As the offshore wind sector grows so will the size of the turbines used to power its energy into electricity? According to the Offshore Wind Supply Chain Strategy Report 2011 the average size of offshore wind turbines is set to grow from its present 2 to 7MW capacity range to between 10 and 20MW in the next 10 to 15 years.

On the basis of a wide-ranging industry survey of offshore wind turbine manufacturer OEMs the new report finds that 40 per cent of respondents see 10 to 20MW as the standard size in future years, 35.6 per cent sees it growing to between 8 and 10MW and a notable 6.7 per cent believe it will go even larger beyond 20MW.

The report’s authors say that one of the main drivers behind the increase in size is to improve OEMs economies of scale on offshore projects and reduce cost.

The ramp-up will bring a myriad of challenges for offshore component suppliers. According to OEMs it will lead to the need for “compact and lighter designs” of blades and towers, reliable electronic components and the location of manufacturing plants closer to offshore wind farms.

One leading OEM said: “Components increasing in size is a natural development of an immature industry. The real problem will be in the logistics and how to transport extremely large components.”

Another told the report: “The coming 10-20MW turbines will be floating.  This means that the critical components will be blades, drive train and generator. Less critical but still challenging will be a floating foundation.”

When asked which components would prove to be the most difficult to scale up OEMs said rotor blades because they take a long time to manufacture, towers because of the increased costs of raw materials, direct drive because of the cost of copper and rare earth metals and bearings due to technological constraints and a limited supply base.

One OEM said: “It’s rotor blades because of the logistical difficulties. There will be a challenge in handling the blades which will be much bigger and stronger.”

OEMs told the report’s authors that they were pushing the “design envelope” on both blades and bearings to drive improved scale.

Indeed new designs, technologies and offshore innovation will be vital tools for component manufacturers to embrace in both the present and the near future if they want to gain offshore contracts from OEMs.

One of the main findings of the report was that OEMs wanted to work closer with their component suppliers on design and innovation issues including the sharing of conceptual ideas and data to shared testing.

The report highlights the case study of blade component manufacturer LM Windpower and its partnership work with OEM Alstom. Both parties are developing new 61.5m blades for use on a new 6MW turbine to be used on the Thornton Bank offshore site in Belgium. More of these partnerships are likely to follow in the years ahead.

To learn more about how to access a copy of the Offshore Wind Supply Chain Strategies 2011 Report please go to the following link:

https://secure.windenergyupdate.com/offshore-wind-turbine-report/purchase.shtml