Yellow transition piece being lowered onto the monopile at the Hornsea Two site off the UK

Ørsted Picks Partner to Test New Offshore Installation Methods

Leading offshore wind developer Ørsted has selected Per Aarsleff A/S to join in on a project to test new foundation installation methods on offshore wind farms.


The project aims to make the first offshore tests of three new offshore installation technologies, which are currently under development, on six monopiles at offshore wind farm sites.

This will be the first-ever full-scale test of the technologies, Ørsted said.

The scope of work comprises further development and scaling up of the equipment.

The developed equipment from former onshore trial tests is scaled and customized to enable the equipment to accommodate the offshore full-scale tests on monopiles.

The scope of work does also cover relevant testing of the equipment as well as control and monitoring of the installation.

Per Aarsleff A/S is to develop, procure/fabricate and operate the installation equipment used during the offshore installation test.

The new installation technologies and equipment are developed as an alternative installation approach to conventional impact hammers with the aim to reduce damages to the pile during installation, while at the same time reducing the noise emission. If the tests are successful, the technologies can be used in future full-scale offshore monopile installation projects located in similar ground conditions.

The development track of the specific alternative installation methods was initiated in 2016 with a small-scale desktop assessment and a small-scale test to prove the concept. The tests were successful, and onshore pilot tests were carried out at a medium scale to further assess the potential at a larger scale. A total of three different technologies have been developed.

Following, successful tests and additional development, Ørsted is now ready to test the technologies offshore at full-scale on a limited number of monopiles.

After installation of the monopiles, the monopiles will be used to support real wind turbines, and therefore, part of the tests will also be to assess the foundation performance after installation of the monopiles by the alternative installation methods.

Ørsted intends to test one of the three new technologies on one site, and the combination of two other technologies on the other site.

On each of the two offshore wind sites, a limited number of three monopiles will be equipped with newly developed equipment. Procurement of the final design, including mounting of newly designed equipment to the six monopiles, is performed onshore. Project management related to the installation methods is also covered in the procured scope.

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