Alas, on the path to greater things achieved, quarrels of mankind see no relief; to build a house of time and stone, requires an ounce of flesh and bone.
MacKay's work makes a complex subject simple, is certainly effective at unit harmonization in a domain (energy) where an array of units can be thrown around without any regards for ease of comparison.
Given technological trends, maybe it makes sense for the next version of this work to be some sort of 'living' document/website, where calculations with changing variables (like efficiency of commercially deployed PV cells) change over time?
just because you're callin' that pollen dust -- don't mean your allergic nose won't sneeze bust.