Service ship to be converted to hybrid operation - saves 680 tonnes of carbon dioxide

27 December 2021

During the second quarter of 2022 the service ship Northern Skagerrak will be converted to hybrid operation. It will run mostly using electric power although there will also be an auxiliary engine that runs on the renewable fuel HVO.

Northern Skagerrak will collect oily engine room waste, known as sludge, from ships arriving at the Port of Gothenburg. The Gothenburg Port Authority procured the service from Northern Energy & Supply and the service ship will begin operating during the second quarter of 2022. The conversion will save 680 tonnes of carbon dioxide.

“We are a company that is very much at the forefront in developing innovative solutions. We are grateful once again to be entrusted with the task of working with the Port of Gothenburg on a project that will result in an improved environment in the Gothenburg area,” said David Kristensson, Group CEO at Northern Energy & Supply.

When the invitation to tender for sludge collection was issued, the Port of Gothenburg climate objectives were used as a starting point in the evaluation model. Carbon emission mitigation was one of the quality criteria applied when assessing potential service providers. Following collation and evaluation, the Northern Energy & Supply fossil-free solution proved to be the best option.

“Our aim at the Gothenburg Port Authority is to reduce carbon emissions at the port by 70% by 2030. Northern Skagerrak will serve around 6,000 incoming ships each year and the conversion to hybrid operation will be a significant step in the right direction,” said Erik Waller, Deputy Harbour Master at the Gothenburg Port Authority.

All ports in Sweden are obliged to receive sludge from ships arriving at the port. During operation, the vessels accumulate sludge, which is essentially wastewater containing a mixture of oil residue, cleaning agents, and solvents. The ships leave the wastewater to the port, then it is transported to a purification plant where oil and heavy-metal contaminants are separated from the water.

Fact file: Northern Skagerrak
Length: 45.99 m
Beam: 9.6 m
Draught (fully loaded): 4.0 m
Deadweight: 700 tonnes


Northern Skagerrak will collect sludge from ships arriving at the Port of Gothenburg. Photo: Northern Energy & Supply.

Port of Gothenburg
The Port of Gothenburg is the largest port in Scandinavia. Around 30% of Swedish domestic and foreign trade passes through the Port of Gothenburg and around 50% of all container traffic. The port is a full-service port, and offers industry guaranteed, climate-smart access to the whole world. Direct services to key markets ensure highly efficient, sustainable, and reliable transport 24 hours a day, 365 days a year. The focus is firmly on sustainability, innovation, and digitalisation in a concerted effort to maintain the ongoing development of climate-efficient freight transport and calls by vessels. With 25 rail shuttles offering daily departures, companies throughout Sweden and Norway have a direct, climate-neutral service to the Port of Gothenburg. The port operates energy product, vehicle, ro-ro, container, and passenger terminals and has 22,000 employees.

Port of Gothenburg press release