Mains electricity: undervoltage and overvoltage

Home Improvement
5

I believe once you make a complaint, your electricity retailer installs a data logger to keep track of the voltage fluctuations, before deciding on whether they will do anything about it.
A lot of the problem is due to undersized transformers and cabling, so they jack up the winding voltage on the transformer a bit to compensate for high load periods, in order to keep the voltage above the mandated minimum. This can cause problems when one or more PV systems are installed in an area serviced by one of these undersized transformers or cabling, forcing the voltage to go high. I understand they limit the size of PV systems in some areas, and wont allow them at all in some areas, due to this problem.