I was also within sight of five different wind farms. The most impressive (visually) was the three parts of the Smoky Hills complex near Ellsworth, Kansas. The wind farm is strung out along 24 miles of I-70, with some of the turbines within 300 yards or so of the highway. Phase I consists of 56 1.8 MW Vestas turbines; phase II has 99 1.5 MW GE turbines; and the Post Rock project, still under construction, will have 134 1.5 MW GE turbines. Phases I and II have a maximum output of 250 MW; the Post Rock portion will add another 200 MW.
I'm always curious about state-level statistics. The table to the left shows the percentage of power generated in each of several states in April. I've selected states that contain large stretches of the Great Plains, or had large tall-grass prairie areas before the prairies were plowed under. There's some overlap, of course -- eastern Nebraska, for example, was tall-grass prairie, while western Nebraska is Great Plains. On this scale, a couple of smaller states approached one-third of their generated power coming from wind sources. On a somewhat larger scale, these 13 states accounted for 27.6% of all US generation in April, but for 70.0% of all US wind generation.
At least to me, this suggests a region in the center of the US that has a good chance of deriving a big percentage of its electricity from wind. How big a percentage depends on lots of things: dispatch rules that favor wind power when it is available, north-south transmission links to provide geographic diversity, etc. Whether it can produce a significant share for the country as a whole is a much harder question to answer.