The public’s widespread desire to become informed about energy has been, in part, satisfied by excellent media coverage and by a plethora of good books on the subject. Most of these books are, quite naturally, journalistically slanted and treat technology superficially. Granted that of the various components of the problem—technology, economics, politics—technology represents only a small fraction of the total, but it is the one fraction that must be tackled first.
Those who need to understand the limitations of technical solutions require a good scientific grasp of what is being proposed. This book tries to explain how each energy process discussed actually works. A reasonable degree of mathematics is used to unify and clarify the explanations. By discussing fundamentals more than the state of art, it is hoped to delay the obsolescence of this writing, especially in this moment of very fast evolution of ideas. Those who wanting to labor in this field may find this book useful in preparing themselves to comprehend more specialized articles on whatever energy process that especially interests them.
After more than two centuries of intense development, even very mature technologies such as heat engines (Chapter 2) can still find new and improved forms. This is the case of the free-piston Stirling engine whose high efficiency and very long mantenance-free life has made it now a favorite for generating electricity in remote, unmanned locations, such as in spacecraft and in planetary exploration. This second edition expands the seven pages of the first edition dedicated to Stirling engines, and these ultramodern free-piston devices are included.
Thermoelectrics (Chapter 5) has also progressed in recent years with a better understanding of artificially created nano materials and superlattices that, in a way, get around the limitations of the Wiedemann–Franz–Lorenz law, allowing the synthesis of materials that have large electric conductivity but small heat conductivity.