Off-peak electricity costs vary by state, retailer and tariff, but the rate is usually lower than the peak rate and is charged in cents per kilowatt-hour. Off-peak periods may apply overnight or at other times set by your retailer or distributor, while controlled-load tariffs can have separate schedules and charges. Your bill or electricity plan should show the applicable rates, times and daily supply charge. Check your retailer’s current tariff details or compare plans through the government-backed Energy Made Easy website before switching.