Rooftop Solar and a Home EV Charger: Do They Really Pay Back? The Subsidy, the Bill Savings and the Payback Years, Worked Out

Rooftop solar is an odd purchase. The government pays part of the price, the bank lends against it at the repo rate plus half a per cent, and your electricity company keeps the accounts. So does it actually pay back? The answer depends less on the sun than on one line of your electricity bill: what you pay for your last units each month. A 3 kW system costs about ₹1.45 lakh at the government's own benchmark, and the PM Surya Ghar subsidy covers ₹78,000 of it. At this year's tariffs, it earns back the rest in about 22 months in Pune, 20 months in Delhi and 33 months in Gurgaon. A small household already paying ₹2.95 a unit, or nothing at all, can wait six to eleven years. Below are three real tariff schedules worked line by line, the loan, and what happens when an electric car joins the bill.

Written on 22 October 2026. Sources for each part:

• Subsidy rules: MNRE's operational guidelines of 7 June 2024. The amounts were restated unchanged in Parliament in July 2026.
• Tariffs: MSEDCL's for 2026-27 (MERC order of 25 March 2026), DHBVN's for 2026-27 (Sales Circular D-06/2026), and Delhi's DERC schedule, which has not been revised since 2021.
• What the bills leave out: electricity duty, fuel surcharges and Delhi's power-purchase adjustment, so real savings are a little higher than shown.
• Petrol: Delhi's price on 22 October 2026, from PPAC.

The short answer: five homes, five paybacks

The table puts the same arithmetic through five households. "Benchmark" means the cost the government itself uses to set the subsidy: ₹50,000 a kW for the first 2 kW and ₹45,000 for the third. "₹70,000 a kW" is the top of the range Punjab National Bank uses to size its solar loans, a fair stand-in for a dearer quote. Every system makes 100 units a month per kW, the government's own average.

Same panels, same sun, five very different answers. What separates them is the price of the units the panels replace. In Pune those units cost ₹12.40 each, in Delhi's 401–800 slab ₹6.50 plus surcharges, and in Gurgaon ₹5.25 to ₹6.45. A small Gurgaon home pays ₹2.95, and a small Delhi home pays nothing. Solar cannot save you money you were not spending.

What the subsidy pays, and what it does not

The central subsidy under PM Surya Ghar: Muft Bijli Yojana is a fixed amount per kW. It is not a share of your bill, and it stops growing at 3 kW.

The figures come from a simple rule in the guidelines: 60% of the benchmark cost for the first 2 kW and 40% for the third. A 6 kW system gets ₹78,000, exactly what a 3 kW one gets. The conditions attached are what trip people up:

• Registered vendor only. The installer must be registered on the national portal, pmsuryaghar.gov.in. There is no state tender; you and the vendor agree the price between you.
• Indian-made modules. The panels must be made in India from Indian-made cells (the "DCR" rule). One imported module anywhere in the system cancels the subsidy.
• Net meter and inspection. The electricity company inspects the system and fits the net meter, or you buy one from its approved list. Only then is the subsidy released.
• Payment. The guidelines promise it within 15 days of the company's approval, into your bank account, or into your loan account if you borrowed.
• Five years of free upkeep. The vendor must repair and maintain the plant free for five years from commissioning.
• A closing date. The scheme runs till 31 March 2027. MNRE's portal counts down to it, and no extension has been notified.

States can add their own money on top. Delhi does: ₹2,000 a kW, up to ₹10,000, credited in the first bill after commissioning. It also pays a generation-based incentive of ₹3 for every unit a home system up to 3 kW produces (₹2 a unit for 3–10 kW), for five years, with no cap on units. It applies to systems commissioned while the state's policy runs: three years from March 2024 unless it is renewed. That incentive is why the Delhi row in the first table pays back fastest.

The scheme is no longer a pilot. By 21 October 2026 the national portal counted 53,47,708 installations and 63,32,815 households covered (one society system can serve many flats). In August 2026 the government reported ₹28,024 crore of subsidy paid by direct transfer and nearly 19 lakh households with zero bills.

