Solar Capacity from Shadow-Free Area
Solar Capacity from Shadow-Free Area — quick estimate
Reserve the right roof at schematic stage. Enter your usable, shadow-free area and the mounting type for an instant capacity estimate — then get it verified against a real shadow analysis and your DISCOM sanctioned load.
Your roof
Rule-of-thumb area and yield factors for concept sizing only. Actual capacity depends on a measured shadow analysis, module wattage, roof obstructions, structure and DISCOM policy.
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We'll run a real shadow analysis, confirm the structure and check your DISCOM sanctioned-load headroom, then send an engineered system size and layout.
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Assumptions & formula
Formula: system size (kWp) = shadow-free area (m²) ÷ area-per-kWp. Annual generation (kWh) = kWp × annual yield band.
- Area per kWp (rule of thumb): flush/coplanar ≈ 9 m² (MNRE guidance ≈ 10 m²/kWp), tilted on flat roof with inter-row spacing ≈ 12 m², ground/canopy ≈ 15 m² for the array (a full fenced ground plant runs ~20 m²/kWp). Tilt spacing avoids self-shading but uses more area.
- Annual yield (rule of thumb): ~1,400–1,600 kWh per kWp per year for India; varies with location, orientation, tilt, soiling and shading.
- Module wattage assumed ~550 Wp for the module count; actual count depends on the selected panel.
- CO₂ factor ≈ 0.71 kg CO₂ per kWh (CEA CO₂ Baseline Database — ~0.71 weighted average for FY2024-25, ~0.727 for FY2023-24) — verify the latest CEA edition.
Verify: these are concept-stage rules of thumb. Confirm capacity with a measured shadow analysis, structural check and your local DISCOM net-metering / sanctioned-load rules (PM Surya Ghar applies to residential rooftops only).
Indicative estimate only — not a binding design. Final capacity depends on a site survey, shadow analysis, structural assessment and DISCOM policy.
Need an exact BOQ, rate analysis or measurement sheet?
This is a quick engineering estimate. For tendering, billing or audit, our QS & estimation team prepares an item-wise BOQ, rate analysis and a verified measurement sheet to IS / CPWD norms — backed by 15+ years of estimating our own projects.
Got your number — what next?
A calculator gives you a first figure. These take it further.
The work itself
Read before you specify
The terms behind it
Delivered work with this scope
- 120 kW Rooftop Solar for Bindal Agencies — Chennai — Bindal Agencies Pvt Ltd (Bindal Group)
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