The present invention relates to a device for a jib-carried tool (200), said device (100) comprising: a stator (102); a rotor (104) rotatably arranged relative to said stator (102); a generator (106); and transfer means (108) mechanically coupled to said generator (106), wherein said transfer means (108) is arranged to mechanically transfer the relative rotation between said stator (102) and said rotor (104) to said generator (106) so as to drive said generator (106). The present invention also relates to a system comprising such a device for a jib-carried tool (100).