Hybrid power sets sail in ‘green’ ferries

Volvo Penta heads to Electric & Hybrid Marine World Expo in Amsterdam in June with proof that hybrid technology is becoming increasingly mainstream: Scotland’s Caledonian MacBrayne (CalMac) is now transporting passengers between the remote western isles of Scotland via a pair of ‘green’ ferries powered by Volvo Penta marine gensets.


The islands off Scotland’s west coast are known for their castles, lochs and whiskey distilleries. But with Caledonian MacBrayne Ferries making some fuel-efficient upgrades to its fleet, environmentally friendly maritime transport — powered by Volvo Penta — can now be added to that list as well. Volvo Penta’s hybrid technology solutions are on display at Amsterdam’s Electric & Hybrid Marine World Expo June 24-26.

Caledonian MacBrayne (CalMac) operates 25 routes along the west coast of Scotland during peak season, shuttling more than 4.5 million passengers, 1.1 million cars and 93,000 commercial vehicles each year. Since 2013, CalMac has introduced two new hybrid ferries into its fleet of nearly 30 vessels: the MV Hallaig and MV Lochinvar, which are believed to be the world’s first roll-on roll-off ferries equipped with a low-carbon hybrid system.

Batteries included…
Both ferries run on electric propulsion and 750 kWh lithium ion batteries, and are equipped with three Volvo Penta 13-liter diesel marine gensets (330 kW each) that run the hybrid system. A fourth Volvo Penta five-liter genset is on board in case of emergency.

When the ferries depart on their runs between islands, all but one of the gensets turns off, and the propulsion system then runs in hybrid mode, or the genset can be switched off and the propulsion system will run on battery power alone — drastically reducing fuel costs and carbon emissions.

The gensets were provided by the local Volvo Penta dealer Fettes and Rankine in Aberdeen and chosen by Calmac because of their excellent fuel efficiency.

“In our research we found Volvo Penta engines to be the best in their size range,” says Caledonian Maritime Assets senior technical manager Jim Anderson. “We’re very pleased with the fuel economy we’re getting — through a combination of the hybrid propulsion system and the fuel efficient Volvo Penta diesel gensets.”

That system has yielded an impressive 38% fuel savings for the Hallaig and 30% for the Lochinvar, as determined during three weeks of optimization trials for each ferry.

Because Caledonian Maritime Assets — which owns CalMac’s ferries, as well as the ports and infrastructure necessary to run the ferries — is government-owned, the hybrid project is a part of the solution to reaching aggressive targets the Scottish government has set for reducing carbon emissions in shipping by 20% by the year 2020.

Volvo Penta at Electric & Hybrid Marine World Expo
Volvo Penta is exhibiting at the Electric & Hybrid Marine World Expo in Amsterdam, showcasing its hybrid solutions alongside more than 100 exhibitors. The expo is the world’s first exhibition and conference exclusively dedicated to showcasing the latest and next generation zero and ultra-low emission marine propulsion technologies.

The hybrid world is changing rapidly and generating more interest than ever before. Volvo Penta diesel marine gensets — ranging from five to 16 liters — provide boat builders with easy and efficient off-the-shelf solutions, well suited to hybrid applications and often far more cost effective than larger engines. Using an installation of 10 mass-produced Volvo Penta marine gensets — which can produce a combined 5,000 kW of power — is a far less expensive solution with a lower total cost of ownership than using three or four larger bespoke gensets. And with a global network of dealers and service outlets, Volvo Penta can provide dedicated aftermarket support wherever commercial boats work.

CalMac hybrid ferry facts
Length: 43.5 meters
Passengers: 150
Vehicle capacity: 23 cars and up to four commercial vehicles
Speed: Nine knots
Routes: Hallaig — Sconser to Raasay; Lochinvar — Portavadie to Tarbert

Photo: The CalMac MV Hallaig hybrid ferry, powered by a hybrid system that is run by three Volvo Penta D13 engines.

For more information, please contact

Ann-Charlotte Emegård
Volvo Penta PR & Brand Management 
AB Volvo Penta
Tel: int +46 (0) 31 323 42 19