A bucket-style foundation designed to compete with traditional monopiles will be put to the test in UK waters, following installation at Danish offshore wind farm, Horns Rev 2.
Known as the Universal Foundation, it is due to be installed this September at Round 3 sites, Dogger Bank and Firth of Forth. The two test foundations will be used to host met masts.
Speaking with Windpower Offshore, Universal Foundation’s technology director, Søren Nielsen, explained that the goal is for the bucket-style design to deliver cost savings of 20-25% compared with monopiles. Savings will be achieved, in part, thanks to a 20% lower demand for steel and double the installation speed compared with monopiles.
Other advantages include an absence of noise impacts during installation, since there is no need for a hammer, and the fact that installation itself provides scour protection.
The design has clearly won the confidence of some players in the offshore wind industry, with Fred Olsen purchasing a 60% stake in the company last year. Dong Energy has been a long-term investor, currently holding a 25% stake.
The Universal Foundation design – and the company that bears the same name – was spun out of Denmark’s Aalborg University. The design was first put to the test in a Danish harbour in 2002, mounted with a Vestas v90 3MW turbine. This test continues to function well.
The two foundations earmarked to carry met masts at Dogger Bank and Firth of Forth are currently being built by Harland & Wolff in Belfast. They will be installed using Fred Olsen Windcarrier’s new vessel, the Brave Tern. The Firth of Forth installation will be at a water depth of 38m.
"We are also looking for testing opportunities with full-scale turbines," said Nielsen. In addition, the company hopes to test the Universal Foundation at five separate locations within Dogger Bank in order to assess the impact of different soil conditions on installation.
This five-location soil condition test is earmarked to begin in summer 2013, led by Statoil and forming part of the Carbon Trust’s offshore wind accelerator (OWA) programme. However, funding to support the test is not yet confirmed.