The presentation from NREL is good stuff, but why have people waited so long? Back in the late 1960's, troglodyte hippy chemistry majors were getting high and riffing about the end of the petroleum era, and the need to convert to cellulose as a feedstock. (I know; I was there.)
By the way, we also had a curious little model for the second law of thermodynamics (increase of entropy.) One was to imagine a huge projection screen, showing the entire earth. The motions of all the atoms comprising the body of any individual in the room were imagined to be illuminated on an otherwise dark background, and to have their motions projected on the screen, with 500 years time -- centered on the year in which the chosen individual was born -- passing in about 30 seconds -- that is, a very accelerated view. What would it look like? A confused mass of meandering dots suddenly coalescing into a bright blob, which would stay intact for a moment or two, before reverting to a confused mass of meandering dots.