Mumbai Solar Calculator (Tata Power Mumbai)
Rooftop solar payback for Mumbai homes on Tata Power, on MERC's FY 2026-27 schedule with its ₹2.40 wheeling charge.
Updated · By Niraj Kumar · 1 source
https://checkpre.com/energy/solar-calculator-mumbai-tata-power
Your home
About 343 units a month on the Tata Power Mumbai tariff. Use a year's average if your bill swings with the seasons.
Fine-tune
Sized to cover a year of your consumption, at 5.4 peak sun hours a day in Maharashtra.
About 100 sq ft per kW. Leave at 0 for no limit.
Typical for an on-grid system from an empanelled vendor. Replace it with your quote.
Indian residential tariffs have historically risen 4-7% a year.
Monocrystalline panels typically lose about 0.5% a year.
A 2.5 kW system makes about 316 units a month, 92% of your use. Your bill drops from ₹3,000 to about ₹248 in year one.
- Installed cost
- ₹1,50,000
- PM Surya Ghar subsidy
- − ₹69,000
- Net cost to you
- ₹81,000
- Saving in year one
- ₹33,106
- Return (IRR)
- 45.2% a year
- over 25 years, before tax
- CO₂ avoided
- 64 tonnes
- over 25 years
- You pay54%
- Central subsidy46%
Year-by-year cash flowShowHide
| Year | Units made | Bills without solar | Bills with solar | Upkeep and EMIs | Running total |
|---|---|---|---|---|---|
| 1 | 3,794 | ₹36,080 | ₹2,974 | ₹0 | -₹47,894 |
| 2 | 3,775 | ₹37,884 | ₹3,229 | ₹0 | -₹13,239 |
| 3 | 3,756 | ₹39,778 | ₹3,502 | ₹0 | ₹23,038 |
| 4 | 3,738 | ₹41,767 | ₹3,793 | ₹0 | ₹61,012 |
| 5 | 3,719 | ₹43,856 | ₹4,104 | ₹0 | ₹1,00,763 |
| 6 | 3,700 | ₹46,048 | ₹4,437 | ₹1,500 | ₹1,40,875 |
| 7 | 3,682 | ₹48,351 | ₹4,791 | ₹1,500 | ₹1,82,935 |
| 8 | 3,663 | ₹50,768 | ₹5,169 | ₹1,500 | ₹2,27,034 |
| 9 | 3,645 | ₹53,307 | ₹5,572 | ₹1,500 | ₹2,73,269 |
| 10 | 3,627 | ₹55,972 | ₹6,002 | ₹1,500 | ₹3,21,739 |
| 11 | 3,609 | ₹58,771 | ₹6,460 | ₹1,500 | ₹3,72,550 |
| 12 | 3,591 | ₹61,709 | ₹6,948 | ₹19,000 | ₹4,08,311 |
| 13 | 3,573 | ₹64,795 | ₹7,468 | ₹1,500 | ₹4,64,138 |
| 14 | 3,555 | ₹68,035 | ₹8,022 | ₹1,500 | ₹5,22,651 |
| 15 | 3,537 | ₹71,436 | ₹8,611 | ₹1,500 | ₹5,83,976 |
| 16 | 3,519 | ₹75,008 | ₹9,238 | ₹1,500 | ₹6,48,246 |
| 17 | 3,502 | ₹78,758 | ₹9,905 | ₹1,500 | ₹7,15,599 |
| 18 | 3,484 | ₹82,696 | ₹10,615 | ₹1,500 | ₹7,86,180 |
| 19 | 3,467 | ₹86,831 | ₹11,370 | ₹1,500 | ₹8,60,141 |
| 20 | 3,449 | ₹91,173 | ₹12,173 | ₹1,500 | ₹9,37,641 |
| 21 | 3,432 | ₹95,731 | ₹13,026 | ₹1,500 | ₹10,18,846 |
| 22 | 3,415 | ₹1,00,518 | ₹13,933 | ₹1,500 | ₹11,03,931 |
| 23 | 3,398 | ₹1,05,544 | ₹14,897 | ₹1,500 | ₹11,93,078 |
| 24 | 3,381 | ₹1,10,821 | ₹15,921 | ₹1,500 | ₹12,86,478 |
| 25 | 3,364 | ₹1,16,362 | ₹17,009 | ₹1,500 | ₹13,84,331 |
How the Mumbai Solar Calculator (Tata Power Mumbai) works
Saving₍y₎ = [Bill(U) − Bill(U − G₍y₎/12)] × 12 × (1 + e)^(y−1), G₍y₎ = kW × H × 365 × PR × (1 − d)^(y−1)This page uses the same method as the Solar ROI Calculator India, which explains each term and assumption in full.
Worked example
A Mumbai home on Tata Power Mumbai with a ₹3,000 monthly bill and a flat RCC roof, assuming prices rise 5% a year.
- 1Working the bill back through the Tata Power Mumbai slabs, charges and duty gives about 343 units a month
- 2At 5.4 peak sun hours, 2.5 kW makes about 316 units a month, 92% of that use
- 32.5 kW at ₹60,000 per kW costs ₹1,50,000; PM Surya Ghar pays ₹69,000, leaving ₹81,000
- 4The first year saves ₹33,106, and the saving grows as tariffs rise
The system pays for itself in about 2.4 years and leaves the household about ₹13,84,331 ahead over 25 years.
Frequently asked questions
What does Tata Power Mumbai charge per unit in 2026-27?
MERC's schedule for 1 April 2026 to 31 March 2027 sets energy charges of ₹1.90 up to 100 units a month, ₹4.70 to 300, ₹9.24 to 500 and ₹10.24 above, plus a ₹2.40 wheeling charge on every unit. Fixed charges run from ₹90 to ₹160 a month, and 16% electricity duty is added.
Does Tata Power Mumbai's solar-hours rebate matter with net metering?
Only a little. Smart-metered homes get 55 paise off each unit used between 9 am and 5 pm in 2026-27, which slightly lowers what daytime units cost. Net metering still credits your panels' output against the units you draw at any hour.
How does net metering settle on Tata Power Mumbai?
Surplus units are banked month to month and settled once a year at the MERC-approved rate. MERC has confirmed that residential net metering continues under the new ToD meters, with banked units usable at any hour.
Sources
Related calculators
- Maharashtra Solar CalculatorCompare rooftop solar payback across Maharashtra's four residential DISCOMs: MSEDCL, Adani Electricity, Tata Power and BEST.
- Mumbai Solar Calculator (BEST)Rooftop solar payback for South Mumbai homes on BEST, where units above 300 a month cost over ₹10 before wheeling and duty.
- Pune Solar Calculator (MSEDCL)Rooftop solar payback for Pune and the rest of MSEDCL's Maharashtra, on the FY 2026-27 MERC slabs, wheeling charge and 16% duty.
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