Pune, 300 units a month, 3 kW
₹3,036 a monthPays back in 1 year 11 monthsMSEDCL bill ₹3,166 → ₹130. Every unit replaced was costing ₹12.40. You pay ₹67,000 after the subsidy.
Solar Savings Calculator
Pick your State, type the units on your electricity bill, and the calculator sizes a rooftop system to your use, takes off the PM Surya Ghar subsidy and works your bill slab by slab on your State’s own tariff, before and after the panels. It shows what you save each month, how long the panels take to pay for themselves, what is left over in 25 years, the solar loan’s EMI, what an electric car costs a kilometre, and the carbon kept out of the air.
PM Surya Ghar: Muft Bijli Yojana, MNRE guidelines of 7 June 2024 · open till 31 March 2027 · tariffs: MSEDCL 2026-27, HERC 2026-27 (DHBVN), DERC · SBI Surya Ghar loan from 15 October 2026 · CEA grid factor 2025-26 · reviewed 22 October 2026
Where you live
Sets the subsidy rate and, for Delhi, Haryana and Maharashtra, the tariff
On your bill; it sets the fixed charge
The whole bill up to 200 units a month; up to ₹800 off from 201 to 400
₹2,000 a kW up to ₹10,000, and ₹3 for every unit made (₹2 above 3 kW) for five years
The rate of the highest slab on your bill: those are the units the panels replace
Your regulator’s year-end rate; leave 0 if you do not know it
Your electricity use
On your bill as “units consumed”; an average month
₹
The calculator works back to your units on your State’s tariff
Your roof and system
About 100 units a month for each kW, so the panels match your use
About 100 units a month for each kW
100 units per kW a month, or 139 at a 19% capacity factor
About 10 to 12 sq m a kW
Price, subsidy and loan
Benchmark: ₹50,000 a kW for 2 kW, ₹45,000 after
₹
Including GST: 5% on 70% of the price, 18% on 30%
Needs Indian-made panels and a vendor registered on pmsuryaghar.gov.in
SBI: 6.00% up to ₹2 lakh, 8.15% above; 10% from you; 10 years
An electric car (optional)
Adds its units to your use and compares the cost a km with petrol
1,000 km is about 33 km a day
For the comparison
Benefits of rooftop solar, in one look
What a home gets from panels on the roof under today’s rules, and where each benefit comes from: the scheme’s guidelines, the State tariff orders and the bank’s own page.
- A smaller electricity bill
The panels replace your dearest units first. A 3 kW system cut a 300-unit Pune bill from ₹3,166 to ₹130 a month.
- Up to ₹78,000 from the Government
PM Surya Ghar pays ₹30,000 a kW for the first 2 kW and ₹18,000 for the third, straight into your bank or loan account.
- A cheap loan
Repo plus 0.5%: 6.00% at SBI up to ₹2 lakh, for up to 10 years, with no processing fee.
- Five years’ free upkeep
The registered vendor must repair and maintain the plant free for five years from commissioning.
- Twenty-five years of output
Modules must keep more than 90% of their output for 10 years and more than 80% for the next 15.
- Cheap kilometres
An electric car charged at home on your own roof’s units costs a few paise a kilometre to run.
- Cleaner air
About 2.4 tonnes of CO₂ a year kept out of the air for every 3 kW, at the grid’s 0.675 kg a unit.
- Credit for what you send out
Under net metering the grid banks your extra daytime units and sets them against what you use at night.
How much can you save with solar? Five homes, worked out
The calculator’s own engine, run on five real tariffs at the Government’s benchmark price. The worked bills are explained line by line in the guide rooftop solar and a home EV charger: do they really pay back?
Delhi, 800 units a month, 3 kW
₹2,243 a monthPays back in 1 year 8 monthsBill ₹5,003 → ₹2,760, plus ₹10,800 a year from Delhi for five years and ₹6,000 off the price. You pay ₹61,000 after the subsidy.
