Enhanced reliability for rotor blades

For many years, various standards for design, manufacturing and testing of wind turbine rotor blades have been developed, and widely applied for certification. Modern wind turbines are developing fast and industry standards need to keep pace with changing trends and technologies. To ensure a safe and cost-efficient growth of wind energy, reliable and robust rotor blade standards are needed to meet the challenges of the modern blade technological advancements. Many stakeholders in the industry (including designers, manufacturers, and operators) are asking questions like:

• How can blades become more reliable in operations?
• How can blade maintenance costs be reduced?
• How can design and testing for certification be improved?

The two standards (IEC 61400-5 and DNVGL-ST-0376) which have been published recently are based on extensive research and development and integrate the experiences from blade and wind turbine designers and manufacturers, test laboratories and research institutes, and operators.

DNVGL-ST-0376	IEC 61400-5 (in connection with IEC 61400-23)
Design analysis and materials Materials testing Manufacuring tolerances Full scale blade and intermediate level testing Manufacturing, transport and installation In-service inspections and maintenance Repair of manufacturing non-conformities Repair of in-service damages	Design analysis Manufacturing tolerances Full scale and sub-component testing Manufacturing, transport and installation

The new standards account for different analysis methods, implement additional validations and focus on the effect of manufacturing tolerances on the design strength. These innovations increase the flexibility and the reliability of blade designs.

In addition, they define the safety concept based on advanced analysis methods and fills the gaps of previous guidelines which ensures higher reliability of the blade design and lower risk to end customers.

To support customers with the upcoming challenges with the two blade standards (IEC 61400-5 and DNVGL-ST-0376), DNV offers trainings and design accompanying assessment services which will help designers and engineers to understand the background and interpretation of the standards, speeding up innovation process and implementing higher reliability into development process.