In the past month, four wind turbine parts manufacturers have
announced plans to put factories in the heartland, otherwise
known as the wind belt. New factories in Arkansas and Iowa will
make turbine blades. Two others in Indiana and Minnesota will
make gearboxes, which control a turbine’s rotational speed. This
continues a trend. Nine new wind manufacturing plants — many of
them foreign-owned — were announced last year, according to a
Department of Energy report on wind power installation released
in May (see p. 11 in the embedded document after the jump). By
the end of this year, about half of turbine components installed
in the United States will be manufactured domestically, up from
30 percent in 2005, according to the American Wind Energy
Association. Locating manufacturing plants in the United States
may shave a bit off wind-power costs, which have risen in recent
years. Commercial turbine blades are heavy and huge, with rotor
spans of about 200 feet. Transporting them requires a lot of
costly fuel, so