John Bosche, principal engineer, Chinook Wind says the inspections should be conducted by an independent group without conflicts of interest or ties to the OEM, the owner, or any 3rd party O&M provider who might be stepping in after the OEM is...

By Ritesh Gupta

Owners need to opt between the OEM, the option to self-manage or select a third party when a maintenance situation arises.Therefore the choice an owner makes in this regard has an impact on the proper management of a wind farm and maximising the return of the investment. The main purpose of wind farm operations and maintenance is to minimise the costs per kWh spent on O&M activities and maximise production and return on investment.

This is mainly achieved by the proper operation of turbines; improving turbine performance and availability; and managing maintenance activities.

“The common response is to seek a provider with an established track record with the turbine technology deployed in their farm and a fair price,” says Dan Shreve, Partner at MAKE Consulting.

“Yet, the devil is often in the details, where asset owners may neglect to interrogate the providers on their inspection techniques, record of failure detection, or even the ability to serve as an expert resource when negotiating repair costs with turbine OEMs.”

Changing scenario

Bill Jacks, director of operations and maintenance, director of quality at San Diego, California-based Gemini Energy Services, says over the past few years, a host of start-up independent service providers have entered the market and are highly competitive in price compared to the OEMs.

Many of these ISP’s are very well known in the post warranty circle of the industry, he says. To its credit, Gemini Energy Services has been focusing on the post warranty operation in the New England area, as the company chose to complement its expertise of handling full blown operations and maintenance.

Decision-making

“When a project owner is working through the selection process they are looking at a multitude of qualifications; safety culture and history, past and current projects managed, overall experience, performance, and of course price are all things an owner needs to evaluate before making a decision.

One question an owner needs to ask themselves is, “How much do I want to be involved in the daily operations of the wind farm?” Once they can answer this question it will give them a better sense of direction in making their choices,” explains Jacks.

When it comes to arriving at a decision, John Bosche, principal engineer, Chinook Wind says the inspections should be done by a group with the necessary technical capability and expertise. The inspections should include oil sampling, vibration monitoring, and megger testing.

“It should also be an independent group without conflicts of interest or ties to the OEM, the owner, or any 3rd party O&M provider who might be stepping in after the OEM is gone,” says Bosche.

Pricing factor

According to Alex Potier, director of sales, Broadwind Services, cost is of course an important factor for determining who should perform post-warranty operations and maintenance, and track record and experience are also crucial to selecting an ongoing maintenance and service provider.

“OEM pricing can often be higher than that of an independent service provider, but the turbine vendor may offer more comprehensive services and greater overall knowledge of a specific platform. By paying a premium, owners can better protect themselves against any kind of issue as most would be covered by the OEM. This is especially important for wind assets that may not be performing as well as originally anticipated, or with newer, less-established wind turbine platforms,” says Potier.

He further adds, on the other hand, an independent service provider may be able to offer a very competitive, “a la carte” type of service offering, which can be more suitable for owners of better performing turbines, or for those owners with a broader range of in-house capabilities.

Significance of inspections

End of warranty inspections are a form of insurance for asset owners. Quality inspections cost money, but the cost of unscheduled major component repairs cost more. The ability to perform minor repairs uptower or amortize crane costs for scheduled major repairs can more than make-up for the cost of inspection.

At a minimum, inspections can aid asset owners budgeting for post warranty operations by lowering the uncertainty around major component failures in the near term.

Potier recommends that one of the best ways to maximise wind turbine longevity and performance is for owners to have end of warranty inspections conducted by an independent service provider. End of warranty inspections support owners by compiling written documentation and photographic evidence for any existing problems or potential areas of concern.

“These inspections typically include all major components, such as blades, gearboxes, bearings, generators, electrical components, as well as various other sub-systems, and can also include non-destructive testing methods on certain components,” he says.

By taking action within the 6 to 12-month window prior to warranty expiration, owners can present these issues to the wind turbine OEM and file warranty claims with sufficient time for remediation by the vendor. Owners can also aim to optimise energy production and minimise turbine downtime by scheduling inspections around existing maintenance activities.

As for coming to grips with post warranty costs prior to post warranty operation, the same is all about benchmarking and budgeting.

The onshore O&M market has matured over the past five years and with that has come greater understanding of the “true” costs of maintaining a wind turbine, says Shreve. Additionally, as turbine warranties become longer and predictive maintenance tools become mainstream, the level of financial uncertainty associated with wind assets diminishes.