What a rooftop system costs before the subsidy

No government body publishes the price households actually pay. Four official or research figures give the range:

• MNRE's benchmark: ₹50,000 a kW for the first 2 kW and ₹45,000 for the third, fixed in February 2024.
• Karnataka's regulator: its August 2026 tariff order took ₹45,000 a kW, all taxes included, for home systems of 1–10 kW that do not take the subsidy.
• Punjab National Bank: sizes its solar loans at ₹50,000 to ₹70,000 a kW.
• Indian-made modules are the dear part. IEEFA, an energy-research group, found them at ₹23–26 a watt in late 2025, nearly double imported ones.

* The benchmark is defined for the first three kW. For the fourth and fifth kW we have used the same ₹45,000 as the third.

GST is already in these prices, and it fell in 2025. Since 22 September 2025, solar power systems carry 5% GST instead of 12%. A turnkey contract, panels plus installation, is taxed by a deemed split: 70% of the price counts as goods at 5%, and 30% as services at 18%. The blended rate works out to 8.9%, down from 13.8%. The Ministry of New and Renewable Energy put the saving at about ₹9,000 to ₹10,500 on a 3 kW system. If your quote charges 12% or 18% on the whole amount, ask why.

How many units a rooftop actually makes

• On a good day: one kW of panels makes 4 to 5.5 units on a clear sunny day, the ministry's FAQ says. Cloud, monsoon and winter haze pull the average down.
• Over a year: the Cabinet's own figure is that a 3 kW system makes "more than 300 units a month on an average", so 100 units per kW per month, or 1,200 a year. That is the figure used throughout this article.
• A higher estimate: Karnataka's regulator assumes a capacity factor of 19%, about 1,660 units per kW a year. Our numbers are on the cautious side; a sunny, south-facing roof should do better.
• Space: each kW needs 10 to 12 square metres of shade-free roof, so 3 kW needs 30 to 36. A water tank or a neighbour's wall that shades the panels for part of the day costs real output.
• Ageing: under the scheme's technical rules, modules must keep more than 90% of their rated output for the first 10 years and more than 80% for the next 15. Mounting structures must be built to last at least 25 years.

The government's own sizing guide links system size to your monthly use:

What each solar unit saves: your top slab, not your average

Household tariffs are stepped. The first block of units is cheap, and each later block costs more. Under net metering you are billed only on net units: what you drew from the grid minus what your panels sent back. So the units your panels cancel are the ones at the top of the ladder, the dearest ones.

Here are the ladders for the three cities in this article. Delhi adds 8% and 7% surcharges on top; Gurgaon adds a ₹50 a kW fixed charge once use passes 300 units.

Two rulings decide how this ladder treats a solar home.

• Maharashtra kept net billing. MSEDCL asked its regulator to count solar units against the cheapest slabs first, so solar homes would still be billed at their highest slab. In its 2025 multi-year tariff order the commission refused. Under its net-metering regulations, the company must bill the net units at the normal tariff.
• Surplus units are worth far less than the ones you buy. Extra units carry forward from month to month, but those left over at the end of the financial year are bought back at the regulator's generic tariff. In Maharashtra for 2026-27 that is ₹2.82 a unit. So size the system to what you use, not to the size of your roof.

One proposal to watch: in March 2026 the Ministry of Power circulated draft amendments to the consumer rules. They would let state regulators levy a net-metering charge on systems above 5 kW, and move the deadline for time-of-day tariffs for homes to April 2028. They are a draft for comment, not the law, but they show the rules can change after you have bought the panels.

