Challenge

Powering 1.4 million homes and spanning an offshore area of 462km² off the east coast of England, Hornsea 2 is the world’s largest operational windfarm and is owned by Danish energy company, Ørsted A/S.. With approximately 25% of the cost of an offshore wind turbine lying in its foundation, engineers face the difficult challenge of designing a foundation capable of withstanding the impact of construction and the long-term effects of the sea and weather on the structure during operation – all while using the minimal amount of (costly) material during construction.

By learning about the performance of the structure during operation, engineers can further improve the design for future offshore wind farms. Sourcing reliable data in these harsh conditions requires the
placement of strain and temperature sensors in seawater and even beneath the seabed. A robust measurement system and the right technical expertise is needed for this.

Benefit to customer

Working with Ørsted’s main contractor, Norwegian Geotechnical Institute, HBK helped design, install and commission a fibre-optic strain gauge measurement system for the Hornsea 2 project. The low
mass of the measurement arrays supports the best possible chance of survival during the piling installation, and the optical sensors survive well in seawater especially when protected by a marine patch provided by HBK’S engineering services team.

Real-time data is streamed to shore for continuous evaluation and the monitoring program is expected to last from three to fifteen years. HBK’s fibre-optical sensor arrays are not only technically excellent, but they also provide a cost-effective solution – particularly when compared to other measurement methods and the high quantity of measurement points required to get the data needed. The data  generated will help the customer to best understand the geotechnical behaviour of the wind turbine in the varying conditions of the North Sea, helping validate design models, and ensuring safe and profitable generation of green energy for years to come.