CheckPre

West Bengal Solar Calculator (WBSEDCL)

Rooftop solar payback for West Bengal homes outside Kolkata on WBSEDCL's quarterly bill, from Siliguri to Durgapur.

Updated · By Niraj Kumar · 1 source

Your home

Solar forSolar for
From your bill, enterFrom your bill, enter
₹
₹100₹50K

About 354 units a month on the WBSEDCL tariff. WBSEDCL bills every three months: enter a month's share.

Roof typeRoof type

Fine-tune

kW

Sized to cover a year of your consumption, at 4.6 peak sun hours a day in West Bengal.

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 in3.1 yearsthen ₹14.69 L ahead after 25 years

A 3.5 kW system makes about 377 units a month, 100% of your use. Your bill drops from ₹3,000 to about ₹99 in year one.

Installed cost
₹1,92,500
PM Surya Ghar subsidy
− ₹78,000
Net cost to you
₹1,14,500
Saving in year one
₹35,674
Return (IRR)
35.4% a year
over 25 years, before tax
CO₂ avoided
77 tonnes
over 25 years
Subsidy41%
  • You pay59%
  • Central subsidy41%
Your money over 25 yearsStill to recoverAhead
₹-5 L₹0₹5 L₹10 L₹15 LPayback, year 3.104812162025
Year-by-year cash flowShow
YearUnits madeBills without solarBills with solarUpkeep and EMIsRunning total
14,525₹36,031₹1,188₹0-₹78,826
24,502₹37,833₹1,247₹0-₹41,478
34,480₹39,724₹1,310₹0-₹2,369
44,457₹41,710₹1,375₹0₹38,594
54,435₹43,796₹1,444₹0₹81,508
64,413₹45,986₹1,516₹1,925₹1,24,547
74,391₹48,285₹1,592₹1,925₹1,69,743
84,369₹50,699₹1,672₹1,925₹2,17,208
94,347₹53,234₹1,755₹1,925₹2,67,059
104,325₹55,896₹1,843₹1,925₹3,19,419
114,304₹58,691₹1,935₹1,925₹3,74,417
124,282₹61,625₹2,032₹26,425₹4,07,688
134,261₹64,706₹2,133₹1,925₹4,68,374
144,239₹67,942₹2,330₹1,925₹5,32,061
154,218₹71,339₹2,679₹1,925₹5,98,796
164,197₹74,906₹3,056₹1,925₹6,68,721
174,176₹78,651₹3,462₹1,925₹7,41,985
184,155₹82,584₹3,901₹1,925₹8,18,743
194,135₹86,713₹4,373₹1,925₹8,99,157
204,114₹91,048₹4,881₹1,925₹9,83,399
214,093₹95,601₹5,428₹1,925₹10,71,647
224,073₹1,00,381₹6,016₹1,925₹11,64,087
234,052₹1,05,400₹6,647₹1,925₹12,60,915
244,032₹1,10,670₹7,324₹1,925₹13,62,336
254,012₹1,16,203₹8,051₹1,925₹14,68,564

How the West Bengal Solar Calculator (WBSEDCL) 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 West Bengal home on WBSEDCL with a ₹2,000 monthly bill and a flat RCC roof, assuming prices rise 5% a year.

  1. 1Working the bill back through the WBSEDCL slabs, charges and duty gives about 246 units a month
  2. 2At 4.6 peak sun hours, 2.5 kW makes about 269 units a month, 100% 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 ₹23,630, and the saving grows as tariffs rise

The system pays for itself in about 3.3 years and leaves the household about ₹9,62,120 ahead over 25 years.

Frequently asked questions

Why do I enter a monthly bill when WBSEDCL bills every quarter?

To keep one monthly field for every state. WBSEDCL's quarterly bands are divided by three to give monthly equivalents, which gives the same result for a steady household. Divide your quarterly bill by three, or enter units from the bill directly.

Does Hasir Alo affect rooftop solar?

Not for most homes considering solar. Hasir Alo gives free power to lifeline consumers using up to 75 units a quarter. A household large enough to need a rooftop system is billed on the normal domestic tariff, which is what this calculator uses.

How does net metering settle on WBSEDCL?

Net metering under WBERC's regulations, with surplus units carried forward and settled at the end of the year.

Sources

Related calculators

More in Energy, Solar & EV