A solar-powered waste compactor comprises a waste container for housing waste, a compactor ram actuated by a hydraulic cylinder and piston assembly for compacting the waste in the waste container, and a hydraulic power unit operably associated with the hydraulic cylinder and piston assembly for powering the compactor ram. The hydraulic power unit comprises a motor/pump assembly including a pump unit, a single-phase electric motor driving the pump unit and a flow control valve operating the motor/pump assembly at first or second flow rate depending on an operating pressure. The hydraulic power unit further comprises a battery unit, a solar panel to charge the battery unit, a DC-to-AC inverter, a single-phase AC power inlet connectable to a source of a single-phase electrical power grid, and a reversing contactor providing the electric current only from the inverter or the power inlet at any given time.