The operating time of a wind turbine / wind farm can be extended by assessing for extended life time after the design life cycle has expired. The prerequisite for continued operation is the proof that the wind turbine can also be operated safely in the future and that the structural integrity is guaranteed in accordance with current regulations. We analyze the type certification and check whether it still complies with the applicable guidelines after the designed service life has expired. The process for assessment and verification for life time extension of wind turbines (BPW) is divided into an analytical part (determination of the arithmetical remaining useful life, component wise) and a practical part (on-site inspection) and thus follows the “Basic Principles for Performing an Assessment and Verification of the Lifetime Extension of Onshore Wind Energy Converters (BPW)” of the German Wind Energy Association (BWE). The result of the assessment on the remaining useful life is explained in an expert opinion and the LTE is confirmed in a certificate.

Professional analysis for BPW
- Proof of structural integrity for more than 1,000 wind turbines according to DIBt guidelines and the BWE “Basic Principles”.

- Well-founded competence from more than 30 years of experience in load simulation of WECs for detailed and sustainable analysis for LTE.

- Multiple successful assessments of our analytical reports by building authorities through competent support in the verification.

- "Cooperation Life Time Extension": Cooperation with the specialists from the expert offices of the Windexperts Network to fulfill the practical part and final overall report on life time extension.
Analytical basis
In the analytical part, it is calculated when load-transferring components reach the limits of their design life. The loads actually occurring are compared with the loads under the design conditions for which the manufacturer designed the system and dimensioned the components, from which the remaining useful life is calculated. Downtimes as well as yield results and operation times are also included in the calculations. The basis for simulating the site loads is a turbulence report, which is to be provided to the analysis. In this way, loads resulting from possible extended operation as well as loads according to design conditions can be simulated. With this method, the remaining useful life of the wind turbine can be precisely evaluated for each component and the period for safe continued operation after design life can be determined.

Predictive life time extension
- In agreement:
General analysis or consideration of individual needs.

- Precise determination of the remaining useful life by component.

- Principle "weakest link in the chain": Additional options for replacing components to extend the remaining useful life time are demonstrated.

- Significant increase in the remaining useful life, if required, through individual component analysis using FEM calculations.