Fab claims 'XL monopile' advance

German specialist pipe fabricator EEW SPC has produced a 10-metre-diameter cylindrical steel section from a single plate, giving a shot in the arm to the development of so-called “XL” monopiles for offshore wind turbines.

The Rostock-based company used a newly-installed Haeusler bending  machine to manufacture the ring from a plate measuring  31.4 metres long, three metres wide and 95mm thick.

Current monopiles have diameters of up to around six metres, limiting the foundations to water depths of around 30 metres. To move the technology into waters of 40 metres or more, monopiles would have to be around eight metres in diameter and 70 metres long.

“EEW SPC is equipped for the production of XL monopiles in the future. The XL monopiles increase the usage of foundation structures for offshore wind farms up to a water depth of 40 metres, and therefore currently are the most reasonable foundation structure available,” says the company.

“EEW SPC is expecting to receive first enquiries for projects with diameters of up to nine metres already this year.”

Development of XL monopiles will put the squeeze on the steel jackets and concrete  gravity base foundation concepts that have been taking shape to cover the 30-50-metre water depth wind farm market.

EEW SPC has built a new production hall that will allow it to begin producing XL monopiles in their entire length by the end of next year.