How to Tackle an Ageing Fleet?
The only measures to protect against catastrophic failures are good engineering practices. This includes effective inspection regimes, measurement and good maintenance practice to the level expected from the general industry.
One of the common problems faced by the wind sector has been that compared with conventional power generation (such as coal or gas power plants) where you typically have a one or two high-value assets in one location you now have hundreds of generating units distributed across the country in remote mountainous areas. These turbines are also operating in the harshest of weather conditions which mean they demand more maintenance attention to protect them from the elements.
Monitoring and repair costs can quickly rise due to these facts and this has led to the industry adopting less than satisfactory approaches to mounting concerns for operational and structural integrity. The solution to this problem is not an easy one. The financial factors that have led to this are understandable however they do not offer an adequate defence for inaction where simple monitoring or repair solutions could have been applied to avoid the risk of failure.
We have experience of this first hand and know the best solutions the industry has evolved over time to approach the issue. Our experience in this area allows us to determine what the industry best practice is and whether or not these actions are being carried out effectively by those in control of the assets.
Keeping in mind the reality of the fact that operational costs must be kept to a minimum the best ways to minimise risk are;
Quality & Routine Inspection
It is very important that a routine inspection programme is carried out by knowledgeable engineering personnel. The extent and quality of the inspection should be matched to the type of asset, its design, age and known defects. Furthermore, it is important that inspections are carried out by impartial wind turbine inspectors at least once every 2-3 years or where other serious factors may dictate. This avoids biased parties (such as the wind farm Owner, Operator or Maintenance Contractor) from downplaying or side stepping issues they may not wish to highlight or have become familiar with over time.
Measurement & Monitoring
Remote assets such as wind turbines largely rely on active monitoring (such as SCADA and CMS systems) and repeat field measurement programmes to monitor equipment condition and status of existing issues (such as foundation issues or cracks in structural components). When these systems are being appropriately monitored and field measurement programmes are being carried out correctly it is possible to use the information generated to prioritise maintenance and repair actions to the highest risk areas.
Maintenance and Repair Action
All good maintenance and repair actions are informed by the inspection and measurement programmes that precede them.
The findings of these programmes help to determine;
- Where the highest risks are
- What are the appropriate measures to minimise these risks
- The status of existing issues and decide whether increased monitoring or repair actions are required
The cost and effectiveness of repairs is closely related to the quality of inspection and monitoring which precedes them. Catching issues early and taking action saves extensive costs further down the line (“A stitch in time saves nine” so to speak). Poor information gathered through the inspection regime will also typically result in insufficient repairs as they may not deal with the fundamental root cause of the issue.
Validating whether or not the monitoring systems, field inspection programmes or maintenance activities are being appropriately managed or whether important information generated from these is being acted upon is of vital importance. These activities are the only line of defence for assets operating in such remote environments and are the primary way in which integrity risk is managed on operating wind farms.
As with any profession or trade, deep technical knowledge is required to interpret this information. Having an ability to understand the data, make important connections and draw conclusions from these is what allows us to provide a valuable service to our clients.
