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I was amused to read that he bought LED bulbs for everything. I don't deny that they're efficient, but are they so efficient they're worth spending 3-5x the pr

by scott_w 14y ago

I was amused to read that he bought LED bulbs for everything. I don't deny that they're efficient, but are they so efficient they're worth spending 3-5x the price of a standard energy efficient bulb?

dagw 14y ago
He said that for him it was about winning the 'game' and getting a higher(lower) score, not about saving energy or money per se.
indiecore 14y ago
> but are they so efficient they're worth spending 3-5x the price of a standard energy efficient bulb Don't they last like a billion years longer than even compact florescent blubs?
mavhc 14y ago
I was just looking at this, seem to be 2-3x the price, and, in theory, last 6 times longer, so you win without the cost savings, which are about $1/(hour/day)/year/100W (incandescent equivalent, so 4 rooms with 100W lighting each on for 3 hours a day saves $12/year, compared to CFL, so worth replacing CFL with LED as the CFLs die.
- adwf 14y ago
  One thing I'm interested in seeing with my new LED bulbs is the potential failure modes. If an incandescent or CFL goes - it's done for. But a quick check of my LED bulbs shows 22 emitting diodes. When it fails, is it more likely that the controlling circuitry goes or that an individual diode goes and it carries on at slightly reduced output? I'm waiting to see, but they've already outlasted the average lightbulb in my house by a long way - so I don't know how long I'll have to wait to verify.
  - keenerd 14y ago
    It depends. LEDs use current-regulated power supplies. Lets say your bulb had two chains of eleven LEDs in parallel. When one LED burns out the whole chain is lost and the regulator would increase the voltage across the remaining chain until it was using enough current for two. Naturally this will greatly shorten the life of the remaining eleven LEDs. This is the worst case scenario and probably won't happen. Two ways around it. 1) Since current is (non-linearly) proportionate to voltage, the regulator need to increase the voltage to compensate. But all regulators have a maximum output voltage. If the regulator is cheap and running near its limits, it can't increase the voltage high enough to damage the remaining chain and the bulb will run a little hot but be fine. 2) LEDs get warm and should not operate above 85C. A good regulator has a thermistor connected to the LEDs and will automatically drop the current to safe levels. The bulb will once again run a little hot but will be mostly fine. If there are more than two wires connecting the regulator to the LED it might have over-temperature protection. Or if the regulator is physically connected to the heatsink. The regulators themselves are pretty reliable. I work mostly with low voltage DC lighting (12V-48V, 20W-100W) and there is nothing in the regulator that would wear out easily. Line AC might be a different story, those probably have large filtering capacitors. If the caps are electrolytic they might dry out eventually from the heat.

by scott_w 14y ago

I was amused to read that he bought LED bulbs for everything. I don't deny that they're efficient, but are they so efficient they're worth spending 3-5x the price of a standard energy efficient bulb?

dagw 14y ago

He said that for him it was about winning the 'game' and getting a higher(lower) score, not about saving energy or money per se.

indiecore 14y ago

> but are they so efficient they're worth spending 3-5x the price of a standard energy efficient bulb Don't they last like a billion years longer than even compact florescent blubs?

mavhc 14y ago

I was just looking at this, seem to be 2-3x the price, and, in theory, last 6 times longer, so you win without the cost savings, which are about $1/(hour/day)/year/100W (incandescent equivalent, so 4 rooms with 100W lighting each on for 3 hours a day saves $12/year, compared to CFL, so worth replacing CFL with LED as the CFLs die.

adwf 14y ago
One thing I'm interested in seeing with my new LED bulbs is the potential failure modes. If an incandescent or CFL goes - it's done for. But a quick check of my LED bulbs shows 22 emitting diodes. When it fails, is it more likely that the controlling circuitry goes or that an individual diode goes and it carries on at slightly reduced output? I'm waiting to see, but they've already outlasted the average lightbulb in my house by a long way - so I don't know how long I'll have to wait to verify.
- keenerd 14y ago
  It depends. LEDs use current-regulated power supplies. Lets say your bulb had two chains of eleven LEDs in parallel. When one LED burns out the whole chain is lost and the regulator would increase the voltage across the remaining chain until it was using enough current for two. Naturally this will greatly shorten the life of the remaining eleven LEDs. This is the worst case scenario and probably won't happen. Two ways around it. 1) Since current is (non-linearly) proportionate to voltage, the regulator need to increase the voltage to compensate. But all regulators have a maximum output voltage. If the regulator is cheap and running near its limits, it can't increase the voltage high enough to damage the remaining chain and the bulb will run a little hot but be fine. 2) LEDs get warm and should not operate above 85C. A good regulator has a thermistor connected to the LEDs and will automatically drop the current to safe levels. The bulb will once again run a little hot but will be mostly fine. If there are more than two wires connecting the regulator to the LED it might have over-temperature protection. Or if the regulator is physically connected to the heatsink. The regulators themselves are pretty reliable. I work mostly with low voltage DC lighting (12V-48V, 20W-100W) and there is nothing in the regulator that would wear out easily. Line AC might be a different story, those probably have large filtering capacitors. If the caps are electrolytic they might dry out eventually from the heat.