German energy company RWE Innogy announced that 25 foundations for wind farms and one for a transformer station were in place 18 miles off the coast of Belgium.
The company said the wind turbines would be installed next year. Once completed, the Thornton Bank wind farm would be able to meet the yearly electricity demands of roughly 600,000 people.
The second and third phases of construction for the project, the largest of its kind in Europe, will feature at least 48 wind farms. Construction in the final third phase is to begin in 2012.
Installation on Thornton Bank 2 foundations started in June and was finished on schedule, the company said.
"The expeditious construction progress of Thornton Bank 2 shows that we are advancing quite well in the construction of offshore wind farms," Martin Skiba, head of offshore wind power at RWE Innogy, said in a statement.
Eight commercial banks are providing around $1.28 billion in funding for the project.