yeah, that sure makes it infeasible 👀

uh-huh. do you have the source data for that infographic?

it's a bit hard to read because it's ridiculously low-res (almost a full quarter of a megapixel), but I can at least make out the caption, which says "European cities with district heating systems (population)"

from that alone I suspect it's a bit misleading - it's ambiguous whether the population they're highlighting is the population of the city total, or the population served by the district heating system.

eg, if there's a city with 100k population, and a college campus in that city that serves 1000 students with district heating, does that show up on the map as a dot representing 1k population? or 100k?

as I said, this depends heavily on high population density. I don't doubt that it can work in European cities, or on American college campuses (because those tend to be some of the few places in the US that have population density approaching a European city, as well as the political tolerance for that sort of centrally managed infrastructure)

but the OP I replied to was talking about trying to do district heating in suburban / exurban Texas. I don't know if you're from the US, or if you've ever been to Texas. if you haven't, you probably don't understand the sheer scale of the sprawl we're talking about here. go pick one of the cities on that infographic, look up its population density (in people per square km), and compare it to the population density of suburbs in Dallas / Fort Worth. if they're even within an order of magnitude of each other, I'll give you a cookie.