A WINDFARM off the coast of Barrow which will become the world's largest once complete has reached the halfway mark in construction.

Taking shape 19 kilometres off the Cumbrian coast, the 659 megawatt Walney Extension offshore windfarm will, on completion in 2019, be able to meet the electricity needs of over half a million UK homes.

When fully commissioned, it will leapfrog the 630 megawatt London Array to become the world’s largest offshore windfarm.

The massive offshore substations which will gather power generated by each wind turbine and step up its voltage for transmission to shore each weigh around 2,500 tonnes.

Turbine components and foundations are being stored in Belfast and the construction is co-ordinated from the port of Barrow, which already hosts the operating and maintenance teams for three other DONG Energy offshore wind farms; Barrow, Walney and West of Duddon Sands.

“We remain on our original construction schedule with both offshore substations in place and 40 per cent of the foundations for wind turbines installed,” said DONG Energy’s Walney Extension programme director, Andrew Cotterell.

“We are proud to be building the windfarm from Barrow which has already become an established hub for this technology on the UK West coast."