Time of Use Tariff (TOU)

A time of use tariff is an electricity rate that charges different prices for energy, and often for demand, depending on the hour, the day of the week, and the season.

The tariff is a schedule: seasons made of months, day groups made of weekdays, and periods made of hour windows, each with its own energy and demand rate. A storage EMS holds that schedule as data and uses it as a control input, charging in off peak hours and discharging in on peak ones, and as the basis for the savings it reports. Entering the tariff correctly is one of the first steps in commissioning a site.

Also called: TOU rate, Time of use rate