The conversion efficiency of a PV system is fundamentally governed by the magnitude and quality of incident radiation. However, two external factors can drastically reduce this: Shading and Orientation.
The Disproportionate Impact of Shading: You might think shading 10% of a solar panel reduces output by 10%. In reality, it can shut down the entire module or even the entire string. Because solar cells are connected in series, a shadow acts like a kink in a hose pipe—it blocks the flow of current for all cells in that series. This is why site assessments must identify even small obstructions like antennas, chimneys, or trees.
Tilt and Azimuth: To capture the most energy, modules must face the sun.
Azimuth: In the Northern Hemisphere (like India), modules should generally face True South to capture the midday sun.
Tilt: The angle of the module from the horizontal. A good rule of thumb is to set the tilt equal to the location’s latitude. This optimizes for annual generation. However, steeper tilts are sometimes used to maximize winter generation (when the sun is low) or to shed snow.
Understanding these geometric relationships allows engineers to design mounting structures that maximize the “energy harvest” from every square meter of rooftop.
