fig1 shows a front view of a wind power installation 10 including rotor blades 14 according to the invention the wind power installation 10 has a rotor 12 which carries the rotor blades 14 the present invention provides that an electrical field 16 is produced at least on the suction side of the rotor blade 14 that electrical field 16 is preferably an electrostatic field with a voltage of for example about u2212 4 kv at the top side of the rotor blade 14 fig2 a is a plan view of the suction side of one embodiment of a rotor blade 14 according to the invention the electrical field 16 is provided in the region from the leading edge of the rotor blade 14 as far as the trailing edge at at least 30 of the rotor blade 14 in the rotor blade tip region that is to say the region which is furthest away from the rotor blade root of the rotor blade 14 fig2 b shows another embodiment of a rotor blade 14 in which the electrical field 16 is provided to cover lager region of the rotor blade 14 preferably a network like conductor structure 18 is provided on the suction side of the rotor blade 14 to produce the electrical field 16 the network like conductor structure 18 can comprise a conductor matrix for example of copper wherein a plurality of conductors are disposed in mutually juxtaposed transverse relationship with each other in a mesh configuration and the spacing.