Swedish firm Vattenfall has placed an offshore turbine order with Siemens Gamesa, claimed to be the world’s largest this year.

The total installed capacity will be close to 1GW for three wind farms – Kriegers Flak in the Baltic Sea and Vesterhav Syd and Nord in the North Sea.

The order includes 113 8MW turbines, which will generate enough power to supply one million Danish households.

The agreement, which is one of the Vattenfall’s largest renewable investments, will cover design, manufacturing, installation, commissioning, testing and service of the turbines.

The company said the construction costs for offshore wind can be further reduced as the combined purchase gives it a lower price.