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Embodied energy of digital technology
- femto 7y agoThis paper also adds information on absolute energy usage and per kilogram produced. http://web.mit.edu/ebm/www/Publications/energy_required.pdf http://web.mit.edu/ebm/www/Publications/energy_required.pdf
- Gibbon1 7y agoI've found this paper tantalizing. https://www.researchgate.net/publication/222566309_Electrowinning_of_iron_from_sulphate_solutions https://www.researchgate.net/publication/222566309_Electrowi... ""High purity iron was produced, with a current yield of 85% and a power consumption of 4.25 kWh/kg iron."" If you run numbers you get energy costs of about $400-$500/ton.
- dvh 7y agoIs electronic grade silicon created by chemical vapor deposition? I thought czochralski process.
- namibj 7y agoNeither. It's a zone meelt technique that uses the fact that the solubility of impurities is higher in a more liquid state of silicon.
- BostonEnginerd 7y agoIt's both, I believe. Highly purified polysilicon is created using the Siemens CVD process. This is then broken up and used as feedstock for a CZ crystal puller.
- mikestew 7y agoI'm going to have to cut down on my titanium addiction. OTOH, my nephew's grandchildren will be fighting over that double-walled coffee mug long after I die.
- jsilence 7y agoGather the good stuff while energy is still cheap!
- Waterluvian 7y agoRecycle your aluminum, people!
- philipkglass 7y agoNumbers are not sourced and, in at least some cases, suspiciously high. Virgin aluminum is more like 14 kWh/kg, not 63. https://www.iea.org/tcep/industry/aluminium/ https://www.iea.org/tcep/industry/aluminium/
- dredmorbius 7y agoThe stated source is http://web.mit.edu/ebm/www/publications.htm http://web.mit.edu/ebm/www/publications.htm
- philipkglass 7y agoThat page does not include any of the numbers in the Low Tech Magazine table. It lists 165 academic and 14 popular publications. The other paper posted by femto shows aluminum at ~16 kWh/kg. The slightly higher value is due to an earlier date cutoff around 2009. See figure 4(b): http://web.mit.edu/ebm/www/Publications/energy_required.pdf http://web.mit.edu/ebm/www/Publications/energy_required.pdf
- dredmorbius 7y agoFair point, though it's also not untirely unsourced. I'd agree to "poorly".
- 8bitsrule 7y agoThe OP-linked page points to a source URL at the bottom (An MIT 'Environmentally Benign Manufacturing' bibliography). http://web.mit.edu/ebm/www/publications.htm http://web.mit.edu/ebm/www/publications.htm After that URL it points back to a Low-Tech page called 'The monster footprint of digital technology' https://www.lowtechmagazine.com/2009/06/embodied-energy-of-digital-technology.html' https://www.lowtechmagazine.com/2009/06/embodied-energy-of-d... For a summary graphic, see figure 2 in this cited PDF (Gutowski et.al) http://web.mit.edu/ebm/www/Publications/energy_required.pdf http://web.mit.edu/ebm/www/Publications/energy_required.pdf
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- quixoticelixer- 7y agoDoes the value from wood come from processing it or does it include the energy the tree used to make it?
- rebuilder 7y agoIt says "From standing timber", so I'd say that's the energy used in processing, whatever that is defined as.
- roberto 7y agoA plot here would go a long way.
- dredmorbius 7y agoComparable: http://www.epa.vic.gov.au/agc/resources/img/research/r_emmissions_image2.gif http://www.epa.vic.gov.au/agc/resources/img/research/r_emmis...
- chronolitus 7y agoHere is a quickly made plot, both linear and log-yaxis. https://i.imgur.com/BIRAZzJ.png https://i.imgur.com/BIRAZzJ.png
- dredmorbius 7y agoAnd my versions of the plot, log and linear axis: https://imgur.com/a/DYlT9GO https://imgur.com/a/DYlT9GO
- JKCalhoun 7y agoI understand we put aluminum recycling plants near rivers (like the Columbia) where energy costs is cheap.
- deepsun 7y agoOr the other way around. In USSR, at least, few power plants were built closer to aluminum ore deposits.
- hollerith 7y agoI heard the same about the plants that refine the aluminum from ore. Also that those plants being there was a major reason a large airplane manufacturer (Boeing) is nearby.
- Gibbon1 7y agoYeah three really strong covalent bonds takes a lot of energy to break. And strong enough you can't use carbon alone to reduce it. Basically it's bottled electricity.
- kensai 7y agoThe original article is also interesting: https://www.lowtechmagazine.com/2009/06/embodied-energy-of-digital-technology.html https://www.lowtechmagazine.com/2009/06/embodied-energy-of-d... "The 180 watt laptop While these reports are in themselves reason for concern, they hugely underestimate the energy use of electronic equipment. To start with, electricity consumption does not equal energy consumption. In the US, utility stations have an average efficiency of about 35 percent. If a laptop is said to consume 60 watt-hours of electricity, it consumes almost three times as much energy (around 180 watt-hour, or 648 kilojoules). So, let's start by multiplying all figures by 3 and we get a more realistic image of the energy consumption of our electronic equipment. Another thing that is too easily forgotten, is the energy use of the infrastructure that supports many technologies; most notably the mobile phone network and the internet (which consists of server farms, routers, switches, optical equipment and the like)."
