Danish wind turbine maker Vestas unveiled a new giant 7-megawatt offshore turbine on Wednesday and said it expected it to be in serial production in early 2015. Vestas, the world's biggest wind turbine manufacturer by market share, had only been expected to unveil a 6 MW turbine, not the towering 135-meter (443 feet) 7 MW unit, with its rotor diameter of 164 meters. The new turbine, whose rotor will trace a circle bigger than the London Eye ferris wheel and whose 80-meter blade is longer than nine London double-decker buses, is part of a push toward larger and larger units further offshore, where the wind power potential is high and public resistance can be avoided. Chief Executive Ditlev Engel told a news conference in London that the new turbine, designed for North Sea conditions, was the first that Vestas has developed specifically for offshore wind parks and its single largest research and development ever. Wind currently accounts for just 2 percent of the global energy mix, but Vestas expects it to provide 10 percent in 2020, Engel said in a presentation. Most of the growth in offshore wind power capacity to 2025 will be in Europe, he said. President of Vestas Offshore, Anders Soe-Jensen, told the news conference the company expected the offshore wind market to grow by 8.4 percent annually from 2015 to 2025.