Energy efficiency is often called alternate energy or an alternate source of energy. Why is that? Five years from now, if we are able to cool the same amount of food using 20 per cent less electricity, we could say that we gained 20 per cent more electricity or power capacity, because the 20 per cent savings could then be used by other people, equipment or appliances requiring electricity.

Globally, energy efficiency is a big component of energy conservation. It allows us to have the same quality of service (lighting, cooling, heating, entertainment, productivity, mobility etcetera) or comfort level for a smaller amount of energy as technology advances with time. However, in Pakistan, when people hear the phrase “energy conservation”, they think of turning off the lights when leaving the room, or not using their air conditioners. These measures are also very important to remember. However, the biggest challenge we have faced in the Karachi Energy Conservation Awareness campaign are people who say "Hum kahan bijli zaya karte hai" or "We don't waste electricity". Pakistani consumers don't realise the criminal wastage of energy from using old or inefficient equipment in a bid to ’save’ money.

How much gains have new appliances really made? The biggest example is fridges. Our parents, aunts and uncles still use fridges that are 20 years old. However, an energy efficient fridge manufactured in 2013 uses 75 per cent less electricity than the one manufactured 15 years ago.

For a standard household-size, 14 cubic feet combi fridge-freezer means a difference of 1000 kWh per year, or nearly 15,000 rupees per year in electricity bills. By upgrading to a new energy-efficient fridge, you could get your money back in 2-3 years. And the rest of the savings will go in your pocket.

While it makes sense to upgrade your fridge if it is older than 10 years, remember that not all new fridges are created equal. In fact, the electricity consumed in a year by various fridges available in the market in Pakistan differs by 1500kWh! That means a difference of 22,000 rupees on your electricity bill if you were unfortunate enough to buy the wrong fridge, since it will push you into Tier 4 of electricity billing (shown later in the article).

Regrettably, we do not have access to the most energy-efficient appliances in Pakistan. Even if the world’s most energy efficient brands like Bosch, Siemens, Electrolux and Daikin are available, they are overpriced, taking into account the energy savings. However, as consumers, we have to make the best possible decision with the choices we have.

For those of you who already use a separate chest freezer, you may wish to buy another freezer and convert it into a new chest refrigerator. Here are the links for buying a conversion kit, as well as instructions if you wish to make your own kit: For 220V: - For 110V

Instead of using 1-3 kWh per day, your new chest refrigerator would use only 0.1-0.2kWh per day; just 25 per cent of the electricity that the most efficient Siemens/Bosch upright refrigerator uses. You will barely pay 700 rupees per year in electricity costs.

Considering the current energy crisis, we cannot afford to make wrong decisions in our appliance purchases. We have to stop thinking of the purchase price of an appliance and start thinking of the lifecycle costs of running that appliance. Otherwise we are just putting our hard-earned money into the electricity company’s pockets. What are the lifecycle costs of an appliance?

The lifecycle cost of an appliance is simply the sum of its purchase price and the cost of electricity or fuel to run it, as well as its maintenance costs throughout its life. Table 2 showed lifecycle costs in the last row, assuming that maintenance costs are equal for all appliances. The principle of lifecycle costs is applicable to every energy-consuming appliance or device we use. We have to start using fuel and electricity wisely by making smart purchasing decisions.

What are the pieces of information we need to make these decisions? We need to know how much electricity an appliance uses. And we need to know how much we pay per unit of electricity. For the first answer, there are two very simple formulae that we learned in grade 7 and 8. They are:

The power an appliance uses is measured in Watts or kiloWatts (1000 Watts). So if you see ‘W’ or ‘kW’ on your appliance's back or its packaging, that shows you the amount of power it uses. For instance, an 18W energy saver bulb uses 18 Watts of power in an instant. If you run that bulb for five hours, the amount of electricity it uses is:

kWh is the unit of electricity most companies use globally to bill their customers.

If your appliance does not show how much power it uses, it should at least mention the amount of current it draws in Amperes (Amps or A). In that case, you can easily determine the power it uses:

In Pakistan, the voltage provided is officially 230V (240V for KESC), however, in reality it can fluctuate between 200 and 240V, based on the connection. But assuming the official value of 230V, we can easily calculate how much power our 1-ton AC would use, if it draws 5.5 amperes of current.

