Value chain · CLM-0839
In plain terms
A 2022 European consultancy study for ESA calculated that launching one space solar power satellite of the SPS-Alpha type would release about 2.6 million tonnes of greenhouse gas, from roughly 760 Starship flights each responsible for about 3,400 tonnes.
The claim as recorded
SRC-207 gives a one-off bottom-up total of approximately 2.6 million tonnes CO2e to deploy the SPACE SEGMENT of one SPS-Alpha reference system of stated mass 7,600 t, derived as approximately 760 Starship and Super Heavy launches at approximately 3,400 t CO2e per launch, with the per-launch figure built from 4,800 t of propellant at 78 per cent oxygen and 22 per cent methane giving 1,056 t of methane, oxidised at 2.75 kg CO2 per kg methane to 2,904 t CO2, plus 1.7 t of NOx at a global warming potential of 298 giving 506.6 t CO2e.
Scope and limits
This is a TOTAL in tonnes CO2e for the space segment of ONE system, NOT an intensity and NOT a per-kWh figure, and it may never be compared with any gCO2e/kWh number without first dividing by a stated lifetime energy output. It covers the space segment only, excluding the rectenna and ground segment, which other assessments find to be the largest single contributor. As a commissioned consultancy study it may be used for method, parameter ranges and structure, but NOT as independent confirmation of the commissioning party's own case. The intermediate 1,056 t, 2,904 t and 506.6 t are arithmetic from the inputs the page prints, and the page calls the 2.6 million tons a total CO2 emission although it is built from per-launch CO2-equivalent figures. The derivation is that of the companion TN 03 (SRC-206 p.23, 14 July 2022), which takes the 7,600 t from an IAC 2021 paper on SPS-ALPHA Mark-III (its [RD03]), the propellant mass from a Twitter post ([RD15]) and the factor 298 from a German Environment Agency web page ([RD17]); the 6,100 to 16,500 t space-segment range this document gives on p.42 and p.72 is TN 03's own estimate at 71 and 42 per cent wireless power transmission efficiency (SRC-206 p.55, Table 8-4), so the launch total does not use the study's own mass estimate. The study applies a global warming potential of 298, conventionally that of nitrous oxide, to generic "NOx", which is imprecise; TN 03 calls NOx "Nitrous Oxide".
What it assumes
No assumptions are recorded against this claim.
Where it comes from
p.73. Derivation chain checked arithmetically in this session: 1,056 t methane x 2.75 = 2,904 t CO2; 1.7 t x 298 = 506.6 t CO2e; sum 3,410.6 t per launch, consistent with the printed "c.3,400 t". 7,600 t at the document's stated ratio of 10 launches per 100 t delivered to GEO gives 760 launches; 760 x 3,400 = 2,584,000 t, consistent with the printed "2.6 million tons", which the page calls the total CO2 emission.
Related records
- Answers question
- QST-008 not published in this release
Cite this
energyaperture.com/c/clm-0839
CLM-0839, Energy Aperture, as of 2022.
Connected records
Other published records linked to this one. A list, not a judgement.
- Also from SRC-207
- CLM-0710The second European study, which had never been obtained here, is now in the archive. It puts the cost of a two-gigawatt first system at...CLM-0840This 2022 ESA-commissioned study gave a total tonnage of greenhouse gas for launching a satellite but never converted it into emissions per...CLM-0841This 2022 study was written by two European firms under contract to the European Space Agency, and it cites none of the earlier life-cycle...