According to data provided in 2014 Wind Technologies Market Report by U.S. Department of Energy, at least 12 existing wind turbine or component manufacturing facilities were consolidated, closed, or stopped serving the industry in 2014. In addition, for a second consecutive year, no major new announcements were made in 2014 about prospective future wind turbine and component manufacturing and assembly facilities.
In addition, AWEA (2015a) reports that U.S. manufacturing facilities have the capability to produce more than 10,000 individual blades (~7 GW) and 3,700 towers (~7 GW) annually. Figure 17 contrasts this equipment manufacturing capability with past U.S. wind additions as well as near-term forecasts of future U.S. installations. This figure clearly illustrates that even in 2020 there will be an excess of production capacity.
Figure 17. Wind additions: historical installations, projected growth, DOE Wind Vision report
For that reason, there are no objective interests in local manufacturing in United States. However, it might be possible to make manufacture for some details of wind turbines. As mentioned in Figure 12, less than 15% of wind turbines generators manufactured in US. As an example, in wind turbine type: REpower MM92 Turbine, cost of wind turbine generator is 3,44% of the total cost of the wind turbine (Annex 5), so we can conclude that generators for other types of wind turbines can be approximately from 2,5% to 4,5% of wind turbine cost. The cost of the generator is relatively small fraction of the total cost of the wind turbine, but in the pursuit of cost optimization, even a small cost reduction can provide a competitive advantage, and this fact can be a strong reason for US producers.