Interestingly, we see our AC uses 140 times the electricity that our energy saver light-bulb uses! Of course, an AC cycles on and off, and may use less electricity in 10 hours than shown here, but the above formulae are at least useful to compare different brands of appliances. Also, when the temperature outside is 35°C or higher, your AC will run continuously, without cycling on and off. As a smart consumer, these formulae are your best friends.

Washing Machines

Front-load washing machines use 30-50 per cent less electricity than top-load washing machines of the same brand. Again, all brands are not equal, so look for how much electricity each machine uses. Till the time your washing machine breaks down and you decide to upgrade, you can save money on your electricity and gas bills by running your washing machine on cold wash. Or as a friend suggested, run your washing machine from 12-4pm, when the water in the pipes is naturally hot.

Air conditioners

There is exactly one right size for an AC for every room. Pakistani salesmen often try to sell us over-sized ACs, saying they will cool the room faster. These oversized ACs will just use more electricity and won’t provide more comfort. Calculators for the right size of AC are given in The Sites section.

Typical houses, offices and other buildings in Pakistan are not insulated. For these buildings, a general rule of thumb is that 20 BTU of cooling is required per ft2, assuming the room ceiling height is 8 ft. For well-insulated buildings, only 12 BTU/ft2 is needed. If the room is regularly used by more than two people at a time, then add 600 BTU per additional person. For reference, a 1 ton AC provides 12000 BTU or 3500 W of cooling.

So, a 300 ft2 room will need just 6000 BTU of cooling, or a 0.5 ton AC. I recommend you to look at the links given above, since they take into account other factors, like hours of sunlight, insulation levels etcetera. In addition, once again, all air conditioners are not created equal. After you have decided what size AC you need for your room, you need to decide what brand AC to buy. A good way to make a decision between brands is to look at the EER* (Energy Efficiency Rating) of the AC:

Since we know that a 1 ton AC provides 3500 W of cooling capacity, we see that the EER of a Haier AC is 2.8, whereas that for Panasonic is 4, in the examples shown the table below.

Considering that the salesman tried to sell me a Haier 1.5 ton AC, I’m glad I did my homework before I entered his shop. Otherwise, I would have been paying 33,000 rupees more on my electricity bill per AC every year. The above example assumes a 10 hour/day average usage in an office or house setting, for the hottest seven months of the year.

Lighting

Stop thinking of how many Watts of lighting you need! Start thinking of how many Lumens of light you need, since that is the actual unit for light. For standard lighting (living rooms, bed rooms, corridors etc), 15 lumens/ ft2 is enough. For task lighting (factories, workshops, etc) you may need up to 50 lumens/ ft2. Office and academic spaces fall somewhere in the middle.

Once you know how many lumens you need, find the type of lighting method that provides you that amount using the least amount of electricity. The number to look out for is the Efficacy of the bulb, that is, the amount of lumens it provides per Watt of electricity. This number can be found on the packaging.

The table below shows the example of a small company housed inside a 1000 sq. yd double-storied house.

As you can see there is really no need to pay five times more for incandescent bulbs in your office or household. In fact, for offices and factories, LFLs (new T5 and T8 tube lights) are the preferred method of lighting, while for your house, use LFLs or CFLs (energy saver bulbs).

The best part about CFLs, LFL and LEDs is that they not only save electricity in lighting, but they also save money on air conditioning. An old incandescent 100W bulb would have raised the temperature of a 4x4x4m3 room by five degrees every hour, heat that your AC would have needed to remove. The corresponding CFL bulb uses just 18W and raises the temperature of the same room by less than one degree an hour.

Desktops vs laptops

Laptops, on average, use about 50W, whereas energy-efficient desktops use 100W plus 50W for the monitor. So, laptops should be the preferred method of computing in your households and offices. The difference adds up to 8000 rupees per year in electricity bills per computer.

However, if you have heavy computing needs to run engineering software, for instance, and do need a desktop or workstation, then keep a lookout for your Power Supply Unit (PSU). An inefficient PSU could draw up to 500W to power a basic desktop, instead of the 100-150W you should expect. So make sure to use only an 80+ certified PSU, which offers efficiencies of 80-95 per cent. Otherwise, you could be paying 16,000 rupees more per computer every year for your electricity.