Following extensive research and investment, Balmoral has brought HexDefence – a novel and globally patented product – to market which aims to drastically reduce scour phenomena around fixed wind turbines that cause seabed erosion and a reduction in foundation strength and stiffness.
These conditions can lead to turbine foundation instability and inter array cable damage, so scour protection is used to defend the seabed around a monopile. This typically involves the installation of a layer of material around the base of the structure to prevent sediment erosion. This can be made of various materials including rock, concrete or a specially designed geotextile fabric.
These measures need to be carefully monitored to avoid damage to the turbine, seabed and any associated cabling. The costs involved in this process, along with the carbon footprint implicated with extra quarrying and vessel time for installation, is significant.
To address these issues, Balmoral developed Balmoral HexDefence, an exclusive scour protection system that integrates seabed protection and flow reduction to minimise offshore operational costs and potential cable failure.
HexDefence eliminates the requirement to dump rock, instead providing a non-invasive approach to protecting the monopile and the immediate surrounding area.
The lightweight advanced composites construction and streamlined installation method makes it easy to install without the need for additional vessels, resulting in an improved carbon footprint for all operations. Additionally, the system is capable of use with anti-fouling coatings and does not require special equipment for end-of-life recovery.
Fraser Milne, the company’s engineering and projects director, said: “We believe Balmoral HexDefence represents a significant step forward for scour protection, offering highly cost-effective performance enhancement across installation, management and maintenance.
“The interlocking panels are generally 10m long and custom-sized to fit varying monopile diameters and feature integrated lifting and access points. In simple terms, the installation process involves sinking the foundation, sleeving it with HexDefence, fitting the transition piece and assembling the pylon and blades.
“The system is also suitable for retrofitting to existing monopile structures. We believe the system can save wind farm developers around 70% in installation costs when compared to traditional rock dumping methods.”