Radio interference from photovoltaic systems

The Swedish climate goal for 2040 is to exclusively produce renewable electricity. This readjustment has resulted in a dramatic increase in the number of solar power producers, an increase which is expected to continue in the coming years. Concurrently however, this rapid growth has also raised the concern of radio frequency interference in the proximity of such photovoltaic systems. During last year, a number of interference incidents were reported. Though problems have mainly been observed at frequencies pertaining to the high frequency (HF) band, interference has also been noticed in even higher frequency bands which are used by cellular systems and communications for rescue services and police. The objective of this report is to give an overview of the interference emitted from photovoltaic systems that has been reported on in Sweden as well as in other countries. The report also provides an overview of the scientific research on the topic of electromagnetic compatibility (EMC) and photovoltaic systems, which has been studied under many years. Of great interest is also the measurement campaigns which has been conducted on interference generated by photovoltaic systems. Considering the observed radio interference and the recently published scientific reports on the subject, there is no doubt in the existence of interference caused by photovoltaic systems. However, how frequently such interference occurs and how strong the interference level is for different types of systems, remain unanswered questions. Nevertheless, if the issue of radio interference is not addressed, the ever increasing number of photovoltaic systems risk to inherently lead to more interference incidents.