Windmills have powered the Netherlands for hundreds of years and now the age-old technology will help power its future.

The country has officially opened its new 600-megawatt offshore wind park under schedule and under budget, according to its developer Gemini.

The wind farm will deliver 600 megawatts of renewable electricity to the Dutch grid and eventually generate enough power to meet the electricity needs of around 1.5 million people, or around 785,000 households.

The $3 billion project consists of 150 Siemens wind turbines spread across 26 square miles in the North Sea, about 53 miles off the country's northern coast.

Gemini is the second largest offshore wind farm in the world, slightly smaller than the 630-megawatt London Array.

"Now fully operational, Gemini will produce 2.6 TWh of sustainable energy every year, reducing the Netherlands' CO2 emissions by 1.25 million tonnes," the company's managing director Matthias Haag said. "We are proud to make this contribution to the realization of the Netherlands' sustainability targets."

Fossil fuels still make up about 95 percent of The Netherlands' energy supply, but the Dutch government is looking to ramp up the nation's share of renewable energy from 4 percent in 2014 to 16 percent in 2023, with the eventual aim of being carbon neutral by 2050.

The AFP reported that over the next 15 years, the wind park will be able to generate about 13 percent of the country's total renewable energy supply, and about 25 percent of its wind power.

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 said.