The pdf is referring to radiant energy, no??
The series of pdfs postulates something that many others (Leedskalnin, Schauberger, Davson, Ighina, and yes even Moray to some extent) have put forward before - the idea of the polarized entities (north and south pole magnets for instance in Leedskalnin) making up all matter, and all life in particular. To quote part 4:
When we realize that our bodies are made up of "polarized entities," and that the erth is a great magnet revolving in a universe of polarized energies, then we shall understand that the more we are in harmony with these COSMIC energies, the more benelit Nature will bestow upon us.
It deals with various anomalous facts observed in nature, particularly in farming, where yield appears to have been improved by what the author refers to as "electroculture". This includes not only "radiant energy" from sunlight, but alignment with the magnetic fields of force that are so vital on this planet for shaping biological evolution... subtle formative forces of nature that we have of course unbalanced in the process of putting such energy to work in our machines.
It is somewhat dated (this was written in the 1940s), but I suppose I have a taste for this kind of stuff, anything that attempts to probe these inner dynamics of life, and I've already benefited from reading similar things before