The state ranks 11th in the country for installed wind capacity and ranks 6th in the country for wind energy potential. Photo credit: B. Nutsch
The wind turbine locations in this dataset are sourced weekly from the Federal Aviation Administration's Daily Digital Obstacle File (DDOF) which contains only obstruction data for those man-made objects that affect domestic aeronautical charting products and does not purport to indicate the presence of all obstructions that may be encountered. The Activity by County graph above represents the data entry dates of the the FAA "C" (change) and "A" (add) values shown in the ACTION field. To determine when a tower was built, visit https://oeaaa.faa.gov/oeaaa/external/searchAction.jsp?action=showSearchA... and enter in the ASN value found in the FAASTUDYNUMBER field (but do not include the leading 0 value that follows the 3-characters, e.g., AGL).
Note that there can be a substantial delay from the time the tower is observed to have been constructed until the time it shows up in this data. From the FAA website: "The Obstacle Data Team investigates and evaluates existing obstacles that may be hazardous to safe flight navigation. We receive obstacle data from a variety of sources both inside and outside the FAA. After determining proof of a completed structure by receiving supporting documentation and performing all necessary verification checks, the team assigns an accuracy code to the obstacle and enters it into the Obstacle Repository System (ORS) database as verified."
It is highly suggested to visit http://www.faa.gov/air_traffic/flight_info/aeronav/digital_products/dail... to learn more about this data.