The start-up Fluves, which is part of the imec.istart acceleration program, is specialized in continuously measuring and monitoring underwater depth. A niche market with potential. Their technique cannot only be used to monitor the movement of contaminated sediment in rivers, but can also be used to make sure that the submarine power cables that are used to transport electricity from offshore wind farms to the shore remain safely hidden underneath the ocean floor.
The weakness of submarine electricity cables
The energy generated by wind turbines at sea is transported to the shore through a thick power cable. In an ideal situation, this cable is buried about 1 meter underneath the ocean floor, but due to the natural movement of sandbanks in combination with the effects of fishing (fishnets) it’s possible that the cables become exposed after a while.
It’s very important to avoid this, because cables that are not at the right burial depth can easily be damaged, e.g. by the anchor of a fishing boat.
If that happens, the whole wind farm has to be switched off until the cable is repaired. This could cost up to 10 million euros.
To solve this problem, Fluves teamed up with Parkwind (a consortium of the Colruyt Group, PMV and Korys). Parkwind develops, finances, builds and operates wind farms in the North Sea. Together they developed a cost-efficient solution – based on fiber optic technology – to continuously monitor the burial depth status of submarine power cables. In 2016 they managed to get a grant from Flanders Innovation & Entrepreneurship (VLAIO) to further develop this concept.
Glass fibers can determine how deep they are buried
Optical fibers are used in different ways in a variety of sectors. In the oil and gas industry, for example, they are used to measure the pressure in boreholes and to map oil fields. But the most well-known application field of optical fibers is undoubtedly telecommunication. Optical fibers (like glass fibers) can be used to transmit information fast and across long distances.
For this reason, optical fibers are often integrated into submarine power cables. Offshore wind farms use glass fibers to transmit data about the turbines’ functioning. A submarine power cable contains up to 100 optical fibers. Generally, only about 50 of those are in use.