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The energy it takes to create a single bulb. See this related question. For example, to create a tungsten-filament light bulb, you need tungsten, glass, some metals, some plastics, a mixture of specific gases, cardboard and plastics for the packaging, ... Extraction/production/transportation of these materials takes an amount of energy per kg. Shaping it into a filament/glass housing/metal fitting/etc. takes an amount of energy, etc. In other words, from the "stuff that's in the ground" to "finished product in the store".

Replacement time (this is why LED's will probably have a smooth line, and tungsten-filament bulbs-line will probably show frequent upward jumps due to replacement). The nominal amount of burn hours stated on the packages (mean time before failure, MTBF) is not really sufficient here; these are averages somehow, and frequently come from calculations or laboratory setups rather than actual real-life usage (how else can they claim that LED's can be lit for 10 years continuously?). Also, there is a finite chance that the average user will accidentally drop the bulb, crash into it with a ladder, etc, which is far worse for tungsten-filament bulbs and luminescent tubes than for LED's in protective casings. So, a far more realistic statistical model should be assumed here, which I can't find any reliable, authorative sources for...

Energy expenditure due to disposal and/or recycling

Transportation. This is a broad topic and strongly depends on geographical location, but let's assume some worst-case scenario (where tungsten-filament bulbs have the advantage)

anything else I've forgotten :)

The energy it takes to create a single bulb. See this related question. For example, to create a tungsten-filament light bulb, you need tungsten, glass, some metals, some plastics, a mixture of specific gases, cardboard and plastics for the packaging, ... Extraction/production/transportation of these materials takes an amount of energy per kg. Shaping it into a filament/glass housing/metal fitting/etc. takes an amount of energy, etc. In other words, from the "stuff that's in the ground" to "finished product in the store".

Replacement time (this is why LED's will probably have a smooth line, and tungsten-filament bulbs-line will probably show frequent upward jumps due to replacement). The nominal amount of burn hours stated on the packages (mean time before failure, MTBF) is not really sufficient here; these are averages somehow, and frequently come from calculations or laboratory setups rather than actual real-life usage (how else can they claim that LED's can be lit for 10 years continuously?). Also, there is a finite chance that the average user will accidentally drop the bulb, crash into it with a ladder, etc, which is far worse for tungsten-filament bulbs and luminescent tubes than for LED's in protective casings. So, a far more realistic statistical model should be assumed here, which I can't find any reliable, authorative sources for...

Energy expenditure due to disposal and/or recycling

Transportation. This is a broad topic and strongly depends on geographical location, but let's assume some worst-case scenario (where tungsten-filament bulbs have the advantage)

anything else I've forgotten :)

The energy it takes to create a single bulb. For example, to create a tungsten-filament light bulb, you need tungsten, glass, some metals, some plastics, a mixture of specific gases, cardboard and plastics for the packaging, ... Extraction/production/transportation of these materials takes an amount of energy per kg. Shaping it into a filament/glass housing/metal fitting/etc. takes an amount of energy, etc. In other words, from the "stuff that's in the ground" to "finished product in the store".

Replacement time (this is why LED's will probably have a smooth line, and tungsten-filament bulbs-line will probably show frequent upward jumps due to replacement). The nominal amount of burn hours stated on the packages (mean time before failure, MTBF) is not really sufficient here; these are averages somehow, and frequently come from calculations or laboratory setups rather than actual real-life usage (how else can they claim that LED's can be lit for 10 years continuously?). Also, there is a finite chance that the average user will accidentally drop the bulb, crash into it with a ladder, etc, which is far worse for tungsten-filament bulbs and luminescent tubes than for LED's in protective casings. So, a far more realistic statistical model should be assumed here, which I can't find any reliable, authorative sources for...

