3M Wind Energy has extensive experience providing solutions to improve blade build, enhance aerodynamic efficiency and help protect against leading-edge erosion.
Education is what 3M is bringing to the industry when it comes to enhancing the efficiency of wind turbines for operators and protecting against erosion. Studies have consistently shown that erosion can lead to a loss in annual energy production (AEP) of up to 20% in severe cases. The heart of the issue is the fact that wind blades come into contact with various elements in the air at rotation speeds up to 250mph, leading to erosion in the form of pitting, gouging and delamination of the leading edge of the blade.
This erosion not only compromises the integrity of the blade but also impacts its aerodynamic efficiency, causing a significant loss in AEP. This loss can be compounded by the downtime necessary to make repairs to turbines. Owners have important motivations for protecting blades against erosion and making repairs quickly. A variety of effective solutions are available for this task.
Wind protection tapes
Downtime for turbine repairs is costly, so the best defence for operators is to ensure blades are as protected as possible against erosion. When repairs do occur, they are performed with high efficiency. Wind protection tape is the product with the longest track record in the industry, and is based on similar tapes used to protect helicopter blades and aircraft radomes.
Wind blade protection coating
Another good option for protecting blades is a polyurethane coating. Designed for toughness, the coating gives a blade the layer of defence needed to reduce damage caused by rain erosion combined with effects of nature such as ultra violet (UV). This solution can help maintain efficiency, reduce downtime and ultimately extend the useful life of blades.
Epoxy and polyurethane fillers
Fillers play an important part in getting the final aerodynamic shape of the blade in production. 3M fillers are not only efficient with a fast cure time but they also, when combined with 3M Leading Edge Protection, provide a high performance against erosion.
When a blade is past the point of protection and needs repair, minor damage can be treated with fillers made of epoxy or polyurethane. Fillers can also be used to finish and smooth blade surfaces during manufacturing. When selecting a filler, users should consider their needs for performance, cure time and application methods; varieties are available to suit a range of purposes. The right filler can also contribute to prevent leading-edge erosion.
Acrylic foam tapes
Performance can also be gained with products designed for improving aerodynamic efficiency. Acrylic foam tape is often an excellent alternative to liquid adhesives and mechanical fasteners for attaching items to a wind turbine. Acrylic foam tape has the advantage of being highly conformable and flexible, which accommodates the flexing and fatigue forces encountered by the blade.
Vortex generators (VGs)
Recent innovations in VGs have helped these devices live up to their true potential. Usually made from metal or plastic, VGs are affixed to wind turbines to help airflow stay attached to the blade for a longer duration, helping to increase efficiency. With a VG solution that is custom positioned for a blade design based on aerodynamic studies, turbines can deliver AEP increases of 1-3%.
Conclusion
Turbine owners have more useful tools than ever to ensure that wind turbines can stand harsh conditions with improved efficiency and reduced downtime. The solutions described here are an excellent starting point designed to help extract every watt of energy, making the turbine more efficient and thus helping to improve ROI.