Gurgaon, 450 units a month, 3 kW
₹2,005 a monthPays back in 2 years 10 monthsBill ₹2,448 → ₹443; the ₹50 a kW fixed charge goes too, once billed units fall under 300. You pay ₹67,000 after the subsidy.
Gurgaon, 150 units a month, 1.5 kW
₹443 a monthPays back in 5 years 10 monthsA small bill at ₹2.95 a unit: ₹5,310 a year, so the panels take much longer to repay. You pay ₹30,000 after the subsidy.
Delhi, 180 units a month, 1.5 kW
₹450 a month from DelhiPays back in 5 yearsThe bill is already free under Delhi’s subsidy; the panels earn only Delhi’s ₹3 a unit, ₹5,400 a year for five years. You pay ₹27,000 after the subsidy.
How the solar savings calculator works
- Sized to your use
Your units a month, divided by what a kW makes: 100 units on the Government’s average.
In detail
The Cabinet’s release on PM Surya Ghar says a 3 kW system makes more than 300 units a month on an average, so a kW is taken at 100 units a month; a sunny, unshaded roof can use Karnataka’s regulator’s 19% capacity factor, about 139. The suggestion is rounded to half a kW, between 1 and 10 kW. An electric car’s units are added first, at 0.125 units a km plus 10% for charging losses. - Price less the subsidy
MNRE’s benchmark, ₹70,000 a kW or your quote; then the central subsidy, capped at 3 kW.
In detail
The benchmark is ₹50,000 a kW for the first 2 kW and ₹45,000 after (₹55,000 and ₹49,500 in the special-category areas). The subsidy is ₹30,000 a kW for the first 2 kW and ₹18,000 for the third, ₹78,000 at most, or ₹33,000 and ₹19,800 in the special-category areas. In Delhi the State’s ₹2,000 a kW, up to ₹10,000, comes off too. - Your bill, slab by slab
Today’s bill against the bill on net units, on your State’s own tariff.
In detail
Under net metering you are billed on the units you draw less those you send out, so the units the panels cancel are the top of your ladder. Maharashtra uses MSEDCL’s 2026-27 slabs with wheeling and the ₹130 fixed charge; Haryana the HERC 2026-27 schedule by category; Delhi the DERC slabs, fixed charge and surcharges, with the Delhi government’s subsidy. Other States use the rate you enter. Duty and fuel surcharges are left out. - Payback over 25 years
Month by month: the bill saving, surplus units, Delhi’s incentive, less upkeep after five free years.
In detail
Surplus units are valued at the regulator’s year-end rate where it is known (₹2.82 in Maharashtra for 2026-27). Delhi’s ₹3 a unit runs for five years. After the vendor’s five free years, upkeep is taken at 1% of the price a year, Karnataka’s regulator’s assumption. Tariffs are held at today’s level and output is not reduced for age; panels must keep more than 80% of their output to 25 years.
The figures behind the calculator, and where each comes from
Where it comes from
₹30,000 a kW for the first 2 kW, ₹18,000 for the third, nothing beyond 3 kW; ₹33,000 and ₹19,800 in Uttarakhand, Himachal Pradesh, J&K, Ladakh, the North East including Sikkim, A&N and Lakshadweep. Indian-made (DCR) modules, a registered vendor and the electricity company’s inspection are required; payment within 15 days of its approval. The scheme runs till 31 March 2027. MNRE operational guidelines; national portal.
Where it comes from
MNRE fixed the benchmark at ₹50,000 a kW for the first 2 kW and ₹45,000 for the additional kW from 13 February 2024. Punjab National Bank sizes its solar loans at ₹50,000 to ₹70,000 a kW (PNB); Karnataka’s regulator took ₹45,000 a kW, all taxes in, for home systems without the subsidy (KERC order of 25 August 2026).
Where it comes from
“A 3 kW system will be able to generate more than 300 units a month on an average” (PIB, 29 February 2024); 4 to 5.5 units a day on a clear sunny day and 10 to 12 sq m of shade-free roof a kW (MNRE FAQ); 19% capacity factor for distributed solar (KERC).
