Most articles about saving electricity in India are written for one state. Ours were too — we are based in Coimbatore, so the worked examples used TNEB's bimonthly slabs. Customers in Bengaluru, Kochi, Hyderabad and Pune kept asking a fair question: does any of this apply to me?
It does. The structure is nearly universal; the numbers are not. This post is about the difference, and about how to get the numbers right for your own connection without relying on anything a web page tells you.
The one thing every state has in common
Domestic electricity in India is almost never a flat rate per unit. Your board defines slabs — bands of consumption — and each band is charged at a higher rate than the one below it. Cross a boundary and the units above it cost more, sometimes a lot more.
This produces the effect that surprises people: usage rises 10% and the bill rises 30%. The extra units were not charged at your usual rate; they were charged at the next band's rate. We covered the arithmetic of that cliff, with a worked example, in slab-aware bill prediction.
Everything after this point is what varies.
What changes from state to state
1. Where the boundaries sit
Each state's regulator sets its own bands. A boundary that matters enormously in one state may not exist in another. There is no shortcut here — the boundaries are on your bill or in your regulator's current tariff order.
2. How long the billing cycle is
This one catches people out more than the rates do.
- Bimonthly (60-day) billing — Tamil Nadu is the well-known case. Your slab position is measured over two months, so a mild month followed by a hot one can push you over a boundary even though neither month felt unusual.
- Monthly (30-day) billing — used by several other boards. The window is shorter, which means the cliff arrives sooner but also resets sooner.
A prediction built for the wrong cycle length is not slightly wrong, it is useless: the same daily usage puts you in completely different places on a 30-day and a 60-day scale. Check the "Bill Period" or "Service Period" line on your bill before anything else.
3. Free units, subsidies and how they interact
Some states allot a number of free units, sometimes only below a consumption threshold. The interaction matters: whether the free units come off the top before slab rates apply, or whether crossing a threshold removes the allotment entirely, changes the shape of the cliff near that threshold.
4. Fixed charges and everything that is not per-unit
Fixed charges, meter rent, electricity duty and fuel surcharges do not respond to behaviour the way per-unit consumption does. They matter for the total, not for the decision of whether to run the geyser this afternoon. Read them once so you know what portion of the bill you cannot influence.
How to read your own bill in five minutes
Pull out the most recent bill and find these five things. Write them down; they are all you need.
- The bill period — the start and end dates, and therefore whether you are on a 30-day or 60-day cycle.
- Total units consumed in that period.
- The slab breakdown — most bills print each band with its unit count and rate. This is the important one.
- Any free-unit or subsidy line, and the threshold it applies at.
- The fixed charges — everything not multiplied by units.
That is your tariff. It is authoritative in a way no article can be, because tariff orders are revised and articles are not. This is exactly why we do not publish any state's current rates: a stale number in a blog post is worse than no number, since it looks like information.
Turning that into a warning before the cliff
Knowing your tariff tells you what a unit costs. It does not tell you where you are in the cycle, which is the part that actually saves money. For that you need two more things:
Per-appliance measurement, not a house total. A bulk meter reading of "you have used 320 units" cannot tell you that the bedroom AC accounts for 44% of it and has doubled since last week. Per-circuit metering can, which is why the metering switches and the smart breaker with per-circuit kWh exist — the measurement is what makes the forecast specific enough to act on.
A forward projection against your own boundaries. Daily trend, seasonality and recent ramp, extrapolated to the end of your cycle, compared against your slab boundaries. The output that matters is not "you have used 320 units" but "at this pace you cross on day 51, and here are the three appliances driving it."
In the Nexomatic app, the tariff itself lives in Settings → Tariff Config: slab boundaries and rates, monthly or bimonthly cycle, free-unit allowance and threshold. Tamil Nadu is the default preset because that is where most of our installations are — it is a starting point, not a limitation. Enter your state's numbers and the prediction, the slab-boundary alerts and the savings recommendations all work off them.
This is not only a household problem
The same arithmetic runs at every scale, and the larger the load the more it is worth:
- Cold storage — refrigeration is most of the site's consumption, and compressors can be shifted out of peak windows within safe temperature limits. Shedding load at the right hour, inside limits you set, is the difference between a manageable bill and a punitive one.
- Industrial facilities — motors, pumps and process loads scheduled around tariff windows, measured per machine so the saving is attributable rather than assumed.
- Farms — pump run-times aligned to the supply hours you actually get, with dry-run protection so shifting the schedule does not cost you a motor.
- Homes — the geyser, the AC and the standby drain, which between them account for most avoidable household spend.
The short version
The slab structure is the same across India; the boundaries, the cycle length and the free-unit rules are not. Take those four numbers off your own bill, put them into whatever tool you use, and the cliff becomes something you see coming instead of something you discover when the bill arrives.
If you would like us to walk through your last six bills and show what a slab-aware system would have flagged, book a free site visit or call us on +91 75500 58208.