[In How Did We Find Out About Energy?] Isaac Asimov gives us a history of the development of man's intellectual concept of energy; [in Energy for the 21st Century] Franklyn Branley confines his discussion of the basic concept to a brief first chapter and devotes most of the book to a consideration of practical energy sources. (p. 182)

Since Branley discusses the abstract concept of energy only in the first chapter, the idea does not come across too clearly. For example, the discussion of energy as work done against a force field (such as gravity) is rather weak; the distinction between recoverable and irrecoverable energy is missed. In the rest of the book, the history of man's increasing demand for energy is especially well done; the quantitative examples are good….

Some of his details are questionable. In the nuclear chapter he speaks of the heat wasted by atomic power plants and of the damage done to the environment; he fails to mention that a fossil fuel plant wastes at least as much heat in producing the same power. On page 30, he perpetuates the superstition that a nuclear power plant can explode like a nuclear bomb. All in all, Asimov is more optimistic about the energy situation than Branley. Whether anyone without an advanced degree in physics is qualified to choose between their viewpoints seems debatable. (p. 183)