Solar Electricity Bill Calculator

See what your electricity bill looks like after solar. Enter your current bill and a system size and this solar bill calculator works out your new monthly bill, with net meter export credit and savings included.

As a rule of thumb, every ₹1,000 of monthly bill needs about 1 kW of solar. With a correctly sized system, a ₹3,000 bill usually drops by 80 to 95% to the fixed charge plus a few units. Monsoon months bill a little more, while summer surplus is banked as net-metering credit.

See Your Bill After Solar

State

City

Current monthly electricity bill

₹

Solar system size (kW) Tip: the system size calculator suggests the right kW for your bill.

Your Bill Estimate

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estimated monthly bill after solar

Current bill–

Monthly consumption–

Solar generation–

Units still billed by DISCOM–

Export credit (net metering)–

Monthly saving–

Planning estimate: real bills add fixed charges, duties and fuel surcharges set by your DISCOM. For the actual system size and price, contact a local solar contractor.

Built and maintained by Solar Calculators Pro · The tariffs and net-metering rules we model

How Net Metering Changes Your Electricity Bill

With net metering, your DISCOM bills you only on net consumption: the units you draw from the grid minus the units your solar system exports. During the day your panels feed the home first, surplus flows to the grid, and at night you draw back. A system sized close to your consumption can bring the energy portion of your bill to nearly zero, leaving mostly fixed charges.

Export compensation varies by DISCOM. Some credit exported units one-for-one against imports, others pay a lower feed-in rate for the surplus. This calculator uses a conservative ₹3.00 per exported unit so your estimate stays on the safe side.

Example: 3kW Solar System on a ₹3,000 Monthly Bill

A home paying ₹3,000 a month at ₹8.5 per unit consumes roughly 350 units. A 3 kW system in a city with 4.8 peak sun hours generates about 345 units a month, offsetting almost all consumption. The new bill is typically ₹200 to ₹500, mostly fixed charges, which is a saving of around ₹2,500 to ₹2,800 every month. Check your exact savings and payback with the solar savings and payback calculator.

Know Your Billing Structure Before You Estimate

Your post-solar bill depends on how your DISCOM bills, not just on how much you generate:

Slab tariffs cut both ways. Solar removes your most expensive units first: the ones in the top slab. A home billed across three slabs saves more per unit than its average tariff suggests.
Fixed charges stay. ₹50 to ₹200 a month of fixed and meter charges survive even a zero-consumption month; no rooftop system removes them.
Net metering vs gross rules vary. Most states net imports against exports monthly and settle surplus annually at a lower rate; a few use different windows. Your sanctioned net-metering capacity also caps how much export is even counted.

Using It With Your DISCOM Bill: TNEB, KSEB, MSEDCL, UPPCL and Others

Two-month bills: Tamil Nadu (TNPDCL, formerly TANGEDCO) and Kerala (KSEB) bill homes every two months. Divide the bill by two before entering it here, and double the result to compare with your next bill.
Exact slab tariffs: this tool uses a planning tariff for your city. For your DISCOM's exact domestic tariff, use the TNEB, KSEB, MSEDCL or UPPCL bill calculator. To convert a bill into units elsewhere, the main solar calculator applies 29 state and DISCOM domestic slab tables, including WBSEDCL and Telangana.
Units are best: if your bill shows the units (kWh) consumed, size your system from those with the solar system size calculator; it skips tariff assumptions entirely.

Hyderabad: a ₹3,500 Bill With 4kW of Solar

A Hyderabad household paying ₹3,500 consumes about 467 units at the ₹7.5 planning tariff. A 4 kW system in the city's 5.0 sun hours generates roughly 480 units a month, covering the full consumption with a small surplus worth about ₹40 in export credit. The energy portion of the bill drops to effectively zero, leaving only fixed charges of ₹100 to ₹200 on the actual DISCOM bill. Monthly saving: about ₹2,900 to ₹3,400, tracked against the estimate in the savings calculator.

