Ørsted and Vattenfall Being Neighbourly Offshore Denmark

A new eight-kilometer cable link between Horns Rev 2 and Horns Rev 3 wind farms in the Danish North Sea has recently been used for the first time while one of the export cables was undergoing scheduled maintenance, Vattenfall said.

Energinet recently shut down the export cable connecting Horns Rev 2 to the grid for four days due to scheduled maintenance. During that time, power from Horns Rev 3 was sent to Horns Rev 2 to avoid any potential damage to the wind turbines and to enable a faster start-up after cable maintenance work is completed.

Ørsted, the owner and operator of Horns Rev 2, and Vattenfall, the owner and operator of Horns Rev 3, jointly invested in the 33kV cable link.

“Offshore wind turbines must always be equipped with electricity, otherwise there is a risk of considerable damage, for example from moisture. At the same time, the cable enables a quick and easy start-up of the offshore wind farm when the export connection is back online. And we save large amounts of diesel and working hours for both the emergency generators on the turbines and for service boats,” said Niels Møller Jensen, Interface Manager for Horns Rev 3.

The new cable connection was commissioned back in April, Vattenfall said, describing it as ”an optimal solution both in terms of the environment and investment and operating costs.”

“We have been really happy to be able to supply our 91 turbines with back-up power via Horns Rev 3 in connection with Energinets planned inspection of the export cable’s high voltage switch. The new cable meant that we have been able to restart production of green electricity more quickly,” said Allan Due Overbeck, Head of Operations at Horns Rev 2.

The wind turbines on Horns Rev 2 normally receive emergency power from a generator located on an offshore platform. On Horns Rev 3, each wind turbine is equipped with an emergency generator.

This is the first time two offshore wind farms with different owners back up each other, Vattenfall said.

Ørsted’s 209MW Horns Rev 2 has been in operation since 2009. Vattenfall’s Horns Rev 3 delivered its first power to the electricity grid in December 2018 and will be fully operational during the summer.