Working out a way to make sure that all essentials of the wind turbine remain in secure operating state throughout the project life is necessary to provide a project the likelihood of becoming profitable. One key aspect in any O&M programme is clarity. The owner’s O&M strategy should definitely be clarified before entering the turbine procurement process as required contract conditions can vary significantly depending on the owner’s strategy.

Generally owners need to decide whether they want to pursue a minimum risk strategy with predictable, constant but higher O&M costs or whether they have the means to take over some operational risks to maximise profitability over the lifetime of the wind farm.

The minimum risk approach would typically be a long-term full service contract with the turbine OEM and availability warranties. Probably a more profitable approach however requires the owner to take over a more active role managing a cost efficient mix of OEM-, ISP- and in-house services without any availability warranty but good chances to reach a higher utilisation of the wind farm over the life time at a lower cost.

Evolution

The industry now has some longer term offerings allowing a company to potentially opt for a warranty that extends well into the turbine life, which should allow better protection against major component failure, says Matthew Burt, Vice President Operations at RES Americas. RES Americas only operates onshore wind turbines, but as Burt says, some of the same challenges, albeit with lesser impacts, are faced with onshore O&M works “Not all OEMs are equal, and in some cases a longer term deal, if available, is financially more attractive if agreed upon before the project is constructed.”

Burt adds that generally there is not a “one size fits all” O&M strategy that will work for all companies. “It’s largely dependent on the size and the risk profile of the owner and the type of technology used. Learning from the experiences of your company as well as others will help improve your strategy going forward,” he says.

Approach

“So far mainly the big utilities like RWE or E.ON are pursuing this “hybrid” approach successfully and some regional utilities also take a more active role at least after an initial 5 year full service contract with the OEM which gives them time to prepare for the coming hand-over,” says Thilo Langfeldt, Partner & Managing Director, Strategy Engineers.

According to Dan Shreve, Partner at MAKE Consulting, the wind industry in the Americas represents a myriad of different business models pertaining to wind turbine maintenance, largely dependent upon the maturity of the market and the size of the installed base.

“In the United States we expect asset owners will increasingly apply hybrid O&M strategies to lower operational expenditures associated with scheduled maintenance while leveraging the wide array of specialty service providers in the market. In an emerging South American market, newly established asset owners are heavily engaged with turbine OEMs, engaging in longer full service type agreements due in large part to an immature services infrastructure.”

Thinking from a LCOE perspective

Burt says the potential bearing on the levelised cost of energy or LCOE, from the way it can be projected as of today, can be attributed to loss of production, both downtime and reductions in equipment performance, and cost of major component replacement, whether it’s an isolated incident or a more regular occurrence. “These items can have a significant effect on both the operational costs and income of the project, both of which could drive the LCOE up. Also, a serious safety incident or form of regulatory non-compliance could significantly impact the bottom line,” he says.

Burt says the biggest upside to physical O&M costs will likely come from better planning, condition-based maintenance and condition monitoring, which should in turn reduce the amount of visits to a wind turbine by both crane and service crews. “It’s also helpful to review all costs, not just the physical O&M costs, to see if there are other areas in which improvements can be made. Another strategy is to look at multi-project deals, as sometimes grouping projects together will result in lower O&M rates. Lastly, consider performance upgrades for your project, such as blade enhancements,” he says.

Burt says entities should focus on the following aspects to bring down the costs:

-Assuming no major components will fail, the impact of O&M costs can usually be reduced by using condition monitoring and / or warranty products.

-Entities should review O&M works annually to determine if they were performed efficiently and effectively, or if there was room for further improvement.

-Assuming the wind resources is consistent from year to year, having a model that is robust enough to accommodate the odd bad year is imperative. Generally the wind resource will equal out over the long run, but there can be significant differences between years.

Optimisation

As highlighted by Wind Energy Update’s recently released white paper, Big Data – how applied analytics can enhance your O&M programmes, a detailed information about the plant is required for an effective O&M programme. Key requisites are service intervals, spares inventory, access to labour, crane hire agreement, access restrictions etc.

Further, the white paper shared that there is dependence to an extent on the engineering expertise available at owner or project level. Plus, the application of data analytics to O&M can assist in indicating loss drivers from a time and cost perspective. These outputs can then be used and applied by experienced engineers to reconfigure and optimise existing O&M programmes.

There is a huge amount of data now available from a wind energy project, including (but not limited to):

- Supervisory Control and Data Acquisition (SCADA Data) – whether in real time or reported out on a specific interval (e.g. 10 minutes) or change-only basis.

-CMS Data – whether from vibration monitoring, acoustic emissions or lube oil monitoring.

-Work Order Data – detailing where, when and how much each repair costs.

-Anemometer Data – extracted from the SCADA but processed separately

It should be noted that asset optimisation has become a focal point for competitive differentiation among turbine OEMs, independent service providers and specialty repair shops. Shreve says the earliest iterations of MW class wind turbines were built with substantial design margin. Clever optimisation packages are able to take advantage of the latest design innovations and monetise that available design margin. Optimisation efforts are a delicate balance between maximising revenue potential and managing technical risk, and as such the need for advanced modelling and loads analysis is critical.

Being Focused

A company should look at cost throughout the project, looking at both O&M costs and revenue gained and lost.

“Having a solid O&M strategy is key to consistently delivering against budget. Typically, we see the industry as potentially having large losses caused by downtime / lost revenue due to major component failure, poor parts supply, and BOP failures,” says Burt.

He also recommends that the effect of major component failures can be greatly reduced by using condition monitoring. With a good condition monitoring system you can detect most failures months in advance and either change sub-components or have parts and a crane on site before the part actually fails.

Performing regular analysis on the plant’s performance is key to identifying areas where downtime and lost production can be easily improved. RES Americas has used its own in-house suite of software tools to do this efficiently, minimising the man hours needed to complete tasks. Performing regular BOP maintenance and having fast response to BOP outages/ failures is also important.