Reading Your First Post-Solar Bill

The first bill after net metering confuses almost everyone. Check these lines:

Import and export readings: the bidirectional meter reports both; billing applies to the net figure.
Banked or carried-forward units: surplus that rolls to next month appears as a credit balance, not a payment.
Settlement month: once a year (often financial year end) accumulated surplus is paid out or lapses at the DISCOM's notified rate. Note which month yours is.
Fixed and regulatory charges: unchanged by solar; if the energy charge is near zero, the bill you still receive is these.

If the first two bills look wrong (for example export units missing), raise it immediately; meter configuration errors at commissioning are common and fixable.

Why Post-Solar Bills Surprise People

Expecting a literal ₹0 bill. Fixed charges and monsoon imports keep a small bill alive in most months.
Oversizing for export income. At ₹3 or so per surplus unit, exporting is a poor investment; size near your consumption instead with the system size calculator.
Ignoring sanctioned load limits. DISCOMs generally cap net-metering capacity around your sanctioned load; a 5 kW system on a 3 kW sanction needs a load extension first.
Judging by a monsoon bill. July and August import more grid power by design; the annual picture is what the system was sized for.

How the New Bill Is Estimated

Monthly units = Current bill ÷ City tariff (slab-aware where verified)
Residual units = max(0, Monthly units − Solar generation)
New bill = Residual units × Tariff − Exported units × ₹3.00

Tariff and export settings

Tariffs: city planning tariffs; verified DISCOM slab rules used where available
Export rate: conservative ₹3.00/unit planning proxy; actual net metering policy varies
Fixed charges: a small monthly fixed charge usually remains even at zero net units
Generation: city peak sun hours × 0.8 performance ratio, annualised monthly average

Electricity Bill and Net Metering Questions

Will my electricity bill be zero after installing solar?+

Close to zero on energy charges if the system is sized to your consumption, but a fixed charge of roughly ₹50 to ₹200 usually remains, and monsoon months may leave a few billed units. Most homes see 80 to 95% of the bill disappear.

How does net metering credit work on my bill?+

The DISCOM meters both import and export. Your bill is calculated on net units, and surplus exports either roll over as credit or are paid out at a feed-in rate at settlement, depending on your state policy. This tool assumes a conservative ₹3 per exported unit.

What happens to my bill during monsoon months?+

Generation drops 30 to 40% in monsoon, so more of your consumption is billed by the DISCOM in those months. Summer months over-generate and offset this. Judge your system on the annual total, not a single month.

What size solar system do I need to eliminate my bill?+

As a rule of thumb, every ₹1,000 of monthly bill needs roughly 1 kW of solar in a typical Indian city. A ₹3,000 bill needs about 3 kW. Get a proper answer from the solar system size calculator, which uses your city sun data and tariff.

Does this calculator work for commercial connections?+

It is tuned for residential slab tariffs. Commercial tariffs are higher and flatter, so real commercial savings per unit are usually better than this estimate shows, but demand charges and DISCOM policy need a site-specific review.

Why is my actual DISCOM bill different from the estimate?+

Bills include fixed charges, duties, fuel surcharges and slab jumps that vary by DISCOM, and your exact tariff may differ from the planning tariff used here. Treat this as a close planning estimate rather than a billing statement.

What happens to extra units at the end of the year?+

At the annual settlement, accumulated surplus is either paid out at the DISCOM's notified rate (often ₹2 to ₹4 per unit) or lapses, depending on state policy. This is why sizing close to consumption beats deliberately over-generating.

Does net metering credit carry over month to month?+

In most states, yes: surplus units bank forward and offset later months, with a final annual settlement. A strong summer surplus commonly carries you through the weaker monsoon months on paper.

How do I estimate my KSEB or TNEB bill after solar?+

Kerala (KSEB) and Tamil Nadu (TNPDCL, still called TNEB) bill domestic consumers every two months. Divide your two-month bill by two, enter it with your city, then double the result to compare with your next bill. For the exact two-month slabs, free units and fixed charges, use the TNEB bill calculator or the KSEB bill calculator, which also show the bill after solar.

How do I read my net meter reading?+

A net (bidirectional) meter records import, the units you take from the grid, and export, the units your panels send to the grid, separately. Your bill is based on net units, import minus export, plus fixed charges. If export is higher, the surplus is carried forward as credit under most state rules.