CHATTANOOGA, Tenn. (AP) — The head of the Tennessee Valley Authority says five of the top 10 energy usage days in TVA history occurred last month as the region saw three waves of low temperatures.

TVA President and CEO Bill Johnson says January was demanding for the nation’s largest public utility, which serves about 9 million people in seven southeastern states. During a board of directors meeting Thursday in Chattanooga, Johnson thanked the public for helping reduce demands and TVA and power company employees for operating the system reliably.