Ahhh, I understand now. So, ignore my comments & go from here.
It took a double read, but now I understand WoodnCoal's idea also. If you implement his idea, it might actually save you some electricity.
Right now the electric water heat is using some electricity. If it weren't you'd never know the limit had tripped. W&Coals's idea is to never use the electric heater, just use it's tank. Have a circulator pump plumbed in, when the electric tank calls for water to be heated, the pump comes on and circulates water through the AA coil, heating, or reheating, the tank. When you use water, it would do as it does now, go through the coil first. It would be a project. You'd need a pump, aquastat, mixing valve (maybe you already have one). I haven't thought it all the way through, but it would be cool! Maybe someone else can fill in details.