Longer-lasting light bulbs: it was complicated
Planned obsolescence - it’s an insidious thing. A business that designs the perfect product which lasts forever will run out of customers once everybody has one. And running out of customers is a pretty bad strategy for a business which strives to be immortal. This simple reality, when viewed with a slightly twisted mindset, can be seen as a reason to never build the perfect product, and it is often argued - quite convincingly, I should say - that companies today are actively making their products worse to guarantee you’ll have to buy another one before too long.
Now, I’m not here to make any accusations. Though I do certainly wish to see us endowed with a right to repair the things we own, and maybe some other things while we’re at it. Uh, anyway, though I won’t comment on what may or may not be happening today, between the first and second world wars, an actual, documented conspiracy between light bulb manufacturers across the globe existed. The Phoebus cartel, an arrangement between Osram, Philips, General Electric, and several others, established a maximum light bulb life expectancy of 1,000 hours.
The organization even conducted tests on each other’s products and issued fines to its members when their light bulbs took just a little too long to burn out. Most insidiously, they defined this 1,000 hour maximum after light bulbs with significantly longer 2,500 hour lifespans already existed. That would seem to point straight at planned obsolescence - after all, the lifespan of light bulbs had steadily been going up before the cartel was formed, so surely we were on our way to some sort of everlasting lightbulb stopper.
The manufacturers coming together to impose an artificial limit like they are known to have done seems on the surface at least nothing but a ploy to sell more light bulbs. And light bulbs sales just so happened to increase after the lifespan limit was enforced, which reversed a worrying trend. Sure smells like planned obsolescence to me! Indeed, the smell is so strong that many people point to the Phoebus cartel as the genesis of planned obsolescence, or at least a very clear and undeniable example. And perhaps the most irrefutable piece of evidence comes from, of all places, a garage in California.
Hanging in the firehouse in the town of Livermore is the Centennial Light, an incandescent light bulb that has been burning nearly continuously since 1901. Surely that light bulb with its century-plus longevity proves that light bulbs never truly “need” to burn out. Well… ok so have you ever actually seen an image of the Centennial Light? Here it is. Yeah, it’s barely glowing, is it? See… *sigh* This topic is actually one that actually feels weird to cover.
I definitely think that planned obsolescence has happened and arguably is still happening today, and I wasn’t just making wordplay back then - I am genuinely on the side of the right to repair movement, and giving something an artificial expiration date just to ensure you can sell more is, uh, pretty gross! However… the incandescent light bulb is just not a good example of planned obsolescence for lots of reasons, and using it as evidence of planned obsolescence genuinely bothers me. Am I about to “well, actually” the Phoebus cartel story? [through gritted teeth] Yeah... Here’s the thing - when the story of the Phoebus Cartel is told, those telling it have a bad habit of downplaying or even outright ignoring the fact that there were real, significant, actual advantages to a light bulb that only promised 1,000 hours of operating time. Such bulbs produced a whiter-looking light which was easier to see under, and they could produce more light with the same amount of power - which meant they cost you, the person paying that power bill, less to operate. That’s a pretty important caveat, don’tcha think? Glossing over that little bit of context is bad enough, but a second rather important fact tends to get skipped, too: that being that light bulbs were never a durable good, and once we figured out how to automate their production, they weren’t exactly expensive.
I mean, it’s literally just a little bit of glass, a little bit of wire, and a little bit of metal and resin to form the screw base. There is more than 5 times as much glass in this empty jar of maple butter than there is in this 40 watt light bulb. It took us years and years to figure out how to make these things, sure, but once we were able to use machines to crank these out in big ol’ light bulb factories… well this isn’t a very complex object now, is it? No, it’s not, but before we continue we need a little bit of background: incandescent light bulbs are called that because they rely on the phenomenon of incandescence to produce light in a bulb. Incandescence is this weird thing that happens when stuff gets really hot - all things emit electromagnetic radiation, and as they get hotter, they start to emit waves with shorter and shorter wavelengths until, eventually, those wavelengths hit the visible light spectrum that our peepers detect. That’s why the wires in your toaster glow an orangey-red - they’re just so hot that they’re emitting some visible light. But, not a lot.
