TenneT, in collaboration with contractor Equans/Smulders, has created several artificial reefs near the offshore transformer platform Hollandse Kust (west Alpha) to gain further knowledge about nature-inclusive construction. This offshore transformer platform will connect the Ecowende consortium (Shell/Eneco) wind farm to the high voltage grid. The aim is to build this wind farm with a healthy ecosystem and as little impact on nature as possible. The artificial reefs are part of a series of ecological measures by TenneT to monitor and encourage underwater life around offshore wind farms.
By 2050, energy production in the Netherlands must be completely climate-neutral. One of the main pillars to achieve this goal is offshore wind energy and the North Sea is becoming the country’s, and one of Europe’s, main power plants. However, all this infrastructure may have an impact on the ecology of the North Sea. Saskia Jaarsma, head of offshore development at TenneT: "We are aware of the potential impact on the North Sea. That's why we pay a lot of attention in researching what happens underwater. The installation of artificial reefs is another step in researching, monitoring and stimulating marine life."
Shelter and food
To find out which form works best, two types of artificial reefs have been placed near the Hollandse Kust west alpha jacket, located about 50 km off the coast of Egmond aan Zee. Earlier, similar structures were placed at the TenneT platform at Hollandse Kust north. Six reef cubes are attached to one frame. Hollow square blocks made of nature-friendly recycled material with round holes in the walls. On the other steel frame are six reef balls, a similar structure but in the shape of a ball. These artificial reef structures are meant to stimulate marine life.
The aim of the trial is to investigate which shape – ball or cube – works best in waters off the Netherlands coast. The hollows provide protection for young fish, but are also meant to increase the structure's bonding surface. "In this way, we hope to provide a suitable place for numerous other animal and plant species in addition to juvenile fish, crabs and lobsters," says Annemiek Hermans a marine biologist on the project.