Wind energy in the United States faces strong cross-currents—some blowing in from overseas, and others being stirred up right at home.

The nation that comfortably led the world in wind power (in both installed capacity and growth) as recently as three years ago saw a 17 percent increase in wind capacity to nearly 47,000 megawatts (MW) in 2011, the American Wind Energy Association said today.

While the 6,800 MW in new installations marked a slight increase in growth compared to 2010 (5,100 MW, or a 16 percent increase) it was nowhere near the 40 percent to 50 percent annual growth rate the industry saw in the United States from 2007 through 2009.

Still, “American wind power is really at the heart