
Ask HN: Environmental Cost of Semiconductors? - drallison
Is there a recent review of the environmental cost of semiconductor electronics covering the full life-cycle from resource acquisition (including mining footprints) through manufacture (including release of greenhouse gases) through disposal or recycling?
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beefman
You are asking for an LCA of electronic components. The best ones are
proprietary, such as the one we put together at Apple ten years ago, which is
probably still updated and unrivaled.

The good news is that electronic components often obey commodity pricing. And
for commodities there is a very good approximation for LCA: their market
price.

An LCA is a sum environmental impacts, weighted by importance. Market price
represents some sort of consensus weighting. You can argue for other
weightings, but such arguments are at least as subjective as the market
weights and seldom give a significantly different result.

Interestingly, even non-commodities reveal their environmental impact through
their price. The difference is, their prices include all downstream
environmental impacts, whereas traditional LCA and commodity prices only
reflect impacts within some "system boundary".

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rcfox
LCA = Life cycle... assessment?

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beefman
Usually (sometimes Analysis)

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sevensor
Toxic materials (photoresist and associated solvents, acids for cleans, dopant
chemicals, among others) and lots of electricity get used in the semiconductor
manufacturing process. And that's just at the wafer manufacturing site. It
doesn't include materials for packaging or PCBs. Nor does it include the
chemical plants that supply materials, or the environmental impact of
producing the manufacturing equipment (which will only be used for a decade,
15 years at the outside), and its consumables. If you're concerned with the
environmental footprint of your personal computing, you should probably use
older equipment for longer. I think the balance is different for datacenters
given their high utilization.

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thrilleratplay
This would be a fascinating read if one exists, however, if I had to guess
with no actual basis for it, what you describe is too broad and would need to
be broken down. A few simplifications:

* The environmental impact of mining, refining and shipping of the ultra pure silicon needed for semiconductor development.

* The energy required to research/development then produce next generation semiconducting and at what yield or adoption rate would it make sense to push Moore's Law.

* Percentage of electronics that end up in landfill verse what is recycled.

I am having trouble trying to think of other clear examples beyond the fab due
to too many variables. How do distinguish processors and GPUs in someone's
gaming rig using power from a local coal plant to a cloud farm that is using
wind and solar to power it? To throw another wrench into this there is also
you[https://en.wikipedia.org/wiki/Jevons_paradox](https://en.wikipedia.org/wiki/Jevons_paradox).

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mchannon
Call it anecdata, but a few of the things I noticed after a couple decades in
the industry:

1\. Water

Water is extensively used and it has to be as pure as you can imagine. This
requires a regular investment in filters and energy. I wouldn't be surprised
to see hundreds of water wash steps for a wafer of chips, plus water wash
steps for the equipment.

2\. Acids and bases

You can dump these in the third world, sure, but neutralizing them tends to be
favored, and also very expensive. Sulfuric or Hydrofluoric acid may require
almost zero energy input, but the caustic soda, soda ash, or baking soda you
need to add to passivate their waste requires a lot.

3\. Silicon itself

This one's a bit of a surprise. A gram of hyperpure silicon doesn't really
take that much energy, or even generate all that much waste. There's the
reduction cost where you burn out the oxide with coal and wood chips, plus the
follow-up stages of purification and crystallization. You lose half again by
wafering. But even if it's 10 grams waste per gram of chip, you're not doing
all that poorly. An idling car engine makes 10 grams of waste in no time. Plus
the waste is almost entirely mg-Si, CO, and CO2; very manageable. China has a
bit of a silicon-tetrachloride problem from some of its purification steps,
but that stuff is avoidable.

4\. Photoresists

These are the absolute worst. Carcinogenic and complicated to manufacture.

5\. Specialty gases

What's a little diborane, phosphine, or arsine among friends? These players
are bad news, but you use such trivially small quantities of them that their
impact is pretty light. You still have to scrub their waste gases out before
you release them, and that's a bit of a pain.

6\. Bulk gases

Hyperpure nitrogen, oxygen, and argon get used in large amounts as well but
they're almost as cheap as air in bulk. Release at will.

7\. Air handling

Cleanrooms require more airflow than some bitcoin farms, and specialty filters
have to be changed out occasionally. It's just electricity though.

8\. Packaging

All that copper, tin, silver, and gold, plus whatever weird plastics they're
using these days may end up being far worse for the environment than the chips
they encase.

9\. Actual use

Unless they're generating power (PV) they're going to suck down power, whether
in your cable box set to off or the switchgear. This is by far the biggest
energy consumption associated with semiconductors.

10\. Vacuum!

Along with to a lesser extent compressed air, vacuum greases and machinery can
get up there in terms of cost. Roughing pumps will spew oil, and turbo pump
and cryopump units cost a lot to build, run, and maintain.

11\. Organic solvents

Cheap to make, expensive to dispose, doubly so when you mix them with some of
the other expensive-to-dispose stuff.

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sevensor
Great answer, and nice to see another person from semiconductor manufacturing
on this site! Are you still in the industry?

~~~
mchannon
Trying to be, but can't get people excited about making silicon wafers with
higher purity, zero waste products and at 10% the cost.

So in the meantime I write apps.

~~~
sevensor
> higher purity, zero waste products and at 10% the cost

That's disappointing! For an industry that's at the heart of so much modern
technological advancement, it's surprisingly conservative. And that goes
double for choosing suppliers, unfortunately. Myself, I got worn down by the
hours and left the industry.

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ChuckMcM
An independent review? I haven't seen one. There was a pretty egregious report
alleged to be from the Silicon Valley Toxics Coalition[1] which appears to
have been taken down. (It was conflating ground water contamination from fabs
in the 60's with modern fabs, for example)

If you were looking for a project it would probably be a good one, I for one
would be interested in reading something that was backed up by solid research
and objectivity.

[1] [http://svtc.org/resources/reports/](http://svtc.org/resources/reports/)

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davidjnelson
A nice map view of how polluted Silicon Valley is
[https://whatsdown.terradex.com/#10/37.3489/-121.9228/](https://whatsdown.terradex.com/#10/37.3489/-121.9228/)

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vkaku
Follow the law. We need to have Federal laws that require Electronics
Companies or Importers to recycle their equipment. Those Federal laws do not
exist today.

In the USA, corporations fight right to repair laws. That's the current state
of the affairs. It has to transition from that into a more thoughtful usage
driven buying/selling process.

There is nothing wrong in buying newer, better electronics - but junking the
old ones as e-waste is absolutely wrong.

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sigmaprimus
I'm not sure if there is or not, but I would hope that any review would also
include the reduction of power consumption from using semiconductors instead
other non solid state devices. Eg Vacuum tubes vs transistors. Also the
increased efficiency of switching power supplies over linear.

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mistrial9
yes, there are .. contact BAN-Waste in Seattle to start if you are in a hurry,
and given 48 hours or so, more doc references here in this thread TBD. A
keyword search with "Industrial Ecology" from the early 2000s might get things
rolling, too.

