INTRODUCTION
Traditionally, wind blades have been overlooked as a part of a wind turbine that needs maintenance. Blades are meant to last 20 years. After they are mounted on the turbine and begin service, they are expected to last the life of the turbine, baring lightning or other natural disasters that might affect the blade. Since the blade does not have mechanical parts (or so it seems), oil changes and other mechanical maintenance is not needed.

Blades need another type of attention that may not be immediately evident when purchasing a turbine. They need a scheduled maintenance followed by preemptive blade repair.

Before observing a case study, it is important to know what causes blade problems and what those problems are.

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ABSTRACT
A dynamic modeling effort of a swept-blade wind turbine rotor has been conducted. The swept-blade concept was used for increased energy capture without an increase in the turbine loads. The work is part of a Department of Energy contract for increased wind energy capture at low-wind speed sites. The blade works by twisting to feather under aerodynamic loads at the outboard region. Conceptual design of the blade resulted in a 28 m blade radius for eventual testing on a normally 50 m diameter turbine. The blade was modeled with codes developed by the National Renewable Energy Laboratory. Comparisons were made to an unswept rotor of the same diameter and a baseline 50-m rotor. The results demonstrated the twisting and load-reduction behavior of the swept rotor. Little detriment in the power curve was shown with the swept blade, and substantial power increase over the 50 m baseline was obtained in below-rated power.

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