(AFP) - Dutch officials on Monday opened what is being billed as one of the world's largest offshore wind farms, with 150 turbines spinning in action far out in the North Sea.

Over the next 15 years, the Gemini windpark, which lies some 85 kilometres (53 miles) off the northern coast of The Netherlands, will meet the energy needs of about 1.5 million people.

At full winds the windpark has a generating capacity of some 600 megawatts, and will help supply some 785,000 Dutch households with renewable energy, the company said.

"We are now officially in the operational stage," the company's managing director Matthias Haag told AFP, celebrating the completion of a project first conceived in 2010.

The 2.8-billion-euro ($3 billion) project is a collaboration between the Canadian independent renewable energy company Northland Power, wind turbine manufacturer Siemens Wind Power, Dutch maritime contractor Van Oord and waste processing company HVC.

It has been "quite a complex" undertaking, Haag said, "particularly as this windpark lies relatively far offshore... so it took quite a lot of logistics".

Gemini will contribute about 13 percent of the country's total renewable energy supply, and about 25 percent of its wind power, he added.

It will also help reduce emissions of carbon-dioxide emissions, among the so-called greenhouse gases blamed for global warming, by 1.25 million tons, the company says.

The Netherlands remains dependant on fossil fuels which still make up about 95 percent of its energy supply, according to a 2016 report from the ministry of economics affairs.

But the Dutch government has committed to ensuring that some 14 percent of its energy comes from renewable sources such as wind and solar power by 2020, and 16 percent by 2023, with the aim of being a carbon neutral by 2050.

Gemini "is seen as a stepping stone" in The Netherlands, and has "shown that a very large project can be built on time, and in a very safe environment," Haag added.

© Agence France-Presse