Just because we've always done it that way doesn't mean we still should...
At the end of November 2012 I met with Professor Rong Zeng of Tsinghua University, and he told me of his long-term vision of an electric power system that only used Direct Current (DC). There is much to recommend this vision if one were starting a power system from scratch, but the US (and thus the world) settled on AC power about a century ago, after fierce competition between Edison and Tesla. Edison advocated DC power, Tesla advocated AC power, and eventually the AC power proponents triumphed. This historical conflict is one of several terrific examples of the importance of path dependence in technological and economic systems.
I was reminded of Professor Zeng’s vision when I read an article in EE times about the power systems needed for Light Emitting Diode (LED) fixtures. This article describes the circuitry needed to minimize electromagnetic interference from the switching power supplies in LED, circuitry that adds costs and complexity to end-user devices. If the houses were wired for DC, this complex circuitry simply wouldn’t be needed.
Of course, there might be other disadvantages to widespread use of DC power for power systems, but it’s not at all a given that the current state of a technological system is how we’d design it if we were creating it from scratch. And in fact, the point of whole systems design is to capture the benefits of designing from scratch, precisely because most technological systems are characterized by path dependence. So it’s important for those approaching problems for the first time not to assume that the way things are is the way things have to be. The future is ours to choose, and technological developments often push us into new design spaces that simply weren’t reachable before. Your goal is to find those spaces and use them to your advantage.
