The stator (24) of a permanent magnet axial flux alternator comprises two annular stator components which are each wound with a respective two phase winding arrangement (48). Each of the two phase winding arrangements (48) is wound so that there is no mutual inductance between the windings of each phase. Each phase of the two phase winding arrangements (48) wound on the two stator components has a high internal impedance and is for energising a respective high intensity lamp of a light tower.