As individuals, we most often focus upon a single energy technology: One we particularly like (e.g., solar or wind), or one we particularly dislike (e.g., fossil fuel or nuclear).
And then we all start arguing.
At Bell Labs I researched semiconductor devices for fiber optic communications. These were kissing cousins to solar cells, and I got to know a lot of people in the solar cell field (including the founders of two U.S. solar energy companies). So, naturally, for me, that "single energy technology" was solar cells. But for years, my friends told me that "when the cost of cells falls below $X.YZ / Watt, they will take over the world!" And then they fell below that cost. And they did not take over the world. I was clearly missing something. So I began reading almost every article, paper and book on energy I could find. And I eventually figured out what I'd missed: Sustainable energy is not just about the component technologies, it's about how they fit together to create a complete energy system. Put another way, the individual technologies are only pieces of a much larger puzzle. And, frustratingly, many of those pieces still have shapes that are blurred, ill-defined, and/or changing with time.
But why not build an energy system based on just one "piece," for instance solar cells? Because, for now, no single "piece" can affordably produce the amount of energy we need, when we need it. To illustrate, say that solar cell efficiencies suddenly skyrocketed, and costs plummeted. Wouldn't that make an all-solar energy system possible? Yes, but only if you were willing to spend your evenings in the dark, either shivering or sweating. The problem? Solar cells require intense sunlight to produce energy, which only happens (with luck) near midday. But our power consumption peaks in the evenings. So for a solar-based energy system to work, we would also need an effective and affordable way of storing huge quantities of midday energy for many hours - a technology "piece" we do not yet have. Or, if you lived on the U.S. east coast, you might tap into solar cells on the west coast, where the solar peak comes three hours later. But this would require another missing technological piece: efficient and affordable long-distance power transmission lines. So, even with miraculously improved solar cells, we would still need other (miraculously improved) pieces to build an energy system. And without such miracles, it's more likely that we will need many different energy-producing pieces, and many different complementary energy storage/transmission/ . . . pieces.
In my class, and now through this website, we'll examine the science and technology behind those energy "pieces," trying to define at least their present day shapes. But the real goal will be to then use that knowledge to figure out how those pieces might someday complete the "puzzle" of a truly sustainable energy system.