Many present-day industrial systems are dramatically overengineered, built to be prepared for maximum demand even though maximum demand is, by definition, rare.
This is easy to see when it comes to the private automobile. Take your average SUV. It has a range of hundreds of miles, the power to navigate hostile offroad territory, seating for seven people, and enough armor to survive direct collision from any angle, yet it spends 90 percent of the time parked and 9 percent ferrying one or two people back and forth to work. It's a marvel of modern engineering, a monster, a f*cking spaceship, and we use it to get groceries.
An SUV carries around the capacity to do the most extreme things ever asked of it, even if they are under 1 percent of use cases. The same goes for the road and highway system around it, which is built to handle peak traffic even though most roads and most parking spaces are empty most of the time. The whole system is wildly overbuilt.
The electricity system is too, though I'm not sure most people fully understand why. The reason is simply that there's no storage for electricity. Every electron worth of demand must be met by the simultaneous generation of an electron; similarly, every electron generated must be used immediately or it is lost. That imposes a certain logic on the system: There must always be enough power generation capacity available to handle the maximum possible demand (what's called "peak load"). The result is that most of our power plants, like most of our cars, spend most of their time parked, idled. They are there for those few minutes of the day when everyone gets home from work and turns on the TV.
This "real-time" nature of the grid is also what makes it vulnerable to blackouts. If power is not continuously fed to an area, the grid shuts down. (Super Bowl viewers were treated to a vivid demonstration of this vulnerability last week.) And sometimes, because most electricity grids are "dumb" and slow to react, the failures can cascade, leading to powerlessness for hundreds of thousands of customers.
Overbuilt and vulnerable is no way to go through life.
Jack Hidary explains this in his latest column and offers a telling comparison to a system that isn't so vulnerable to disruption: