In the old days the utility company offered peak/off peak meters. We had one and nighttime electric was about a third of the cost of daytime electric. We had a large water heater that only heated at night. With careful use, our family of 6 never ran out of hot water. I still have one of those meters at my farm, but there are no new ones available. I wouldn't bother if you don't have a way to get cheaper electric at night. Not knowing where you are located, I suggest a call to the electric company to see if they offer off peak metering.