As wind farms approach the end of their operational lives, wind-energy asset owners are faced with pivotal business decisions regarding life extension, repowering, or full decommissioning of these assets.
Despite continuous advancements in designs, lubrication systems, and materials, maintenance issues in wind turbines persist due to component fatigue or external contamination, leading to a significant reduction in their useful life.
Challenges in the lubricant industry, exacerbated by events like the Covid-19 pandemic and the Russia-Ukraine conflict, particularly impact the availability of processed oil. This shortage delays manufacturing processes and prompts wind-turbine manufacturers to implement new strategies to extend product life.
Through the study of degradation modes, new alternatives within Oil Condition Monitoring (OCM) programs have been proposed. These programs improve early detection of potential failures, thereby extending the useful life of wind turbines.
Introduction
With service contracts including upgrades, wind turbines can continue operating for up to 10 additional years with minimal risk. Repowering with larger and more efficient turbines is also an option, albeit hindered by lengthy authorization procedures and additional investments.
Decommissioning may be considered if neither life extension nor repowering are viable. However, this incurs immediate clearing costs and opportunity costs from permit expiration.
To assess the viability of continued operation, wind-turbine components must be inspected for integrity and failure risk. Inspection methods vary based on available operational data and past component issues.
Despite options available, many turbines can operate beyond their design lives.
Future Trends in OCM
In the next five years, approximately 38 gigawatts of European wind farms will reach 20 years of operation, prompting decisions on lifetime extension. End-of-life solutions are expected to develop a significant market.
The application of load simulation and inspections for technical lifetime extension varies between countries, influenced by uncertainty in future electricity spot-market prices.
Minor repairs may extend wind-farm lifetimes, with oil analysis aiding in failure anticipation.
Conclusions
Oil Condition Monitoring (OCM) is a valuable tool in the wind industry for identifying component changes and planning cost-effective remedial action.
Thorough maintenance programs must evaluate critical components, including gearboxes, bearings, yaw systems, and hydraulic systems.
Wear levels may result in lower load capacity, but repairs are often minor and cost-effective.
Condition-based maintenance using OCM can provide early warning of potential failures.
Advanced oil degradation analysis techniques allow for quantitative assessment of oil condition, aiding in early detection of degradation.
While OCM is beneficial for lubricating components, its application is limited to certain turbine parts.
As wind farms approach their planned service life, decisions on life extension, repowering, or decommissioning are crucial. Life Extension, supported by OCM, ensures careful consideration of condition-based factors for major decisions.
This article was adapted from a conference presentation at the 2023 Reliable Plant & Machinery Lubrication Conference & Exhibition by Adolfo Málaga.
