Wind Power

A 1.5 MW wind turbine gearbox showed persistent contamination risk despite routine oil analysis. To understand the true internal condition of the gearbox, debris captured inside an offline filtration unit was analysed after extended in-service operation. Standard oil samples alone were not showing the full extent of varnish, wear debris, and moisture present within the system.  

A wind farm operating 117 × GE 1.5 MW wind turbines faced high ongoing costs from regular gearbox oil changes every ~4 years, including oil flushing, downtime, labour, and disposal. Oil analysis showed that standard inline filtration was not sufficient to manage varnish, sludge, moisture, and long-term contamination buildup in aging gearboxes.  

A Bonus 300 kW wind turbine gearbox with over 10 years of operation showed persistent oil discolouration and internal contamination, even after repeated oil changes and flushing. New oil was observed to degrade rapidly, indicating legacy varnish and debris within the gearbox that conventional maintenance could not remove.  

A 2MW wind turbine gearbox had its oil condemned for disposal after 10 years in service. The 320 cSt synthetic gearbox oil showed severe varnish formation, extremely high particle counts, and degraded cleanliness, making reuse impossible under normal maintenance standards. The oil was scheduled for disposal, with full replacement costs unavoidable.