Advanced technology batteries manufacturer, Saft, is to supply state-of-the-art Li-ion battery systems to Imtech Marine for a new hybrid ferry destined for Scotland.

Two Saft Seanenergy systems will be at the heart of the diesel-electric hybrid propulsion system and energy management system for ‘Hybrid III’, the ro-ro passenger and vehicle ferry designed for use on Scotland’s short sea crossing routes around the Clyde and Hebrides.

“Interest in hybrid propulsion is growing fast in the maritime sector as ship owners and operators come under pressure to meet more stringent energy efficiency targets,” said Jayesh Vir, key account manager, marine, Saft.

“This contract for a very high profile ferry service in Scotland is further confirmation that Saft’s Li-ion technology offers a reliable, high performance and fully commercialized solution for hybrid propulsion on even the largest sea-going vessels,” he added.

The new vessel, currently under construction by Ferguson Marine Engineering Ltd for Caledonian Maritime Assets Ltd (CMAL), will be Scotland’s third hybrid ferry when it enters service in autumn 2016, carrying up to 150 passengers and 23 cars or two HGVs.

It is being funded by the Scottish Government to help meet the target set in its Climate Change Delivery Plan to reduce CO2 emissions in the transport sector by at least 20% by 2020. It will have a service speed of nine knots and because it uses both diesel and electric power, Saft says its fuel consumption will be significantly lower than a conventional ferry, leading to fuel and CO2 emissions that are at least one fifth lower than a conventional arrangement.

As a modular system, Seanergy can be scaled to meet any requirements up to 750 V. The modules are based on Saft’s Li-ion Super Phosphate (SLFP) cell chemistry, which is said to offer the advantage of improved high energy capability and optimised total cost of ownership when compared with standard Li-ion phosphate technologies.

The two Seanergy systems, which provide a total of 800 kWh of energy storage, can power the vessel in battery mode only and in hybrid mode in combination with a diesel generator. The batteries will be charged overnight from shore supply while the ferry is in port. When at sea, Imtech’s energy management system will balance the energy delivered by the diesel genset and battery systems to make propulsion as efficient and clean as possible, enabling the genset to run at peak efficiency.