “We are concentrating on electric, hybrid and green ferries, having started with Ellen in 2015. This is the way the industry is going and we have good experience having built the most powerful electric ferry in the world. And we delivered Kanalen last year, so we have experience with both hybrid and fully electric. This is a huge advantage as we know all the rules and it is very different when you build fully electric ferries.”
The shipyard was one of nine partners in the consortium building Danish operator Ærø Kommune’s all-electric ferry Ellen, which breaks several barriers. With its route covering a 22-nautical mile crossing, it travels a greater distance than any other all-electric ferry and has the largest battery pack installed at sea. It is also the first electric ferry to have no emergency back-up generator.
Creating this e-ferry prototype, delivered in May last year, involved building a fully electric-powered green ferry which can sail without CO2 emissions. The project is supported by the European Commission’s €80Bn (US$90.5Bn) research and innovation initiative Horizon 2020.
On 15 June 2015, Søby Værft started the project. Mr Frederiksen highlights the main challenge. “In terms of building Ellen, the challenge was that it was electric, so we had to invent it from the beginning. This was the case for class; the Danish Maritime Authorities did not have a complete set of rules for how to build an electric ferry so we had to use an alternative design. As a shipyard it was interesting for us to be involved in developing the entire project.”
He says the first thing he did was to travel to Norway to tour the world’s first electric ferry Ampere. Mr Frederiksen says “We wanted to see how they did it, and we decided to avoid having any oil or hydraulic systems on board to keep the ferry as quiet as possible.”
He says the shipyard’s goal was that passengers unaware that the ferry was electric, would realise there was something different about the ferry due to the lack of noise and vibration. Mr Frederiksen continues “That is why we removed hydraulic systems as they make noise. All our ventilation systems are quiet and our bow thruster system is a special design that works quietly. Together, this means the ferry is very quiet and comfortable and does not create noise when entering and leaving the harbour and during manoeuvring.”
Instead of hydraulic systems, electric solutions were used.
Mr Frederiksen says another notable achievement was the sea trial. “The ferry performed very well on the endurance test when it was at 100% load. It had to run six hours straight to check it could stand the full load. For six hours there was 100% sailing – this is very good for a first try on a fully electric ferry.”
The shipyard built the electric hybrid ferry Kanalen, for the Thyborøn-Agger route on Denmark’s northwest coast at the same time it built Ellen, giving it valuable experience of constructing a battery hybrid. The 46-m double-end hybrid battery ferry contains two separate enginerooms, with one battery pack and genset in each.
Mr Frederiksen says “The goal was to save fuel on the gensets. The idea for this ferry operator, which has a very short sailing distance of 13-14 minutes, is that we use two gensets which are smaller than the propulsion requires. When you are in port, the genset produces power for the propellers and charging batteries and when crossing to the other side, you need more power than the propulsion is able to give, so the ferry also takes power from the battery pack. In that way it is possible to put in smaller gensets to save fuel.”
He highlights the benefits. “On a hybrid ferry, it is more comfortable, as there are two gensets working on a constant load, so you do not have all the machinery moving up and down. This cuts vibration and noise and is much quieter than a diesel-driven ferry.”
He singles out a comparison: in 2012 the shipyard built a similar ferry, but a traditional diesel-driven one. “We can see a huge difference between that and Kanalen, as it is much more comfortable and quieter than the traditional one,” says Mr Frederiksen.
The shipyard is hoping to harness its experience of building Ellen and Kanalen to win more e-ferry and hybrid electric orders.
Mr Frederiksen comments “We want to build e-ferries and we hope that now Ellen has been operating for some time, people will see it is working properly and we get the chance to build more. We have the experience and know how to do it.”
The shipyard also hopes to use its green ferry experience to apply its knowledge of batteries to these types of vessels.
On the ferry retrofit side of the business, Mr Frederiksen is sure the shipyard will start to apply battery retrofits. He says smaller local ferries in Denmark use its facilities for drydock and “we have had a lot of requests about going fully electric or hybrid”.
“We are sure that in the next three to five years there will be a lot of conversions. We have no doubt that will be a big part of our job on the repair side.”
He sums up “Many have been waiting for Ellen to enter operation. It is a lot of money to invest and operators want to see how it performs. That is what we hear from our customers. Now is the time for lots of modifications and green solutions.”
Snapshot CV: Henrik Frederiksen (Søby Værft)
Henrik Frederiksen is chief technical officer and head of newbuildings at Søby Værft shipyard in Denmark. Former roles include warranty engineer at MAN B&W and superintendent at Maersk Supply Service. He was educated and trained as a marine engineer.