Radiated electromagnetic emissions of photovoltaic systems causing interference, for example with radiocommunication, can pose a major barrier to further increase photovoltaic penetration. This is particularly critical in the vicinity of sensitive infrastructures and activities such as hospitals, airports, military, search, and rescue. To understand the impact of each component and installation detail, we performed systematic radiated electromagnetic emission measurements on comparable commercial photovoltaic systems in the frequency range 150 kHz to 30 MHz. Our measurements indicate that module optimizers are the main cause of increased radiated emissions. However, replacing aluminum framed, half-cut modules with frameless, bifacial, glass-glass modules increase radiated emissions from string inverter and module optimizer systems, while changes in cable management and earthing do not substantially affect radiated emissions. The right choice of inverter concept and module type decreases the likelihood that installed photovoltaic systems interfere with nearby radiocommunication. The results are relevant for photovoltaic system designers and installers, enabling them to build photovoltaic systems with an acceptable level of radiated electromagnetic emissions.