- dasd99 7y ago> Another thing that is too easily forgotten, is the energy use of the infrastructure that supports many technologies; most notably the mobile phone network and the internet (which consists of server farms, routers, switches, optical equipment and the like) While I agree with you, it's worth noting that the server farms of our tech giants are already powered by renewable energy (Google 100%, AWS 50%, Microsoft 50%, ...).
- londons_explore 7y agoGas turbine powerplants are easily in the 60% + efficiency band... Coal at 30% is dying out in most of the western world. Granted every fossil fueled device ever has quoted efficiency with the Lower Heating Value, whereas the HHV is the fairest measure. The difference consists of if you should extract energy from the humidity in the exhaust, and the clear answer is yes.
- dredmorbius 7y agoAFAIR "easily" is a stretch -- there are highly efficient combined-cycle gas-turbine plants, and I think some of those actually get above 50% efficiency. For most thermal generation, however, it's Carnot-cycle limits which get you down, and that's governed by hot vs. cold side efficiency. Coal actually has some of the higher efficiencies, in some cases, exceeding 45%, though whether that's through high temps or combined cycle I'm not sure. (I'm not defending coal, just noting efficiency numbers I've encountered.) Update: Wikipedia's language is "possibly 62%" efficiency, FWIW: https://en.wikipedia.org/wiki/Combined_cycle_power_plant https://en.wikipedia.org/wiki/Combined_cycle_power_plant
- l0b0 7y agoThe "source" is just a list of almost 200 publications, with no indication of which numbers come from where. So it's effectively unsourced. That means it's either bullshit, terrible reporting, or both, and there's no reason to believe this over i-have-an-agenda.org. I've got karma to burn, so bring it. But it really is time that reporters get their bloody act together. Without the research this is as worthless as an opinion piece, and it's not going to convince anybody who needs convincing.
- amirhirsch 7y agoThe fun part is seeing those ranges for silicon after having spent the last several weeks researching ways to decrease the energy costs of producing “solar grade” (one nine less than monocrystalline wafer) silicon from silica. There’s a paper showing 1.6kg of 6-nines silicon from rice hull ash in 6hours in a 50kw arc reactor (300kwh) (https://pubs.rsc.org/en/content/articlelanding/2015/gc/c5gc00622h#!divAbstract https://pubs.rsc.org/en/content/articlelanding/2015/gc/c5gc0...)
- rosser 7y ago> Furthermore, burning rice hulls to produce electricity and RHA, generates more energy than required for the overall process. I don't have access to the paper, but assuming I'm reading that correctly, the notion of burning rice hulls to power the process and thereby source their ash is a fantastic efficiency.
- londons_explore 7y agoThat lies between "silicon" and "electronic grade silicon" in the posted table, as you'd expect. Rice hulls cost something to produce too, and I bet you need a lot more than a kilo of them to make a kilo of silicon...
- dredmorbius 7y agoThe sourcing could definitely be better. The values smell about right to me (I've been exploring this space for a few years), and spot checks suggest they're reasonable. Alternative sourcing: https://www.sciencedirect.com/topics/engineering/embodied-energy https://www.sciencedirect.com/topics/engineering/embodied-en... (Hits: timber, recycled and stainless steel, aluminium, glass, plastics.) Enough so that I'd be inclined to believe the values. Low Tech Magazine is generally reliable in my experience.
- edejong 7y agoWould be nice to contrast this with the energy necessary to produce 1 kilogram of various foodstuffs.
- dredmorbius 7y agohttps://www.treehugger.com/green-food/energy-required-to-produce-a-pound-of-food.html https://www.treehugger.com/green-food/energy-required-to-pro...
- mrpurple_ 7y agoWhat about fuels like petrol? :)
- stewbrew 7y agoThe list is somewhat biased: Iron (from iron ore) [...] Steel (from iron) Paper (from standing timber) Is the energy for digging up the ore or felling that tree + transport + machinery for production included? Steel should probably also include the numbers for iron. The list would benefit from a common baseline. Without that these are just random numbers.
- londons_explore 7y agoI'd prefer it said: Steel (from the things Steel is typically made from in 2019 - 80% iron ore, 50% process X, 20% recycled) That gets tricky, because many industrial processes use large amounts of energy, but only because that energy is effectively 'free' as waste heat from other processes.
- dredmorbius 7y agoThe list is specifying clearly what the derived energy values are for. Not that they're necessarily typical (though I suspect these are). There's a tremendous variability to industrial processes and material utilisation, including virgin vs. recycled materials. Listing from among options may help clarify engineering / manufacturing / consumption values and choices.
- ahigherugliness 7y agoIs measuring in kilograms a good way to think about this? How many kilograms of chips does my phone have?
- dredmorbius 7y agoIt normalises the metric across all levels of production. Scale according to use. A 5" iPhone weighs 138g. Much of that is probably battery, display, and case, so chips are on the order of 10% or less of the total. I'd estimate at <10g. The core processor is the A10 Fusion SoC, 125mm^2, probably a few mm thick. Silicon has a density of 2.3290 g/cm^3. That adds up to about 20-30g, depending on thickness, though I'm not sure of the density or thickness of a silicon wafer. I suspect actual mass is less.
- dredmorbius 7y agoFor those seeking sources for embodied energy, ICE seem to be among the more rigorous and accepted sources (I've encountered them before). Wikiedia cites similar values referencing ICE. http://www.circularecology.com/embodied-energy-and-carbon-footprint-database.html http://www.circularecology.com/embodied-energy-and-carbon-fo... https://en.wikipedia.org/wiki/Embodied_energy https://en.wikipedia.org/wiki/Embodied_energy