Wärtsilä will supply its hybrid propulsion system for three new RoPax vessels being built for Stena RoRo. Two of the ferries will have a battery capacity of 11.5 MWh, making them the marine industry’s largest hybrid vessels to date. This battery power is approximately double that typically being used for hybrid propulsion.
The ships have been designed and developed by Stena RoRo and Brittany Ferries and they will be long term chartered to Brittany Ferries for operation between Portsmouth in the UK and the French ports of St Malo and Caen. The ships will be capable of operating on either LNG fuel or batteries.
Wärtsilä had already been contracted to supply a broad range of solutions for the vessels, including the main and auxiliary engines, gearboxes, controllable pitch propellers (CPPs), thrusters, the fuel gas supply system, Nacos navigation and automation as well as integrated control alarm and monitoring system.
Batteries and shore power
The vessels will be equipped with the latest generation Leclanché energy storage system – the Navius MRS-3 – which has both a size and weight advantage versus comparable marine batteries.
‘The extensive battery size will allow the vessels to operate with full power, using both propellers and all thrusters to manoeuvre emissions-free in and out of ports, even in bad weather,’ explains Håkan Agnevall, President & CEO of Wärtsilä. ‘The built-in shore power solution will charge the batteries while berthed.’
‘Stena wants to be a frontrunner in decarbonising its fleet and, together with our partners, pushing developments towards zero-emission operations,’ says Per Westling, Managing Director, Stena RoRo. ‘Hybridisation allows our vessels to be highly flexible as we adapt to future technology developments, including green fuels, fuel cells, bigger batteries, and solar or wind supported propulsion.’
Important elements of hybrid vessels include the ability to integrate multiple vessel systems and real-time optimisation of the on-board energy system. Combining the benefits of the hybrid propulsion system and shore power leads up to fifteen per cent GHG emissions’ saving compared to a conventional diesel mechanical propulsion system.
The vessels are being built at the China Merchants Jinling (Weihai) Shipyard. Delivery of the ferries is expected to take place in 2024 and 2025.
Picture: One of the world’s largest hybrid ferries is Brittany Ferries’ E-flexer, which will operate between Portsmouth in the UK and French ports of St Malo and Caen (courtesy of Brittany Ferries).