The Lightbulb Conspiracy/Pyramids of Waste: Interesting Documentary on Planned Obsolescence

[Hannah Bell]

http://dotsub.com/view/aed3b8b2-1889-4df5-ae63-ad85f5572f27

People could live their whole lives without ever scorching their fingertips trying to change an incandescent bulb. Long after they were gone, the lights above their kitchen tables and bathroom mirrors would burn on.

That sci-fi vision might have become a reality if Adolphe Chaillet, inventor of Livermore's famous Centennial Light, and other early light bulb creators had continued on their way, according to the 2010 European documentary "The Light Bulb Conspiracy."

Livermore's bulb -- considered the world's longest burning as it nears 110 years -- is one of the stars of this illuminating film by director Cosima Dannoritzer, of Spain. On trial in "Conspiracy" is planned obsolescence -- the practice of deliberately designing products with limited life spans to drive consumerism.

"There's all these lovely conspiracy stories -- grannies always saying that everything used to last longer. I wanted to know (whether) that was just subjective or (if it) was really true," Dannoritzer said. In fact, it was profit-driven scheming by industry titans, not technological limitations, that led to the evanescent incandescent bulbs of today, she contends.

http://www.mercurynews.com/ci_17287091?source=most_emailed&nclick_check=1


In the comments section there's this:

A 100 watt incandescent (can you still buy one?) has a rated lifetime of about 2000hrs. If you run it at 1/4 power (by lowering the voltage) you will have a 25 watt bulb that will last over 100 years. It's not really surprising that this nominal 60 watt bulb running at 4 watt equivalent has lasted so long.

Any engineer-types who know whether it's true or not?


Interesting article on the discontinued Philips IQ bulb that turned itself off after 15 minutes:

http://savehouseholdenergy.com/energy/save-electricity/the-10-year-light-bulb-conspiracy/

[PoliticAverse]

1. Yes it is true, but...

It is true that the lower the voltage the longer the light bulb will last however you will get less light.
The problem is one of efficiency - how much of the power that you put into the light bulb gets converted into light vs
how much just heats the bulb. The higher the voltage the more efficient the bulb is but the shorter the lifetime.
It's a trade off of efficiency vs lifetime. Industrial users that have bulbs that are in hard to reach places often
use 130 volt rated bulbs that they run at the standard 120 volts - this 'undervolting' results in a light that doesn't
have to be replaced as often. You can use a lower voltage with any of the regular bulbs by using a dimmer on the circuit.
When I last bought 100-watt bulbs I paid 25 cents each for them (4/$1). I've since switched to compact fluorescents
which are about 2 1/2 times as efficient as the old incandescent bulbs and also last much longer (and only cost $1 each).

The 'livermore bulb' has a home page: http://www.centennialbulb.org/

BTW the comments you mentioned claimed a normal 100 watt bulb lasts about 2000 hours, but if you look at the package of common
bulbs it's usually around 750 hours.

Wikipedia has a good article on incandescent bulbs: http://en.wikipedia.org/wiki/Incandescent_light_bulb

It discusses efficiency and bulb lifetime. An excerpt:

This means that a 5% reduction in operating voltage will more than double the life of the bulb, at the expense of reducing its light output by about 20%. This may be a very acceptable trade off for a light bulb that is in a difficult-to-access location (for example, traffic lights or fixtures hung from high ceilings). Long-life bulbs take advantage of this trade-off. Since the value of the electric power they consume is much more than the value of the lamp, general service lamps emphasize efficiency over long operating life. The objective is to minimize the cost of light, not the cost of lamps.<33>

The relationships above are valid for only a few percent change of voltage around rated conditions, but they do indicate that a lamp operated at much lower than rated voltage could last for hundreds of times longer than at rated conditions, albeit with greatly reduced light output. The Centennial Light is a light bulb that is accepted by the Guinness Book of World Records as having been burning almost continuously at a fire station in Livermore, California, since 1901. However, the bulb is powered by only four watts. A similar story can be told of a 40-watt bulb in Texas that has been illuminated since September 21, 1908. It once resided in an opera house where notable celebrities stopped to take in its glow, but is now in an area museum.<69>

[left is right]

3. around 750 hours I only wish

assuming that you use a lamp for 5 hours a day that would be 150 days before it blows I barely get 35 days

[wysimdnwyg]

5. The life span of an incandescent bulb will vary from house to house

In most municipalities in America, the stated voltage is 120v AC. However, that number typically varies by as much as 10v AC in either direction (usually down to 110, but sometimes it can be higher than 120). Incandescent bulb stated life spans are based on a voltage output of 110 to 115v AC. Check the package for the particular ones you get. If it says 1000 hours at 110v AV, it's probably the same bulb (or statistically equivalent) as another than says 750 hours at 115v AC. If you happen to get closer to 120v AC, your bulb life span will be be less.

When it comes to compact fluorescent bulbs, the stated life span is much longer than that of an incandescent. However, most CFs will not last nearly as long as their stated span because of usage patterns. CFs work best when they are warmed up. This means leaving them on for more than just a few minutes at a time. If you use a CF in an area where the light is used sporadically (like in a bathroom where the light is typically turned on for a few minutes, then back off again when you leave the room), the life span of the bulb may end up being as short as - or even shorter than - that of an incandescent. The trade off here is that the power consumption of the CF is significantly less than with the incandescent.

[surrealAmerican]

4. Thank you.

That was a good, clear explanation.

[iamtechus]

2. There are no free lunches in physics.

The simple incandescent light bulb converts electrical energy into light and heat. The ratio of light/heat can be considered a measure of the bulb's efficiency. The higher the ratio, the more efficient the conversion is.

Raising the voltage applied to a given bulb shortens its life and produces more light and less heat: more efficient operation.
Lowering the voltage increases its life but is less efficient because lowers the ratio of light to heat.

I suppose that if you lived in cold climate it might be desireable to operate light bulbs at lower than their design voltage to make them last longer and to help heat your house (just kidding).