Thanks for the map! A 10-m high study, that is very low-altitude. I am guessing that it is either an old study, or one based on normal meteorology stations. The 500-kW-class turbines on 40-m-high towers would certainly get better wind in larger areas (80-m-high towers probably again significantly more), that may explain the Stara Zagora turbines.

_{*Lunatic*, n.
One whose delusions are out of fashion.}