Photovoltaic water heating control system and process

A photovoltaic water heating control system comprising:

• a photovoltaic power input coupled to a photovoltaic inverter;
• a grid power input;
• at least a first electrical heating element electrically coupled to a first thermostat forming a first heating element circuit, the at least first electrical heating element and first thermostat immersed in a water tank wherein the first thermostat opens the first heating element circuit above a predetermined water temperature threshold and closes the first heating element circuit below the predetermined water temperature threshold;
• a photovoltaic controller having control circuitry comprising a processing unit, memory, a means for external communication, and software comprising operating efficiency routines;
• the photovoltaic inverter and the grid power input coupled to the control circuitry wherein the photovoltaic inverter and the grid power input are isolated through a power input switch controlled by the operating efficiency routines;
• the first heating element circuit coupled to a current sensor and the control circuitry;
• and
• wherein the control circuitry determines if a water temperature is above or below the predetermined water temperature threshold by polling the current sensor to detect whether the first heating element circuit is open or closed.