Work out your net cost after central financial assistance, the years to pay back and the saving over the life of a home rooftop solar system.
How to use it. Enter the total installed price from a registered vendor's written quotation, including GST, then the subsidy you expect. For a residential household under PM Surya Ghar: Muft Bijli Yojana, the central financial assistance (CFA) published by MNRE is ₹30,000 per kW for the first 2 kW and ₹18,000 per kW for the third kW, so ₹30,000 for 1 kW, ₹60,000 for 2 kW and ₹78,000 for 3 kW or more (higher rates apply in special category states and UTs). Add a state top-up only if your state has notified one. Confirm the amount on the national portal before you sign.
Estimating the saving. Yearly generation depends on location, tilt, shading and cleaning. As an illustrative thumb rule, 1 kW often produces around 1,200–1,500 units a year in much of India. Multiply the units you will use yourself or export under net metering by the rate you would otherwise pay at your top slab, because solar displaces your most expensive units first.
Worked example (illustrative). A 3 kW system quoted at ₹1,80,000 minus ₹78,000 CFA leaves ₹1,02,000. Generation 3 × 1,300 = 3,900 units; at ₹5.40 per avoided unit that is about ₹21,000 a year, so simple payback is just under five years.
Limits. The calculator ignores panel degradation, an inverter replacement during the system life, loan interest and changes in your state's net metering rules. If your state already gives you free units, your avoided cost may be low and payback much longer. All defaults are illustrative.
Sizing, Payback Examples and Checklists
How apartment societies and RWAs in India can install rooftop solar for common areas, the PM Surya Ghar CFA of ₹18,000 per kW, approvals, metering options and cost sharing.
Costs, Subsidy and 2026 Rules
How net metering, gross metering and net billing work for home rooftop solar in India, what the Consumer Rules say about the 500 kW limit, and how to read your state's rules.
Costs, Subsidy and 2026 Rules
How much central financial assistance PM Surya Ghar: Muft Bijli Yojana gives per kW, who is eligible, how state top-ups and RWAs work, and when the money is paid.
Costs, Subsidy and 2026 Rules
What a home rooftop solar system costs in India in 2026, how PM Surya Ghar subsidy, net metering, GST and your tariff decide the payback period, with worked examples.
Failures, Scams, Complaints and Official Sources
Why a rooftop solar system in India produces fewer units than promised: dust, shade, heat, monsoon, inverter faults and wiring, with a step-by-step check and maintenance routine.
Sizing, Payback Examples and Checklists
Step-by-step payback arithmetic for 1 kW, 3 kW and 5 kW home rooftop systems in India, with subsidy, tariff, surplus and 25-year savings, all marked illustrative.
