It’s the owners.
Turbine owners are making bank.
Think of the cost overhead of inking deals with likely hundreds of land owners for a single wind farm in the middle of Iowa farm ground.
After a couple farms went in, several farmers decided to put together an LLC and put up a few turbines themselves nearby.
I don't know the exact numbers but when you scale a farm to a couple hundred turbines and there are 2-3 such farms within a 15 mile radius of a central point, we are taking about a lot of money. And that's just one area along I-80 in Western Iowa.