Worked out step by step: a 3 kW system in Pune

1. The price. ₹1,45,000 at the benchmark. The subsidy is ₹78,000, so you put in ₹67,000.
2. The output. 3 kW × 100 units = 300 units a month.
3. The bill before. 100 units × ₹5.56 = ₹556, plus 200 units × ₹12.40 = ₹2,480, plus the ₹130 fixed charge: ₹3,166.
4. The bill after. 300 units used minus 300 made leaves zero net units. You pay only the ₹130 fixed charge.
5. The saving. ₹3,036 a month, or ₹36,432 a year, before electricity duty and the fuel adjustment, both of which would add to it.
6. The payback. ₹67,000 ÷ ₹36,432 = 1.84 years, about 22 months. On a ₹2.1 lakh quote you pay ₹1,32,000 after the subsidy, which takes 3.6 years.
7. The long run. After the five free years, Karnataka's regulator allows 1% of the capital cost a year for upkeep: about ₹1,450 here. Over 25 years at today's tariff the household saves ₹9,10,800 and spends ₹29,000 on upkeep. Net of the ₹67,000 it paid, it is about ₹8.15 lakh ahead. Spread over the 90,000 units the roof makes, each unit has cost about ₹1.07.

The same steps for Gurgaon:

• Before: 450 units = 150 × ₹2.95 + 150 × ₹5.25 + 150 × ₹6.45, plus ₹250 of fixed charge on a 5 kW load: ₹2,448.
• After: 150 net units cost ₹443, and the fixed charge disappears because use is now under 300 units.
• Saving: ₹2,005 a month.

For Delhi's 800-unit home:

• Before: ₹4,350 of slabs and fixed charge, plus 15% in surcharges: ₹5,003.
• After: 500 net units: ₹2,760.
• Delhi's incentive: another 3,600 units × ₹3 = ₹10,800 a year for five years. The state's ₹6,000 capital subsidy brings the cost down to ₹61,000.

Each 3 kW system also avoids about 2.4 tonnes of carbon dioxide a year at the grid average of 0.675 kg a unit, the Central Electricity Authority's figure for 2025-26.

Paying with the solar loan

The scheme's loan is tied to the repo rate: repo plus 0.5%. The government advertised it at about 7% at launch and at 5.75% in July 2026. After RBI's repo rise to 5.50%, SBI's rate is 6.00%.

Twelve public sector banks offer a standard version of this loan through the national portal. Their margins and credit-score rules differ, so read the page of the bank you pick.

On a ₹1,45,000 system, here is how the loan works out:

• The loan: you put in ₹14,500 and borrow ₹1,30,500. Over 10 years at 6%, that is an EMI of ₹1,449.
• After the subsidy: the ₹78,000 is paid into the loan account, leaving ₹52,500. Spread over 10 years at 6%, that is about ₹583 a month, and roughly ₹17,400 of interest in all. Your bank may shorten the term instead of cutting the EMI, so ask which it does.
• Against the saving: in Pune the bill falls by ₹3,036 a month. Even in Gurgaon it falls by ₹2,005. Either way the household is better off in cash from the first full month.

Adding an electric car: the charger and the cost per kilometre

An EV changes the arithmetic, and not always in the obvious direction.

What the car itself gets:

• No central purchase subsidy for private electric cars. PM E-DRIVE, which runs to 31 March 2028, covers electric two- and three-wheelers, ambulances, trucks, buses and charging stations, but not private cars.
• GST at 5% on electric vehicles, and also on EV chargers.

The charger:

• MG includes a 7.4 kW wall charger in the price of its Windsor Pro versions. It gives charging times of about 6.5 to 9.5 hours on that charger, depending on the battery, against about 13.8 hours on a 3.3 kW portable one.
• Mahindra prices its 7.2 kW or 11.2 kW wall box separately, after a survey of your home.
• Bought on its own, Havells lists its 7.4 kW home charger at ₹33,499 (22 October 2026).

How home charging is billed:

• The Ministry of Power's 2024 charging guidelines say charging at home is billed at domestic rates. You may ask your electricity company for more sanctioned load if needed.
• You may also ask for a separate meter on a dedicated EV tariff. Delhi's EV-charging tariff is ₹4.50 a unit with no fixed charge. Ask your company whether a home charging point qualifies.

How many units the car uses. Tata Motors gives its Nexon.ev 45 a 45 kWh battery and a real-world range of 350 to 370 km, which is about 0.125 units a kilometre. Allow roughly 10% for losses while charging (our assumption, not a maker's figure). Driving 1,200 km a month, about 40 km a day, then takes about 165 units.

