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0 pointsamluto3y ago0 comments

> The same light quality is vastly more expensive to achieve with LEDs, even if you account for high electricity prices.

In a screw base, maybe. But compare:

https://www.digikey.com/en/products/detail/luminus-devices-i...

$25 for an excellent 700mA driver, 86% efficient.

https://www.digikey.com/en/products/detail/bridgelux/BXRH-30...

$3.45 for a very nice, ~2000lm 97 CRI LED, about 99 lm/W. (Efficiency goes up quite a bit if you settle for 90 CRI.)

So that gives about 2000lm at about 25W, for <$30.

Wikipedia gives about 16 lm/W for incandescent, so 125W. At 10 hour per day, the LED options pays for itself quickly even at national average prices. In CA, it’s very fast.

To be fair, for high-end LEDs like this, the balance of the system is more expensive, because you need a heat sink. Incandescent lamps run very hot and don’t need heat sinks.

I think this is potentially promising, but I don’t think you can buy it:

https://tlo.mit.edu/technologies/high-efficiency-incandescen...

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5 comments · 5 top-level

DougN73y ago

This is just an anecdote, but I’ve had multiple “10 year” LED bulbs fail after just a year or two. I suspect much of the claims for these bulbs are theoretical as they just don’t hold up, probably for reasons the grandparent poster is pointing out.

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titzer3y ago

Your comment is just regurgitating tech specs. In reality, the bulbs that are at hand vary so much in quality, that tech spec discussions are almost useless. The flickering is a real issue. I'm not aware of any standard way of rating the flickering of LED bulbs; they can vary from really bad (literally dark 50% of the duty cycle because one stupid diode) to decent (bidirectional diodes), to very good (full voltage regulator).

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b1123y ago

https://www.hydroquebec.com/data/documents-donnees/pdf/annua...

Sadly, with San Fran anywhere from 4.5x, or more than where I live (Quebec), and with LED products lastly barely longer than incandescent bulbs, it is typically a loss.

Maybe a 5 year warranty on LED bulbs should be a law, to ensure better quality control and build. The competitors can compete around that requirement.

1 more reply

oh_sigh3y ago

Where exactly would you mount a light like the one you linked?

10 hours per day sounds like a crazy amount of time to use a light. I think we use some lights in our house maybe 4 hours per day on average max. Maybe I just have a lot of windows and don't live in Alaska in the winter.

2 more replies

megous3y ago

Heatsink costs?

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