They’re definitely really hot, but you need to get much much hotter to shift from a dull orange glow to something more useful. And we knew how to do that just fine! We had been playing about with this electricity business for quite some time and plenty of experiments were done showing thin wires glowing quite brightly. The trouble was that when you make things so hot that they start emitting white light, those things tend to either melt or react with oxygen in the air and burn. And that little problem is what the light bulb sought to fix. After years and years of experimentation, various people whom I won’t name to avoid comment-section flame wars arrived upon a filament which could get extremely hot without melting. When exposed to the atmosphere with all that oxygen floating around, it would still burn, though, and quickly go up in smoke.
So, we put it in a clear, glass bulb that we sucked all the air out of with a vacuum pump. Now there was no oxygen in there for the material of the filament to react with, so it couldn’t possibly burn. And there you go. That’s what a light bulb is. An impossibly hot bit of wire protected from burning away by its own little envelope of nothing. The first functional light bulbs didn’t last long at all, but we were still learning how best to make them.
We tried all sorts of things - different shapes and materials for the filament, the bulb itself, the support structures, more-perfect vacuums, and eventually we got pretty good at it! But we still had an insurmountable barrier: the melting point of the carbon filament. There was a hard limit to how hot you could run the filament before it broke, so early light bulbs produced a rather dull, orangey-yellow light. Still beat the pants off of gas lamps, though.
But then, we figured out how to form thin wire filaments from tungsten. That alone was quite the engineering feat - tungsten’s hardness and brittleness make it very difficult to work with. But figuring it out was the holy grail of light bulb makers because of tungsten’s extremely high melting point: the highest of any known element at 3,422 degrees Celsius, 6,192 degrees Fahrenheit, or 3,695 Kelvin… degrees. [stares knowing exactly what he did] If we could just crack that code, we could make the most brilliant light bulbs anyone had ever seen. Of course, we did - and with tungsten filaments, whiter, brighter, longer-lasting light bulbs started to become the norm. A couple of other innovations were still on the way: the coiled coil structure of the filament, through its compact and dense shape, allowed it to run hotter with less input power.
And we found that adding a little inert gas to the bulb like argon or krypton worked better for tungsten filament longevity than a pure vacuum. But really, aside from those two things… the light bulb wouldn’t change anymore. This appliance bulb I just bought in a store the other day is no different from the light bulbs manufactured a century ago - it’s just a piece of tungsten wire glowing because it gets literally white-hot when we run current through it, positioned inside of a thin glass bulb filled with an inert gas at low pressure to prevent the filament from reacting with oxygen and burning away.
Not exactly the pinnacle of complexity. However, the filament reacting with oxygen and burning isn’t the only issue we have. Although tungsten won’t melt until it hits 3,695 Kelvin, it does have this annoying habit of evaporating when it gets close to there. Or, I guess technically that would be sublimating. Anyway, as the lamp is operated, little bits of hot tungsten become liberated from the filament and wind up on the inside surface of the glass, which both darkens the glass bulb and weakens the filament with time.
Eventually, the filament becomes so weak that it breaks, and pop goes the light bulb. And here’s where the heaping spoonful of oft-omitted nuance from the Phoebus cartel story comes back into play: how quickly a light bulb burns out depends on how hot you run the filament. The closer you get to tungsten’s melting point, the faster evaporation happens, which leads to the filament weakening more quickly and thus results in a shorter lifespan for the light bulb. Sounds like we should just not run them too hot, then, but see… as you get closer to tungsten’s melting point, you also get a brighter, whiter, more energy-efficient light bulb. There’s a trade-off between quality and efficiency of the light produced by an incandescent light bulb and how long that light bulb will run before it fails. This is merely a physical reality of all non-halogen tungsten-filament lamps.
It’s a reality we understood in 1925 when the cartel was formed, and it’s a reality that continues to be real for what few incandescent light bulbs remain on the market. For example, these are both 40 watt incandescent light bulbs. One of them is an appliance bulb like you’d put in your oven rated for 2,500 hours of runtime. The other is a “ceiling fan bulb” which is really just a general-purpose bulb with a candelabra base. This bulb only promises 1,000 hours of runtime, and boy are these runtimes weirdly similar to how the cartel story started, that’s strange.
