Blade manufacturing procedures can create conditions in the composite that greatly
influence fatigue life and potential failures. These conditions include local variations in resin blend homogeneity, local variations in porosity, local fiber curvature and fiber displacement, and local residual stresses. These conditions are variables in all composite manufacturing processes and should be taken into account in the design.
The molds themselves may have minor imperfections and variations. While composite materials such as fiberglass and carbon fiber offer incredible strength, the process of layering, resin saturation, and curing can create slight differences in the finished blade due to factors such as air bubbles, fiber alignment, and uneven resin distribution. These variations are taken into account during the design phase, but affect the life of the blade.
Regardless of whether the same production process is achieved with the same production conditions and materials, a composite sample will never be completely identical to a previously manufactured composite sample.
Blade accessories such as balancer, grills, spars, etc. are made separately and glued to the housings when the resin has already cured, before closing the blade.
Challenges and opportunities
Making the perfect wind turbine blade requires a balancing act:
- Size vs. weight: Larger blades mean more power, but cause logistical and weight issues;
- Strength vs. durability: blades must withstand enormous loads, including harsh weather, to increase service life;
- Price vs. performance: Finding the best solution involves a trade-off between materials and production methods;
- Environmental impact: recycling issues and production footprint require continuous improvement;
- Manufacturing imperfections: Minimizing small differences between blades is unavoidable, but can increase service life and reliability. Improvements in materials and methods will play an important role.
Through continuous innovation, the future of wind turbine blades will be one of higher efficiency, lower costs, and an even greater impact on our clean energy landscape.