They scale just fine. Plus, they have no ongoing fuel or electricity costs.
All of the petroleum coke necessary for operating the A.S.S. is belted in on a single Mk5 belt from that impure oil well near the southern edge of the swamp, designated the Automated Swamp Site Heavy Oil Liquid Extractor. The A.S.S.H.O.L.E. is also where the S.H.I.T. gets all of its gas, from the nitrogen well in the nearby dangle spires.