Calculators

Bangalore Solar Calculator (BESCOM)

Rooftop solar payback for Bangalore homes on BESCOM's flat KERC tariff, fixed charge per kW and this year's true-up charge.

Your home

₹
₹100₹50K

About 343 units a month on the BESCOM tariff. Use a year's average if your bill swings with the seasons.

Roof typeRoof type

Fine-tune

kW

Sized to cover a year of your consumption, at 5.4 peak sun hours a day in Karnataka.

sq ft

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.

%
0%15%

Indian residential tariffs have historically risen 4-7% a year.

%
0%2%

Monocrystalline panels typically lose about 0.5% a year.

How you payHow you pay
Pays for itself in2.8 yearsthen ₹11.06 L ahead after 25 years

A 2.5 kW system makes about 316 units a month, 92% of your use. Your bill drops from ₹3,000 to about ₹687 in year one.

Installed cost
₹1,50,000
PM Surya Ghar subsidy
− ₹69,000
Net cost to you
₹81,000
Saving in year one
₹27,792
Return (IRR)
38.3% a year
over 25 years, before tax
CO₂ avoided
64 tonnes
over 25 years
Subsidy46%
  • You pay54%
  • Central subsidy46%
Your money over 25 yearsStill to recoverAhead
₹-2.5 L₹0₹2.5 L₹5 L₹7.5 L₹10 L₹12.5 LPayback, year 2.804812162025
Year-by-year cash flowShow
YearUnits madeBills without solarBills with solarUpkeep and EMIsRunning total
13,794₹36,035₹8,243₹0-₹53,208
23,775₹37,837₹8,801₹0-₹24,173
33,756₹39,728₹9,394₹0₹6,162
43,738₹41,715₹10,023₹0₹37,854
53,719₹43,801₹10,690₹0₹70,964
63,700₹45,991₹11,399₹1,500₹1,04,056
73,682₹48,290₹12,150₹1,500₹1,38,696
83,663₹50,705₹12,947₹1,500₹1,74,953
93,645₹53,240₹13,793₹1,500₹2,12,900
103,627₹55,902₹14,690₹1,500₹2,52,612
113,609₹58,697₹15,641₹1,500₹2,94,169
123,591₹61,632₹16,649₹19,000₹3,20,152
133,573₹64,714₹17,717₹1,500₹3,65,648
143,555₹67,949₹18,850₹1,500₹4,13,247
153,537₹71,347₹20,050₹1,500₹4,63,044
163,519₹74,914₹21,322₹1,500₹5,15,136
173,502₹78,660₹22,670₹1,500₹5,69,626
183,484₹82,593₹24,097₹1,500₹6,26,622
193,467₹86,722₹25,609₹1,500₹6,86,235
203,449₹91,058₹27,210₹1,500₹7,48,583
213,432₹95,611₹28,906₹1,500₹8,13,789
223,415₹1,00,392₹30,702₹1,500₹8,81,979
233,398₹1,05,412₹32,602₹1,500₹9,53,289
243,381₹1,10,682₹34,615₹1,500₹10,27,856
253,364₹1,16,216₹36,745₹1,500₹11,05,827

How it works

The bill you enter is worked backwards through your DISCOM's slabs, fixed charges, surcharges and duty to the units you use. The panels' yearly output is set against that use under net metering, and each month is re-billed on what is left. Because the units solar removes come off your most expensive slab first, the saving per unit is often well above the average rate on your bill. Tariffs rise by the escalation rate each year while the panels slowly lose output; maintenance, an inverter replacement in year 12 and any loan repayments are taken off, and the running total gives the payback year.

Saving₍y₎ = [Bill(U) − Bill(U − G₍y₎/12)] × 12 × (1 + e)^(y−1), G₍y₎ = kW × H × 365 × PR × (1 − d)^(y−1)
U
Units you use a month, worked out from your bill
G₍y₎
Units the panels make in year y
H
Peak sun hours a day in your state
PR
Performance ratio: the share of rated output that reaches the meter, 0.77 here
e
Yearly rise in electricity prices
d
Yearly loss in panel output

Worked example

A Bangalore home on BESCOM with a ₹3,000 monthly bill and a flat RCC roof, assuming prices rise 5% a year.

  1. 1Working the bill back through the BESCOM slabs, charges and duty gives about 343 units a month
  2. 2At 5.4 peak sun hours, 2.5 kW makes about 316 units a month, 92% of that use
  3. 32.5 kW at ₹60,000 per kW costs ₹1,50,000; PM Surya Ghar pays ₹69,000, leaving ₹81,000
  4. 4The first year saves ₹27,792, and the saving grows as tariffs rise

The system pays for itself in about 2.8 years and leaves the household about ₹11,05,827 ahead over 25 years.

Frequently asked questions

Does Gruha Jyothi change whether solar is worth it?

For homes within Gruha Jyothi's free allowance, there is little bill left for solar to cut. The scheme covers up to 200 units a month, based on each home's past average, so it mainly helps smaller users. Homes above their allowance pay the full tariff on every unit, and that is where this calculator applies.

Why is the payback longer in Bangalore than in Pune?

KERC replaced domestic slabs with a single energy rate of about ₹5.80 a unit, so each unit solar removes saves the same modest amount, unlike Maharashtra where the top slabs cost ₹15 or more. The return is still strong, but it depends more on the subsidy than on escaping an expensive slab.

How does net metering settle on BESCOM?

Net metering with banked units carried forward and any surplus settled yearly at the KERC-approved rate.

How much is the PM Surya Ghar subsidy?

₹30,000 per kW for the first 2 kW and ₹18,000 for the third, so ₹30,000 for 1 kW, ₹60,000 for 2 kW and ₹78,000 for 3 kW or more. It is paid into your bank account after the DISCOM inspects and commissions the system, and only for installations by an empanelled vendor using ALMM-listed panels, applied for through pmsuryaghar.gov.in.

Why is my saving per unit higher than my average rate?

Residential tariffs are telescopic: the first units are cheap and each slab above costs more. Solar takes units off the top of your bill, so it removes the dearest ones first. A home in a ₹10-plus slab saves that rate on every unit the panels cover, even if the bill averages out lower.

Why not simply fit the biggest system my roof will hold?

The central subsidy stops rising at 3 kW, and under net metering surplus units are usually bought back at the regulator's average power purchase cost, often ₹2-3 a unit, far below what you pay for grid power. Sizing to your own consumption earns the full retail rate on every unit. The calculator suggests that size; override it to see what a bigger system does to the return.

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