Operation and maintenance

Preventive maintenance
        Since weather conditions may prevent service personnel from approaching the wind turbines at times of bad weather, it is extremely important to ensure a high availability rate of offshore wind turbines. Preventive maintenance check programmes may need to be optimised for remote offshore locations.

Remote Surveillance
        Remote surveillance of the parks will obviously be even more important than on land. Radio links for this purpose have already been in operation at the Tunoe Knob and Vindeby offshore wind parks for some years.
        With the the large 1.5 MW units foreseen for these parks, it may be economic to install e.g. extra sensors on each piece of equipment, (and continuously analyse its minute vibrations which tend to change their pattern as the part is worn down). This technology which is well known in certain parts of industry to ensure optimum maintenance of machinery.

Video frames
- Contribution of O&M to energy cost: costs of O&M in total costs
- Maintenance concepts: corrective-preventive maintenance
- Failure frequencies multi MW class: table with subcomponents failures
- Present maintenance demand: visits per year per turbine, notes
- A measure for availability: definition
- Accessibility of site (Vessel): accessibility of two offshore sites
- Reliability/Availability/Maintenability/Serviceability: how they interact, onshore/offshore, graph
- Means of crew transport (A): helicopter/vessel comparison
- Means of crew transport (B): photos of vessel use
- Means of crew transport (C): photos of helicopter use
- Means of crew transport (D): cost comparison vessel/helicopter
- Importance of Reliability and Accessibility: graph with all three parameters, notes
- Experienced Availability: example from offshore wind farm, graph
- Importance of (improved) Reliability: graph, comments for Horn Rev
- Reliability vs turbine design: trends in offshore design to improve reliability
- Recent wind turbine failures: photos with failured wind turbines
- Wind turbine's reliability: graph with reliability
- O&M conclusions: summarizing table