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Here is a reference (thanks to jka) with lifetime emissions per energy source (including infrastructure and supply chain): https://www.ipcc.ch/site/assets/uplo

Here is a reference (thanks to jka) with lifetime emissions per energy source (including infrastructure and supply chain): https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5_annex-iii.pdf#page=7 https://www.ipcc.ch/site/assets/uploads/2018/02/ipcc_wg3_ar5... It shows nuclear lifetime emissions are lower than solar, but I think this report excludes the carbon footprint in manufacturing/recycling the renewables.

ceejayoz 6y ago
Refineries, mines, etc. don’t either.
- SCHiM 6y ago
  But that's why the energy density matters. For every KG of material mined you get more bang for buck.
  - ceejayoz 6y ago
    If you’re gonna do that, you need to measure the energy density of the uranium ore mined, not the purified product. Then, you have to figure out where photons net out on the wh/kg chart.
ineedasername 6y ago
Seems like a boot strapping problem to me. If we create enough solar/wind energy then we can devote some of that energy back to production of materials used to produce solar panels.
jka 6y ago
[outdated] You might be misinterpreting that report slightly - it estimates that all renewables -- with the exception of utility-scale solar -- currently emit fewer lifetime emissions than nuclear. Digging into why utility-scale solar is currently an exception, one potentially relevant factor is that utility-scale solar is working through some regulatory and infrastructure obstacles[1] as it scales up. [outdated] That said, I couldn't see any indication that manufacturing solar panels themselves is an issue. If residential solar has lower lifecycle emissions, then I wonder why the panel manufacturing would be a problem. Do you have any more information on that? Edit: noting that first and third paragraphs are outdated following edits to parent comment [1] - https://www.ipcc.ch/site/assets/uploads/2018/03/Chapter-3-Direct-Solar-Energy-1.pdf#page=34 https://www.ipcc.ch/site/assets/uploads/2018/03/Chapter-3-Di...
- deleted 6y ago
  [deleted]
- jka 6y ago
  Self-reply: d'oh, I may have misinterpreted on this too; the data in the report is a little more complex. I was comparing the 'max' lifetime estimates per-source (the third value in the column) rather than the medians (second value). Using the medians, wind is cleanest, followed by nuclear, followed by solar. I'd encourage anyone interested to read the linked report to confirm their understanding. It'd be nice to find trends over time to see whether these estimates (and thus the overall ordering) is likely to remain stable, or whether recent developments may change the situation.
  - bra-ket 6y ago
    yeah, thanks for this, and sorry for edits, I need to search for a good reference on manufacturing/recycling emissions for renewables, i think the report either excludes or underestimates the bootstrapping and maintenance carbon footprint. I got my original info from a professor in nuclear engineering program years ago, I wish I still had the notes.
    - jka 6y ago
      All good, and no problem - I try to follow a mostly-append-only commenting approach where possible, hence the edit notes. Glad to read what you find; I think some of these figures may also be due for updates given the latest updates around small modular reactors -- and no doubt renewable tech continues to advance too.

ceejayoz 6y ago

Refineries, mines, etc. don’t either.

SCHiM 6y ago
But that's why the energy density matters. For every KG of material mined you get more bang for buck.
- ceejayoz 6y ago
  If you’re gonna do that, you need to measure the energy density of the uranium ore mined, not the purified product. Then, you have to figure out where photons net out on the wh/kg chart.

ineedasername 6y ago

Seems like a boot strapping problem to me. If we create enough solar/wind energy then we can devote some of that energy back to production of materials used to produce solar panels.

jka 6y ago

[outdated] You might be misinterpreting that report slightly - it estimates that all renewables -- with the exception of utility-scale solar -- currently emit fewer lifetime emissions than nuclear. Digging into why utility-scale solar is currently an exception, one potentially relevant factor is that utility-scale solar is working through some regulatory and infrastructure obstacles[1] as it scales up. [outdated] That said, I couldn't see any indication that manufacturing solar panels themselves is an issue. If residential solar has lower lifecycle emissions, then I wonder why the panel manufacturing would be a problem. Do you have any more information on that? Edit: noting that first and third paragraphs are outdated following edits to parent comment [1] - https://www.ipcc.ch/site/assets/uploads/2018/03/Chapter-3-Direct-Solar-Energy-1.pdf#page=34 https://www.ipcc.ch/site/assets/uploads/2018/03/Chapter-3-Di...

deleted 6y ago
[deleted]
jka 6y ago
Self-reply: d'oh, I may have misinterpreted on this too; the data in the report is a little more complex. I was comparing the 'max' lifetime estimates per-source (the third value in the column) rather than the medians (second value). Using the medians, wind is cleanest, followed by nuclear, followed by solar. I'd encourage anyone interested to read the linked report to confirm their understanding. It'd be nice to find trends over time to see whether these estimates (and thus the overall ordering) is likely to remain stable, or whether recent developments may change the situation.
- bra-ket 6y ago
  yeah, thanks for this, and sorry for edits, I need to search for a good reference on manufacturing/recycling emissions for renewables, i think the report either excludes or underestimates the bootstrapping and maintenance carbon footprint. I got my original info from a professor in nuclear engineering program years ago, I wish I still had the notes.
  - jka 6y ago
    All good, and no problem - I try to follow a mostly-append-only commenting approach where possible, hence the edit notes. Glad to read what you find; I think some of these figures may also be due for updates given the latest updates around small modular reactors -- and no doubt renewable tech continues to advance too.