A solar photovoltaic power generation system comprising: a plurality of solar PV panels each having a dc output for delivering dc power; a plurality of power conditioning units each having a dc power input coupled to said dc output of said respective one of said plurality of solar PV panels and an ac mains power supply output for delivering an ac mains supply; characterised in that a dc power distribution bus that is coupled to each of the plurality of solar PV panels through a first connection for receiving dc power from the solar PV panel and each of the plurality of power conditioning units through a second switch for distributing the received dc power to the power conditioning unit; and a plurality of power distribution controllers that are each coupled to a corresponding power conditioning unit, wherein each power distribution controller is configured to control the second switch of the corresponding power conditioning unit for receiving dc power from the dc power distribution bus; wherein each of said plurality of power distribution controllers comprises a fault detector to detect a faulty one or more of said plurality of power conditioning units, and wherein responsive to said detecting a faulty one or more of said plurality of power conditioning units each of said plurality of power distribution controllers coupled to said faulty one or more of said plurality of power conditioning units is configured to communicate with others of said plurality of power distribution controllers that a fault has occurred and to distribute said dc power from said dc output of said solar PV panel coupled to said faulty one or more of said plurality of power conditioning units to each of others of said plurality of power conditioning units coupled to said others of said plurality of power distribution controllers via said dc distribution bus. a plurality of solar PV panels each having a dc output for delivering dc power; a plurality of power conditioning units each having a dc power input coupled to said dc output of said respective one of said plurality of solar PV panels and an ac mains power supply output for delivering an ac mains supply; characterised in that a dc power distribution bus that is coupled to each of the plurality of solar PV panels through a first connection for receiving dc power from the solar PV panel and each of the plurality of power conditioning units through a second switch for distributing the received dc power to the power conditioning unit; and a plurality of power distribution controllers that are each coupled to a corresponding power conditioning unit, wherein each power distribution controller is configured to control the second switch of the corresponding power conditioning unit for receiving dc power from the dc power distribution bus; wherein each of said plurality of power distribution controllers comprises a fault detector to detect a faulty one or more of said plurality of power conditioning units, and wherein responsive to said detecting a faulty one or more of said plurality of power conditioning units each of said plurality of power distribution controllers coupled to said faulty one or more of said plurality of power conditioning units is configured to communicate with others of said plurality of power distribution controllers that a fault has occurred and to distribute said dc power from said dc output of said solar PV panel coupled to said faulty one or more of said plurality of power conditioning units to each of others of said plurality of power conditioning units coupled to said others of said plurality of power distribution controllers via said dc distribution bus.