Wednesday, October 20, 2004

Oil in "clean green" wind turbines

Of course there has to be some oil for the blade control systems (pitch, yaw, and braking) and the turbine gears, but how much, before it's hard to keep calling it "clean and green"?

In the "Spillage Prevention and Control" section of the Kittitas Valley (Washington) Wind Power Project Application (available here), the expected maximum quantities are described for each of the 1.5-MW turbines planned:
  • cooling fluid (glycol & water) for the generator, 50 gallons
  • lubricating oil for the gears, 105 gallons
  • hydraulic oil for the blade control systems, 85 gallons
  • mineral oil to cool the transformer at the base of each turbine, 500 gallons
In addition, the transformers (1 or 2) at the substation connecting the facility to the grid will each contain up to 12,000 gallons of mineral oil. All of these fluids have to be periodically replaced. Several 50-gallon drums of replacement oils, and of waste oils, will be stored at the site.

Planners in Valencia, Spain, admit the likelihood of spills as well as the dripping and flinging off of these and other fluids (see here). Older transformers may also contain PCBs.