Rajkot Solar Calculator (PGVCL)

Rooftop solar payback for Rajkot and Saurashtra on PGVCL, using Gujarat's strong sunshine, the FPPPA charge and 15% duty.

Your home

Average monthly electricity bill

₹

₹100₹50K

About 352 units a month on the PGVCL tariff. Use a year's average if your bill swings with the seasons.

Roof type

RCC flat roof

RCC, elevated structure

Metal sheet roof

Fine-tune

System size

Sized to cover a year of your consumption, at 5.8 peak sun hours a day in Gujarat.

Usable shadow-free roof area (optional)

sq ft

About 100 sq ft per kW. Leave at 0 for no limit.

Installed cost per kW, GST included

₹

Typical for an on-grid system from an empanelled vendor. Replace it with your quote.

Yearly rise in electricity prices

0%15%

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

Panel output lost each year

0%2%

Monocrystalline panels typically lose about 0.5% a year.

How you pay

Upfront

Solar loan

Pays for itself in2.3 yearsthen ₹14.3 L ahead after 25 years

A 2.5 kW system makes about 340 units a month, 96% of your use. Your bill drops from ₹3,000 to about ₹117 in year one.

Installed cost: ₹1,50,000
PM Surya Ghar subsidy: − ₹69,000
Net cost to you: ₹81,000
Saving in year one: ₹34,670
Return (IRR): 47.0% a year; over 25 years, before tax
CO₂ avoided: 69 tonnes; over 25 years

Subsidy46%

You pay54%
Central subsidy46%

Your money over 25 yearsStill to recoverAhead

Year-by-year cash flowShow

Year	Units made	Bills without solar	Bills with solar	Upkeep and EMIs	Running total
1	4,075	₹36,076	₹1,406	₹0	-₹46,330
2	4,055	₹37,880	₹1,629	₹0	-₹10,079
3	4,035	₹39,774	₹1,869	₹0	₹27,826
4	4,014	₹41,762	₹2,129	₹0	₹67,459
5	3,994	₹43,851	₹2,410	₹0	₹1,08,900
6	3,974	₹46,043	₹2,712	₹1,500	₹1,50,731
7	3,954	₹48,345	₹3,038	₹1,500	₹1,94,538
8	3,935	₹50,762	₹3,388	₹1,500	₹2,40,413
9	3,915	₹53,301	₹3,764	₹1,500	₹2,88,449
10	3,895	₹55,966	₹4,169	₹1,500	₹3,38,746
11	3,876	₹58,764	₹4,604	₹1,500	₹3,91,406
12	3,857	₹61,702	₹5,070	₹19,000	₹4,29,038
13	3,837	₹64,787	₹5,571	₹1,500	₹4,86,754
14	3,818	₹68,027	₹6,107	₹1,500	₹5,47,174
15	3,799	₹71,428	₹6,682	₹1,500	₹6,10,420
16	3,780	₹74,999	₹7,298	₹1,500	₹6,76,621
17	3,761	₹78,749	₹7,957	₹1,500	₹7,45,914
18	3,742	₹82,687	₹8,662	₹1,500	₹8,18,439
19	3,724	₹86,821	₹9,416	₹1,500	₹8,94,343
20	3,705	₹91,162	₹10,222	₹1,500	₹9,73,783
21	3,686	₹95,720	₹11,084	₹1,500	₹10,56,920
22	3,668	₹1,00,506	₹12,004	₹1,500	₹11,43,922
23	3,650	₹1,05,532	₹12,987	₹1,500	₹12,34,966
24	3,631	₹1,10,808	₹14,036	₹1,500	₹13,30,238
25	3,613	₹1,16,349	₹15,173	₹1,500	₹14,29,914

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 Rajkot home on PGVCL with a ₹2,500 monthly bill and a flat RCC roof, assuming prices rise 5% a year.

1Working the bill back through the PGVCL slabs, charges and duty gives about 300 units a month
2At 5.8 peak sun hours, 2 kW makes about 272 units a month, 91% of that use
32 kW at ₹60,000 per kW costs ₹1,20,000; PM Surya Ghar pays ₹60,000, leaving ₹60,000
4The first year saves ₹27,316, and the saving grows as tariffs rise

The system pays for itself in about 2.1 years and leaves the household about ₹11,27,996 ahead over 25 years.

Frequently asked questions

Does this work for DGVCL, MGVCL and UGVCL too?

Yes for the tariff: GERC sets one residential tariff for all four state DISCOMs, so Surat (DGVCL), Vadodara (MGVCL) and north Gujarat (UGVCL) are billed the same way. Ahmedabad and Surat city customers of Torrent Power are on a different tariff.

What is FPPPA and why is it so large?

The Fuel and Power Purchase Price Adjustment passes changes in the cost of buying power on to consumers, and in Gujarat it is set quarterly and applies to every unit. At about ₹3.15 it is often close to the energy charge itself, which is why each unit solar replaces saves more than the slab rate suggests.

How does net metering settle on PGVCL?

Net metering with surplus units bought back by the DISCOM at the GERC rate at the end of each billing cycle.

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.