Tried and tested

A recent study in the US looked at a comparison of CFLs and LEDs. The claim has been that LEDs are more efficient than CFLs. LEDs also cost more than CFLs but they last longer, so you’ll make up the initial cost over the lifetime of the bulb. Are these facts really true?

What the survey found was that lab conditions differed from 'real world' conditions. In a lab, which can be controlled for the best possible conditions, light can be generated at optimal efficiency. Because manufacturers are able to utilize components that are made to work together, they can claim to produce results with greater efficiency.

For instance, a leading LED-chip manufacturer announced they had achieved an efficiency of 231 lumens per watt in an LED chip. However, this was conducted in a lab where technicians were able to use lighting fixtures capable of producing such high output. In the “real world,” this LED-chip manufacturer does not sell a LED lighting fixture with a claimed efficiency over 75 lumens per watt.

Therefore, among other factors, consumers would not be able to produce as high efficiency in their own homes.

For the study, they used two roughly equivalent CFL and LED lamps that would commonly be used in the home. When comparing the two on paper, the efficiency of the bulbs is nearly identical, within 0.5 lumens per watt. However, with the “real world” being taken into consideration, there are certain environmental and consumer factors that make a case for both.

One factor is cost. If your primary concern is price, the CFL would be a better choice. Although the CFL has a shorter lifespan, even if you replaced the CFL three times to achieve an equivalent lifespan to the LED, you’d still have spent lesser than on the LED.

The bottom line is that in a household setting, where optimal components and ideal conditions cannot be controlled, the LED and CFL light bulb are very close competitors. The decision for one over the other should be made based on the need.

But in terms of quality of lumens delivered, ask any electrical engineer and he will tell you that the good old T5 FTL (or tubelight) is the best! While a CFL gives 50-65lumen/watt, the T5 or T8 gives up to 95 lumen/watt. Lamp life too is lesser for CFLs.

Then why are organizations connected to energy efficiency promoting CFLs? Any idea?