It's not new under the sun: harnessing the movement of air in the atmosphere to drive turbines that generate electricity on a scale much bigger than niche. In the 25 years since a Danish manufacturer of farm equipment initiated the revolution, wind energy has been much of the time and in many places the fastest growing component of new electricity generation.
The current issue of IEEE's Power & Energy magazine, devoted to "the waves of wind," testifies to the technology's technical maturity. Members of IEEE's Power & Energy Society have free access, but for those who are not members, here's a sampler of what kinds of things can be found.
--p. 28: a list of PES working groups devoting time and effort to one technical aspect of another of wind development and wind integration (part of an exhaustive round-up article, "A Blast of Activity")
--p. 29 in the same article: a sidebar explaining issues of harmonics and resonance in wind power plants, arising from the fact that such plants have both inductive and capacitative elements.
--p. 34: a table charting wind capacity value against wind power penetration as a percentage of peak load in selected operating areas around the world (still in the same article).
--p. 48, in an article about the European experience with wind, a table charting some European penetration levels, defined in various ways (the bottom line: In Denmark yearly wind generation as a proportion of gross electricity demand is 21.9 percent, in Portugal 17 percent, Spain 16 percent, Ireland 10.5 percent, and Germany 6.7 percent)
See for yourself: Other articles cover wind development in China, inter-regional planning in the United States, work by a NERC taskforce on wind integration, and reliability. An introductory article in the form of a guest editorial takes stock of what's changed in wind integration during the last two years. The starting point for that assessment is China's surpassing the United States in 2010 as the country with the most installed wind capacity: 42 GW versus 40 GW.