Italy is blessed with plenty of sunshine, so it’s not surprising that the country’s photovoltaic (PV) sector is booming. The grid operated by energy supplier Enel, for instance, includes PV facilities with a power output of over 11,000 megawatts (MW), most of which are connected to the medium-voltage distribution network.
But there’s a dark side to all this: When the midday sun is shining, solar cells produce a large amount of electricity that is then fed into the grid, where it needs to find consumers. However, if clouds appear, power output will drop suddenly. In general, the more fluctuating energy sources, such as sun and wind power, are connected to the grid, the more difficult it is to ensure grid stability. Supply and demand have to be balanced at all times. If they are not, the resulting fluctuations in voltage and frequency can disrupt or even destroy electronic equipment.