Rooftop solar cost and payback period in India (2026 guide)

A grid-connected rooftop solar system for an Indian home usually pays back in roughly four to seven years when it qualifies for the PM Surya Ghar subsidy and replaces units you would otherwise buy at ₹5–8 each. That is an illustrative range, not a promise. Your own payback period is set by four numbers: the installed price in your vendor's quotation, the central financial assistance (CFA) and any state top-up you receive, the units the system actually generates on your roof, and the tariff of the units it displaces on your bill. Change any one of them and the answer moves by years. This guide explains each factor, shows the arithmetic, and links to the detailed guides in this section.

The payback formula in one line

Simple payback (years) = net cost ÷ yearly bill saving.

• Net cost = installed price (including GST) − central financial assistance − any state subsidy.
• Yearly bill saving = units generated in a year × the rate you avoid paying for each unit, adjusted for net metering rules.

Because tariffs tend to rise over time, the real payback is usually a little shorter than this simple figure. Because panels lose a small amount of output every year and an inverter may need replacing once in the system's life, the long-term saving is a little lower than "year one saving × 25". The solar payback calculator with CFA handles the tariff rise for you.

Factor 1: the installed price

Prices for on-grid home systems in India are quoted per kW and vary with the state, the module and inverter brand, the height and material of the mounting structure, cable lengths and the vendor's own costs. Systems that qualify for PM Surya Ghar subsidy must use Domestic Content Requirement (DCR) modules, which have generally cost more than imported modules. The table gives illustrative bands only, to help you judge whether a quote is in a sensible area.

Since 22 September 2025, GST on solar power generators and photovoltaic modules is 5% (down from 12%), following the 56th GST Council meeting. Ask for GST to be shown separately; see GST on rooftop solar. Use the system cost estimate by kW for a rough range.

Factor 2: the subsidy

Under PM Surya Ghar: Muft Bijli Yojana, the Ministry of New and Renewable Energy (MNRE) publishes the CFA for residential households as:

So a general-category household gets ₹30,000 for 1 kW, ₹60,000 for 2 kW and a maximum of ₹78,000 for 3 kW or more. Housing societies and RWAs get ₹18,000 per kW for common facilities. Some states add their own subsidy on top. The CFA is credited to your bank account after commissioning, inspection and net metering, so you usually pay the full price first. Details are in the PM Surya Ghar subsidy explained.

Notice what the cap does to the economics: the subsidy per kW falls sharply above 3 kW. A 5 kW system gets the same ₹78,000 as a 3 kW one, so the subsidy covers a smaller share of the price.

Factor 3: generation on your roof

As an illustrative thumb rule, 1 kW of well-placed panels in much of India produces around 1,200–1,500 units (kWh) a year, or about 3.5–4.5 units a day on average. Real output depends on:

• Location and climate: sunnier, drier regions produce more; long monsoon cloud cover reduces output.
• Orientation and tilt: in India panels generally face south at a tilt close to the site's latitude.
• Shading: water tanks, parapets, trees and neighbouring buildings can cut output far more than their size suggests.
• Dust and cleaning: dusty roofs that are rarely cleaned lose output.
• Temperature: panels produce less when very hot.

See how many kW of solar you need and, if output falls later, low generation and maintenance.

Factor 4: the rate you avoid

This is the factor most people get wrong. Indian domestic tariffs are usually telescopic slabs: each block of units has its own rate. Solar units reduce your consumption from the top, so they replace your highest-slab units first. A household that pays ₹7 for its top units saves more per solar unit than one whose whole bill sits in a ₹3 slab.

Three situations change this:

1. Free or heavily subsidised electricity. If your state already gives you a large number of free units, solar may save you little in rupees.
2. Net metering settlement. Surplus exported units left over at the end of the settlement period may be paid at a much lower rate than your retail tariff. See net versus gross metering.
3. Fixed charges. Fixed or demand charges per kW, meter rent and some duties stay on the bill whatever you generate.

Worked example (illustrative)

A household in a general-category state uses about 330 units a month and pays roughly ₹5.40 on average for the units solar will replace.

1. System: 3 kW on-grid with DCR modules, quoted at ₹1,80,000 including GST.
2. Subsidy: ₹30,000 × 2 + ₹18,000 = ₹78,000. Net cost = ₹1,80,000 − ₹78,000 = ₹1,02,000.
3. Generation: 3 kW × 1,300 units = 3,900 units a year (325 a month).
4. Saving: 3,900 × ₹5.40 = ₹21,060 a year.
5. Simple payback: ₹1,02,000 ÷ ₹21,060 ≈ 4.8 years.

If the same household's state gave it 200 free units a month, only the remaining ~130 units would be avoided purchases, and the rest would be exported surplus valued at the state's rate for surplus units. The saving could fall by more than half and the payback could stretch past ten years. More cases are worked in payback examples for 1, 3 and 5 kW.

Financing changes the picture

If you borrow, the interest adds to your cost. Public sector banks offer collateral-free solar loans under PM Surya Ghar at the repo rate plus 0.5% for loans up to ₹2 lakh (6.00% with the repo rate at 5.50% in October 2026; check your bank). A ₹1,60,000 loan at 6.00% over seven years costs about ₹36,300 in interest (illustrative). Using the CFA, once credited, to prepay part of the loan cuts that sharply. See solar loans from public sector banks and the solar loan EMI calculator.

The other guides in this section

• PM Surya Ghar subsidy (CFA) explained
• PM Surya Ghar application steps on the national portal
• Net metering vs gross metering in India
• GST on rooftop solar systems
• DCR modules, ALMM and BIS explained
• Solar loans from public sector banks

Frequently asked questions

Is a 25-year panel warranty the same as a 25-year payback horizon?

No. Module performance warranties often run 25 years, but inverters typically have shorter warranties and may need replacing once. Budget for that when you count savings beyond year ten.

Does a bigger system always pay back faster?

Not under PM Surya Ghar. The CFA stops at 3 kW, and surplus units beyond your own use may earn a low rate. Size to your consumption, not to your roof.

Should I wait for prices to fall?

Module prices move, but scheme terms, tariffs and your own electricity spend also change. Waiting a year means paying that year's bills in full. Compare the saving you would forgo with any likely price drop.

Is payback the only test?

No. Also consider roof life (re-waterproofing under panels is harder), how long you will stay in the house, and backup needs.

Official sources

• PM Surya Ghar national portal — current CFA, registered vendors and application status
• Ministry of New and Renewable Energy — scheme guidelines and ALMM lists
• GST Council — 56th meeting recommendations on renewable energy devices
• Ministry of Power — Electricity (Rights of Consumers) Rules