Anyway, when we compare the two side-by-side, the longer-lasting appliance bulb is noticeably dimmer and yellower despite using a nearly-identical amount of power. It is a longer-lasting light bulb, but it is also objectively worse at its single job of producing light with electrical power. So which is really the better light bulb? Sorta depends on what you’re going for, doesn’t it? But these are two different light bulbs - maybe there’s some sort of manufacturing issue with the appliance bulb and it shouldn’t be that dim.
Well, to demonstrate slightly more scientifically, I’ve got a big ol’ box of 555 indicator lamps. These little light bulbs are designed to run at 6.3 volts and consume about 1.5 watts of power. When run at their rated voltage, they’re definitely not the brightest things out there - they barely produce a visible glow when under this lampshade. But watch what happens when I double the voltage.
The light has gotten much brighter, and whiter, too. It’s also now drawing nearly 5 watts of power - and boy is this the brightest 5 watt light bulb I’ve ever seen. Look how much brighter it is than this 4-watt night-light bulb. That’s impressive. So… why don’t we run all light bulbs like this? Well, you probably already know. It’s because they don’t last long at all when you do this.
While we are getting way more light out of this thing, the filament is getting weaker by the minute. This bulb was only run for 10 minutes at double its rated voltage, and already we can see significant darkening of the glass. That’s from the evaporated tungsten which has deposited on the glass and that happens in all non-halogen incandescent bulbs, but it’s particularly noticeable with these little fellas since the bulb itself is so small. To give a true running-time at this voltage, I ran a stopwatch on a test of a fresh bulb and found it only survived for 65 minutes at 12.6 volts. And that’s what it looked like in the end.
And I want to be clear here, the melting point of tungsten isn’t the issue. I’d estimate that at 12.6 volts we’re running the filament at somewhere near 3,100 Kelvin, and tungsten won’t melt until 3,695 (plus tax). The problem is the rate of evaporation of the filament.
That happens faster with every increase in temperature, so the hotter you run it, the shorter the life it will live. If you just keep on cranking the voltage up, you will hit the melting point and will experience an instant burn-out, but after sacrificing several bulbs for the good of science, I found that 20 volts would keep us just below the melting point and we could see just how bright we can get one of these suckers. And boy is it astonishingly bright - here’s that table lamp running the 40 watt general-purpose incandescent bulb again.
And now, here’s that same lamp but with our teeny little 555 indicator running at 20 volts. That’s nothing short of amazing, and a side-by-side comparison reveals it’s just about as bright. It might even be a little brighter, but it’s hard to make a direct comparison because of how drastically whiter the light is.
In-person this was weird, as it was an incandescent light bulb burning with the appearance of a bright-white LED or fluorescent lamp. The brightness is impressive enough on its own, but look at the power draw - we’re only using half an amp at 20 volts which works out to about 10 watts, so we’re seemingly getting four times as much light per watt. That’s amazing and rivals the efficiency of some LED bulbs today.
The catch? Well, let’s let the video actually play. Immediately the light begins to darken. Before long it’s much less bright than the bulb on the left.
And it lasts a mere 41 seconds before the filament breaks - and this was a really good showing. What’s going on here is that as the filament loses material through evaporation, small weak spots form. We can actually see multiple breaks in this footage, but the filament keeps falling in on itself and keeping the circuit intact. Eventually, though, one of these fractures leaves a gap, the circuit is broken, and the light goes out.
Depending on how that happens, though, you can sometimes bring the bulb back to life with a little percussive maintenance. If you manage to complete the circuit, the tungsten will sort of spot-weld itself back together. For a while, anyway. Here’s the rub: as I’ve hopefully demonstrated, the design of the tungsten-filament incandescent light bulb was always an exercise in balancing lifespan with energy-efficiency and quality of light output. And this is why using the Phoebus cartel as evidence of planned obsolescence rubs me the wrong way. By the time it was formed in 1925, scientists and engineers understood the lifespan-efficiency trade-off.
There are even equations for it! We had essentially perfected the tungsten-filament lamp by the time the cartel was formed, and you simply cannot optimize for lifespan without making the light bulb worse at being a light bulb. The 1,000 hour operational target was simply a decent sweet-spot in the middle (plus, of course, it was a nice round number figure and those are hard to resist). Somebody just had to define what the sweet spot was and make it a standard.
