Lisa:

We deal with these a lot in central WA. I DO NOT think the wind machine is permanently attached to the slab. I have had many clients buy used wind machines and have them moved and re-installed in a new location - all it takes is a new slab.

I have always treated them a Farm Machinery and Equipment, 7 yr property for 2021, eligible for either section 179 or Bonus depreciation. That is the only way I have ever seen them treated in our area.

Jeff