[oil pan 4]

Originally Posted by darcane

Right.

That usually averages about 20-25 years.



Yes. But...

If you have a wind farm full of 20 year-old, 750kW, 50m towers how do you plan to keep them running?

Parts for old turbines are hard to find and expensive because the manufacturer has moved on to larger turbines.
You can do a partial repower and replace the nacelle... but you can't put one on that is larger because the blades will hit the ground and the tower isn't designed to handle the load.
Or you can do a full repower and decommission the entire wind turbine and put a new one in it's place (actually, usually replacing several small turbines with one large one as they need more space). This is what is usually done.

And, since that grid was based on 750kW turbines, your new 3.0+MW turbines will likely overpower your grid, so you may need to upgrade that too.

Full disclosure: My company supplies components to wind turbine manufacturers.

You don't buy obsolete parts. From what I gather the plan is to strip all the outdated warn out parts and rebuild pretty much from the top of the pole or nacelle deck up.
New 1 and 2 Mw parts could be available as long as the demand is there.
Nothing built around here is smaller than 1Mw.
The Fiesta ones to be rebuilt this way will be a few hundred mitsu 1.5Mw about an hour north of me.