From The New Atlantis, Summer 2025:
If you think the power system must run itself by now, you’re wrong. Behind every nicely toasted bagel is a vast network of generators, transformers, computers, wires — and, yes, people in backrooms sweating to make sure the juice flows exactly where, and when, it needs to go. What could possibly go wrong?Put a bagel in a toaster oven and push a button. In a few seconds, heating elements inside the oven glow red and heat the bagel. The action seems simple — after all, ten-year-olds routinely toast bagels without adult supervision. Matters look different if you inquire into what must happen to make the oven work. Pushing the button engages the mechanism of an incomprehensibly vast multinational network: the North American electrical grid.
The numbers are dazzling. The United States alone has more than 6 million miles of power lines, enough to stretch to the Moon and back twelve times. An average U.S. single-family home contains almost 200 pounds of copper wire — and there are more than 80 million U.S. single-family homes. The Empire State Building alone has more than 470 miles of electrical wiring. And all these miles upon miles upon miles of wire and cable and circuit are so routinely and reliably coupled that most of us think nothing of the fact that southern California gets power from hydroelectric dams a thousand miles away in northern Washington State. Constructed over more than a century, embodying entire political and economic histories, the North American electrical grid may be the most complex object ever created by our species.
Despite its complexity, though, every bit of that vast system is focused on just one task: transmitting an electric current.
To create an electric current, rotate a coil of copper wire around a child’s bar magnet or, conversely, rotate the bar magnet inside the coil. Either way, the magnet’s magnetic field moves with respect to the wire. All of us know the solar-system image of an atom, with a central nucleus orbited by electrons. Metals like copper — conductive metals, as they are known — are different. The electrons aren’t tied to individual atoms. Instead, they float among them, like dust motes in sunlit air. In conductive metals, a moving magnetic field “pushes” the electrons through the metal in a direction dictated by the magnetic field. The result is an electric current.
Electric generators, whether they are fueled by coal, oil, wind, water, natural gas, nuclear fission, or geothermal energy, all consist of the same two things: a rotor (a rotating part, as the name suggests) and a stator (a stationary part). One of these is a conductive metal, usually copper wire; the other is a magnet. The coal, oil, water, fission, and so on provide the power to spin the rotor around the stator, which produces electricity.
The big exception to this general rule is solar power. Solar power is primarily derived from photovoltaic panels, which directly convert the energy in sunlight into electricity. Rather than having rotors or stators, photovoltaic panels are made of “cells” of materials called semiconductors. When sunlight strikes the semiconductors, its energy knocks electrons free from their atoms. One surface of the panel is treated to make it receptive to the dislodged electrons, so they shift toward it. Electrons all carry a negative charge. When they move toward the treated surface, it becomes relatively more negative; meanwhile, the other side becomes relatively more positive. This imbalance creates a situation akin to the negative and positive terminals of a battery. When the cell’s terminals are connected, electricity flows through the circuit.
Whatever the energy source, making a current is straightforward, even easy — but everything else is a problem. Early electric utilities discovered this the hard way. The first commercial electric power plant in North America opened in Appleton, Wisconsin, on August 20, 1882. The second, built by the famed inventor Thomas Edison in Manhattan, opened two weeks later, on September 4. The Appleton plant, on the Fox River, was also the world’s first hydroelectric plant. The plant channeled the Fox’s current through the plant to turn a turbine — an axle with waterwheel-style blades. The turbine, spinning, turned a set of gears. The gears rotated a cylinder of conductive metal (the rotor) by six big magnets (the stator). An electric current emerged.
Edison made money from his patents on electric plants — his plant in Manhattan was mainly a demo. The people in Appleton had to cover their costs, which included paying Edison to license his patents, by selling and distributing electricity. This meant putting up big poles all over town and stringing wire on them, a pricey endeavor. Unfortunately, the costs didn’t go down as the customer base grew. Connecting the ten-thousandth home was nearly as expensive as the first.
Equally high were the costs of maintaining the system. The flow of electrons in a power line is not, so to speak, friction-free — it heats the metal, a phenomenon called resistance. (Resistance is why the elements in an electric range glow red and get hot.) If resistance heat can’t dissipate, a metal wire will soften, expand, and lengthen. If the wire is a power line, the heat will make the line sag between its supports. If the line droops too low, it can spark out onto nearby trees or other objects, causing a spike in the current or shorting out the line entirely. Today’s electric cables reduce the risk of flashes by being built with a complex multilayer design and sheathed with insulation. But sagging power lines are still responsible for a large fraction of the big wildfires in the West....
....MUCH MORE
