“In terms of the environment, electricity is a better alternative to fossil diesel fuel. The new technology is also taking us closer to the Government’s objective of becoming emission-free,” says Mats Rosin, CEO of Finferries, which operates the majority of Finland’s commuter ferries.
The technology behind the electric ferry that runs between Grannäs and Högsar in Nauvo is simple. The electric motor on the ferry, which is equipped with a frequency converter, pulls the ferry along a steel cable from one side of the strait to the other. The electricity is supplied by Caruna’s distribution network. As the ferry makes progress, the electricity cable is automatically wound up on a coil inside the ferry.
For a couple of years now, the Nauvo electric ferry has served as a longer-term testing site for the increasing electrification of cable ferries. Despite the testing, the ferry provides a normal service, making around 100 trips per day across the strait, which is approximately 300 metres wide.
Färjerederiet, which operates ferries in Sweden, has substantially increased the number of electric ferries it operates in recent years. Rosin has visited Sweden to witness this himself.
“Ferry traffic is a basic service in Finnish society, so the technology needs to be mature and reliable before it can be adopted more widely. Good piloting is essential to ensure functionality and gain experience in various circumstances. In particular, the technology must be tested in the winter to ensure that it is guaranteed to work.”
The Nauvo cable ferry is also equipped with a diesel engine and a normal propeller system so that customer service is assured even in the event of an electricity outage.
“It has been necessary to fall back on the diesel engine from time to time when changes have been made to the electrical technology. In general, the electric ferry has worked effectively and reliably. The experience has been encouraging.”
According to Sami Sjöman, who drives the Nauvo ferry, the electric ferry is significantly easier to drive than a diesel ferry. The ferry is operated using a single joystick.
“The ferry is also quieter. In the summer, there have been plenty of passengers,” Sjöman says.