And that’s what happened. To be clear, I’m not forgetting that this was a literal oligopoly with documented collusion efforts that undoubtedly set prices artificially high and did all sorts of other slimy things, too. I’m not here saying the cartel was some sort of wonderful organization.
But I feel like ignoring the reality of the efficiency-lifespan tradeoff in tungsten lamps is... dishonest. It would definitely be insidious if the 2,500 hour light bulbs the cartel sought to extinguish were just as good and just as efficient as the agreed upon 1,000 hour light bulb… but that just wasn’t the case. Longer life light bulbs were always duller, dimmer, and thus required more power to produce the same amount of light. What I think really bothers me is that you don’t have to look that deeply to uncover this context. Just looking up the cartel on Wikipedia reveals that “Some engineers deemed 1,000 hours a reasonable figure to balance the various operational aspects of an incandescent bulb, since longer lifespan means reduced efficacy (lumens per watt): a longer-life bulb of a given wattage puts out less light (and therefore proportionally more heat) than a shorter-life bulb of the same wattage.
Nevertheless, long-life incandescent bulbs were and are available with lifespan ratings up to 2,500 hours, and these do in fact produce less light per watt.” There is even an excerpt from a report from the Monopolies and Restrictive Practices Commission of the United Kingdom from 1951 which says quite plainly that while it might look like hanky panky was going on, conflicting factors make it impossible to view the great light bulb life shortening as anything nefarious. But then, I hear you asking, why establish tests to make sure the bulbs didn’t last too long? Assessing a fine to your members for making a light bulb that’s just a little too good seems pretty iffy. Well, again, would it actually be good? That’s up for debate, and it’s kind of the whole point I’m making, here.
Also of note, many of the companies in the cartel were also in the business of running power grids - or at least building much of the machinery that made those power grids work. They intimately understood that long-life light bulbs would make that part of their business harder and more expensive, especially as more and more people got electricity in their homes and electricity demand grew. That’s a pretty solid reason to start favoring energy efficiency over lifespan and enforcing a standard to that end.
Especially when, to repeat myself, this is just a little bit of glass and a little bit of wire made not by human hands but by machines which could crank out tens of thousands per day. They were not by any means precious objects. Now, I foresee some of you viewing that light-bulb makers were also being in the business of power generation as evidence of a conflict of interest, and maybe it was but they sure didn’t take advantage of that position. If their only goal was to maximize the money you gave them, well then they should have been selling nothing but long-life light bulbs that needed much more power for the same amount of light. But that’s not what happened.
It was better for all parties involved to run cheap light bulbs as hot as you could in exchange for lower operating costs. I know how some folks feel about higher authorities making decisions on the consumer’s behalf, though I can assure you that’s happening all the time in the private sector, you just may not be so aware of it, but honestly establishing a 1,000 hour lifespan was the correct decision - or, at the very least, far less insidious than it seems. The ultimate evidence of this is that it never changed! The cartel dissolved in 1939 and yet, decades later, 1,000 hours remained the operational target for general-purpose light-bulbs. Later on you could get so-called “long-life” bulbs if you wanted to, much like this appliance bulb here, but to produce the same amount of light, they needed more power and thus consumed more energy. This Washington Post article from 1981 points out that to produce the same amount of light as a 75 watt standard-life bulb, you need to move up to a 100 watt long-life bulb. Is it really worth a 33 percent increase in energy consumption just to avoid buying a $0.90 light bulb every six months?
As a matter of fact, objectively no! In 1981 the average cost for electricity in the US was 6.9 cents per kilowatt hour, nice. Over the 2,500 hours of lifetime, those extra 25 watts would amount to 62.5 kilowatt-hours of energy expenditure which would cost you $4.31. So, by choosing the equally-bright but longer-lasting light bulb, you will spend $4.31 more on energy but you won’t even save $2.00 on light bulbs. That means, objectively, you were spending more money running one of those long-life bulbs than you would if you were just buying standard-life bulbs and changing them more frequently.
