I would like have a "refinery" with, wich could different components from Gas/other fuel as I already suggested: for example, it would have multiple output because of random chance of getting each component, chance wich would be lower and lower with their rarety/energy value.
And I think we should have tar or something else to craft bitumen/asphalt with gravel to build Industrial streets (maybe with a bonus of speed when walking on)
A new fuel based-gen sounds very good to me, as it would be the Thrird Non-Renewable Gen (I do not count the basic gen, wich is a gen only useful when starting/playing with forestry-EE)