Wind Farm Maintenance and Associated Challenges
Myth 5: Wind farms perpetually produces electricity without much attention
Operations and Maintenance costs account for a large portion of total cost of ownership of wind turbines. They account for 20-25% of levelized cost of electricity generated for onshore (land) over life of wind turbines and almost double for offshore (water). Since the initial investment is high and the ongoing O&M costs are also high, developing a sound maintenance strategy is key to enhance wind farm’s competitiveness. [Source: https://onlinelibrary.wiley.com/doi/epdf/10.1002/we.2552]
Most of the wind farms are newly constructed and within the warranty period of OEMs [Original Equipment Manufacturers]. This has made OEMs as also primary providers of maintenance services for wind farms. At times, OEMs also work as independent service providers and hence are familiar with not only their own wind systems but also of the competitors. However, as the warranty period expires, utilities have to choose between extension of warranty/service contract with OEMs and developing in-house expertise to do maintenance considering long term life-cycle costs.
Given below are key aspects of wind farms from maintenance perspectives:
- Wind turbines consist of thousands of different parts and assemblies. Complex critical parts require proper tracking and configuration management, particularly with evolving technology advancements leading to change in configurations as existing wind farms expand
- Asset downtime is required for most of the maintenance activities and any downtime has a direct impact on the revenue
- Replacements of large assemblies is very expensive not just because of the assembly cost but also additional expenses associated with logistics, removal, and recommissioning
- Degradation of components are very common considering the nature of wind energy and exposure of rain, heat, thunderstorms
Myth 6: Wind turbines are pretty stable with low downtime
Downtime of wind turbines is on the higher side and frequent, especially due to relatively low reliability of critical parts [like gearbox, drivetrain] directly impacting revenue. However, with advancements in design and engineering, wind turbine failure rates are generally falling with time, so the industry is producing more reliable wind turbines as time progresses.
Tools, Equipment and Spares:
- Specialized tools for carrying out maintenance, instrumentation, and calibration
- Heavy equipment like cranes, trucks, vessels could be required based on maintenance need
- Spare parts inventory optimal balance is required managing the service levels while keeping the inventory costs low
Maintenance Crew and Safety:
- One of the key decisions related to maintenance strategy is to outsource maintenance vs do it in-house
- Health and Safety is of prominent importance given that crew is operating at extreme heights for maintenance. This becomes even for challenging for offshore turbines
- Specific qualifications and certifications (like Wind Turbine Service Technician Certificate) are required for technician roles. There is a growing demand for wind turbine technicians
Myth 7: Electric maintenance crew can be directly involved in Wind Farm maintenance
Wind turbine maintenance involves working at extreme heights, understanding of mechanical gears and electrical components, therefore specialized training and qualifications are required to work in wind farms. Most wind turbine technicians get skilled by attending a 2-year technical program followed by on-job training.
- Wind turbines come with OEM recommended preventive maintenance guidelines, so timely preventive maintenance needs to be performed
- Different sensors and monitoring equipment send data about the current status of different parts of wind turbine. Data from these sensors need to be read to assess the condition and trigger a work order for inspection and maintenance if needed
- Wind energy is still a nascent industry and critical data capture of inspections, failures and work execution details are important for any downstream analysis to spot insights and move towards predictive maintenance