Products of the year: Rotor blades

WORLDWIDE: Ease of manufacture plays a growing role in development as blades continue to grow in size.

Art installation… SGRE’s B82 builds on lessons learned from B75 series, on show when Hull launched its tenure as the UK’s city of culture in 2017


Siemens Gamesa B82 rotor blade

The B82 blade an evolution of the B75 unit, of which more than 1,260 are in operation, mainly on SWT-6.0-154 turbines. The design has been continuously optimised. The main development drivers were curbing mass, reducing risk and manufacturing ease.

The 81.4-metre blades do not contain carbon (characteristically used to enhance stiffness and limit mass). The focus was instead on structural fine-tuning, core materials choice and optimised layout. The blade-root design did not change significantly despite the increased diameter. Advanced solutions include aero-elastic blade tailoring, a passive control and load-reducing feature. Load sensors in the blade root section form an integral part of the turbine's load-based pitch control system.

The in-house "one-shot" IntegralBlade concept provides a relatively low blade mass and eliminates structural weakening from bonding lines. The 8.0-167 turbines run in 8MW mode at 10.3rpm, which corresponds to a tip speed to 90m/s.

This increases to 10.8rpm and 94.4m/s with Power Boost engaged. For additional erosion protection a compressible inset layer is incorporated in the leading-edge laminate section. It "takes energy out" when a wave-swept droplet or other particle hits this rounded surface during operation. The overall solution, according to SGRE, exceeds the 25-year operating life of the turbine.