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Comment by skrap | Hacker News Reader

I'm gonna have to call you on that one. Even high-end brand LED bulbs are so much more cost efficient than incandescent bulbs, it's the rational act to immediately replace nearly every single incandescent.

Whether you're interested in saving energy or saving money, you should remove and smash your incandescents.

Here's a blog entry I wrote with some of the simple math: https://blog.sense.com/articles/smash-incandescent-bulb-swit...

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A bit less than two decades ago, when I was still living with other (post-graduate) students we got a flyer which announced a low price for Compact Fluorescent Lighting compatible with our rented house. We went into the living room where there was a whiteboard, and worked out the TCO of these more efficient lamps over their lifetime compared to just the ongoing cost of our incandescents (since we had these already we didn't need a total cost).

We then immediately set out to purchase an entire house full of CFLs. They were still going years later when we split up and each took our share, I still have one somewhere, maybe in my living room.

Personally, the reason I don't run out and replace all my existing incandescents is because I don't want to waste perfectly good bulbs; I would rather for them to reach EOL and then replace. The energy used to create a good is usually significantly more than the energy the good itself uses. I'm OK paying a little more for the energy used by the incandescents when it's overall less wasteful.

> The energy used to create a good is usually significantly more than the energy the good itself uses.

Not when you're talking about a cheap consumable product which mostly converts power into heat. A 75W bulb is about $2.50/yr worth of energy consumption per hour of daily use at $0.09/kWh. An LED equivalent is +/- $0.35/yr at a cost of $3-$6.

Maybe 5%-10% of my home's bulbs weren't worth replacing out of cycle, but LEDs are so cheap and the overall savings so high that it's not even worth thinking about.

But I'm not concerned about the money, I'm concerned about the wastefulness. The existing bulbs are completely functional until they reach EOL, at which point they will be discarded into landfill. The less frequently things are replaced, the less waste ends up in landfill (and is consumed in initial production).

I think you're looking at this wrong. Using an incandescent lamp until it burns out consumes far more resources than making that lamp did.

We can readily quantify how 'perfectly good' incandescent bulbs are no longer perfectly good in terms of energy consumption costs, to which you might also factor the environmental and health impacts of consuming more energy than you could be.

But quantifying the wastefulness of prematurely sending them to the landfill is much more difficult. We can suggest that LEDs longer expected lifetime is another benefit to the environment but that is equally challenging to quantify for the premature replacement scenario.

More than 99% of the total lifecycle energy of a incandescent is in its use.

Let's just repeat that.

More than 99 percent of the total lifecycle energy of a typical incandescent bulb is in its use. That includes raw materials, manufacturing, and transport.

Source: https://energy.gov/sites/prod/files/2015/10/f27/lca_factshee...

I think the grandparent is saying there's a limit to the number of additional efficient light fixtures one would add with promise of low runtime costs because of higher initial fixture, bulb, and dimmer costs for LED.

I haven't found an LED yet that works in my dimmable ceiling fixture, where I can dim it to the lowest possible level and get a pleasing light. The incandescent gives a very dim, warm orange glow which is great for movie watching or other mood-setting purposes. The LED still emits a rather harsh and not-as-dim light even if it's rated in the warm spectrum. Have you seen a solution for that?

LEDs are terrible with dimmers. They flicker, and they have bad response curves to the dim-level. Yes, there exist properly dimmable LEDs, but buying 5 different bulbs to find one that works negates the savings.

This isn't the LED's fault. It's the fault of the fact that dimmers are awful designs. They feed a nasty chopped-up waveform to the fixture that has RMS voltage proportional to the desired power output. Aside from the fact that it has a bad power factor, it's more or less okay for plain old line voltage incandescent lights. For LEDs, several things go wrong. First, LEDs want DC or high frequency PWM. The driver is given a nasty waveform at 60 Hz. So the driver needs to rectify that waveform to DC, filter it, and then decode the waveform to dim the LED as the user requested. This is a big hack and doesn't work all that well. Second, modern power supplies aren't resistors. Supplying them with input power with rapid voltage swings is not so great. Third, the dimmers themselves are usually wired in series with the bulb without access to a neutral wire, and incandescent dimmers expect to draw their own power using current through the bulb. Given that LED drivers are highly nonlinear, this makes it very awkward for the dimmer to power itself. "Dimmable" LEDs will intentionally leak some current to power their dimmers. High-end dimmers in newer homes will have a neutral connection.

If you can find a "ELV" or "reverse phase" dimmer and you have the wiring for it, you can at least avoid the inrush current problem.

An anecdote: I have a fancy computer power supply that buzzes rather loudly when the lights are on. This is presumably because the lights are drawing a big inrush current spike 120 times per seconds due to dimming.

To top it off, LEDs have much higher frequency response than incandescent bulbs. This means that, unless you drive them with clean DC or with a very high-frequency PWM input, they'll flicker. (Not the kind of flicker you're talking about -- the kind you're seeing is the system malfunctioning. I'm talking about the kind where it flickers as designed and someone waved their fingers and decided it was hard to notice.) There's a new standard called IEEE 1789 that describes what levels of flicker are likely to be harmful (causing low productivity, headaches, general crappy feelings, etc.) and what levels are very likely to be safe. Very few LED drivers meet this standard so far. At least California has imposed a less stringent but still helpful for Title 24 compliance [1] for the last couple of years.

(This is extra nasty given that incandescent bulbs don't actually produce light proportional to the power with which they're driven.)

[1] It's Title 24 JA8.

Ok, but the dimmers worked fine with the incandescents. Your post gives a lot of reasons why the high-efficiency of LEDs comes at a cost of lower flexibility to adapt to important use cases.

I believe some fixtures solve this by having two sets of LEDs; as you dim down the standard LEDs, the low-level LEDs kick in.

I've seen that in a few theatrical/architectural lights, no idea if it's available in the consumer market yet.

For our hallway, rather than buying an LED lamp that's compatible with a dimmer, we bought one with built-in dimming. You flip the wall switch twice and it goes into a dim warm orange "nightlight" mode. Flip it twice again and it goes into full brightness daytime mode.

Where do you find 100 watt equivalent LED bulbs in 2700K for $1/bulb?

You won't find LED's for $1/bulb, but the total cost of ownership over X years is massively in favor of the LED.

Also I simply find it convenient that LED's just. don't. die. I haven't had to change a single bulb since I upgraded ~4 years ago.

I had one out of around 50 die over ~3 years, which I'm sure is much better than I experienced with incandescents and CFLs.

Smart bulbs are so cheap now that I've obsoleted nearly all of my "dumb" LEDs.

Note that the lifetime of a bulb is quadratic, if not exponential, with its wattage.

The 100W bulb always lit in the living room will last 6 months but a 30W will do a decade.

You don't, not yet anyways. But if that 100w bulb is on 3-hours per day and you want a 1-year ROI, your replacement budget is probably in the $8-12 range.

I usually go to Ocean State Job Lot or Home Depot. There's a wide selection for $1-2/bulb. I like Cree or Philips as brands.

I just saw some 2700K bulbs in Poundland (£1~=$1.38), at a selection of power levels. Not sure what the brightest was, might have been 60W equivalent?

I deliberately got a dimmer model because I wanted something to encourage my mum to sleep more; due to Alzheimer’s she has no idea what the time of day is any more, and has developed a fear of the dark and only sleeps with the light on.

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