Floating windmill positioned off Karmøy

November 9, 2005, 14:30 CET

"Deep waters close to land, as well the proximity of established shipyards and supplier industries, make the sea off Karmøy on the west coast of Norway the perfect location for the world's first floating windmill," said Alexandra Bech Gjørv, head of the New Energy unit in Hydro, at the company's energy seminar in Bergen on Wednesday.

This autumn Hydro tested how floating windmills will perform in different wind and wave conditions. The trials were conducted in the ocean basin of Sintef Marintek in Trondheim and results show that the concept can withstand some very rough weather conditions. Hydro has therefore decided to proceed with its research and demonstration project, called Hywind.

"As Hywind is for purposes of research and demonstration, it is advantageous to see the windmill from land. And it's important, from the point of view of inspection and maintenance work, that the transport distance is as short as possible," says Bech Gjørv, Hydro's director of new energy forms.

In deep water

The floating windmill will extend 120 metres beneath the surface and therefore requires a water depth of at least 200 metres. Ocean depths meeting this requirement are found 10 to 15 kilometres west of Karmøy.

Bech Gjørv emphasizes that the plant will be positioned away from protected zones, and where it will not represent a hazard for shipping and fisheries.

Hydro is planning to install the demonstration plant, which is rated at 3 MW, so that it comes on stream in 2007. The windmill will rise about 80 metres above sea-level and have a rotor diameter of roughly 90 metres. For the longer term, Hydro is looking at wind turbines rated at 5 MW and with a rotor diameter of about 120 metres.

"The goal for the future are large offshore windparks of up to 200 turbines. Such a windpark will produce power equivalent to the annual consumption of 200,000 average Norwegian households and will be capable of delivering renewable electricity to both offshore and onshore plant and installations. This objective is still some years ahead, but if we are to achieve it in 10 to 15 years' time, we need to start working today," added Bech Gjørv.

Karmøy has been chosen irrespective of where a future offshore windpark might be located.

Plans for land-based windmill park

In addition, Hydro wishes to build a land-based windmill park on Karmøy, also for completion in 2007.

"Establishing land-based windmill parks is important with a view to developing the technology for floating windmills," said Bech Gjørv at the Bergen energy seminar .

Hydro has applied to Enova for a NOK 50 million grant to help realize its research and demonstration project. Hydro has also submitted a licence application to the Norwegian Water Resources and Energy Directorate (NVE) for its Karmøy installation.