Immersion Heater Controller
Immersion heater controller
Immersion heater controllers are intelligent devices that automatically convert energy generated by existing PV panels into hot water, by diverting any excess solar electricity into the immersion heater before it’s exported to the national grid.
In a domestic situation you are automatically paid through the Feed-in Tariff for exporting 50% of the electricity, even if you use all of it. Therefore it makes sense to use your immersion heater as an "energy storage battery".