Alpha Wind plans 816MW Hawaiian floaters

UNITED STATES: Alpha Wind Energy has submitted a proposal to construct two 408MW floating offshore wind projects off the coast of Hawaii.

The turbines would be fully constructed before being towed into position

The Danish-owned developer has placed a lease request with the Bureau of Ocean Energy Management for the Oahu Northwest and Oahu South projects.

If they get the go-ahead, each will each be made up of 51 floating 8MW turbines. The foundations would be based on Principal Power's WindFloat semi-submersible foundations. A turbine supplier is yet to be selected.

Alpha Wind said the majority of the main components would be produced or assembled on Hawaii creating up to 100 permanent jobs.

After assembly the fully commissioned turbines would be towed and connected to preinstalled anchors and electrical cables offshore.

Oahu South would be located 27 kilometres south of Diamond Head in depths of up to 700 metres over a lease area of about 49 square kilometres. Oahu Northwest would be located 19 kilometres north-west of Kaena Point in depths of up to 1,000 metres, over an area of 46 square kilometres.

If Alpha Wind secures a lease it will then initiate talks with the Hawaiian Electric Company regarding a grid connection.

Alpha Wind anticipates that each of the projects will cost $1.64 billion, or around $4 milllion per megawatt.

The company has based its BOEM application on turbines with a design life of 50 years, significantly longer than the maximum of 25 years that is currently offered by manufacturers.

If the project gets the green light, construction could start in 2018, with commissioning from 2020, Alpha Wind said in its application.