Off-peak electricity is supplied during set times when demand is usually lower, often overnight, and may be used for appliances such as electric hot-water systems. The available times, rates and eligibility depend on your state, meter type, distributor and energy retailer, so off-peak power is not automatically cheaper for every household. Check your bill or contact your retailer to see whether you have a controlled-load or time-of-use tariff and when it operates. Comparing the tariff structure with your actual usage can help you decide whether it may reduce your costs.