Reusable flange cover

In the offshore wind industry, reuse is a key to a sustainable future. That is why we have developed a reusable flange cover that extends the lifespan of crucial components while minimizing waste.

This new type of cover has been produced for the Thor offshore wind farm. These flange covers will be reused in the course of 2026 for use during the build of an upcoming offshore wind farm.

Flange cover THOR project
Flange cover THOR project_11
Flange cover THOR project_2

Composite monopile cover

Up to now three types of covers have been used on monopiles by the offshore industry. Tent covers, steel- and aluminium covers. All three have disadvantages. Tent covers are not suitable in wintertime. At high wind speeds there is a risk that they are blown away, contaminate the sea and leave the monopile unprotected. The steel and aluminium covers are quite expensive and the recycling process of the cover requires a lot of energy again with aluminium being the top energy consumer. As monopiles often differ in diameter per project, none of the steel or aluminium MP covers have been reused on a new project up to today.

Ingenious design

The Composite Monopile Cover is an ingenious and sustainable design, composed with unconventional materials. The construction consists of different fiber reinforced polyester panels and looks a little bit like pieces in a pie. The idea behind the different panels is that you can reuse the top panels of the cover for every diameter of offshore monopile which is currently on the market. Without a cover, the work platform inside the monopile can become wet and slippery from rain or splash water and soiled by bird faeces. Our covers ensure a safe and healthy working environment for all offshore workers.

We have previously achieved success with supplying sustainable monopile covers for the Hollandse Kust Zuid offshore wind farm. These covers have been brought back after use and are currently reused for other projects, highlighting the circularity and sustainability of the product.

Advantages monopile cover

  • Cost-effective; cheaper in terms of production costs compared to aluminium or steel monopile covers.
  • Translucent; the panels, are made of translucent polyester reinforced fibre, providing natural day light on the airtight platform. In this way offshore workers do not need to bring additional heavy-duty batteries for lighting when working inside the monopile. The panels are connected to each other with metal strips and bolted together. Hatches for entering the monopile are also included the cover design.
  • Safe and healthy; the covers are water- and dirt resistant to prevent any chance of mould growth and condensation on the inside of the monopile above the airtight platform.
  • User-friendly; well ventilated making it clean and dry working. The cover is handy, because you can open the hatch on your own.
  • Durable; no risk that covers can be blown away and contaminate the sea which can happen with tent covers at high wind speeds.
  • Circular; to minimize the environmental footprint the covers are reusable for at least 10 years instead of immediate recycling after a project as currently done with aluminium and steel monopiles covers, costing substantial energy. The panels can easily be dismounted and transported by sea container all over the world for a next project.
  • Reusable; you can reuse the top panels of the cover for every diameter of offshore monopile which is currently on the market. Top diameters of monopiles typically vary between 6 and 8m and the concept perfectly matches for those diameters. The MP covers can be tailor made by using longer or shorter parts on the slope in order to adjust to the exact diameter of the monopile in a next project. Also the number of hatches can be tailor made for each project. It is just a matter of exchanging panels.
Monopile cover THOR project_5
Monopile cover THOR project_transport_3
Monopile cover THOR project_3