Dutch Build Towering Wind Turbines Out At Sea

From: Alexandra Hudson, Reuters
Published September 3, 2007

IJMUIDEN, Netherlands - There is no shortage of wind in the densely-populated Netherlands but there is a shortage of space and in a nation which likes its houses small and its gardens cosy, opposition to wind farms is immense.

That is why a new Dutch wind farm is being built so far out to sea it is barely visible on the horizon, reducing the visual impact of its 60 turbines to virtually nil whilst at the same time harnessing higher offshore wind speeds.

Offshore wind farms are likely to appear more and more frequently off European coastlines as governments seek to increase their use of renewable energy without angering their citizens by placing giant turbines on their doorsteps.

The 383 million euro ($522.3 million) Q7 wind park development, 14 miles from the Dutch North Sea coast, is the farthest offshore wind park anywhere in the world, and its developers Econcern and Eneco Energie say a further five to 10 such wind parks will likely follow in the next few years.

"Q7 will contribute enough electricity for 125,000 households, but it is also a learning process. We are learning how to build these wind farms, how to organize the supply chain, and how to manage and operate them," said Bernard van Hemert, one of the wind farm's engineering directors.

"Most campaigns against turbines are based around the noise and the visual impact, and these have been reduced by going offshore. It is more expensive to do it here than to do it on land, but we have all agreed we don't have enough space on land," said van Hemert.

Blessed with shallow sandy soils around their coastline, Dutch engineers say the foundations for the turbines can be hammered 82 feet into the ground in just a matter of hours, although there are myriad other challenges.

The proportions are breathtaking. The turbines extend about 320 feet from the ocean, with three sharp narrow blades, each 130 feet long.

It is hoped that when they start rotating in early 2008 they will cut carbon-dioxide emissions by 225,000 tonnes, helping the Dutch to meet a target of 20 percent renewable energy use by 2020.

TRICKY LOGISTICS

The turbines are so massive they can only be transported by sea and there is just one factory in Europe which can weld and construct the 15-foot-diametre piles, which must be first driven into the sea to form the base of the turbines, van Hemert explains.

"It is a huge logistical operation which requires lots of space. There are only a few crane vessels which can handle those huge structures and hammer them down."

"But bringing up the cables is the most challenging for all offshore wind projects."

Expert divers are helping to fit the electrics.

Developers have also had to ensure that the wind park is well away from busy shipping channels.

"Studies in the United Kingdom have shown that there can be some radio interference but in the situation we have here it is completely safe and there is no risk of confusion or reduced visibility for vessels."

Jim Mollet, chairman of a Dutch group campaigning against wind energy acknowledges off-shore wind farms have some benefits over land-based wind turbines.

"They can be a better solution. But the problem is people tend to believe they are an entire solution. We think the vast sums spent on wind farms would be better spent on research and innovation in other energy sources."

Wind farms cannot generate the sheer amounts of energy the continent requires with cost or space efficiency, he added.

© Reuters 2007. All rights reserved.