Saving energy calls for investment in time and money. How can you justify it?
Saving energy has to make “money sense”. For industries like telecom, with huge power bills, every bit matters. But at your home, it isn’t just the cost of power. It’s availability. With hours of power cuts, you need backup— inverters, generators. And you can save on those with low-power devices.
How much can you save?
With old light bulbs at home, your inverter would probably run down in an hour. Some people may advise you to add a battery (Rs7,500). Instead, change to CFLs for a fifth of that. And your inverter? A single battery now does 4 hours of backup. Try out LED lamps.
Are low-power appliances expensive?
You can expect a 10% premium. It’s worth it, especially for devices that are often or always on (fridges, tubelights). You should look out for Energy Star and other (e.g. BEE star) ratings.
But what if you already have many appliances?
We all do, and they waste power on standby, when not in use: AC stabilizers, TVs, microwaves. Install a large, easily accessible switch that will power them off—and use it. Simple.
People tend to keep high-power outdoor lights on through the night. How does one save then?
Keep CFLs on. You can connect high-power halogens through a motion sensor with a “daylight switch” (e.g. Honeywell, Philips, Secom: Rs3,000-5,000. See tinyurl.com/sens7) so they come on only at night—and only if motion is detected.
What else can you use motion sensors for?
Any device that should be on only when there are people around. Some Japanese TVs now shut off if they see no motion in the room for 20 minutes. Office or living-room ACs can be controlled through such sensors (not bedroom ACs, else they’ll go off when you fall asleep!). See tinyurl.com/hvac8. Security video cameras also use motion sensors.
Excessive heat in top-floor flats is a problem. What is the remedy?
Cut the sunlight—cool your rooftop by 20 degrees. I covered mine with cement sheets, for Rs1lakh (900 sq. ft). The top floor temperature dropped 10 degrees, and we stopped using air conditioners. And if you don’t want to block your rooftop, you can paint it with high-albedo reflective paint.
On a Hyderabad building with a 7,500 sq. ft rooftop, such a coating brought the surface down from 52 to 32 degrees Celsius, and cut cooling needs by 8%, saving Rs50,000 a year in power (Go to tinyurl.com/hydroof).
Do solar and wind power make sense?
They’re getting there, with subsidies and scale. Just search on Amazon for “solar” and you’ll see panels from $20-1,000. Solar’s good for water heaters, stand-alone lights such as traffic lights or garden lights. Ditto for wind power.
Prasanto K. Roy is chief editor at CyberMedia, a New Delhi-based publishing house.