Save electricity in India: measure cooling use and calculate slab savings

Identify the billing period and tariff category

One electricity unit is one kWh. Find the start and end readings, billing days, domestic tariff category and applicable slab schedule on your bill. Tariffs vary by state and distribution company; a Delhi consumer information page does not establish the price in another state. Check the current order for your own connection.

Separate energy charges from fixed charges, duties, adjustments and subsidies. The example below is a fictional progressive tariff with a 30-day billing period. It is not a tariff offered by any DISCOM, and it does not model subsidy eligibility or minimum charges.

Worked example: reducing 250 units to 220

Assume the first 100 units cost ₹4 each, the next 100 cost ₹6 each, and units above 200 cost ₹8 each. At 250 units, the energy charge is 100 × 4 + 100 × 6 + 50 × 8 = ₹1,400. At 220 units it is ₹1,160. Saving 30 units therefore saves ₹240 in this example.

The original average energy price is ₹1,400 ÷ 250 = ₹5.60 per unit. Multiplying the reduction by that average would give ₹168, which understates the saving because all 30 avoided units were in the ₹8 slab. A reduction crossing a slab boundary must be split between the affected bands.

Connect an appliance measurement to the bill

Suppose two comparable cooling schedules use a measured 5 kWh and 4 kWh per day. The difference over 30 days is 30 kWh. Record room conditions, occupancy and operating hours; a nameplate power rating alone does not establish an inverter air conditioner's daily energy use. Use an appropriate installed meter or manufacturer data where a plug-in meter is unsuitable.

The calculator's single price field cannot reproduce an entire slab bill. For this specific 250-to-220-unit example, ₹8/kWh values the avoided energy. Recalculate the complete bill separately if the change crosses a band or affects a subsidy.

Use appliance labels for a fair replacement comparison

Compare capacity, the numeric energy figure, label period and test basis as well as the BEE star rating. Do not treat a label's annual test consumption as your measured annual use. Check the label and documentation for the exact model.

If an upgrade costs an additional ₹6,000 and saves ₹240 in each of four comparable cooling months, the assumed annual saving is ₹960 and simple payback is 6.25 years. This excludes maintenance, financing and changing tariffs. Do not multiply one hot month's saving by twelve unless that usage actually repeats.

Data sources

Last reviewed: 2026-09-19