Energy expenditure due to disposal and/or recycling

Transportation. This is a broad topic and strongly depends on geographical location, but let's assume some worst-case scenario (where tungsten-filament bulbs have the advantage)

anything else I've forgotten :)

The energy it takes to create a single bulb. See this related question. For example, to create a tungsten-filament light bulb, you need tungsten, glass, some metals, some plastics, a mixture of specific gases, cardboard and plastics for the packaging, ... Extraction/production/transportation of these materials takes an amount of energy per kg. Shaping it into a filament/glass housing/metal fitting/etc. takes an amount of energy, etc. In other words, from the "stuff that's in the ground" to "finished product in the store".

Replacement time (this is why LED's will probably have a smooth line, and tungsten-filament bulbs-line will probably show frequent upward jumps due to replacement). The nominal amount of burn hours stated on the packages (mean time before failure, MTBF) is not really sufficient here; these are averages somehow, and frequently come from calculations or laboratory setups rather than actual real-life usage (how else can they claim that LED's can be lit for 10 years continuously?). Also, there is a finite chance that the average user will accidentally drop the bulb, crash into it with a ladder, etc, which is far worse for tungsten-filament bulbs and luminescent tubes than for LED's in protective casings. So, a far more realistic statistical model should be assumed here, which I can't find any reliable, authorative sources for...

Energy expenditure due to disposal and/or recycling

Transportation. This is a broad topic and strongly depends on geographical location, but let's assume some worst-case scenario (where tungsten-filament bulbs have the advantage)

anything else I've forgotten :)

The energy it takes to create a single bulb. For example, to create a tungsten-filament light bulb, you need tungsten, glass, some metals, some plastics, a mixture of specific gases, cardboard and plastics for the packaging, ... Extraction/production/transportation of these materials takes an amount of energy per kg. Shaping it into a filament/glass housing/metal fitting/etc. takes an amount of energy, etc. In other words, from the "stuff that's in the ground" to "finished product in the store".

Replacement time (this is why LED's will probably have a smooth line, and tungsten-filament bulbs-line will probably show frequent upward jumps due to replacement). The nominal amount of burn hours stated on the packages (mean time before failure, MTBF) is not really sufficient here; these are averages somehow, and frequently come from calculations or laboratory setups rather than actual real-life usage (how else can they claim that LED's can be lit for 10 years continuously?). Also, there is a finite chance that the average user will accidentally drop the bulb, crash into it with a ladder, etc, which is far worse for tungsten-filament bulbs and luminescent tubes than for LED's in protective casings. So, a far more realistic statistical model should be assumed here, which I can't find any reliable, authorative sources for...

Energy expenditure due to disposal and/or recycling

Transportation. This is a broad topic and strongly depends on geographical location, but let's assume some worst-case scenario (where tungsten-filament bulbs have the advantage)

anything else I've forgotten :)

The energy it takes to create a single bulb. For example, to create a tungsten-filament light bulb, you need tungsten, glass, some metals, some plastics, a mixture of specific gases, cardboard and plastics for the packaging, ... Extraction/production/transportation of these materials takes an amount of energy per kg. Shaping it into a filament/glass housing/metal fitting/etc. takes an amount of energy, etc. In other words, from the "stuff that's in the ground" to "finished product in the store".

Replacement time (this is why LED's will probably have a smooth line, and tungsten-filament bulbs-line will probably show frequent upward jumps due to replacement). The nominal amount of burn hours stated on the packages (mean time before failure, MTBF) is not really sufficient here; these are averages somehow, and frequently come from calculations or laboratory setups rather than actual real-life usage (how else can they claim that LED's can be lit for 10 years continuously?). Also, there is a finite chance that the average user will accidentally drop the bulb, crash into it with a ladder, etc, which is far worse for tungsten-filament bulbs and luminescent tubes than for LED's in protective casings. So, a far more realistic statistical model should be assumed here, which I can't find any reliable, authorative sources for...

Energy expenditure due to disposal and/or recycling

Transportation. This is a broad topic and strongly depends on geographical location, but let's assume some worst-case scenario (where tungsten-filament bulbs have the advantage)

anything else I've forgotten :)