Converting the “MV Sjoborg” into a hybrid vessel using Norwegian battery technology

This content was published before 1 July 2021 by GIEK or Eksportkreditt Norge.

 Following the conversion, the ship now uses both diesel engines and batteries while supplying oil and gas installations in the North Sea. According to Skansi Offshore CFO Jógvan Emil Nielsen, the investment effectivises engine operation and reduces the number of operating hours, thereby cutting both costs and CO₂ and NOx emissions. 

“We are very pleased with the conversion. The ship now runs more efficiently, and we expect the battery pack to cut our fuel consumption by 20 per cent,” says Nielsen.

Equinor contract

In September 2017, the Faroese shipping company started work under a contract with Statoil (now Equinor) to supply the Troll, Oseberg, Gullfaks and Statfjord oil and gas installations from the Mongstad base in Hordaland County. The contract contained two particular requirements: that the supply vessel had to be capable of battery-powered operation and that re-charging had to be possible from the onshore electrical grid.

Norwegian shipyards and technology suppliers have always delivered high quality.

Jógvan Emil Nielsen, Skansi Offshore

Since its launch in 2009, Skansi Offshore has collaborated closely with Norwegian companies in both customer and supplier operations. The MV Sjoborg was built at the Havyard Leirvik yard in Sogn, and when the ship was due to be converted the choice again fell on an exclusively Norwegian solution. “Norwegian shipyards and technology suppliers have always delivered high quality. The battery pack represents new technology which few companies are capable of supplying. In the end, we concluded that Norwegian Electric System should provide the battery pack, while GMC Maritime in Stavanger was chosen to install it,” says Nielsen.

Optimal load

Although the ship supplies several oil platforms in the North Sea, the time actually spent travelling from A to B is small compared to the amount of time the ship is stationary. “Most of the time, the ship is docked, waiting under a platform or in stand-by mode pending its approach to a platform. If the ship did not have a battery pack, the diesel engines would be running at low revs throughout these periods. This is very wasteful,” says Nielsen. 

However, optimal engine utilisation is only one benefit of the battery pack, which also has an important safety function. “Strict safety requirements stipulate that the ship must use two engines when operating close to a platform. With the battery pack installed, the ship has no need of a second diesel engine – if the primary engine dies, we can run on battery power for up to 15 minutes,” says Nielsen, adding that the battery pack also improves the effectiveness of the NOx emissions scrubbing system. The battery pack, which is housed in a container aboard the ship, can be charged in two ways: by the ship’s own engines (the more common option) or through a connection to the onshore electrical grid while the ship is docked. The conversion has transformed the MV Sjoborg into one of the most advanced and environmentally friendly supply ships of its type. Nielsen expects to see further such conversions in future.

Financing important

Export Credit Norway provided financing for the conversion of the MV Sjoborg, in the form of a NOK 8 million loan. The loan, which is guaranteed by GIEK, has a five-year repayment period. According to Jógvan Emil Nielsen, the transaction was only possible thanks to the financing solution. “This is a major investment for us, and it was crucial that we had access to good financing. Our cooperation with Export Credit Norway has been very positive, and important for closing the deal,” he concludes.