A Different Approach to the Design of a Rooftop Photovoltaic System

The need to accelerate the energy transition has strongly increased the interest towards the installation of photovoltaic arrays on building roofs. At the same time, for reasons mainly related to the deep digital transformation all the world is experiencing, the number of mobile telephony base stations, the antennas, is growing too. As a result, a high number of such installations is expected, particularly in the most highly populated cities just on the same roofs that should be available for photovoltaic plants. Typically, an antenna is expected to interfere with the operation of the photovoltaic system only because of its possible shading effect on the photovoltaic panels, so that, where possible, countermeasures are undertaken by properly designing the PV array. But the interaction can be much more complicated than that. In this work the interaction of a PV plant with a mobile telephony base station is investigated both in terms of the electromagnetic shielding effect that PV panels can operate on the RF waves propagation and in terms of the passive electromagnetic reflective action that the same array can exhibit. It is found that: a) the shielding effect by the PV array can significantly reduce the risk deriving from exposure to the antenna generated em fields that several studies agree now to result in health risks for the populations living in close proximity to the antennas and b) a suitable design of the array and the selection of a proper orientation could help in a better and more uniform propagation of the RF communication signals.