London, England (CNN) -- The world's largest offshore wind farm opened Thursday off the British coast, with 100 wind turbines capable of supplying enough electricity for 200,000 homes a year.

The farm, off the coast of Kent in southern England, is part of a major renewable energy initiative spearheaded by the previous British government.

Swedish energy company Vattenfall will operate the farm after having invested around 880 million pounds ($1.38 billion).

British waters are an attractive place for wind farm operators because they are so windy. As an example, an offshore turbine around Britain is estimated to produce 50-percent more power than a similar one in Germany.

Blog: Britain flicks switch on giant wind farm

Of the 16 offshore wind farms now under construction around Europe, half are in Britain, according to the European OffShore Wind Industry.

In total, wind can supply energy to nearly 3 million British homes, according to RenewableUK, a trade group for the wind and marine renewables industry.

The Thanet offshore farm opening Thursday will cover an area of 13.5 square miles (35 square kilometers) -- equal to 4,000 football fields, Vattenfall said.

The nearest turbine to land is about 7.4 miles (12 kilometers) northeast of Margate, at the part of England that juts out where the English Channel meets the North Sea.

Companies like Vattenfall must make sure windfarms are in places where locals don't object to the sight of the turbines offshore, though the company said it expected a rise in tourism from people eager to see the site of the windmills in the distance.

Thanet will not remain the world's largest operational offshore wind farm for long. At some point in late 2012 or 2013, the so-called London Array will start to generate electricity just north of the Thanet site.

Plans there are for more than 300 turbines off the Essex coast. The owners of Array say it could become the world's first 1 gigawatt offshore wind farm, far eclipsing the 300 megawatts expected to be generated by Thanet.

CNN's Jim Boulden contributed to this report.