LED Brightness

What makes some LEDs brighter - and more durable - than the others?

The Maglite Solitaire has a tiny LED that uses a 1.5V AAA cell to produce 47 lumens. On the other hand, the standard bulb distributed by electric utility companies like UPs PVVNL uses 7W from the grid to produce 700 lumens of light.

In terms of lumens per watt (lm/W), the stardard measure of lighting efficiency, the Maglite stands at 33.5 lm/W and the UP bulb at 100 lm/W. Both are small change compared to recent innovations from companies like Philips which have produced lighting units that can produce more than 200 lm/W!

However, as anybody who has used a Chinese LED bulb/panel would attest, it takes a lot more than just lighting efficiency to measure durability and useful life of an LED bulb.

Considering the fact that the super efficient LEDs from companies like Nichia-Japan and Philips are beyond the reach of regular users, is there any global standard that sets the benchmark for LEDs that strike the best balance between lighting efficacy and affordability?


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LINKS

- Top 10 LED manufacturers - http://www.ledsmagazine.com/articles/2011/02/strategies-unlimited-unveils-top-ten-list-of-led-manufacturers.html
- Maglite - http://maglite.com/shop/maglite-solitaire-led-1-cell-aaa-flashlight.html#.WCoFWNV97IU
- Philips - now more than 200 lm/w - http://www.philips.com/consumerfiles/newscenter/main/design/resources/pdf/Inside-Innovation-Backgrounder-Lumens-per-Watt.pdf
- Super high luminous efficacy - http://phys.org/news/2010-08-white-super-high-luminous-efficacy.html
- Energy storage in batteries - http://www.allaboutbatteries.com/Energy-tables.html