Sweden's Stena Line is taking the next step in its eco-quest by fitting batteries in one of its ro-paxes.

It has a signed a deal with Callenberg Technology Group for batteries with a capacity of 1 MWh for the 30,000-gt ro-pax Stena Jutlandica (built 1996), which operates between Gothenburg and Frederikshavn.

The first step is switching on battery power for bow thrusters and manoeuvering when berthing in port.

In step two, an extended battery operation is connected to the propellers, meaning that Stena Jutlandica can be operated on electricity within 10 nautical miles.

The third step will be further expanding battery capacity so that a vessel can operate for about 50 nautical miles.

More to come?

If the project is successful, battery operation could be applicable to other vessels in the Stena Line fleet of 38 vessels.

"Sustainability is very high on our agenda and we are constantly evaluating new ways to reduce our impact on the environment," Stena Line CEO Niclas Martensson.

"From 2015, for example, methanol is part of the fuel mix on Stena Germanica, which operates between Gothenburg and Kiel, and we also run around 300 different energy saving projects.

"As both the size and cost of batteries decrease, battery operation becomes a very exciting alternative to traditional fuels for shipping, as emissions to air can be completely eliminated.”