Abstract: A wind turbine for mounting on an existing industrial chimney (1), tower or the like, includes two vertically aligned blades (3) mounted on rotor arms (2) for rotation about the longitudinal axis of the chimney, tower or the like. The rotor arms are supported from an annular structure (8) secured to the outer circumference of the chimney, tower or the like and include at their radially innermost ends a rotor arm ring (11) which cooperates with the annular support structure to enable the rotor arms and blades to rotate about the chimney, tower or the like under the influence of wind pressure. Drive ring (16) carried by one or each rotor arm (2) are connectable to gearing of one or more power generators (9) positioned within or extended to the chimney, tower or the like.