Wind Turbine Gear Oil Market: Overview
Wind turbines have been used in one form or another since the last 7,000 years. The primary function of the gear oil for rolling bearings in a wind turbine is to prevent or reduce contact between rolling and sliding surfaces. As a result, friction and wear are kept to a low level. Gear oil has the following functions: corrosion protection, heat dissipation from the bearing, flushing out of wear particles and contaminants (recirculating oil lubrication with filtration of the oil), and support for the sealing effect of bearing seals (grease collar and pneumatic oil lubrication). Surfaces moving relative to each other are separated completely or almost completely by a lubricant film. This film is called gear oil.
Hydrodynamic lubrication gear oil is preferred for wind turbines with power rating of 0.75 MW to 2.5 MW. This lubricant is conveyed into the narrowing lubrication gap by the motion of the contact surfaces relative to each other. Due to the extremely high pressure in the immediate contact zone, the lubricant here has extremely high viscosity for a short period and facilitates separation of the contact surfaces.
Development of advanced wind turbines in the 4 MW to 5 MW capacity range is under testing phase. The gear box and drive systems of these prototypes demand use of Elastohydrodynamic (EHD) lubrication.
Wind Turbine Gear Oil: Market Dynamics and Trends
Most manufacturers of wind turbine gearbox have compiled or are in the process of compiling new lubrication specifications. These specifications are more stringent than those for industrial gear applications, and more accurately reflect true operating conditions, including low-temperature conditions. Performance expectations for lubricants used in offshore wind turbines are higher due to the demand for extended life.
New trends include FAG FE 8 bearing test (Fatigue test) which is required by all gear box manufacturers, move toward synthetic formulations (PAO/ester based – Poly Alfa Olefin and PAG-based – Polyalkylene Glycol), new oil compatibility specifications for paints-lacquers-sealants and bearing materials, and new extended lifecycle seal tests for static and dynamic seals.
The SKF EMCOR rust test, for example, is being evaluated to include testing with salt water. With the latest trend of offshore wind turbine parks, accessibility is even more difficult than on land. Therefore, proactive prediction of the useful life of lubricants becomes the new maintenance strategy rather than the reactive strategy based on measuring acid number and viscosity.
Another collaborative effort has produced a monitoring system for in-service wind turbine lubricants that detects the remaining concentration of antioxidants. As a quick check for fluid condition, at a minimum, the turbine operators should be measuring cleanliness (contamination by ISO class), oxidation, water, and viscosity.
Wind Turbine Gear Oil Market: Market Segmentation
The wind turbine gear oil market has been segmented by major turbine components (gear box and generator), by oil replacement cycle (6-12 months and 12 months above) and by type of gear oil (semi synthetic industrial gear oil, fully synthetic industrial gear oil, and polyalphaolefin based gear oils).
Wind Turbine Gear Oil Market: Region-wise Outlook
Wind power is a high-growth, rapidly evolving industry with a direct proportion to the lubricant usage (gear oil). Currently, North America is the leading region for the manufacture and usage of gear oils. Europe follows North America in terms of consumption and manufacture of gear oils for wind turbines. With new developments and rising focus on renewable energies, Asia and Latin America are poised to surpass North America and Europe in terms of consumption of gear oils in the near future.
Wind Turbine Gear Oil Market: Key Players
Key players operating in the global wind turbine gear oil market are Lubrizol, Exxon Mobil Corporation, Klüber Lubrication, Shaeffler Group, OKS Spezialschmierstoffe GmbH, Castrol, Evonik Industries, PETRONAS, CNOOC, Petro China, Amsoil Inc., and Suzlon.