Balancing offshore wind farms and the safety of shipping 

The energy transition increases demand for alternative energy solutions and some of these include using space in the North Sea for developing offshore wind farms. However, a consequence of developing these wind farms is the impact on maritime safety. As the density of traffic in the North Sea is one of the highest on the planet, the balance between safety and the new offshore wind farms is a significant challenge. 

MARIN has performed several FormalSafety Assessments (FSA) to investigate the impact of future wind farms. A recent FSA focused on the effect of using predefined passages to sail through wind farm areas, rather than free passages.

The quantitative part of the FSA consisted of an analysis of the traffic pattern in the North Sea based on AISdata and calculations made with our in-house programme SAMSON. The traffic analysis provides a good insight into the current traffic flows in the planned windfarm areas and into how future shipping patterns will evolve if predefined passages are used. In most cases, the locations of the proposed passages were in line with current traffic patterns.

Based on the SAMSON analysis it was concluded that the total number of expected collisions with wind turbines would decrease when using designated passages instead of free routes. However, for some turbines next to the passage the collision risk increased.

In a (virtual) expert session all the possible hazards were identified and rated, both in terms of probability of occurrence and the impact for humans, the environment and economy. The conclusion of the qualitative analysis was in line with the quantitative analysis. One of the outcomes was that experts stated that using designated passages increases the predictability of traffic which in turn, decreases the risk of ship-ship collisions.

Overall it was deemed safer to sail along designated passages. Some hotspotswere identified where the risk of an incident will increase. And one of the recommendations was to monitor vessels in and around the wind farm closely to prevent accidents occurring, and at the same time to make it possible to react swiftly in the event of an incident.

This approach has also been applied to investigate the change of the routes to Skagerrak and the cumulative effects of all the planned wind farms to 2030 and beyond.

Yvonne Koldenhof |

Hans Huisman |