Italy's largest power company has warned people across the country that they could experience power cuts throughout Wednesday.
Drought has strained domestic production
Enel said this was due to a surge in demand for electricity brought on by a heat wave and the use of air conditioners and fans.
The drought in Italy has also reduced the output of hydro-electric power stations.
The national grid operator, GRTN, has cautioned several times that the system is being pushed to the limit due to a higher than expected growth in demand and problems with supply.
Some Italian cities experienced blackouts of several hours last month because of higher-than-usual demand and a drop in electricity supplied by France.
They were the first power cuts to be ordered since 1981.
The cuts resulted in some people being trapped in lifts and traffic lights were switched off.
Italy cannot meet all of its domestic power needs from its own power stations, and imports several thousand megawatts from other countries every day.