Why are synthetic PAO oils used in wind turbine gearboxes instead of oils produced using other technologies?

The cost of maintenance operations on wind farms is a fundamental factor. The longer the life of the gearbox's oil bath, the fewer the number of oil changes needed, and so the lower the maintenance costs will be. The lubricant has to lubricate the equipment, keeping wear to a minimum over the longest period of time possible. Synthetic oils are the most suitable and it is acknowledged that – for reasons to do with compatibility between products, so in order to reduce the risks associated with mixes – oils formulated using PAO bases are the most suitable, even though they are not the best performing in terms of mechanical efficiency.