For reference, in 2010 the US was estimated to have 60,000 km² of road & parking lots https://persquaremile.com/2011/01/20/800-million-spaces-and-nowhere-to-pa

For reference, in 2010 the US was estimated to have 60,000 km² of road & parking lots https://persquaremile.com/2011/01/20/800-million-spaces-and-nowhere-to-park/ https://persquaremile.com/2011/01/20/800-million-spaces-and-... So we have experience building infrastructure of a similar scale, though probably not quite at the speed currently needed to meet carbon emissions targets solely by building photovoltaics. Of course, deserts, and not cities, are the best places to put solar power, especially since the shade generated can be useful for crops, and we have tons of desert in the US