Wind Turbine Inspections Can Save Operators Millions

Wind farm operators who put off having their wind turbines inspected before the warranty ends could be losing millions of dollars. The fate of those millions is in the hands of your maintenance department, the turbine manufacturer, and whether or not they have adhered to the long-term service agreement (LTSA) specifications.

An LTSA is usually included with the purchase of a wind turbine for a period of two to five years, although they can be extended for a price. It is intended to include essential maintenance, including oil changes, to ensure that owners have a well-maintained turbine at the end of the warranty (EOW). The list of items is specific as to what and when different items should be done.

Unfortunately, well-maintained turbines with no issues prior to the EOW are often just a dream, usually because LTSA work hasn’t been done as scheduled or issues haven’t been addressed. Even more problematic is that without an EOW inspection, owners won’t know of any problems, current or potential.

A car warranty provides no protection once it ends and problems occur. You’re just out of luck and out of money. The same is true of the warranty on wind turbines, but the costs are much higher as they can easily run into the millions for a 100-turbine wind farm.

About Inspections

When it comes to getting an EOW inspection performed, it’s best to select a trusted and knowledgeable engineering company to come in and perform a full inspection on all wind turbines six to twelve months before the warranty ends. The inspection report for each turbine should include pictures and a checklist noting each of the different components inspected.

These reports will tell you the condition of your assets and should be arranged in time (about six months prior to EOW) to work with the manufacturer. You can then negotiate whether they will fix the problems or if they will pay you, the owner, the cost of the repairs, and then you can contract with the vendor of your choice to have the repairs completed.

No one wants to forego this type of inspection, have breakdowns occur, and then have to go to court to assign responsibility after the warranty period is over.

Tasks that are typically performed during an EOW inspection for wind turbines include:

  • Visual inspections and walkdowns with pictures
  • Gearbox and main bearing borescoping
  • Blade inspection and analysis
  • Drivetrain vibration analysis
  • Long Term Service Agreement (LTSA) gap analysis
  • Maintenance and retrofit documentation review and analysis
  • Major component inspection
  • Serial defect analysis and review


Post-Inspection Work

When it comes to the post-inspection part of the process, the technician’s reports have been received, and the engineering firm begins their review, analysis, and management of the information, including all maintenance documents.

It isn’t unusual that during the warranty period, the LTSA maintenance cycles get pushed off because of inclement weather, operational issues, or a financial issue. When the long-term service agreement is then coming to an end, owners need to look back and assess what wasn’t completed. An independent engineering firm puts credence to these findings.

The resulting data from an entire wind farm is extensive, and owners usually prefer to have the information organized, analyzed, and interpreted for them. This is especially critical as owners are trending toward turbines with shorter LTSAs so they can save money by taking over the operations and maintenance themselves.

The analysis and final report from a qualified engineering firm can not only help owners to avoid squabbles over what is or isn’t covered, but they also provide the proof to back up the owner’s position. That helps both sides to not only avoid a prolonged court battle but to enter negotiations from a position of trust in a third party such as EN Engineering, who has a reputation for excellence and integrity.

The end result is a huge cost-savings to the owner and turbines that will be taken care of, whether by the manufacturer or a vendor. All it takes is planning ahead and choosing the right engineering firm.

EN Engineering has an expert team ready to help you. We take the view that our job is to make yours easier. For more information on how EN can help you, contact Don Gibson at

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