How to Read Your Electricity Bill

Electricity bills in India vary in layout between states and distribution companies, but they are assembled from the same handful of components. Once you can identify those, the bill stops being a single intimidating total and becomes a short list of things — some of which you control, and some of which you do not.

A unit is a kilowatt-hour

The unit on your bill is a kilowatt-hour: one kilowatt of draw sustained for one hour. A 1000 watt geyser running for an hour consumes one unit. A 10 watt LED bulb running for a hundred hours consumes the same unit.

Your meter records the running total. The bill charges you for the difference between this reading and the last, which is why an estimated or delayed reading can produce a month that looks alarming followed by one that looks impossibly cheap.

Fixed charges and energy charges

Almost every bill splits into two parts. The energy charge is what you pay for units consumed. The fixed charge is levied for being connected at all, and is typically calculated against your sanctioned load rather than your usage.

This distinction matters more than it appears. Consuming less reduces the energy charge and leaves the fixed charge untouched. It is the reason a very low consumption month still produces a bill, and the reason solar can never take a bill to zero.

How slab tariffs work

Domestic tariffs are usually banded, with the rate per unit rising as monthly consumption rises. The critical detail is whether your state applies those bands telescopically or not.

• Under a telescopic structure, each band is charged at its own rate — the first block at the lowest rate, the next block at the next rate, and so on
• Under a non-telescopic structure, crossing a threshold reprices your entire consumption at the higher rate, so a single extra unit can raise the cost of every unit that month

Where the structure is non-telescopic, sitting just below a threshold is worth real money, and drifting just above it is expensive out of all proportion to the extra usage. Your bill or your distribution company's published tariff schedule will tell you which applies. Rates and thresholds are revised periodically and differ by state, so it is worth reading your own rather than relying on a figure quoted anywhere else.

Sanctioned load

Sanctioned load is the maximum draw your connection is approved for, and it usually drives the fixed charge. Adding heavy appliances — air conditioners, a large geyser, an EV charger — can push your actual peak draw beyond it.

Exceeding it can attract penalties, and in some tariffs it triggers a reclassification. It is also a constraint on how large a rooftop solar system you are permitted to install, which catches people out at the sanctioning stage.

Time-of-day tariffs

Time-of-day pricing charges different rates by hour, typically higher during evening peak demand and lower off-peak. Where it applies, when you consume starts to matter as much as how much.

Under such a tariff, shifting a geyser, a washing machine or EV charging out of the peak window reduces cost without reducing consumption at all. Whether this is available to you depends on your state and connection type.

The extra lines on a solar bill

If you have a net-metered rooftop system, the bill carries separate import and export figures. Import is what you drew from the grid; export is what you sent back. The energy charge is levied on the net, and surplus export typically carries forward as a credit rather than being paid out in cash.

A net figure conceals a great deal. Importing 400 units and exporting 100 nets to 300, and so does importing 700 and exporting 400 — the same net figure, from very different systems and very different habits.

Reconciling the bill with reality

The bill tells you what you consumed after the fact. It cannot tell you what consumed it. Two households with identical totals can have completely different causes, and no amount of staring at the bill will separate them.