Swedish owner Stena Line believes it will be running the world's first large fossil-fuel-free ferry line in 2030.

The company has signed a deal with Frederikshavn Municipality and the Port of Frederikshavn in Denmark, committing to having two battery-powered Stena Elektra vessels operational in nine years.

Stena Line said the ropaxes will run to Gothenburg in Sweden, and the deal involves infrastructure investments on shore.