T.O.U. / Time-of-use tariff

TOU means time of use. In electricity tariffs it describes pricing that changes by time period rather than charging one unit rate all day. A simple two-rate tariff such as Economy 7 has cheaper off-peak electricity for a set overnight window and a higher peak rate outside it, while smart time-of-use tariffs can use more periods or prices that change with market conditions. EV charging, home batteries, storage heaters and heat-pump controls can move some demand into cheaper periods. A TOU tariff only reduces costs if enough flexible electricity use can move away from expensive periods and the meter, supplier tariff and device schedules are set up correctly.