The science of bulbs.

I've had to get myself a desktop magnifying glass on an arm. It came with an Osram E14 SES candle bulb. Being the energy conscious person that I am apparently turning in to, I decided to look in to energy saving alternatives.

I ended up spending £17.99 on an LED replacement, as I didn't need the ability to dim the light.

The maths were straightforward. The lifespan of the standard incandescent came in at 1,000 hours while the LED is rated for 50,000. That means the incandescent would need to cost 30p each in order to match the LED for lifespan.

The incandescent pumps out 640 LA for its 60W whereas the LED pumps out 564 for its 4W consumption. No contest. The extra money for the LED is well worth it, especially as the temperatures for both are advertised at 2,700 kelvin.

I did try some other low energy light bulbs, but I couldn't get a straightforward answer for them. At £3.49 the best I could find was five times as cheap as the LED, but using 11W, it was eating nearly three times the power.

The balance of the more common power saving bulb would then be facing off against the LED on terms of life span and light output. Output of 550 was fractionally lower than the LED, but the lifespan figure wasn't an honest one; it claimed a 10 year life span, but you'd have to use the LED bulb for more then 13 and a half hours, every day, 365 days in the year, for ten years in order to run the 50,000 hours to the extent that it would last the same time as the conventional energy saver.

Conclusion is that the incandescent can't hold a, "candle bulb," to the LED, but although the more conventional energy saving bulb gives the LED a good run for its money, I think that with my usage, the LED still knocks the tradntional energy saver in to a cocked hat.

I'l update you with how well it works, when it reaches me.

Yes, there was a 60W LED candle bulb available for another pound or two extra, but I thought that 564 lumens was more than enough for my needs.

The combattents...
Traditional low energy Bulb
LED bulb
Conventional incandescent
- the figures for the incandescent were taken off the packet. The others were taken off the technical specification listings.