A wind turbine is formed of a concrete tower which is erected by slip forming. A primary lifting device is erected onto the tower by being lifted together with the slip form and being subsequently transferred onto the tower from the slip form after the tower has been formed. The nacelle, generator, and rotor of the turbine are then lifted onto the tower using the primary lifting device. A secondary lifting device supported on the tower is used to lower the primary lifting device to the ground after the nacelle, generator and rotor are assembled. The height of the tower is therefore not limited by the availability of suitable cranes so that a greater height of tower can be erected to take advantage of winds at greater elevation.