The average farm in the US is around 2 square kilometers. let say a railway road is about 10 meter across, and let say it goes through those 2 square kilometers

The average farm in the US is around 2 square kilometers. let say a railway road is about 10 meter across, and let say it goes through those 2 square kilometers. How much of that land is taken up by the railroad? 0.5%, leaving the farmer 99.5% to use for everything else. Railroad isn't generally that wide and thus don't use up a lot of land. The biggest problem in those situation isn't that the actually land that get used, it is how the farmer get impacted by the rail road being there. If they got a lot of money for those 0.5% with no negative effect then naturally people would have no objection to sell that for huge profits. I can't speak for your family members or the locations where they are involved, but I do know how much politics there is around where I live. There is a lot of resistance to place wind farms on farm fields, and farmers aren't exactly lining up to rent out their land (or at least not for the price people are willing to pay). Ocean farms are often cited as being easier to build because there is less resistance from land owners and local government. One land location that does seem a bit easier for wind production are forests in mountain areas which is sparsely populated. The draw side is that the consumers isn't generally located there, so you get the situation where the best and easiest locations to install wind is also the worst location to utilize the production.