# Light bulbs
**URL:** https://boards.straightdope.com/t/light-bulbs/346093
**Category:** Factual Questions
**Created:** [February 25, 2006, 8:12pm UTC](https://boards.straightdope.com/t/light-bulbs/346093 "2006-02-25T20:12:48Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@berner](https://boards.straightdope.com/u/berner)
#### Post date: [February 25, 2006, 8:12pm UTC](https://boards.straightdope.com/t/light-bulbs/346093/1 "2006-02-25T20:12:48Z")
How much energy do light bulbs take to produce (both normal and energy saving)? What are the environmental consequences of disposing of both types of bulb?
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### Author:  [@What\_Exit](https://boards.straightdope.com/u/What_Exit)
#### Post date: [February 25, 2006, 9:27pm UTC](https://boards.straightdope.com/t/light-bulbs/346093/2 "2006-02-25T21:27:01Z")
Welcome to the board, great question.
I hope someone comes along that can answer it.
The overall mass/volume of waste in a Compact Florescent should be significantly less.
They have a lifespan of 6000 to 15000 hours. Incandescent are rated for 750 to 1000 hours. The cheaper ones I buy rate 6000 or 8000 hours.
> [@wiki](#):
>
> [Disposing of CFLs](http://en.wikipedia.org/wiki/Compact_fluorescent_light_bulb#Disposing_of_CFLs)
> \*\*It is recommended that compact fluorescent lamps not be thrown away with normal trash. \*\* They should be treated as you would treat batteries. This is because they contain trace amounts of mercury. The amount in them isn’t large enough to pose the users a hazard, but it does become a concern at landfills, where the mercury from many bulbs could leak into the ground. The recommended course of disposal varies depending on the country or city, so a consumer is advised to ask the local authorities. Usually, one can either
>
> Bring back used CFLs to where they were purchased, so the store will recycle them correctly, or
> Bring used CFLs to a local recycling facility.
> It is interesting to note that coal power plants are the single largest source of mercury emissions into the environment. A coal power plant burning enough fuel to power an incandescent light bulb instead of a CFL would release more mercury into the air than is actually contained in a CFL itself.
Jim
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### Author:  [@gazpacho](https://boards.straightdope.com/u/gazpacho)
#### Post date: [February 25, 2006, 9:55pm UTC](https://boards.straightdope.com/t/light-bulbs/346093/3 "2006-02-25T21:55:41Z")
In general I have seen that compact fluorescent light bulbs use 1/4 to 1/3 of the energy of a comperable incondesent light bulb.
They also generally last 5 to 10 times as long.
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### Author:  [@What\_Exit](https://boards.straightdope.com/u/What_Exit)
#### Post date: [February 25, 2006, 10:28pm UTC](https://boards.straightdope.com/t/light-bulbs/346093/4 "2006-02-25T22:28:13Z")
> [@gazpacho](#):
>
> In general I have seen that compact fluorescent light bulbs use 1/4 to 1/3 of the energy of a comperable incondesent light bulb.
> They also generally last 5 to 10 times as long.
All true but Our guest is looking for the energy used in manufacturing. I think I answered the other question.
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [February 26, 2006, 7:04am UTC](https://boards.straightdope.com/t/light-bulbs/346093/5 "2006-02-26T07:04:08Z")
Most of the materials used in manufacturing a light bulb, fluorescent or incandescent, are abundant and easily-obtained. And most of the manufacturing process is automated. It is therefore reasonable to assume that most of the cost of a light bulb is a reflection of the energy needed to make it. Looking online, it appears that compact fluorescent light bulbs are about ten times the cost of comparable incandescent bulbs, so I’m going to estimate that they take about ten times the energy to make. And given the cost of running a bulb for its lifetime, I think it’s safe to say that in either case, the energy used in their manufacture is insignificant.
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### Author:  [@David\_Simmons](https://boards.straightdope.com/u/David_Simmons)
#### Post date: [February 26, 2006, 3:02pm UTC](https://boards.straightdope.com/t/light-bulbs/346093/6 "2006-02-26T15:02:52Z")
> [@Chronos](#):
>
> Most of the materials used in manufacturing a light bulb, fluorescent or incandescent, are abundant and easily-obtained. And most of the manufacturing process is automated. It is therefore reasonable to assume that most of the cost of a light bulb is a reflection of the energy needed to make it.
With the cost of advertising, packaging, inventory storage and transportation also adding a significant amount to that 😉 .