In 2023, China installed an incredible 96 GWac of rooftop solar, up from 51 GW in 2022 – with most of the increase owed to the ‘whole county promotion’ policy scheme, under which large-scale rooftop portfolios of up to the hundred-MW scale are bid for and built in one go across entire municipalities. This raises the question – how long until the distribution networks run into congestion issues? If China had the same per capita ‘latent’ free space on its distributed grid as Vietnam (which got congested after 14 GW of sudden distributed additions in 2020, and has a 100 million population) then 200 GW would be the maximal amount of distributed photovoltaics that China could install before needing to…