And that’s why the article suggests to use long-life bulbs only in hard-to-reach places where the extra running costs are worth avoiding a bulb change-out. And that’s with retail prices for light bulbs. Remember how I said they were really cheap to make? Well, I was talking with my mom and dad about this video project and they told me something interesting - back in the day, ComEd (that’s the power utility here in the Chicago area) would just give you free light bulbs when you paid your power bill! And it turns out they still had some ComEd-branded light bulbs in their bag o’ bulbs. My grandfather used to say that he never paid for light bulbs thanks to ComEd’s free light bulb program. Oh, by the way, this is a three-way bulb which means it has two filaments inside. One of them is 30 watts, and the other is 70 watts.
Using a second ring-shaped contact on the screw base, a three-way lamp socket can select between one, the other, or both filaments, allowing you to operate this as a 30, 70, or 100 watt light bulb. The middle contact powers the larger filament, and the cycle of zero, 30, 70, and 70+30 is the reason some lamps require two clicks to switch between on and off - those lamps are meant to use bulbs like this, and then they let you select between bright, brighter, brightest… and off. You can get LED versions of bulbs like this, but they’re usually tucked away with the specialty bulbs in the store and are weirdly expensive. Anyway, ComEd, because they had to deal with the operational challenges of running a growing power grid, had an incentive to hand out efficient light bulbs like candy to keep people from focusing on the wrong metric and buying longer-lasting but less-efficient light bulbs which would strain the power grid more. In fact they sort-of still do this today.
They’re no longer handing out free light bulbs except in special programs, but they heavily subsidize energy-efficient light bulbs in stores with instant rebates, and many utilities across the country run similar programs. Now, was keeping power demand in-check their only goal? Well, that’s hard to say. Among all the light bulbs in the bag is a 100 watt ComEd bulb labeled “long-life” so that pokes a hole in the argument. Though, to be honest, when powered up that thing is awful bright so I’m not sure how long-lived it actually would be. Perhaps the more cynical among you will choose to believe their free light bulb program was actually done to pad the power bills of their rate-payers and they were terrible light bulbs, though I think the kind of bulb they subsidize today compared to those they don’t points to the exact opposite conclusion. Regardless, the broader point here is that incandescent light bulbs were cheap as chips - so cheap utilities were willing to just give them away or run exchange programs, and even at retail prices they were less than a dollar apiece.
The simple fact is the incandescent light bulb was a consumable good, and thus to me they simply cannot be used as evidence of planned obsolescence. Yes, in a very literal sense their demise is planned - after all, they are engineered to fail after a specific number of hours. But you can’t just say that without acknowledging the reasoning behind it - they deliberately traded lifespan for efficiency, and since incandescent light bulbs aren’t very efficient at all to begin with, their operating costs almost always exceeded the purchase cost anyway and it was absolutely worth reducing their lifespan to eek more light out of ‘em. If you wanted a bulb with a longer lifespan, you either needed to sacrifice efficiency and quality of light which almost always cost you more in the end on your power bill, or move to an entirely different lighting technology like fluorescent lights or high-intensity discharge lights, and those different technologies had their own trade-offs, too. Mainly higher upfront purchase cost and, uh, rather ugly light quality, at least in the beginning.
But that’s the other thing - those other technologies existed! They existed and were on the market and anybody who valued efficiency and/or longevity could decide to install such light fixtures. There was a sea of options by the 1950’s but the good ol’ tungsten filament lamp remained the default because it had excellent light quality, was good enough, and most importantly was cheap. And despite the cartel no longer being a thing, 1,000 hours remained the efficiency-longevity sweetspot target for most applications. The Centennial light in Livermore, California has burned for so long because it’s barely been burning.
Why, exactly, is unclear. Supposedly, it should burn as a 30 or 60 watt bulb but has decreased in power over the years for reasons unknown. Or perhaps, and here’s where my money is, it was simply manufactured incorrectly (after all bulbs were still hand-made back then) and it never burned at the wattages it was supposed to.
