Paving deserts with black heat absorbers that are only 10-20% efficient in converting that energy to electricity could well end up affecting climate more than burning coal would
You can't cite efficiency percentages in a vacuum to imply they are a better or worse than alternatives, because those aren't percentages of the same kinds of things, and they don't tell you about the economics, production in absolute terms or EROEI.
Generating solar energy in deserts is often done with a mirror based heating system for this reason.
PV are designed to account for heat and "less efficiency" means they risk performing at 17-18% instead of 20%. And it's actually generating more total energy at 18% because more total sunlight is hitting it, an advantage in desserts.
I was thinking more long term though, deserts see much faster yearly degradation than places with more normal temps. (up to 2-3% compared to the standard 0.5-0.8%)
That's just an economic factor rather than a blocker. PVs are cheap as right now, and could be even cheaper if they weren't tariffed. I wouldn't be surprised if PVs in the desert is nonetheless the right approach right now, and not concentrators.
Coal starts with pulling down entire mountains to get to the coal. The whole process starts with environmental destruction and that's how it ends.
The thermal mass of the panels is no where near significant. Especially compared to a run away greenhouse effect we know coal to cause.
[0] https://www.nature.com/articles/s43247-024-01619-w.pdf
[1] https://acs.figshare.com/articles/journal_contribution/Net_Radiative_Forcing_from_Widespread_Deployment_of_Photovoltaics/2871685With proper site selection and albedo managed via density and bright ground treatment, you can expect net neutral local heat impact.