A conversion circuit for converting solar power into an alternating 3-phase mains comprises a converter for converting the power from a solar cell into an unipolar converter output voltage provided between a first and a second converter output terminal of the converter, the converter having a constant power output regulation. The conversion circuit further comprises an inverter for cyclically switching one of three 3-phase output terminals to the first converter output terminal, one to the second converter output terminal and one intermittently to the first and second converter output terminal. With this conversion circuit and method, high capacity energy storage components (such as a capacitor having a large capacitance) can be avoided in the conversion circuit.