Significant O&M cost reduction

The challenge 

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.  

Customer savings & impact 

Following long-term trials using Delta-Xero offline filtration across selected turbines, the operator recorded measurable, fleet-relevant outcomes: 

• Gearbox oil restored and maintained in usable condition, removing the need for routine oil changes 

• Additive health preserved, with no evidence of additive stripping during filtration 

• Significant O&M cost reduction, avoiding oil purchase, flushing, disposal, and repeated downtime 

The full case study explains how oil condition stabilised over time, why traditional oil analysis alone missed underlying contamination, and how condition-based oil life extension was achieved across an aging fleet.   

Download the complete wind turbine fleet gearbox oil life extension case study, including trial setup, oil analysis trends, and economic modelling.