combined heat and power isn't a technology unique to eastern block countries, but surely centralized city planning makes it easier to pump waste heat into municipal heating grid (or out to some chemical works or such). tbh it didn't even occur to me that there are serious cities (population 100k+) that don't have city-owned heating grid, even 50k towns and smaller can have their own CHP plants (tiny one, fits in shipping container or two)

and it's not just some towns no no no. it was implemented everywhere where it was practical. near big cities - these need both power and heat, so okayish coal is shipped to them by rail, burned there and provides both heat and energy. beijing for example runs on 10 or so large CHP plants iirc. near lignite mines - lignite is burned there (does not make sense to ship it anywhere else, too shitty) and nearby town has free heat. where there's neither, either coal was shipped to be burned in heating plants, centralized or individual, or gas was delivered by pipelines also for heating, and energy was delivered from larger centralized facilities. if there's fuckton of energy somehow, like in russian far east with their abundant hydropower, or nothing else is practical, in some places heating was electric

NYC has steam pipelines running around the city, doesn't that use CHP plants?