Abstract It is well known that wind energy assessment on a complex territory with scarce data available in an intricate task. In carrying out the wind energy assessment of the Emilia Romagna region, in Northern Italy, it was anticipated that only the mountain area was suitable for wind energy development. This is a very complex terrain, 230 km long and 60–70 km wide. An ad-hoc procedure was consequently developed, using vegetation deformation analysis as the principal method of investigation. The method proved to be successful. Ten sites with estimated annual average wind speed higher than 6 m/s have been identified.