World's largest off-shore windfarm to start generating power

Photo by Orsted The Walney windfarm array, formerly the largest in the world

The world’s largest off-shore windfarm is scheduled to start delivering power to the UK grid.

The Hornsea One field, located 120km off the North Sea coast near Hull, will feature 174 turbines across 407 square kilometres. The new windfarm replaces the Walney array, off the Cumbrian coast, as the world’s largest off-shore windfarm.

When it is completed by Danish developer Ørsted in the second half of this year, the field will produce about 1,218MW (approx. 1.2GW), sufficient to power approximately 1m homes.

There are up to four windfarms approved for the area (Hornsea One through Four). The second is due to be completed in the early 2020s.

The first two phases will comprise 7MW turbines. Later additions could use turbines generating 10MW. The larger turbines would be cheaper overall to install, requiring fewer sea foundations and less cabling.

The 10MW turbines would will feature a rotor diameter of 193m and individual composite blades measuring 94m. Developing 30% more power, first deployments of the larger turbines are expected in 2022.

The turbines, including the composite blades, being installed at Hornsea One are manufactured by Siemens Gamesa at the plant in Hull. In total, about half of the components used to complete the windfarm are sourced in the UK.