The need to take advantage of other energy sources instead of the dominant ones (oil, coal,…) entails going further in technical, economical and social aspects of renewable energy sources. Wind energy as a clean energy is an important energy source in Denmark with at least 5500 wind turbines on year 2000 and with a tendency of more than 7000 wind turbines nowadays (Ministry of Environment, Nature and Environment 2001, Selected indicators). For the former, the implementation of infrastructure and facilities related with Wind energy is vital both at land at in sea.
In general, to conceive offshore structures there is required considerable technical and economical efforts because of the complex and variety of uncertainties. It is important at the same time to achieve reliable structures with adequate safety levels under external demands during the whole life cycle, e.g. for oil & gas extraction platforms, offshore wind turbines and ships. The accomplishment of certain safety levels in structures is associated with the execution of inspection and maintenance plans, allowing some structures to function during longer periods of time for that they were planned and having a reasonable performance. During the last two decades, the structural reliability and probabilistic-based methods have been playing an important role for the establishment of criteria for design and life-cycle performance optimization of offshore structures.
As stated above, it is important to establish criteria to reassess the reliability and formulate reliability-based inspection and maintenance plans for offshore wind turbines to attain an overall suitable life-cycle performance. The main objective in this project is to establish a rational basis for reliability- and risk-based life-cycle optimization of costs due to inspection, operation and maintenance of offshore wind turbines. Experience from other related sectors (e.g. offshore oil/gas platforms) will be used, and practical, illustrative cases will be considered.
DCE Thesis: 27