A photo taken on June 29, 2012 shows a Vestas wind turbine near Baekmarksbro in Jutland

Danish wind technology giant Vestas said on Thursday that the world's most powerful wind turbine has begun operating, sweeping an area equivalent to three football fields.

A prototype for the group's first V164 8 offshore wind has successfully produced its first electricity, the Aarhus-based group said.

"We expect that it will reduce the cost of energy for our customers," spokesman Michael Zarin said.

"You can have fewer turbines to have the same amount of electricity. ... You can save a lot of the expense on things like the foundations, the cabling or the substation," he added.

The 8 megawatt turbine, which will be the flagship product for a joint venture between Vestas and Mitsubishi Heavy Industries, has the capacity to produce electricity for 7,500 European households.

It's been installed on land at the Danish National Test Centre for Large Wind Turbines in Oesterild in northwestern Denmark. Vestas said serial production could begin in 2015 if there is enough demand.

The most powerful onshore wind turbine on the market is currently the 7.5 megawatt E-126 by Germany's Enercon, while the largest offshore turbines are the 6 megawatt models produced by Germany's Siemens and France's Alstom.

Competition in the sector is fierce: South Korea's Samsung Heavy Industries installed a 7 megawatt offshore wind prototype turbine in Scotland last year.

France's Areva and Spain's Gamesa said last week they were holding talks on combining their offshore wind turbine activities, and that they planned to accelerate development of an 8 megawatt turbine.