Glossary · Energy, bills & ratings
Time-of-use (TOU) pricing
Also called: TOU rates · time-of-use rates · time-varying rates · time-based rates · ultra-low overnight · ULO
Electricity prices that change with the time of day, usually cheapest overnight and highest when demand peaks.
What it means
With TOU pricing the same kWh costs more at peak times and less off-peak, so shifting flexible loads such as laundry, dishwashing, EV charging and water heating saves money. Heat pumps and smart thermostats can be scheduled with prices in mind, though comfort comes first.
Why it matters in an audit
Your rate plan changes the dollar value of savings and can tilt the economics of heat pumps, batteries and water-heater timers.
In the United States
DOE notes many utilities offer off-peak programs or time-based rates; availability depends on your utility and state.