Every solar company in Kerala will tell you your bill disappears. It is the easiest thing to say and the hardest thing to take back later, so it gets said a great deal.
What actually happens is more specific, and knowing the specifics is what stops you being sold the wrong system.
First: your bill is not one thing
Open a KSEB bill and you will find several separate charges stacked into one total. They behave very differently once panels go up.
- Energy charge
- Solar removes this
- Fixed charge
- Stays
- Electricity duty · 10%
- Falls with the energy charge
- Meter rent · ₹6 / month
- Stays
- Fuel surcharge
- Falls with consumption
The energy charge is the part that responds to solar, and on most domestic bills it is the biggest part. The fixed charge is tied to your connected load, not your usage, so it is there whether you generate a single unit or a thousand. Electricity duty is calculated on the energy charge, so it shrinks along with it.
So the honest sentence is: your bill becomes the fixed charge, the meter rent, and whatever you draw at night before your daytime export covers it. On a well-sized system that is a small number. It is not zero, and anyone promising zero has either not read a bill or is hoping you have not.
Second: KSEB does not charge you a flat rate
This is where it gets genuinely useful, and where almost nobody explains properly.
Up to 250 units a month, KSEB bills you telescopically — each slab priced on its own. Your first 50 units are cheap. Your next 50 cost more. And so on.
- 0 – 50 units
- ₹3.35 / unit
- 51 – 100
- ₹4.25
- 101 – 150
- ₹5.35
- 151 – 200
- ₹7.20
- 201 – 250
- ₹8.50
Cross 250 units in a month and the whole thing changes shape. The bill stops being telescopic and a single flat rate is applied to every unit you used — including the first fifty, which you had been getting at ₹3.35.
- 251 – 300 / month
- ₹6.75 on all units
- 301 – 350
- ₹7.60 on all
- 351 – 400
- ₹7.95 on all
- 401 – 500
- ₹8.25 on all
- Above 500
- ₹9.20 on all
The step at 250 is not small
Work it through and the cliff is stark:
250 units a month → ₹1,432.50
251 units a month → ₹1,694.25
One extra unit costs ₹261.75 a month. On a two-month bill with duty added, roughly ₹575.
And it keeps going. We have a real 500-unit bi-monthly bill and a real 525-unit one in front of us. The first costs ₹2,865 in energy charge. The second costs ₹3,543.75. That is ₹679 for twenty-five extra units — an effective ₹27 a unit.
There is no protection clause. We checked before writing that down.
Why this matters when you are buying
If your household sits anywhere near 250 units a month, solar is worth more to you than a simple multiplication suggests. Removing thirty units does not just save thirty units' worth — it can drop you back into telescopic billing and re-price everything below it.
It also means a hot month can quietly cost you far more than you expect. Households that hover just under the line in December and just over it in April are paying two quite different prices for the same house.
Where our numbers come from
We tried to look these rates up online. Three different sites gave three different sets of numbers, which is why we stopped trusting them.
So we did it backwards. We took 44 real KSEB bills from homes around Sulthan Bathery — our own, our customers', a few borrowed — and worked out the rates that would reproduce exactly what KSEB had actually charged on each one. On every bill covering a normal two-month period, our calculation matches to the paisa. Bills covering an odd stretch, 26 days or 59 days, come out one to three percent different, because KSEB adjusts the slab widths for the number of days.
Tariffs get revised, so treat any published figure — including ours — as needing a check against your own bill. Your bill is the final word. If our number is far from yours, we would genuinely like to know.
What we would suggest doing
- Find the units on your bill — printed as Import. That number is worth more than the rupee total.
- Divide by two for the monthly average, and see how close you are to 250.
- Remember that usage goes up after solar, not down. Free daytime power changes how a house behaves within months.
- Size for the house you will have in five years, not the bill you are holding.
Or put the bill into our calculator, which does all of the above and shows its working.
NRG SOLUTIONS · SULTHAN BATHERY, WAYANAD