Industrial wind blades were not built to weather a 20 year life without maintenance as they inherently experience fatigue and normal wear and tear ultimately resulting in diminished AEP and increasing repair costs. By adjusting the approach from reactive to proactive and staying ahead of the fatigue cycle, many of these costs can be avoided and in fact if approached appropriately can extend asset life. Let’s examine what supports a proactive approach.
Whether organically developing an in-house program or adopting an existing strategy, identifying an individual or a competent vendor to drive the program development from the start is one key to success.
In house growth will require educating the responsible person and absorbing these costs into the overall budget; some examples are blade focused industry conferences and working groups and composites repair courses. It is of absolute necessity that a deep understanding of the blade structure, material makeup and the manufacturing process be developed as a foundation for driving a quality program.
Working with a vendor to adopt an existing blade maintenance strategy or customizing one to fit your specific requirements will allow for faster program initiation. It is important to compare quality processes to ensure uniformity.
Fleet Analysis Through Baseline Data
Every wind farm has a unique story, the more you understand that history the better we will be at prevention and prolonging life. A baseline needs to be established. This can be accomplished by doing the following:
- Examine what you know about the blade fleet by compiling all blade related details for each individual wind farm such as:
- Blade type and manufacturer/s
- Blade serial numbers and their associated mass and moments. Also include all spare blade data.
- Blade repair reports, blade inspection reports, serial flaw remediation’s etc.
- Inspections can be completed a myriad of ways from On Blade to On Ground Spotting Scope or the use of UAV’s (still not approved by FAA); the quality of which varies.
- On blade inspections are much more costly however result in complete data whereas ground and drone based though much less costly are more limited in their results.
- In general ground and drone inspections allow more cost effective gathering of data more frequently across an entire site and enable targeted on blade inspection or repair where necessary.
- Inspections can also be used if little to no data is available from 1 and 2 noted above to establish the needed baseline
Analyzing the baseline data from each individual wind farm and the prevailing environment conditions is a key step in forecasting annual maintenance volume and the allocation of budget dollars. This baseline data will support early forecasting and initiating the repair season.
It is of the utmost importance to have experience on your side when analyzing the results as the conclusions drawn will drive the maintenance cycle and accuracy is critical. Working with a team that has multi-platform and serial flaw remediation experience is invaluable as many serial issues are beyond skin deep and can easily be misdiagnosed. The goal of the analysis will be to inform the first draft of the maintenance strategy which should consist of:
- Inspection frequency: Initial data will provide insight into how frequently each wind farm requires future inspection
- Repair prioritization: Initial findings may drive immediate action
- Spare blade assessment: Evaluation of available spare blades against the blade fleet will drive urgency for additional spares to be warehoused for potential future blade failures
Now that we have gathered the baseline data, analyzed the data and drawn some conclusions we can begin to calculate and compare the costs to the available budget and to assess future budget requirements. After each working season the goal is to optimize the existing budget; in many cases the budget will follow a bathtub curve as initially the costs will be higher as older blades may not have received adequate maintenance during their adolescence however this can be overcome over a few seasons of program application.
- Ramp up of available funds year on year to meet the need
- Consider multi-year contracts which will drive more competitive pricing
- Schedule inspections in advance during slower seasons to limit delays and exacerbated costs
- Identify and schedule repair teams in advance to limit delays and exacerbated costs
Make Hay While the Sun is Shining by Maximizing the Repair Season
Once the budget is approved, it is time to schedule the work. Many in the industry do not begin their repair season until mid-summer which reduces an already narrow working season.
In an industry consumed with driving down costs the only way to improve the maintenance costs of wind blades is to implement a proactive blade maintenance strategy which includes: regular inspections, early repairs and retrofits when required . Anything less negatively affects AEP performance and blade life. Regular inspection with an experienced team will manage the pulse during the fatigue life identifying issues as they arise rather than responding to the aftermath. Stay ahead of the game and make hay while the sun is shining.