The invention is directed to a photovoltaic apparatus comprising a carrier substrate. The carrier substrate carries printed structures comprising: a plurality of photovoltaic modules, each module including first and second terminals and a plurality of photovoltaic cells electrically connected between the first and second module terminals; a first bus bar extending along one side of the photovoltaic modules; a second bus bar extending along an opposite side of the photovoltaic modules; and a plurality of intermodule rails, each inter-module rail being associated with a photovoltaic module. The apparatus includes a plurality of selectively configurable junctions, one or more of the junctions being configurable to enable a photovoltaic module to be selectively connected to or disconnected from an adjacent photovoltaic module via one or more inter-module rails, and/or enable a module terminal to selectively connect with or disconnect from one of the first and second bus bars, such that the photovoltaic modules can be selectively electrically connected in series and/or parallel on demand.