A new approach to offshore wind turbine installation and maintenance could cut the cost of energy from future deep water sites by around 9%.
The results of a £200,000 Innovate UK Energy Catalyst study involving detailed engineering analysis on the self-erecting nacelle system (SENSE) show the new technology could also trim 4% from the cost of energy at current wind farms in relatively shallow water.
There is currently no proven technology capable of installing the next generation of turbines and towers on foundations in water depths greater than 60m apart from building ever larger and more expensive jack-ups and semi-subs.
The Innovate UK Study was carried out for SENSE Offshore by a project team of leading contractors including GBG, PHG Consulting, Industrial Systems and Control, BVG Associates, Knowtra and Fisher Marine.
It found the SENSE System could cut around £125 million in capital expenditure (CapEx) on a £5 billion, 1200MW wind farm in waters in excess of 70 metres and save £28.5 million a year in operating expenditure (OpEx).
On a shallower large site where water depths are similar to North Sea farms currently being built with jack-ups, SENSE could save £84 million in CapEx and £10 million in OpEx per year.
SENSE transports a pre-assembled and tested rotor nacelle assembly on board a large multi-purpose construction vessel and has solved the problem of transferring 700+tonne loads in significant wave heights from the vessel to the tower.
The SENSE transportation carriage then carries the turbine to the top of the tower on rails. The process is reversible for maintenance and replacement.
Patrick Geraets, a chartered mechaninal engineer and Managing Director, SENSE Offshore, said: “This system means large jack-ups and crane vessels are not needed to install the turbine nacelle and rotor or for maintenance including the change out of major components.
“Wind turbines are getting bigger and developers want to exploit deep water sites, so our self-erecting nacelle system is faster, cheaper – irrespective of water depth – and it is scale-able for larger turbines coming to market in the next five years.”