Most households try to save electricity by switching off lights. Lights are rarely the problem. A few heavy appliances, often an air conditioner, a geyser and an old refrigerator, drive most of the bill. Find those and you can cut the bill substantially without living in discomfort.
Step 1: learn the only formula you need
Units (kWh) = watts × hours ÷ 1000
A 1,500 W air conditioner running 8 hours uses 12 units a day, or 360 units a month. At ₹8 per unit, that is ₹2,880 a month before accounting for the compressor cycling on and off. A 10 W LED bulb running 8 hours uses 0.08 units a day. That is why lights are rarely the culprit.
Step 2: know the heavy hitters
Air conditioner: the biggest lever
- Set it at 24°C or above. The Bureau of Energy Efficiency notes that each degree higher can save around 6% of the AC's electricity.
- Use a ceiling fan along with the AC. Moving air feels cooler, so a higher setting remains comfortable.
- Clean filters every two weeks during heavy use. Clogged filters make the compressor work harder.
- Choose an inverter AC with a high star rating when replacing. It adjusts compressor speed instead of switching fully on and off.
- Shade the outdoor unit from direct afternoon sun, without blocking airflow.
Water heater
A 2 kW geyser left on for an hour uses 2 units. Switch it on only 15 to 20 minutes before use, set the thermostat around 50 to 55°C and insulate hot water pipes. A solar water heater removes most of this cost in sunny regions.
Refrigerator
- Keep 10 to 15 cm of space behind it for ventilation.
- Check the door seal: close the door on a sheet of paper. If it slides out easily, the gasket needs replacing.
- Let hot food cool before placing it inside.
- A fridge over 12 to 15 years old may use double the power of a new star-rated model.
Fans and lights
A regular ceiling fan uses about 70 to 75 W, while a BLDC fan uses about 28 to 35 W for similar airflow. With four fans running 12 hours a day, switching to BLDC saves roughly 60 units a month. Replace any remaining tube lights or CFLs with LEDs.
Standby power and small habits
Set-top boxes, chargers, microwaves and TVs on standby quietly draw power all day. Switching them off at the socket, or using a switched extension board, trims a few units every month. Run washing machines and dishwashers with full loads.
Watch your tariff slab
Most Indian utilities charge higher rates as consumption crosses certain slabs. Cutting just enough units to drop into a lower slab can reduce the bill more than you would expect. Check the slab table printed on your bill.
For the long-term fix, see whether rooftop solar makes sense for your home.
Frequently asked questions
Does the star rating really matter?
Yes. The BEE star label shows expected yearly energy use. For appliances that run many hours, such as ACs and fridges, the savings from a higher rating can repay the price difference within a few years.
Do voltage stabilisers waste power?
A stabiliser uses a small amount of power itself. Many modern ACs and fridges have a built-in wide voltage range and do not need one. Check the manual.