Good residential system sizing is less about finding a standard package and more about matching the roof, load profile, and long-term household plans. That is especially true in Indian homes where seasonal usage can vary significantly.
1. Monthly bill value is only the starting point
Unit consumption gives a baseline, but sizing improves when installers also understand daytime load, inverter needs, and future consumption growth.
2. Roof constraints affect final capacity
Available roof shape, structural conditions, and shadow zones can prevent a home from accommodating the theoretical system size. Practical design matters as much as ideal demand.
Conclusion
The best residential proposals explain why a system size is recommended instead of simply quoting the largest possible installation.