I'd concur. It costs too much research time to unlock, too much coal to run, and just saves you a marginal amount of steel over using steam hubs. The gaps between steam hub coverage don't even matter, as you can just fit buildings that don't require heating in there.

I was thinking some people might find a use for it in The Arks if they had a big spread of buildings. Might be cheaper to extend the range than to heat each outlying building individually. Personally however, I never went beyond three or four outliers in that scenario.

I was thinking Arks as well. Due to the low population, you could cram all your houses, workshops, cookhouse, infirmary, and factory around the generator and run it with just one range upgrade. Since all your industry will be run by automatons, the only other buildings you'd need to worry about heating are the arks themselves and hothouses. However, there's still no reason why you would upgrade the range more than once.

However, this would mean you'd need to be a lot more aggressive with your tech, as you'd need to keep your heater technology ahead of the weather. If you ever had to plot down steam hubs, it's basically a waste of your time and you should have just built around hubs instead.

In all fairness, the generator is far more efficient in terms of ground coverage to coal consumption when the range is maxed out, so it's probably worth doing if for whatever reason you want to be as frugal with your coal as possible. Not that you'd ever actually need to with the game in its current state, but perhaps it'll be harder or feature a scenario based around coal scarcity in the future, so maybe then it'll be useful.

I did some back of the napkin math, and this seems to only be true if you don't get the 33% steam hub efficiency upgrade. If you do get that upgrade then you can run 9 steam hubs (or 4.5 hubs on expanded range) for the same cost as running the generator on max range. That's more than enough to cover an equivalent area, and gives you the freedom to position those hubs near resources to heat those workplaces. It also costs less research (T0/T2/T4 versus T1/T3/T5).

I'm going to give Refugees a shot later using only the range upgrades instead of steam hubs and see how it goes (New Home has way too many people and gets way too cold, and you can't reach all the arks on Arks with it), see if my opinion changes. I have used it before, but never exclusively without touching hubs.

3 x steam hubs can provide heat to 50-60 homes.

1 steam hub can cover up to 30 houses.

Are you looking for a generator?
https://www.dieselgeneratortech.com/