Quality installation is as important as quality materials in a Rooftop Solar PV System . When we take a typical array of solar panels , there will be inevitable mismatches in the solar modules (in voltage and current characteristics) which is beyond the control of the site engineer. However, if one chooses a quality module manufacturer and install the system very well, it is possible to substantially lower the losses due to mismatches (Mismatch losses are of no consequence with micro inverters) . Here is a recent Rooftop solar installation at Bangalore . The points to be observed here are; 1. The modules are installed such that almost all the modules are producing the same power .(That is around 153 units per module if we consider its lifetime so far and around 2.25 units per module on a particular day ) . 2. There is not much of difference in energy production between the solar modules which indicates good modules, good inverter and good installation . 3. The alignment and orientation of the panels are such that there are no shadows on the solar panels and no shadows of one panel over the other. 4. There is access to every panel for cleaning so that all the panels get uniform cleaning.