Photo: Tom Bastin/ BY

Electric ferries – a revolution underway

Norway got its first battery-powered ferry two years ago. This has set a new benchmark for a sector that has previously been wholly dependent on fossil fuels.

Norway has a very long coastline, with countless fiords, sounds and islands. Today, the many stretches of water have to be crossed by a huge number of ferries. Up till recently these have been powered exclusively by marine diesel engines, with the exception of a small number of ferries running on liquefied natural gas – LNG. The first of these were introduced in 2000.

In February 2015, the battery-powered ferry “Ampere” was introduced at a ferry link in the county of Sogn and Fjordane in Western Norway. This is only the beginning. More than 50 car ferries with battery systems will be in active duty by 2020, according to the Norwegian State Highways Authority. A great number of contracts for new battery-operated ferries and conversion of old diesel ferries to battery operation have been signed. The government has put in place much stricter environmental regulations on new contracts for ferry services. Without these, the development would probably not have been so rapid.

In November 2014, The Norwegian Parliament asked the government to ensure that all future contracts for ferry services should require zero-emission and low-emission technologies as soon as the technology was available.

The many new and converted ferries are called electric ferries, but in reality they will be hybrids, with a combination of electric and diesel engines for propulsion. The diesel engine will only be used as a back-up, and will run on bio-diesel. A hydrogen-electric ferry between Hjelmeland-Nesvik-Skipavik in the county of Rogaland will be Norway’s and the world’s first. This was announced by the transport minister Ketil Solvik Olsen on 13 July 2017.

There are 138 ferry services in the data bank kept by the State Highway Authority. A report by DNV GE shows that if the 52 most important ferry services where electrified CO2 emissions could be reduced by up to 40% compared to the present levels. The electrification of these ferry services would require investment in new electricity connections, but the amount of electricity needed for their operation would be negligible compared to Norway’s total generation. The report stipulates that the ferries should be able to fast-charge in five minutes at either ferry terminal.

Investment in new grid capacity to power the ferries could be a barrier. A battery bank in the harbour can store electricity from the grid and make rapid charging of the ferries possible without heavy investments in new power lines.

Another calculation made by the organisation Bellona has calculated that the CO2 emissions from 127 ferry services could be reduced by 300,000 tons (per year) if today’s diesel ferries were substituted and replaced by new ferries, and if 84 of these were 100% battery-powered.

Today, the ferry services suited for battery-operated ferries are mainly stretches that take no more than 30 minutes to cross. However, longer ferry stretches such as the ferry lines between Norway and Sweden and between Denmark and Germany may also become electric in the future. The ferry company Color Line is building a new diesel-electric ferry to run between Sandefjord in Norway and Strømstad in Sweden. The “Color Hybrid” will have a battery pack big enough to operate for 60 minutes. The ferry will recharge the battery pack by cable from shore in the harbour, or if necessary the batteries could be charged from the ship’s generators. The result will be zero emissions of CO2, NOx and particles in the harbour and in the approaches, a significant improvement for the environment.

The present ferry takes 2.5 hours to cover the stretch between Norway and Sweden. If the ferry could be run for one hour with electric propulsion, the goal of a 100% electric ferry service may be within reach with the next generation of ferries.

The ferry between Helsingborg in Sweden and Helsingør in Denmark has already been electrified, and plans are underfoot for the electrification of the stretch between Rødbyhavn in Denmark and Puttgarden in Germany. Norwegians who want to travel to the countries further south by ferry may be able to do so in the future with zero or much lower emissions of CO2 than previously in case the electricity is produced from renewable energy.

Tore Braend


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