Thermal Solar Panel programmation with random values MATLAB

Thermal Solar Panel programmation with random values MATLAB, where you have a water inlet with x temp, coolant liquid temp with y temp and water tank z temp that you have to plot over the time (250sec). Appart fro that you should program a resistance that works only when coolant temp is lower than -20 Degrees and a water pump that only operates when the water tank temp is higher than the water inlet on