Port of Gävle: Tanker switches to shore power during unloading operation for the first time

In a milestone event for the maritime industry, a tanker conducted an unloading operation while connected to shore power at the Port of Gävle, Sweden.

On November 14, 2023, the product tanker Tern Fors was connected to the newly built shore power facility for over three hours and, for the first time, carried out an unloading operation using shoreside electricity as the power source.

The operation is the culmination of years of preparation by Swedish/Danish tanker operator Terntank and the Port of Gävle.

As explained, unloading is the most energy-consuming operation for a tanker as the vessel’s own pumps have to be operated. During the Tern Fors’ unloading operation, a total of 1,424 kWh was consumed.

“It was a completely magical feeling at the moment when we switched to shore power. It felt like we were experiencing something groundbreaking,” Robert Friborg, the chief engineer on board Tern Fors, commented.

A large project that started in Gothenburg

Shore power for tankers has only been available in one port in the USA for regular traffic, nowhere else in the world.

Connecting tankers to shore power is said to be complex due to the permanent risk of explosions when a tanker is docked in energy ports. This is because flammable products are pumped and can easily be ignited by electrical equipment.

The Port of Gothenburg leads the Green Cable project with the aim of developing a new global standard for the electrical connection of tankers at the dock in a hazardous environment, together with classification societies, oil companies, shipping companies, the Swedish Transport Agency, and the Port of Gävle.

Solving challenges along the way

During the charging, the crew on board Tern Fors had direct contact with technicians from subcontractors in both Norway and China, while the port had its electricians on site.

“We did encounter some challenges during the day, but we solved the issues that arose, made some adjustments, and then it went as planned,” Lennart Knutsson, the captain on board, said.

Tern Fors tested the connection in Gävle in February this year without connecting power. Since then, various improvements and adjustments have been made, both to the onshore facility and on board.

“Now everything fell into place, and we were unloading completely without any auxiliary machines connected. If anything were to happen to the connection, we have batteries that kick in, ensuring that there is never a blackout on board.” says Lennart Knutsson.

Evaluations are now awaited

The vessel connects the cable amidships. The connection points, both on board and ashore, are in specially adapted environments.

On the dock, the cable is in a container with overpressure air to prevent any gases from entering. The small connection house on board the vessel is then filled with nitrogen to ensure it is under 5 percent oxygen so that nothing can explode if a spark occurs.

Evaluations are now awaited from both the port and the shipping company before Tern Fors, and also the sister vessel Tern Island, can connect next time.

“The next time we do it, it will probably go much smoother; now we know more about how the connection should be made and that it works as intended. Next time, it will likely be much quicker,” Knutsson concluded.