Once your rooftop solar is commissioned, your KSEB bill looks different: there is an import reading, an export reading and often a generation reading, and the amount can drop to almost nothing. This guide explains how KSEB works out a solar bill, step by step, with real numbers from the current tariff. To try your own bill, use our KSEB solar calculator.
How net metering works in Kerala
When you get rooftop solar, KSEB replaces your meter with a two-way net meter. It records two numbers:
- Import: units you take from KSEB, mostly at night and on cloudy days
- Export: units your solar sends to KSEB when it makes more than your home is using
Units your home uses straight from the panels during the day never pass through the net meter, so they never appear on the bill. Most homes also get a separate generation meter showing everything the panels made.
Your bill is worked out on the net units: import minus export. If you exported more than you imported, the extra units are banked and carried forward to set off against later bills.
The KSEB domestic tariff, in brief
KSEB bills homes every two months, but the slabs work on monthly units, so half the two-month units go through the slabs and the result is doubled. The rates below are KSERC's LT-I domestic tariff for 1 April 2025 to 31 March 2027.
| Units a month | How it is charged | Rate per unit | Fixed charge a month (single phase) |
|---|---|---|---|
| 0–50 | Telescopic: each block at its own rate | ₹3.35 | ₹50 |
| 51–100 | ₹4.25 | ₹85 | |
| 101–150 | ₹5.35 | ₹105 | |
| 151–200 | ₹7.20 | ₹140 | |
| 201–250 | ₹8.50 | ₹160 | |
| Up to 300 | Non-telescopic: every unit at one rate | ₹6.75 | ₹220 |
| 301–350 | ₹7.60 | ₹240 | |
| 351–400 | ₹7.95 | ₹260 | |
| 401–500 | ₹8.25 | ₹285 | |
| Above 500 | ₹9.20 | ₹310 |
Electricity duty of 10% is added to the energy charge. Fuel surcharge and meter rent are small extras not shown here. The key point for solar is the jump at 250 units: above it, every unit is charged at the higher rate. Bringing your net units below 250 a month cuts the bill far more than the units alone suggest.
How KSEB calculates a solar bill, step by step
- Read the net meter: import units and export units for the two months.
- Net units = import − export. Add any banked units from earlier bills.
- Monthly units = net units ÷ 2.
- Energy charge: apply the slab rates above to the monthly units.
- Add 10% electricity duty on the energy charge, and the fixed charge for that slab.
- Double it for the two-month bill.
Worked example 1: a home using 400 units a month
A typical 3 kW system makes about 400 units a month in Kerala (133 units per kW).
| Without solar | With 3 kW solar | |
|---|---|---|
| Units a month on the bill | 400 | 0 (400 used − 400 made) |
| Energy charge | 400 × ₹7.95 = ₹3,180 | ₹0 |
| Electricity duty (10%) | ₹318 | ₹0 |
| Fixed charge | ₹260 | ₹50 |
| Monthly total | ₹3,758 | ₹50 |
| Two-monthly bill | ₹7,516 | ₹100 |
That is a saving of about ₹44,500 a year. With the ₹78,000 PM Surya Ghar subsidy, a 3 kW system costs ₹1,37,000, so it pays for itself in about three years. See solar panel cost in Kerala 2026.
Worked example 2: a home using 600 units a month
With the same 3 kW system, this home still takes 200 net units a month from KSEB. Because 200 units falls back into the telescopic slabs, the bill drops by much more than a third.
| Without solar | With 3 kW solar | |
|---|---|---|
| Units a month on the bill | 600 | 200 |
| Energy charge | 600 × ₹9.20 = ₹5,520 | 50 × ₹3.35 + 50 × ₹4.25 + 50 × ₹5.35 + 50 × ₹7.20 = ₹1,007.50 |
| Electricity duty (10%) | ₹552 | ₹100.75 |
| Fixed charge | ₹310 | ₹140 |
| Monthly total | ₹6,382 | ₹1,248 |
| Two-monthly bill | ₹12,764 | ₹2,496 |
A 4.5 kW system would cover this home fully. Our guide to sizing solar from your KSEB bill shows how to pick the size.
How to read the solar section of your KSEB bill
- Import (or consumption) reading: units taken from KSEB this period
- Export reading: units your system sent to KSEB
- Generation reading: everything your panels made, from the generation meter
- Net units: import minus export, the units you are billed for
- Banked units: extra exports carried forward to the next bill
The exact labels vary a little between bills. A quick check: generation minus export is what your home used directly from the panels. If your generation reading looks low for the season, ask your installer to check the system.
What happens to extra units
If you export more than you import, the surplus is banked and used against later bills, for example in the monsoon when the panels make less. Surplus still left at the end of the yearly settlement period is paid for at a rate set by KSERC, which is much lower than what you pay for units. KSERC has kept ₹3.26 a unit for surplus banked up to 31 March 2025. That is why it pays to size the system to your use rather than to oversize it.
Grid support charge and other charges
A normal home system on net metering does not pay a grid support charge on its bill. Under KSERC's 2025 renewable energy regulations, it can apply to some larger systems and to group or virtual net metering, so check the current rule if you are installing more than 10 kW. You still pay the fixed charge for your slab every month, even when your net units are zero.
Common questions
How do I calculate my KSEB bill after installing solar?
Subtract the export units from the import units, halve the two-month total, apply the domestic slab rates, add 10% duty and the fixed charge, then double it. Our solar calculator does this for you.
Why do I still get a bill with solar?
The fixed charge is billed every month. If your system makes less than you use, you also pay for the net units, but at lower slab rates.
Does KSEB pay me for the units I export?
Exports are first set off against your own use and banked. Only surplus left at the end of the settlement period is paid for, at a low rate set by KSERC.
Is the solar I use during the day shown on the bill?
No. Units your home uses directly from the panels never pass through the net meter. They appear only on the generation meter.
How many units does a 3 kW solar system make in Kerala?
About 400 units a month on average, more in the dry months and less in the monsoon.
Jasper Solar handles the KSEB net meter application and commissioning for you, and explains your first solar bill line by line. Tariffs are set by KSERC and can change, so we check the current rates when we quote.
Sources
- Kerala State Electricity Regulatory Commission, tariff orders and renewable energy regulations
- Kerala State Electricity Board, tariff and billing information
- Kerala State Electricity Board, eKiran solar rooftop portal
Er. Akhil S.TProject Engineer, Jasper Solar Solutions
Project engineer with 7 years in the solar field and more than 400 completed solar projects. Akhil designs and oversees rooftop installations for homes and businesses, from site survey to KSEB commissioning.
