I do similar, but without the batteries. I just have Home Assistant turn on everything: dehumidifiers, heaters, lights, set the freezer thermostat to -25c. So

I do similar, but without the batteries. I just have Home Assistant turn on everything: dehumidifiers, heaters, lights, set the freezer thermostat to -25c. So far I've earnt about 10p, but the real saving comes from having a little bit of thermal inertia to carry through to when prices are higher.