By offering a total solution on everything from foundations to rotor tips, Sika keeps pace with the increasing demands of the wind market. Daniel Vogt, business development manager EMEA of wind energy, shares his insight into this innovative company.

For over 100 years, Sika has provided solutions for sealing, bonding, protecting and reinforcing. This globally integrated company, with more than 170 production and marketing subsidiaries in 94 countries, supplies speciality chemicals and application knowledge. It is, therefore, no coincidence that so many of the world’s leading wind turbine producers rely on Sika. Over 25% of the world’s wind power is bonded with Sika products.

Since the development of the first utility-scale wind turbines in the early 1990s, Sika has supplied solutions for blade manufacturing. During this time, there has been an exponential increase in turbine size and blade length, and Sika’s solutions continue to evolve to meet these needs.

The two fundamentally different blade design concepts in the market have led to mainly epoxy and polyurethane adhesives being used. Daniel Vogt, business development manager EMEA of wind energy, says: "Using unique experience gained from developments in the automotive market sector, Sika has adapted these types of adhesives to wind market requirements, specifically developing the next-generation, GL-approved, super-toughened epoxy-hybrid adhesive for blade bonding to supplement its existing range of high-performance polyurethane adhesives.

"Additionally, Sika offers a range of resins, model boards, pastes and gel coats for mould and model-making, as well as GL-approved high-performance infusion resins for blade and parts manufacture."

The increasing hub height needed for larger turbines has led to higher performance foundations and hybrid towers being constructed.

Broad range

For concrete towers and foundations, Sika has developed super plasticisers to improve strength and casting, as well as epoxy adhesives for pre-setting concrete elements. The range is completed by fast strength-gain grouts for sealing vertical joints in concrete tower sections and fatigue-resistant grouts for steel tower and foundation interfaces.

Sika’s corrosion-protection coating systems for steel tower sections cover the full range of defined corrosion classes to protect onshore steel towers and offshore towers and foundations. Similarly, the cast iron parts of the hub, generator and gear box are also shielded by protective coating systems.

"Wind turbines operate in some of the harshest working environments possible," Vogt says. "The need to protect sensitive electrical equipment housed in the nacelle from loss and damage caused by water ingress is vital.

"Sika has pioneered the development of hybrid sealant/adhesives selected for its UV and weather-resistant characteristics and proven through its in-service performance over many years."

To ensure the long-term performance of the blades, the company has developed a specific range of surface finishing and repair products to allow rapid and reliable repairs to wind turbine blades to minimise down time and maximise generation efficiency.

Looking to the future

Demands to reduce the cost of energy generated from wind power will largely shape the way the market develops. More powerful turbines, to maximise the generation potential of a site, will place increasing demands on its materials to withstand the extra loads.

With onshore and near-coast shallow water sites diminishing, more challenging sites will also add to the complexity of the situation. As the rate of turbine change stabilises, repair and maintenance will become more important to maximise the service life of wind turbines.

The ability to offer a total package of products from foundation to rotor tip allows Sika to keep pace with the ever increasing demands of the wind turbine industry and marks it out as one of the leading supply companies in this market sector.