Rotterdam-headquartered Imtech Marine was asked by Ferguson Shipbuilders in Scotland, the yard building the new CMAL ferries, to supply a hybrid propulsion system for the first ever diesel electric, hybrid seagoing ferries in 2011, with the aim of reducing fuel, noise and emissions.
CMAL operates 30 ferries on the west coast of Scotland to 18 islands, the company said in its press release.
The new vessels are capable of operating on several routes and were designed such that a minimum of a 20% reduction in fuel would be achieved. CMAL developed a Hybrid solution using a lithium battery system, diesel generators and electric propulsion, with Imtech providing the system and engineering. However, during optimisation trials on the first vessel, it was demonstrated that fuel savings of up to 38% could be achieved.
Walter van der Pennen, Imtech Marine consultant, comments: “We are proud to have worked on this project, which brought the world’s first hybrid ferries to the market and to be at the forefront of hybrid technology. And it is great to receive industry recognition for our propulsion system.”
CMAL Senior Technical Manager, Jim Anderson, says: “It is fantastic to win this prestigious award. To think this all stemmed from an innovative idea we had five years ago and now we have two hybrid ferries in the water!”
The hybrid system is installed on the MV Hallaig, which operates between the Isle of Skye and Raasay and on the MV Lochinvar, which operates between Tarbert (Loch Fyne) and Portavadie. “As we have seen from the optimisation trials fuel savings of up to 38% can be achieved and at the same time, we have twice the carrying capacity with the MV Hallaig (23 cars compared to 12) compared to our previous ferry,” he adds.
“The beauty of the system provided by Imtech is that not only do the batteries alone reduce our fuel consumption. The Imtech Energy Management System (EMS) very cleverly optimises the load sharing between the lithium ion batteries and generator whilst in Hybrid Mode, allowing the generator to run at its most efficient point. We are happy that we took the decision to move forward with these new technologies.”
“Undoubtedly, the EMS and the whole optimisation process are the key to these fuel savings. The EMS enables us to run all our machinery and equipment as efficiently as possible. Additionally, by operating the propulsion units in Combinator Mode rather fixed RPM, further improvements in efficiency are gained.”
Mr van der Pennen adds: “Imtech Marine looks at the whole lifetime of the ship - the Total Cost of Ownership - right from the design phase through to operations. We take an holistic approach, optimising at every stage.”
There is also a much higher degree of redundancy on board the two ferries compared to the previous designs. Mr Anderson emphasises: “If we lose all power from the diesel electric generators we can run on batteries alone. On days with a reduced number of crossings the ferries can operate on batteries only all day. This clearly gives us the most reliable service possible. These vessels are a lifeline for these island communities and will hopefully encourage more tourists to visit.”
Additionally, the hydrid propulsion system has enhanced the passenger experience. “Everyone is amazed the ships are so quiet. The islanders have really taken ownership of these vessels and their green credentials - it is their boat and they are very proud.”
“These Awards also highlight the cooperation between Imtech Marine and CMAL, it is not just a customer relationship, we partner each other and this is vital to achieve these successful results,” Mischa Kyanin, Imtech Marine Senior Sales Support Manager adds. “We took all the challenges and responsibility for the propulsion system on our shoulders and this was appreciated by our client.”
Imtech Marine is continuing developing automated control system and considering other technologies such as fuel cells for new hybrid vessels.
Mr Anderson points out that for CMAL this is really the starting point, with the company considering further pioneering systems. “Our goal is to have a fleet of more fuel efficient vessels with lower emissions. Ultimately, we would like to have a zero emissions ferry!”
Winning the Electric & Hybrid Propulsion Awards"As a supplier of complete electrical systems Imtech Marine has built a niche for itself in innovative but practical vessels, as shown by the CMAL hybrid ferries and Sonne, among others" – Bill Thomson, editor, The Motorship.
"The world’s first seagoing passenger and vehicle roll-on, roll-off hybrid ferry with advanced hybrid electric propulsion and energy storage systems is a major accomplishment and a milestone for the sector" – Zuomin Dong, professor and chair of the University of Victoria’s Department of Mechanical Engineering.