Where it comes from
MSEDCL residential 2026-27, energy plus ₹1.60 wheeling: 1–100 units ₹5.56, 101–300 ₹12.40, 301–500 ₹16.64, above 500 ₹19.13; fixed ₹130 a month single phase (order of 25 March 2026, p.95). Surplus at the year end: ₹2.82 a unit (Case 1/SM/2026).
Where it comes from
HERC 2026-27, from 1 April 2026: up to 2 kW, 0–50 units ₹2.20 and 51–100 ₹2.70; up to 5 kW, 0–150 ₹2.95, 151–300 ₹5.25, 301–500 ₹6.45, above 500 ₹7.10, with ₹50 a kW fixed above 300 units; above 5 kW, ₹6.50, ₹7.15 and ₹7.50 with ₹75 a kW. The circular.
Where it comes from
DERC slabs ₹3.00 (0–200), ₹4.50, ₹6.50, ₹7.00 and ₹8.00, fixed charge by sanctioned load, plus 8% and 7% surcharges (DERC schedule); the Delhi government’s subsidy as BSES sets it out (BSES); ₹2,000 a kW up to ₹10,000 and ₹3 a unit (₹2 above 3 kW) for five years (Delhi Solar Energy Policy, 2023).
Where it comes from
Net metering up to 500 kW or the sanctioned load where the State has not set otherwise (2021 amendment); up to 10 kW deemed technically feasible, and commissioning within 15 days (2024 amendment).
Where it comes from
EBLR minus 2.15%, 6.00%, up to ₹2 lakh; EBLR, 8.15%, from ₹2 lakh to ₹6 lakh; both from 15 October 2026, floating; up to 120 months including a 6-month moratorium; 10% margin; no processing fee; the subsidy is paid into the loan account. SBI.
Where it comes from
Nexon.ev 45: 45 kWh, real-world 350 to 370 km (Tata Motors); 10% charging loss is an assumption. Petrol ₹102.12 a litre in Delhi on 22 October 2026 (PPAC). Home charging at domestic rates (EV guidelines, 2024).
Where it comes from
Grid average 0.675 kg of CO₂ a unit for 2025-26 (CEA CO₂ database, version 22.0). Solar systems at 5% GST, with 70% of a turnkey contract taxed as goods and 30% as services at 18% (Notification 9/2025-Central Tax (Rate)).
Solar savings: the questions people ask
How much can I save with rooftop solar?
It depends on what you pay for your last units, because those are the units the panels replace. At this year’s tariffs a 3 kW system saves about ₹3,036 a month in a Pune home using 300 units, ₹2,243 a month in a Delhi home using 800 units (plus Delhi’s ₹3 a unit for five years), and ₹2,005 a month in a Gurgaon home using 450 units. Put your own State and units into the calculator above.
What are the benefits of rooftop solar at home?
A lower electricity bill, often close to nil; a central subsidy of up to ₹78,000 under PM Surya Ghar; a loan at the repo rate plus 0.5% (6.00% at SBI up to ₹2 lakh); five years of free maintenance from the vendor; panels built to keep more than 80% of their output for 25 years; cheap charging for an electric car; and about 2.4 tonnes of CO₂ a year kept out of the air for every 3 kW.
How much subsidy do I get for a 3 kW solar system?
₹78,000 from the centre: ₹30,000 a kW for the first 2 kW and ₹18,000 for the third. It is 10% higher, ₹85,800, in Uttarakhand, Himachal Pradesh, Jammu and Kashmir, Ladakh, the North East including Sikkim, Andaman and Nicobar and Lakshadweep. A larger system gets the same ₹78,000. Delhi adds ₹2,000 a kW up to ₹10,000.
How many kW of solar do I need for my home?