Look at the fifth row, because it surprises people. Once 3 kW of solar has cleared the house's own bill, the car's 165 units are billed on the bottom of the ladder: 100 at ₹5.56 and 65 at ₹12.40. Before solar, the same units landed in the ₹16.64 slab.

So would extra panels just for the car pay back? In this Pune home, an extra 2 kW costs about ₹90,000, and the subsidy adds nothing beyond 3 kW. It would save about ₹17,500 a year: the car's ₹1,362 a month, plus a little for the surplus at ₹2.82. That is about 5.1 years to pay back, or 8 years at ₹70,000 a kW. The extra panels still pay back, but more slowly than the first three kW. The subsidy stops at 3 kW, and net metering had already given the car the cheapest slabs.

When you charge matters less than you might think under net metering. Units are netted over the billing period, not hour by hour. Maharashtra adds a twist: homes with a time-of-day or smart meter get ₹0.85 a unit off for power used between 9 am and 5 pm in 2026-27. That favours daytime charging.

Over 10,000 km, petrol at 15 km a litre costs about ₹68,080. An EV on Pune's top slab costs ₹22,880, and on Delhi's tariff about ₹10,300. Whether the car pays back depends on the price gap between the electric and petrol versions you are choosing between, set against these running costs. That gap varies too much by model to generalise.

When rooftop solar does not pay back, or not soon

The case for solar is strong where your last units are dear. These are the situations where it is weaker:

• Small bills on cheap or free power. In Delhi, BSES's subsidy rules waive the whole bill for homes using up to 200 units a month. For them, solar earns only the state's ₹3 a unit, and only for five years. A 150-unit Gurgaon home saves ₹2.95 a unit, which means six to eleven years to pay back.
• Oversizing. Units you do not use are bought back at a generic rate, ₹2.82 in Maharashtra, against the ₹12 to ₹16 you pay. Panels beyond your own use earn little.
• Power cuts. The scheme's technical rules require a grid-connected inverter to switch off within a short time when the grid fails. That protects line workers, but it means no solar power during an outage unless you add batteries. Fully off-grid systems get no subsidy at all.
• No roof of your own. A flat needs the housing society to install the system for common areas, which earns ₹18,000 a kW. Delhi also has group and virtual net metering rules, under which homes can share one system's output.
• Dearer Indian-made panels. The subsidy requires them, and they cost more than imported ones. If you skip the subsidy, you may use imported panels.
• Waiting. The guidelines promise payment within 15 days of approval. IEEFA found the approvals themselves often take 45 to 120 days, so budget for the full price up front unless you take the loan.
• Moving house soon. A two-year payback assumes you stay two years. The panels are fixed to a roof you may not keep.
• Rules that can change. The draft net-metering charge above 5 kW and MSEDCL's request for slab-wise netting both show that the billing rules can be reopened.

Before you sign: a checklist

1. Check the vendor is registered on pmsuryaghar.gov.in, and apply through the portal with your electricity consumer number.
2. Get the quote split into modules, inverter, structure, wiring, net meter and installation, with GST at 5% on 70% and 18% on 30%.
3. Ask for the DCR certificate showing Indian-made modules and cells, or the subsidy will be refused.
4. Get the five-year free maintenance in writing, with a response time for faults.
5. Read the module warranty for the output guarantee (above 90% for 10 years, above 80% for 25) and the inverter's own warranty period.
6. Agree who pays for and fits the net meter, and a date for commissioning.
7. Size from your bills, not your roof. Take the year's average monthly units and divide by 100 to get kW.
8. Check for shade across the day and the seasons, and for 10–12 sq m a kW.
9. If you will borrow, apply through the portal so the subsidy goes into the loan account, and ask whether the bank will lower the EMI or shorten the term.
10. Finish before 31 March 2027, the scheme's last date.

