Solar Rooftop Savings & ROI Calculator India 2026
Estimate your monthly electricity bill reduction, units generated, and payback period under the PM Surya Ghar Muft Bijli Yojana rooftop solar scheme.
Direct Benefit Transfer (DBT) into consumer bank accounts: ₹30,000 for 1 kW, ₹60,000 for 2 kW, and maximum ₹78,000 for ≥3 kW residential rooftop systems.
Need your exact state tariff with domestic slabs & duty?
Compare your solar rooftop generation directly against state DISCOM domestic telescopic slabs (TNEB, KSEB, BESCOM, MSEDCL, UPPCL, WBSEDCL, etc.).
How to Use the Solar Rooftop Savings Estimator
Select Solar Plant Capacity
Choose your proposed grid-tied rooftop system (1 kW, 2 kW, 3 kW, or 5 kW capacity).
Review Daily Sun Hours
Most Indian states receive 4.5 to 5.5 peak sunshine hours per day throughout the year.
Calculate Net-Metering Savings
See monthly units generated and your total annual financial savings against grid tariffs.
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Understanding Solar Rooftop Generation, Subsidies & Financial ROI
Under the flagship PM Surya Ghar: Muft Bijli Yojana launched by the Government of India, residential households can install grid-connected rooftop solar photovoltaic (PV) systems with up to ₹78,000 direct capital subsidy credited directly to their bank accounts. Rooftop solar dramatically reduces or eliminates monthly electricity bills through bi-directional net-metering.
Ideal for small households consuming 100 to 130 units per month. Generates approx 4.2 units daily. Requires ~85 sq. ft. shadow-free terrace area.
Perfect for standard 2-3 BHK homes consuming 200 to 260 units per month. Generates approx 8.4 units daily. Requires ~170 sq. ft. roof area.
The highest subsidized residential capacity. Generates ~12.6 units daily (375-400 units/mo). Powers multiple ACs and geysers with near-zero power bills.
📐 CEA & MNRE Technical Generation Formulas
Daily Units (kWh) = Capacity (kW) × (Sun Hours / 5.0) × 4.2
Based on Central Electricity Authority (CEA) average insolation across India (~4.2 kWh/kW/day under 5 peak sun hours with standard 15% system losses).
Payback (Years) = Net Cost (₹) / (Monthly Units × Tariff × 12)
With current grid tariffs ranging from ₹6.50 to ₹8.50 per unit in Maharashtra, Karnataka, and UP, payback is achieved in just 2.5 to 3.5 years.
🔄 How Bi-Directional Net-Metering Works with State DISCOMs
When you install a grid-tied solar rooftop system, your electricity distribution company (DISCOM) replaces your existing unidirectional meter with a bi-directional net meter.
Solar panels power your appliances first. Excess units are exported to the grid, spinning your meter backwards.
At night when the sun sets, your home draws grid electricity seamlessly as usual from your electricity board.
You are billed only for:
(Imported Units − Exported Solar Units). Surplus units carry forward to the next cycle.