Off-peak electricity is supplied at a lower tariff during set times, often overnight, when demand is lower. It is commonly used for electric hot-water systems, heating or other appliances connected to a controlled-load circuit, but the available times and rates vary by state, meter and retailer. A smart meter may support different time-of-use periods, such as peak, shoulder and off-peak, rather than a separate controlled load. Check your latest bill and ask your retailer whether an off-peak tariff suits your usage before changing plans.