Off-peak electricity cost depends on your retailer, state, tariff and the times your meter records as off-peak. Rates are often lower overnight or during other nominated periods, but a time-of-use or controlled-load tariff may also have different peak rates, daily supply charges and eligibility rules. Check your latest bill for the tariff name, usage rates and off-peak times, then compare the full annual cost rather than just the cents-per-kilowatt-hour rate. Your retailer can confirm the applicable times and whether another tariff suits your household’s usage.