There are various sizes of wind turbines available for different uses and they are becoming more commonplace throughout the United States as advances in technology occur and costs get lower. It is important to understand scale when discussing turbines, as there are a range of sizes available for a variety of purposes. Depending on who you talk to, you may get a different description of the same turbine.
Here is another example of scale.
Onsie or residential/agricultural -scale: ranges in size from 100's of watts to 50 kW.
Community-Scale: Ranging from 50 kW to 2 MW
Utility or Large-Scale: larger than 2MW
Offshore: 2.5-5MW (up to 7MW under development)