Frequently Asked Questions

How much subsidy do I get for a 3 kW rooftop solar system? ₹78,000 from the centre under PM Surya Ghar: ₹30,000 a kW for the first 2 kW and ₹18,000 for the third. In the special-category states and UTs it is 10% higher, ₹85,800. A larger system gets the same ₹78,000. Some states add their own subsidy; Delhi adds ₹2,000 a kW up to ₹10,000.

Is there more subsidy for a 5 kW or 10 kW system? No. The central subsidy is capped at 3 kW, so ₹78,000 is the most any home gets. Larger systems are allowed and can still use net metering, but every kW beyond the third is at your own cost.

How many units does a 1 kW solar panel produce in a day? Four to 5.5 units on a clear sunny day, according to the ministry. Averaged over the year it is closer to 3.3 units a day: the government expects a 3 kW system to make a little over 300 units a month.

How many years does rooftop solar take to pay back? It depends on the rate of your highest slab. At this year's tariffs, a 3 kW system pays back in about 1.6 to 2.8 years in Delhi, Pune and Gurgaon homes using 300 to 800 units a month at the government's benchmark cost, and in 3.3 to 5.5 years at ₹70,000 a kW. Small homes on cheap or free power can take six to eleven years.

What is the interest rate on a PM Surya Ghar solar loan? Repo plus 0.5%: 6.00% at SBI for loans up to ₹2 lakh since 15 October 2026, floating. SBI charges 8.15% for loans from ₹2 lakh to ₹6 lakh, used for systems above 3 kW. The term is up to 10 years, there is no processing fee, and you put in at least 10% yourself.

Does rooftop solar work during a power cut? Not a standard grid-connected system. Its inverter must switch off when the grid goes down, so that it does not feed live power into lines being repaired. You need batteries for backup, and fully off-grid systems get no subsidy.

Can I charge my electric car with rooftop solar? Yes. Under net metering, the panels' units are netted against everything the house uses over the billing period, car included, so the time of charging does not matter much. Home charging is billed at domestic rates. Once 3 kW of solar has cleared the house's own use, the car's units fall into the cheapest slabs.

Is there a government subsidy for buying an electric car? Not at the centre for private cars. PM E-DRIVE covers electric two- and three-wheelers, ambulances, trucks, buses and charging infrastructure. Electric cars carry 5% GST. Some states offer their own incentives.

What is the GST on solar panels and on an EV charger? 5% on solar power systems and modules since 22 September 2025, and 5% on EV chargers. Where a solar system is supplied with installation, 70% of the price is taxed at 5% and 30% at 18%, a blended 8.9%.

Can I install rooftop solar in a flat? Not on your own, unless you have rights to the roof. Your housing society or RWA can install a system for common facilities, including EV charging, with ₹18,000 a kW of subsidy up to 500 kW. Some states, Delhi among them, also allow group or virtual net metering so that flats can share one system's output.

What is the last date to get the PM Surya Ghar subsidy? The scheme runs till 31 March 2027. The system has to be installed, inspected and approved by the electricity company before the subsidy is released, so allow a few months.

Figures are as MNRE, the Ministry of Power, the electricity regulators of Maharashtra, Delhi and Karnataka, DHBVN, SBI, PNB, PPAC, CBIC and the vehicle makers publish them, read on 22 October 2026. Bills are worked from the printed tariff slabs. They leave out electricity duty, fuel surcharges, Delhi's power-purchase adjustment and any free-power scheme other than the ones named, so check your own bill. Generation is the government's average of 100 units per kW a month, and a well-placed roof may do better. The 10% charging loss and 15 km a litre for a petrol car are our assumptions. Tariffs are set every year and the scheme's rules can change; this is a worked guide, not advice on a particular purchase.

Sources

The rules and figures in this article can be checked against these official sources.

