India Solar Irradiance Map — Global Horizontal Irradiance
Also useful
58 related items across IS codes, knowledge articles, design rules, maps and tools
Related Design Rules· 8 of 45
Related Handbook Entries· 1
About PV system sizing
Annual energy = kWp × GHI × 365 × performance ratio (0.75-0.85). For 1 kWp in “Good” zone (GHI = 5.2 kWh/m²/day): 1 × 5.2 × 365 × 0.80 = ~1,520 kWh/year. Roof area required: ~7 m² per kWp (mono) or 9 m² (poly).
Payback: at ₹6/unit grid tariff and ₹50,000/kWp installed cost (after subsidy): ₹50,000 ÷ (1,520 × ₹6) = 5.5 years. Better in “Excellent” zones (4 years) and worse in “Low” zones (8+ years).
Practical implications
- Excellent: Utility-scale solar parks economically viable. 320+ sunny days.
- Very Good: Residential PV payback 3-5 years.
- Good: Standard residential PV. Payback 5-7 years.
- Moderate: PV viable with subsidy + net metering.
- Low: Hybrid solar + wind/grid recommended. Standalone PV not economical.
Cross-references
Source IS / IRC / NBC standards
Related maps
Calculators & tools
Articles & guides
Frequently asked questions
Where is the best solar in India?
Western Rajasthan (Jaisalmer, Bikaner, Jodhpur), Kutch (Gujarat), and Ladakh — all > 6 kWh/m²/day. Rajasthan hosts Bhadla Solar Park (2.25 GW), among the world's largest. Pavagada (Karnataka) at 2 GW also operates in 'Very Good' zone.
What is GHI vs DNI vs DHI?
GHI (Global Horizontal Irradiance) — total solar energy on horizontal surface = direct + diffuse. Used for fixed-tilt PV. DNI (Direct Normal Irradiance) — direct beam component, used for concentrated solar (CSP) tracking. DHI (Diffuse Horizontal Irradiance) — scattered sky radiation, important for cloudy regions and daylighting design.
What size PV system for a 3-bedroom home?
Average 3-BR home consumes 300-500 kWh/month. In 'Good' zone (5.0 kWh/m²/day GHI): 3-4 kWp covers ~75% of usage. Installed cost ₹1.5-2 lakh after subsidy. Roof area 25-30 m². Payback 4-5 years with net metering.
GHI values are 2005-2020 long-period averages from MNRE Solar Atlas + Solargis. Actual yield varies ±10% by year and ±5% by site (urban shading, soiling, panel orientation). Detailed simulation (PVsyst, NREL SAM) recommended for projects > 10 kWp.