
PSA: legendary burner inserters are fast enough for green belts. (AKA 2862MW solid fuel power)
Remember this delight from back in the day?
Well, as it turns out, you can do the same thing using legendary burner inserters, legendary boilers and stacked green belts and get 636 x 4.5MW = 2862MW of steam.
You do hit issues of pipeline length though, so have to 'split' it about 3/4 of the way up. I've included a pumping array to highlight how much steam is up there, but it'd be way more sensible to have parallel banks of chuffers so you don't need to bother pumping.
Water is still fine with a single pump per 'line' as 8 columns of boilers with an offshore pump each is sufficient - even legendary boilers only use 15/sec, so that's a total of 8 offshore pumps (and thus 8 'inline' pumps at the break is sufficient).
Leading to things like this:
https://factoriobin.com/post/bpt254
Sure. It would probably be way more sensible to use heat towers, but where's the fun in that?
Will attract biters to come and play from a rather substantial distance.