Divide your average monthly units by 100: a kW makes about 100 units a month, the Government’s own average (a 3 kW system, it says, makes more than 300 units a month). So 300 units a month needs about 3 kW. The Government’s own guide: 0–150 units a month, 1–2 kW; 150–300 units, 2–3 kW; above 300 units, above 3 kW.
How many units does a 1 kW solar system produce?
Four to 5.5 units on a clear sunny day, according to the ministry; averaged over the year, about 3.3 units a day, or 100 a month. Karnataka’s regulator assumes a capacity factor of 19%, about 139 units a month, for a well-placed roof; choose “Sunny, unshaded roof” in the calculator for that.
How much roof do I need for solar panels?
About 10 to 12 square metres of shade-free roof for each kW, so 30 to 36 square metres for a 3 kW system. Shade from a water tank, a wall or a tree for part of the day costs real output.
How long does rooftop solar take to pay back?
At the Government’s benchmark price a 3 kW system pays for itself in about 1 year 11 months in Pune, 1 year 8 months in Delhi and 2 years 10 months in Gurgaon for the homes above; at ₹70,000 a kW the Pune home takes 3 years 8 months. A small home on cheap power takes much longer: 5 years 10 months for 150 units in Gurgaon.
What is the cost of a 3 kW rooftop solar system after the subsidy?
MNRE’s benchmark puts a 3 kW system at ₹1,45,000; after the ₹78,000 subsidy you pay ₹67,000. Quotes vary: Punjab National Bank sizes its solar loans at ₹50,000 to ₹70,000 a kW, which would make it ₹2,10,000, or ₹1,32,000 after the subsidy. Choose “My quote” in the calculator to use your own.
Is rooftop solar worth it in India?
It is worth most where your last units are dear: in Maharashtra’s 101–300 slab every unit costs ₹12.40 with wheeling, and a 3 kW system there pays back in under two years at the benchmark price. It is worth least where your bill is already small or free, such as a Delhi home using under 200 units, where solar earns only Delhi’s incentive for five years.
What is the interest rate on a solar loan?
Repo plus 0.5% under PM Surya Ghar: at SBI 6.00% for loans up to ₹2 lakh (systems up to 3 kW) and 8.15% from ₹2 lakh to ₹6 lakh, both from 15 October 2026, floating, for up to 10 years, with 10% of the cost from you and no processing fee. The subsidy is paid into the loan account; on a ₹1,45,000 system the EMI then falls to about ₹583.
Does rooftop solar work during a power cut or at night?
Not a standard grid-connected system. The scheme’s technical rules require its inverter to switch off when the grid fails, so that it does not feed live lines being repaired; and panels make nothing at night. Under net metering the units you send out by day are set against what you draw at night. Backup needs batteries; fully off-grid systems get no subsidy.
Can I charge an electric car with rooftop solar?
Yes. Home charging is billed at domestic rates, and under net metering the panels’ units are set against everything the house uses, the car included. In the Pune home above, 1,200 km a month costs about ₹2,746 on the grid and ₹1,362 once the panels are on the roof, against about ₹8,170 of petrol.
What happens to the extra units my panels produce?
Under net metering they are carried forward from month to month, and any left at the end of the financial year are paid for at a rate the regulator sets: ₹2.82 a unit in Maharashtra for 2026-27, against the ₹12 to ₹19 you pay for units. That is why the calculator sizes the system to your use, not your roof.
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 by your electricity company and approved before the subsidy is released, so leave a few months.
What is the GST on solar panels?
5% on solar power systems and modules since 22 September 2025, down from 12%. A turnkey contract is taxed 70% as goods at 5% and 30% as services at 18%, a blended 8.9%; the Government put the saving on a 3 kW system at about ₹9,000 to ₹10,500.
See also the guide rooftop solar and a home EV charger: do they really pay back?, the EMI calculator for any loan, the GST calculator, the real rate behind a car loan offer, or all calculators.
Quoting this calculator?
You are welcome to use these figures in an article, a forum answer or a client note. A link back is all I ask — here it is, ready to paste.