PM Surya Ghar Rooftop Solar Design Checklist: 10 Steps to Pass DISCOM Inspection

Most PM Surya Ghar delays don't come from the portal — they come from the rooftop. A system that is oversized, shaded or poorly documented gets flagged at inspection. Use this checklist on every residential project.

1. Size the system from the electricity bill

Take the last 12 months of consumption. A rough rule is that 1 kW of rooftop solar produces about 4 units a day in most of India. Size the system to the household's real consumption and the sanctioned load — not the biggest number the roof can hold.

2. Confirm the usable roof area

Plan roughly 8–10 m² of shade-free area per kW for standard modules. Subtract staircase rooms, water tanks, parapets and walkways before you count what's left.

3. Run a shadow analysis

Trace the sun path across all four seasons. A water tank that is harmless in May can shade half the array in December. A 3D shadow analysis shows exactly which modules lose generation and when.

4. Choose orientation and tilt

In India, a south-facing array tilted close to the site's latitude usually gives the best annual yield. On flat RCC roofs, keep row spacing wide enough that one row doesn't shade the next in winter.

5. Use ALMM-listed modules

PM Surya Ghar subsidy requires modules from MNRE's ALMM list. Put the exact model number on your layout and datasheet so the inspector can verify it.

6. Plan the structure

Choose elevated or low-height mounting structures based on roof usage and wind zone. Mark anchor points so the installation team doesn't damage waterproofing.

7. Configure strings for the inverter

Check string voltage against the inverter's MPPT range at the lowest and highest local temperatures. A wrong string size is a common cause of poor performance after commissioning.

8. Mark cable routes, earthing and the lightning arrester

Show DC and AC cable routes, the earthing pits and the lightning arrester position on the layout. Inspectors look for these.

9. Estimate generation honestly

Give the customer a monthly generation estimate that accounts for shading, temperature and system losses. Overpromising generation is the fastest way to lose a referral.

10. Keep documents consistent

The capacity on the application, the layout, the invoice and the commissioning report must match. One mismatched number can hold up the subsidy.

Get the whole checklist done for ₹500

Instant Solar Design delivers steps 2–9 as a single 3D design package: rooftop model, shadow analysis, layout, stringing and generation report. Residential designs up to 5 kW cost ₹500 and arrive within 24 hours.

Teams that want to prepare a first solar draft internally can start with SolarDraft, then send the final design to us for a detailed 3D model. See also our complete PM Surya Ghar guide for EPCs.