Wind Farms in West Texas

The family and I were driving along I10 on our way to New Mexico and were amazzed at the size of the wind farms. They went on for miles and pretty much covered the mesa's and open areas. They were just sitting there turning around and around making energy, pretty cool site. I did notice that there were several that were not working and was thinking who in the heck is the people or company that build them and who services them. They are out in the middle of no where. Any idea how much energy is produced from them?