Wind turbine maintenance includes regular oil changes 100 meters above ground, a cumbersome process causing two days of downtime. The company Energiservice has developed an oil change vehicle that can service two turbines in a single day.

Most environment-friendly products need service and maintenance regularly. Maintenance may be costly, time-consuming, and cause environmental hazards.

A wind turbine’s gearbox contains up to 500 liters of oil which needs to be exchanged regularly. Photo: Energiservice.

”We take care of strategic and operational maintenance for companies focusing on clean technology. This might be things like monitoring of dams, disaster protection, environmentally adapted power plant maintenance, monitoring and repair of electricity grids and much more”, says Olov Boman, CEO of Energiservice in Skellefteå, Sweden. ”We are now launching a new-to-the-world innovation to make the process of wind turbine maintenance faster and less hazardous”.

Quicker and safer oil changes

An oil-lubricated wind turbine gearbox contains about 500 liters of oil, which needs to be exchanged every three to five years. The wind turbine is at a height of 90-150 meters, and an oil change today means that heavy oil barrels have to be moved up and down the tower to transport both the new and the waste oil. The process is time-consuming, and puts both the service personnel and the environment at risk. The new oil also has to be heated before the turbine is operational again, and an oil change can cause two days of downtime.

”Wind turbine oil changes are costly, but they are absolutely essential since the oil quality determines the lifespan of the gearbox. Minimizing the downtime associated with the oil change is very important for the energy producer. When we developed the OBV 4406 oil change vehicle, our incentive was to make the technology easy to handle and environmentally safe”, Olov Boman says.

”There are many aspects to consider when working on a wind turbine. Keeping the working environment safe is always the top priority; after all, much of the work is performed 100 meters above ground. Wind turbines are often located in sensitive natural areas, so environmental issues must not be overlooked, either. An oil change can not be allowed to pollute air or water”.

Less downtime with preheated oil

The oil change vehicle contains preheated oil sufficient to perform two wind turbine oil changes, and the OBV 4406 is insulated with arctic conditions in mind. The oil is filtered on board to the level of purity specified by the wind turbine manufacturer, and the content of particulate contaminants is quantified according to the ISO 4406 standard. The water content is measured as well.

The OBV 4406 oil change vehicle can pump preheated, clean oil up to the wind turbine’s gearbox. The process is quicker, better for workers, and safer for the environment. Photo: Energiservice.

”In the first step, two hoses are raised to the nacelle: one for the clean oil, one for the used. There is no way to mix up the hoses, and no heavy oil barrels have to be lifted – good both for the environment and the working environment. The waste oil is tapped down to the vehicle, while the personnel change filters and perform other maintenance measures. Finally, the new oil is pumped up to the gear box. Since it is preheated, downtime is reduced to a minimum; the turbine can quickly be reset”, Olov Boman says.

“The oil change vehicle allows us to change oil in two wind turbines on one day, instead of spending two days on a single turbine. In snowy conditions, the vehicle can be equipped with runners and drawn by a tracked vehicle like a snowcat. Thus, even in a cold climate, wind turbines can be serviced all year round”.

“Efficient maintenance that live up to high standards in regards to quality, environmental effects and safety is vital for wind power’s ability to be competitive, especially in the harsh conditions of an arctic climate. Large-scale, land-based wind power has an important part to play in the National Renewable Energy Action Plan for Sweden”, says Hans Kreisel, CEO and President at Skellefteå Kraft AB.

The article was published in August 2017.