Thousands of customers were provided an "unacceptable service" following Storm Arwen, which caused nearly one million homes across the country to lose power.
Three network operators - Northern Powergrid, Scottish and Southern Electricity Networks and Electricity North West - have paid nearly £30 million in compensation to those affected by the bad weather last November.
Energy watchdog Ofgem has said that the trio have also agreed to pay another £10.3 million in " redress payments ".
