Retail cost per watt for terrestrial panel: under 45c
Manufacturing cost per watt of space grade solar panel: up to $450
Annual performance degradation of terrestrial solar panel: under 0.5%
That of space-grade solar panel: up to 2%
Life span of terrestrial panel: about 2x that of space panel.
Total difference in cost per watt feeding a DC load in space vs on land: about x400
And that's ignoring launch costs. It makes absolutely zero sense. And given the scale of production and investment in manufacturing, terrestrial is likely to stretch even further ahead in the cost stakes.
The idea is still a real stretch, but according to Google's paper in Joule [1] they're putting satellites in low Earth orbit and only targeting a service lifetime of 5 years. Over that short time, with the correspondingly modest radiation exposure, you can use inexpensive silicon solar cells like you would use for terrestrial solar farms. The expensive space grade solar cells from e.g. Boeing Spectrolab are more resistant to radiation, and achieve higher conversion efficiencies, but silicon cells are fine for satellites like these.
Starlink satellites already use silicon solar cells, since they too are cost sensitive and don't have long lifespans:
On the Starlink V2 mini satellite, we predict that approximately 5% of the mass of the entire satellite could survive reentry. The biggest contributor (~90% of the surviving mass) is silicon from the solar cells, which has a high melting point...
derriz · · focus · HN ↗
Capacity factor of terrestrial solar panel: 23%
Retail cost per watt for terrestrial panel: under 45c
Manufacturing cost per watt of space grade solar panel: up to $450
Annual performance degradation of terrestrial solar panel: under 0.5%
That of space-grade solar panel: up to 2%
Life span of terrestrial panel: about 2x that of space panel.
Total difference in cost per watt feeding a DC load in space vs on land: about x400
And that's ignoring launch costs. It makes absolutely zero sense. And given the scale of production and investment in manufacturing, terrestrial is likely to stretch even further ahead in the cost stakes.
philipkglass · · focus · HN ↗
Starlink satellites already use silicon solar cells, since they too are cost sensitive and don't have long lifespans:
<a href="https://starlink.com/public-files/Starlink_Approach_to_Satellite_Demisability.pdf" rel="nofollow">https://starlink.com/public-files/Starlink_Approach_to_Satel...
On the Starlink V2 mini satellite, we predict that approximately 5% of the mass of the entire satellite could survive reentry. The biggest contributor (~90% of the surviving mass) is silicon from the solar cells, which has a high melting point...
[1] <a href="https://www.cell.com/joule/fulltext/S2542-4351(26)00362-4" rel="nofollow">https://www.cell.com/joule/fulltext/S2542-4351(26)00362-4