• PM Surya Ghar: Muft Bijli Yojana, operational guidelines for central financial assistance to residential consumers (7 June 2024) Ministry of New and Renewable Energy
• Cabinet approves PM Surya Ghar: Muft Bijli Yojana: subsidy shares, the 3 kW system and 300 units a month (29 February 2024) Press Information Bureau
• PM Surya Ghar crosses 50 lakh households: subsidy released, zero-bill homes, concessional loans (4 August 2026) Press Information Bureau
• Lok Sabha Unstarred Question 580: subsidy for rooftop solar, rates and progress (22 July 2026) Lok Sabha
• PM Surya Ghar national portal: apply, registered vendors, progress and closing date Ministry of New and Renewable Energy
• Frequently asked questions on grid-connected rooftop solar: roof area, daily units, net metering Ministry of New and Renewable Energy (via PIB)
• SBI Surya Ghar: loan for solar rooftop, rates, margin and tenure State Bank of India
• Scheme for financing rooftop solar power systems (loan sized at ₹50,000 to ₹70,000 a kW) Punjab National Bank
• Tariff order for distributed solar PV plants: capital cost, capacity factor and upkeep (25 August 2026) Karnataka Electricity Regulatory Commission
• Residential rooftop solar grows under PM Surya Ghar Yojana, but gaps persist (December 2025) Institute for Energy Economics and Financial Analysis
• MSEDCL tariff for 2026-27: Case 75 of 2025, residential slabs, wheeling and solar-hours rebate (25 March 2026) Maharashtra Electricity Regulatory Commission
• MSEDCL multi-year tariff order, Case 217 of 2024: net-metered homes billed on net units (section 7.15) Maharashtra Electricity Regulatory Commission
• Grid interactive rooftop renewable energy generating systems regulations, 2019: carry-forward and year-end settlement Maharashtra Electricity Regulatory Commission
• Generic tariff for 2026-27: ₹2.82 a unit for surplus rooftop solar (Case 1/SM/2026) Maharashtra Electricity Regulatory Commission
• Tariff schedule for Delhi: domestic slabs, fixed charges, surcharges and EV charging (order of 30 September 2021) Delhi Electricity Regulatory Commission
• Eligibility for the Delhi government’s electricity subsidy: 0 to 200 units, 201 to 400 units BSES (citing the Government of NCT of Delhi)
• Delhi Solar Energy Policy, 2023: capital subsidy and generation-based incentive for five years Government of NCT of Delhi
• Delhi Solar Portal: about the policy, incentives and how to install Government of NCT of Delhi
• Schedule of tariff for 2026-27: Sales Circular D-06/2026, domestic categories and fixed charges Dakshin Haryana Bijli Vitran Nigam
• Electricity (Rights of Consumers) Amendment Rules, 2021: net metering and its limits Ministry of Power
• Electricity (Rights of Consumers) Amendment Rules, 2023: time-of-day tariff and the solar-hours discount Ministry of Power
• Electricity (Rights of Consumers) Amendment Rules, 2024: rooftop solar up to 10 kW deemed feasible, 15-day timelines Ministry of Power
• Draft Electricity (Rights of Consumers) Amendment Rules, 2026, for comments (12 March 2026) Ministry of Power
• Guidelines for installation and operation of electric vehicle charging infrastructure, 2024 Ministry of Power
• Retail selling price of petrol and diesel in the metro cities (22 October 2026) Petroleum Planning and Analysis Cell
• Notification 9/2025-Central Tax (Rate): solar systems, EV chargers and electric vehicles at 5%, and the 70:30 split CBIC
• GST on renewable energy devices cut to 5%: about ₹9,000 to ₹10,500 off a 3 kW rooftop system (17 September 2025) Press Information Bureau
• PM E-DRIVE scheme backgrounder: the vehicle categories it covers (1 October 2026) Press Information Bureau
• CO2 baseline database for the Indian power sector, version 22.0 (2025-26 grid emission factor) Central Electricity Authority
• Nexon.ev 45 launch: 45 kWh battery, 489 km certified, 350 to 370 km real-world (24 September 2024) Tata Motors
• MG Windsor EV: batteries, certified range, home charger and charging time JSW MG Motor India
• Your home charger, explained: wall-box options, charging time and installation Mahindra
• 7.4 kW MotrON EV home charger: listed price Havells India