Perhaps that’s why Dennis Bernal donated it to the fire department - it was only bright enough to serve as a night light so that’s what it went on to do. Anyway, the reason isn't important, what is important is that the Centennial Light has spent at least the majority of its existence as a very bad light bulb - albeit one with notable longevity. But now, I need to come up with some sort of conclusion. What exactly is the point I’m making here? Well… if we wanna get deep I suppose that would be that the world is complex, and you should be skeptical of simple narratives. Nobody’s saying that the Phoebus cartel was a wholesome organization, I’m certainly not anyway, but simply saying that “they made sure light bulbs didn’t last too long” leaves out too much of the story.
If there were a way to make 2,500 hour light bulbs perform like 1,000 hour light bulbs then sure, by all means get out the pitchforks. But that just wasn’t possible. I also think that, frankly, the incandescent light bulb just doesn’t speak to the spirit of planned obsolescence at all - they were simply one of many products that got used up over time.
When I think of planned obsolescence, I think of something like a dishwasher, car, or washing machine; a complex, expensive machine that’s a major purchase. Light bulbs weren’t expensive, complex, or meant to be durable. At least to my eyes, a light bulb has more in common with, say, laundry detergent than it does a washing machine. Just as that box of detergent gets used up and runs out, eventually the light bulb gets used up and burns out.
And to really drive the point home, remember that the cartel dissolved in 1939 yet in the years that followed, that reality didn’t change. The arrival of halogen lamps which allowed for much hotter filaments and longer runtimes thanks to some wild chemical interactions between tungsten and iodine or bromine that I won’t go into other than what I just said didn’t even disrupt the practicalities of the light bulb all that much. Incandescent light bulbs were a commodity product that had to balance efficiency, lifespan, and upfront purchase cost. For general household use, the plain ol’ 1,000 hour tungsten lamp remained right in that sweet spot until, honestly, quite recently.
Speaking of quite recently, perhaps ironically the light bulbs of today are now, for real, actually becoming plagued with planned obsolescence - or, at least, lazy engineering with a heaping spoonful of cost-cutting. The arrival of the white light-emitting-diode was nothing short of a game changer to the lighting industry, and has unlocked extremely efficient and incredibly long-lived lighting products. At least… usually. I personally have been very fortunate and can count on one hand the number of LED bulb failures I’ve experienced since 2018, but sadly there are lots of products out there, especially on the lower-end of the cost spectrum, which have terribly flawed designs. Overdriven diodes, bad heatsinks, bargain basement capacitors, or even just shoddy manufacturing plague far too many LED lighting products, as anyone who’s spent any time around Big Clive’s channel would know.
Of course, there’s bound to be bad or defective product designs out there from time to time, purple streetlights anyone? But things like shoving more current through the diodes than they’re designed for just to eek out that extra bit of light are inexcusable, yet disturbingly prevalent. Still, beware the pitfalls of your biases. When a supposed 50,000 hour LED bulb burns out in a year, yeah that’s probably gonna annoy you. But if you’re old enough to remember the days of tungsten lamps, which I realize many of you watching might not be, think back to how often you used to have to change them.
I can remember several times from my childhood when I went to turn on my bedroom light and *plink* it burnt out in a bright blue flash - and that was just a single light bulb in a ceiling fan. Now that I have dozens of LED lights all over the house, many of which run automated routines and come on every night, it’s pretty amazing that in the last five years I’ve changed but a few. Light bulbs may not not be perfect, no, but they sure are better. ♫ optimally smooth jazz ♫ …to guarantee you’ll have to buy another one before too long. That might have been a perfect take but I wanna do it again, Though I won’t comment on what may or may not be happening today [bong from phone] butj… sh-! Well, that was my fault. It’s literally just a little bit of glass, a little bit of wire, and a little bit of me- yeah I picked up the wrong one.
All things emit electromagnetic radiation, and as they get hotter, they start to emit irradia--- what the heck just happened there? …with the appliance bulb and it shouldn't be that dim. Well… that’s distracting. Was keeping power demand in-check their only go? Now, geez. Now, Which works out to 10 watts. So we’re see... oh crap.
I hope this video was illuminating! There's more to this story than it seems on the surface, and I was hoping I could shed a little light on it. There are definitely a lot of burning questions around light bulbs, and it's a hot topic. I hope I helped extinguish some of your fears, but now you can bask in the warm glow of a nice LED. Or a cool glow, if that's your thing.