The largest wind turbine is the V164 series, which has a rotor diameter of 164 m (538 ft). The original version, which was designed to generate 7 MW (later uprated to 8 MW), was designed by Vestas (DNK) in 2011 and first installed on 28 January 2014. Later models have been produced as part of a joint venture with Mitsubushi Heavy Industries (JPN) called MHI Vestas Offshore Wind (JPN/DNK).Each of the V164's blades is 80 m long (262 ft 5 in) and weighs 35 tonnes (77,161 lb). (The 164-m rotor diameter figure includes the 4-m (13-ft 10-in) diameter of the hub). The massive blades are too large to be transported by land, so they are built at a factory on the Isle of Wight, UK and transported to each installation site by sea.The V164 design has been revised several times. Incremental improvements were incorporated into the original model to create the 8 MW variant, followed by more substantial changes (a redesigned, larger nacelle and overhauled mechanism) to create the 9.5 MW and 10.0 MW variants.The 8.0 MW variant is the largest turbine that is installed and generating electricity, with 32 turbines at the Burbo Bank wind farm in Liverpool Bay, UK, and 2 turbines near Esbjerg, Denmark. The 9.5 MW has completed testing and will begin to be installed on sites around Europe in late 2019, no buyers have yet been announced for the 10.0 MW variant.There is another planned wind turbine (the Siemens Gamesa SG 8.0-167 DD) that will be larger (167 m rotor diameter) when completed, but it is not expected to enter production until 2019 at the earliest.