intend to do with it.
The Bottom Line: There’s no such thing as renewable energy. There are mechanisms we can build which tap ongoing energy flows, which are at best rebuildable.
A Joule is a Joule. Or is it?
Summary: Not all energy is created equal. Some energy provides greater benefits to humans and economies than others. So far, we’ve used the term “energy” as though it were more -or-less fungible with anything else labeled “energy.” In nature, most animals at least partly specialize in the types of food they can eat. Similarly, when it comes to our endosomatic energy, we need certain types of fuels. Our bodies run primarily on glucose. This happens in a series of chemical reactions, which transforms much of the food we eat into the molecule ATP, the energy currency of the cell which fuels our movements. It may be no surprise, then, to learn this has corollaries to our exosomatic energy use. We have already pointed out how our front-end energy transformations change calories of natural gas and diesel into calories of corn flakes and chicken, thus allowing us to effectively “eat fossils.” But even the exosomatic energy that remains as exosomatic energy varies considerably in how useful it is for our purposes.
First, a clarification: we’re using the general word “energy,” that mysterious and amazing stuff of which we’ve spoken. But what we’re really referring
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