Complete guide to electricity rates and appliance running costs in Chennai. Tamil Nadu tariff: ₹6.8/unit.
Telescopic slabs — each rate applies only to the units within that band.
| Monthly consumption | Energy charge |
|---|---|
| 0–100 units | Free |
| 101–200 units | ₹4.70/unit |
| 201–300 units | ₹6.30/unit |
| 301–400 units | ₹8.40/unit |
| Above 400 units | ₹11.55/unit |
Fixed charge
₹0–₹60/month, by load
Electricity duty
Exempt (domestic)
Variable surcharge
FSA quarterly
First 100 units/month are free under the state subsidy.
What this means for your AC: a 1.5-ton 5-star inverter AC draws roughly 0.9 kW on average. Running it about 13 hours a day adds ~351 units a month. In Chennai, those extra units mostly fall in the ₹6.30/unit band, so the AC adds roughly ₹2,211 in energy charges per month — before any surcharge.
Source: TNERC Tariff Order No. 6 of 2025 (LT-IA Domestic), effective 1 Jul 2025. Energy charges only; the variable surcharge above is revised periodically. Confirm the current rate on your latest bill.
Three things decide your monthly AC bill in Chennai: the local tariff (you pay ₹6.8/unit on the slab shown above), the efficiency of the unit (a 5-star inverter draws far less than an older 3-star of the same size), and your usage — with tropical wet & dry conditions, households here run their AC around 13 hours a day through the peak months, and every extra hour adds directly to the bill.
The biggest lever most people miss is right-sizing: an undersized AC runs flat-out and never quite cools, while an oversized one short-cycles and wastes power. Match the tonnage to your room with the tonnage calculator, then pick the star rating that pays back for your hours using the BEE star rating guide. Set the thermostat near 24–26°C rather than the lowest setting, keep filters clean, and shade the outdoor unit — each meaningfully cuts consumption.
To see exactly what your own setup costs in Chennai, run your tonnage, star rating, and daily hours through the Chennai AC bill calculator — it applies the Tamil Nadu rate so the estimate reflects what you actually pay.
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