We are using power from the sun to generate energy to heat our water supply. Below you can see the amount of British Thermal Units BTUs produced by the sun. The term "BTU" is used to describe the heat value (energy content) of fuels, and also to describe the power of heating and cooling systems.

The bottom graph shows the activity of our pump and the temperature of the water before and after traveling through the heating system.

The red line is the temperature of the solar panels, the green line is the temperature of the water in the tank, the yellow line is the pump operation and the blue line is the cold water entering the system.