A windmill apparatus includes tower, a tower-mounted hydraulic pump driven by windmill blades, and hydraulic lines connected to a ground storage tank and to a number of separate generator units. Each generator unit includes a hydraulic pump and an electrical generator. In operation, upon startup, as the wind propels the propeller-driven pump the hydraulic fluid circulates freely until a pre-set pressure is achieved, upon which a diverter valve diverts all the fluid pressure to the first generator unit. When the first generator unit is powered sufficiently to achieve a stable output voltage, a subsequent one of the remaining generator units is powered up until its output voltage is stabilized, with this process continuing as long as there is a surplus of hydraulic power available to power up additional units to take full advantage of all of the available wind power.