The first phase is complete of a plan to build the world’s largest offshore wind farm near the Fukushima nuclear plant that was crippled by an earthquake and tsunami in March 2011.

The first turbine has been delivered to the area and the facility is due to become operational in October.

It is part of plans by Fukushima Prefecture to ditch nuclear energy and move towards total reliance on renewable sources over the next 25 years.

By 2020 scores of giant turbines 200 metres high should produce twice as much power as the world’s current biggest offshore windfarm at Greater Gabbard off the UK’s Suffolk coast.

“First and foremost, we want to make this a symbol of Fukushima’s recovery. Secondly, this floating wind farm concept is the ace up our sleeves for the next stage of renewable energy development,” said Keisuke Murakami, Head of New and Renewable Energy at the Economy, Trade and Industry Ministry.

There have been concerns about radioactive water leaking into the sea from Fukushima, and official accounts have given conflicting evidence over whether fish are safe to eat.

The disaster all but shut down Japan’s nuclear industry, forcing the country to rely heavily on imported gas.

It is hoped that wind turbines will be more resistant to earthquakes, typhoons and tsunamis.