Feedback on 12V water heater element as solar diversion load

The different idea on the refrigerator is with the diversion load, where there is no input on my end. The heating element gets some diverted current whenever it is available, which in my head means it gets turned into refrigerator cooling and therefore propane offset. Same logic as the water heater, where heat is being added to the water just because there is spare current available and there is no "control" of it. Just "here I have some extra energy, want it?"