TWI Bulletin, September - October 2009
Case study: A novel approach to offshore wind power
A client contacted TWI's business support systems specialists for help in investigating the economic viability of a new approach to building and operating an offshore wind-farm.
The long term aim of the client was for floating platforms, each comprising a barge, wind tower, wind turbine system and oscillating water column hardware. They needed to be produced at around 100 units a year and cost control was vitally important.
The specific objectives facing TWI were:
- To assess and document the optimum location for building a prototype barge
- To examine the existing shipbuilding and general fabrication infrastructure locally and identify available improvement opportunities
- To document a range of radical fabrication approaches for the high volume manufacture of such barges
TWI's analysis of the currently installed local fabrication infrastructure led to recommendations regarding the construction of a prototype barge using existing facilities and the types of processes that might be most effectively used. Through use of process and costing models it also commented on what steps could be taken to improve productivity within existing locations, through further investment in the latest manufacturing technology applicable within the shipbuilding industry.
TWI's report concluded that wind towers could be provided at the required volumes with relative ease, although some investment, in welding and coating systems would be needed to enable the existing wind tower fabrication infrastructure to cope with the higher manufacturing volumes predicted by the client.
Where the floating structures were concerned, a staged investment plan could be carried out, predicting a potential doubling in capacity from around 10 units per annum to 20 for a single production line. Due to space restrictions and logistic concerns, no single site should be expected to exceed that annual production level, therefore several locations would require development for barge production. Development of a bespoke facility capable of producing up to the 100 barges per annum target level, remained as a high-risk option.
Looking to a more radical approach, TWI advised that stiffened steel panel structures could be replaced with Sandwich Panel Systems. A second alternative highlighted the use of glass reinforced plastic panels, produced by pultrusion. Finally TWI would be able to advise on investment decisions for improved welding and coating technologies required for both the wind tower and barge manufacture.
