ABSTRACT
Denmark has today a leading position within the development of windturbines for electric power generation. During the recent ten years with extremely high progress some very expensive experiences were obtained from serious incidents or breakdowns. A systematic collection and evaluation of operating experiences has not been performed to improve the designs and avoid the costly incidents.
A project within the Danish Energy Research Programme has been performed in cooperation between Systems Analysis Department and Test Station for Smaller Windturbines at Risø National Laboratory. The aim of the work was to develop a technical/economic model representing a small windturbine, taking into account failures, repair times, outage times, investments and maintenance costs.
The project has been divided into three main parte. In the first part an evaluation of public available operating experience from 264 windturbines was performed. The main conclusions were:
The conclusion of the statistical test performed is that the subsequent analysis can be limited to study of one design.
In the second part fault trees describing the logical relationship between failures of single components have been developed for 12 main subsystems of a windturbine.
In the third part an analysis of available failure reports for a specific selected windturbine was conducted. To perform the reliability 91analysis estimation of failure characteristics was forced to apply generic data in several cases due to lack and imcompleteness of relevant data.
The main result of the project is that development of a model taking into account reliability and economics is feasible, but much more work is needed on establishment of data collection routines and data evaluation systems, before full benefit can be obtained.
