Value chain · CLM-1462
Low confidence
The evidence behind this statement is thin, indirect or second-hand. Read it as a lead to check, not as a settled finding.
In plain terms
A 2020 paper's finding that its detailed method gave five to six times the carbon of an earlier, simpler study of the same 1978 design compares a carbon-dioxide-only figure with a figure that also counts other greenhouse gases, and the paper labels the earlier figure two different ways in two places.
The claim as recorded
SRC-212 states that its process-based results for the 1978 DOE/NASA Reference System, 112.27 and 122.63 gCO2e/kWh, are 5.62 and 6.13 times the 20 g/kWh input-output result of Asakura et al. for the same design, but the two are not like for like: SRC-212's own p4 says that input-output model "focused exclusively on CO2" and gives its result as "20 gCO2/kWh", and SRC-216, the same authors' 2002 discussion paper, gives 20 g CO2/kWh with no CO2e conversion found in its 19 PDF pages, whereas SRC-212's results are CO2 equivalent; SRC-212 labels the same comparator "20 gCO2e/kWh" on its p12.
Evidence behind this: Rests on SRC-212, SRC-216 and SRC-009 (each T5); the reasoning and the ratio arithmetic are the register's own.
Scope and limits
This does NOT show that the method difference is spurious. Carbon dioxide dominates the greenhouse gas inventory of most industrial supply chains, so the CO2-only to CO2e correction is very unlikely to account for a factor of five or six (our reasoning; no held source quantifies it for this system). The record shows that the ratio is confounded and its precision unwarranted, not that its direction is wrong, and it may not be used to argue that the two studies agree. SRC-212 cites the 20 g figure to a 2000 conference paper by the same five authors (its reference [17]), which is not held; SRC-216 is their 2002 discussion paper and gives the same figure. By SRC-212's own figures the silicon ratio is 5.61 (112.27 divided by 20), not over 5.62. The same lead author's 2024 paper (SRC-009 printed p.4) describes the input-output study as covering CO2 only, restates the process-based results as 112 and 123 gCO2e/kWh without a ratio, and says the published SBSP life cycle studies are not comparable because their modelling approaches differ. A like-for-like comparison would need a CO2e version of the input-output study, which no held source provides.
What it assumes
No assumptions are recorded against this claim.
Where it comes from
p12: "the calculated value of the silicon option is over 5.62 times higher than the prediction of 20 gCO2e/kWh for the DOE/NASA SPS Reference System made by Asakura et al. [17]". SRC-212 p4 holds the claim's two quoted phrases, in section 2.3. SRC-216 printed p.8 (PDF p.11): Table 6 headed "(units: g CO2 /kWh)"; a text search of all 19 PDF pages, both appendices included, for CO2e, CO2 eq, equivalent, greenhouse, GHG, CH4, methane, N2O, nitrous and global warming finds only the introduction's mention of the greenhouse effect (printed p.1) and an industry sector named methane derivatives in Table 8 (printed p.10).
Related records
- Answers question
- QST-008 not published in this release
- Supersedes
- CLM-0858 not published in this release
Cite this
energyaperture.com/c/clm-1462
CLM-1462, Energy Aperture, as of 2020.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-009
- CLM-0182When two different research teams assessed the exact same 1978 space solar power design, the older accounting method (which spreads...CLM-0825The authors argue that the cost-based way of estimating carbon is too coarse for a custom-built industry like spacecraft, and they conclude...CLM-0826When the authors redid NASA's own 2024 figures for two satellite designs using their materials-based method instead of NASA's cost-based...CLM-0827The authors say NASA's 2024 carbon figures for two satellite designs came out of a model built on NASA's own cost estimates, and that NASA...CLM-0828The authors say ESA's own space life-cycle guidance advises against the cost-based method because it tends to overstate environmental...CLM-0829The authors leave alumina, black carbon and water vapour from rocket exhaust out of their own carbon study because the atmospheric effects...CLM-0830The authors say an environmental claim about a space technology counts for nothing unless a proper standardised life-cycle study backs it...CLM-0831This is a conference paper from October 2024 that does not claim to have been independently peer reviewed, states that it calculated no...More on the source page.
- Also from SRC-212
- CLM-0316In 2009 three researchers guessed that, once the energy to deliver and use it is counted, an oil-based fuel must return at least about 3...CLM-0810A 2020 modelling study estimated that, across its whole operating life from 2040 to 2100, the 1978 NASA/DOE space solar power design would...CLM-0811In a 2020 modelling study of the 1978 NASA/DOE space solar power design, the carbon per kilowatt-hour fell the longer the satellites were...CLM-0812A 2020 modelling study of the 1978 NASA/DOE design estimated that its ozone-depleting emissions, almost all from burning rocket fuel at...CLM-0813The paper's detailed component-by-component calculation gives a carbon figure five to six times higher than an older top-down calculation...CLM-0814A 2020 conference paper's own cost model put the whole 60-satellite programme of the 1978 US reference design at about 3.86 trillion US...CLM-0815The 2020 study of the 1978 NASA/DOE design did not count any warming from the microwave beams themselves, saying that is too hard to...CLM-0816In their 2020 study of the 1978 NASA/DOE design, the authors list their own weak points: only whole-system detail rather than part-by-part...More on the source page.
- Also from SRC-216
- CLM-0818A 2002 Japanese input-output study estimates that building and launching a 1978-design fleet of 60 solar power satellites would release...CLM-0819A 2002 Japanese input-output study estimates that if each new satellite were built with electricity from those already working, a fleet of...CLM-0820For comparison in the same units, a 2002 Japanese study of space solar power reports about 22 grams of carbon dioxide per kilowatt-hour for...CLM-0821In a 2002 Japanese study of the 1978 US design, a table splits the estimated carbon dioxide from building and launching the system by part...CLM-0822In a 2002 Japanese study of the 1978 US design, building the launch rockets and the vehicles that move cargo and crews between orbits...CLM-0823A 2002 Japanese study's carbon dioxide figures for space solar power come from Japan's 1990 economic input-output tables, with 405 industry...CLM-0824This is a 2002 discussion paper that says it summarises two 1998 discussion papers by an overlapping group of authors, does not point to...