When you head to the shops to get new bulbs, you get confronted by energy savings claims for choosing particular bulbs over "traditional" incandescent ones. While it is true that fluorescent and LED bulbs are both several times more efficient than incandescent ones, chances are, you are unlikely to be using incandescent bulbs in your house.
Most people are already using fluorescent lamps, be it the tubular kind or the compact swirl type (Compact Fluorescent Lamp). These offer a big jump in energy efficiency when compared to incandescent lamps. The price too, is a big jump. In the recent years, LED, a newer option appeared in the market as the prices became within the reach of the average consumer. These are often touted as lifetime bulbs as their lifespan is so long that most products that use LEDs are not designed for bulb replacement.
While it is true that each type of lamp have different colours, advantages, lifespan and brightness, it is important to consider how much benefit they offer against the other types.
Colour
Incandescent: In terms of colour spectrum production, Incandescent offer the best colour rendition because it provides a smooth spectrum of colours, just like our sun. This is why they are often used for photography, mood lighting and shop displays.
Fluorescent and LEDs: These are often criticized for their "coldness" and "harshness" of the light quality. Colours of things do not look "right" under these lights because they produce discrete colours instead of a smooth spectrum. This is due to the way they produce light from the excitation and relaxation of electrons. There are Fluorescent and LEDs that offer better rendition, however, those will cost more.
Lifespan
Incandescent: The worst of the worst. The fragile filament is rated in the range of 1000hours. (~7 months of use)
Fluorescent: Fragile design, but still lasts 10,000 hours (~5.5years of use) depending on the model, which is awesome. They become dimmer as they approach their end-of-life. The lifespan is also dependent on how often they are switched on and off.
LEDs: Hardy design. No breakable parts. 20,000hours (~11 years of use)
Brightness/Efficiency/Price
For the same application and similar brightness level, the power needed for each bulb are -
Incandescent: ~70W / $3 (Halogen E27)
Fluorescent: ~20W (CFL $12.90)
LED: ~8W ($14.90)
Prices from IKEA.SG
Notable things
Numbers are not all that matters
Dimming capability: Incandescent bulbs are completely capable of dimming while Fluorescent and LEDs are not always dimmable and they tend to be more expensive if they are capable of dimming. Incandescent bulbs are extremely versatile for this aspect because of their simplicity. Producing light by heating something up is simple!
Components: Most incandescent bulbs can be plugged in directly to the mains without requiring any other circuitry. Fluorescent bulbs need a ballast and a starter, while household LED bulbs have a step-down and regulation circuitry. These can also fail in time to come.
Cost Benefit Analysis
While it is clear enough while incandescent bulbs are really cheap to buy, they cost a lot more to operate in the long run. Hence, I will not be comparing incandescent bulbs.
Do LEDs really better value for money in the long run? To answer this, lets do a life-cycle cost analysis!
Take 20,000hours of operation (If switched on for 5h per day, this works out to be ~11 years of usage)
Fluorescent:
2 bulbs needed = 2 x $12.90 = $25.80
Energy consumed = 20W x 20,000h x 25.95c/KWh (Singapore electricity tariff) = $103.80
Total cost after 20,000h = $129.60
LED:
1 bulb needed = $14.90
Energy consumed = 8W x 20,000h x 25.95c/KWh = $41.52
Total cost after 20,000h = $56.42
Savings over Fluorescent = $73 (a 64% savings)
Conclusion
Initially, I was skeptical that LED are any better than fluorescent in terms of cost effectiveness. After doing a simple life-cycle cost analysis, it turns out that using LED will cost less than half the cost of using fluorescent in the long run. Sure, there are many different manufacturers and the price differs wildly. High end bulbs costs a lot more than the bulbs used here for comparison and they offer a lot higher efficiency while producing high brightness. If they are optimally placed, they may be able to replace 2 less-efficient fluorescent bulbs, thus reducing the number of bulbs needed in a home.
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