Swedish energy company Vattenfall has announced the start of construction on the 600MW Kriegers Flak offshore wind farm, to be located in the Baltic Sea.

Vattenfall said that the first of the monopile foundations are presently being manufactured at EEW Special Pipe Constructions in Rostock, Germany.

By next spring, up to 800 tonnes of heavy monopoles are expected to be sailed from the manufacturing facility in Rostock to the offshore construction site, to be installed between 15 and 40km off the Danish coast, in water depths ranging between 16 and 25m.

The 72 monopile foundations will support the 8.4MW of Siemens Gamesa’s turbines, which will have a combined power-generating capacity of 600MW.

Once fully operational in 2021, the Kriegers Flak offshore wind farm is expected to increase the annual Danish electricity production by 18%, equivalent of supplying electricity to nearly 600,000 households.

Vattenfall Danish country manager and offshore wind head Michael Simmelsgaard said: “This summer we will be finalising Horns Rev 3 offshore wind farm in the North Sea. Perfectly timed with the construction start of Kriegers Flak. Together they will increase Vattenfall’s offshore wind capacity significantly contributing to our goal of enabling a fossil-free living within one generation.”

In December 2014, the Kriegers Flak wind project received final investment approvals from the Danish Minister for Climate, Energy and Building.

A contract worth more than $100m was awarded to ABB for the installation of an AC cable system to integrate and transmit power from the Kriegers Flak offshore wind farm to the mainland grid.

Kriegers Flak Offshore Wind Farm project director Ian Bremner said: “We have been preparing this project for some time and are well on schedule. Now it’s time to start construction. It’s always great to reach this point, when the elements of the wind farm are starting to take shape.”