This month’s blackout reminded all of us how vulnerable our modern lifestyle can be. We depend on cell phones, on the Internet, on satellite TV and computer-controlled traffic lights. And all of these things depend on electricity, and our electricity depends on a complex system of power plants, switching stations and long-distance, high-voltage, high-tension power lines. The system even goes by a catchy, science-fictional name: the grid (although actually it’s three separate grids).
Ironically, the power systems of many Third World countries are simpler and less vulnerable, because they rely on power which is locally generated, locally consumed and locally unavailable when a piece of the system breaks down. However, for better or worse, North America (United States, Canada and parts of Mexico) have opted for much more interconnected system. And there is a logic to this, because one of the primary consumers of electricity is refrigeration: our freezers, air conditioners and household and industrial refrigerators. As a result, electricity use tends to spike sharply during a summer heat wave, and these heat waves appear unpredictably, here and there on the map, coming and going without warning. Using the Third World model of electricity generation, every state–probably every major metropolitan area–in North America would need enough surplus energy-generating capacity to handle even the biggest, wettest, nastiest heat wave it could possibly expect. This would mean building extra power plants (or extra boilers and turbines and generators in existing power plants) that would sit idle 99 percent of the time. Multiply this by the number of states and metropolitan areas in North America, and we’re talking about a lot of costly construction.
It’s unnecessary construction as well, because heat waves rarely if ever occur over the entire continent all at once. Even in the hottest of summers, this Third World model still leaves a lot of idle power plants in the areas that happen, on any particular day, to be rainy and cool. These plants would need to remain in “ready” load, fully staffed and able to turn on the juice with, at most, a few days’ notice. This is, to put it mildly, a waste of time and money. The obvious solution is the one we actually use: to provide excess capacity at the national and regional level and transport electricity to where it’s most needed.
This is all well and good, but it still requires a fair bit of infrastructure, which needs to be paid for and cared for by someone. In decades past, that someone was a network of regulated monopolies–private utility companies controlled by state and federal governments, and charged with generating and distributing power for all users. More recently, though, that system has been deregulated. We still get electricity from local providers, but these days we may have a choice among several competitors with different price structures and different levels of service. More importantly, these companies no longer trade their excess megawatts to each other at regulated (and artificially low) prices, but instead sell them to the highest bidder.
This isn’t necessarily a bad thing either; free markets are quick and self-correcting, and by their nature they bring inefficiencies into plain view. For example, the “NIMBY” (not in my backyard) tendency of us North Americans is to find power plants ugly and smelly and disagreeable, and to place our homes and communities as far from them as we reasonably can. Unfortunately, the electrical resistance of even the best power lines causes a net loss of energy, which increases with the length of the lines. Over a distance of 100 miles, for example, you lose, on average, about 1 percent of the power you generate. This is a waste in every possible way: extra effort, extra pollution, extra depletion of the world’s resources and, as a natural byproduct, extra costs. Under the old model, these costs were shared more or less equally, and as a result many states were free to get by producing far less energy than they consumed, simply obtaining the rest from the grid. With transmission losses, yes, and with the ugly, smelly power plants in somebody else’s state. Today, this wasteful practice is much harder to get away with, as it drives up the local price of electricity–sometimes to absurdly astronomical levels as power is shipped halfway across the continent.
But still, why the blackout?
he simple answer is: because blackout are better than brownouts. Electrical devices are often finicky about the exact voltage levels they receive, and sensitive electronic devices (like the computer on which you’re reading this) are particularly vulnerable to ripples and spikes, and especially sudden, long-lasting drops in the power line’s voltage. To put it simply, they require a fixed amount of energy in order to run, and less voltage means they draw more current, and heat up more and wear out much, much faster. If you don’t believe me, plug your computer in to a dimmer switch and see what happens! Similarly, the draw through power lines also increases in a brownout, resulting not only in more waste, but also in excess heat, which damages both the lines and the switches that operate them, and can even start fires.
In imagining the behavior of electricity, I like to use water as an analogy: Voltage is like the pressure in your pipes, in psi or Pascals or however you choose to measure it. Current is like the flow rate, in gallons or liters per minute, of water physically flowing through the pipe, and resistance is like friction, which slows the water down, so you have to work harder to push it through. A pipe can take only so much pressure or flow rate before it bursts, and a stream of water can take only so much friction before it stops flowing. So, to avoid the widespread chaos that a brownout would cause, our grid is designed the same way as the wiring in your house: with large numbers of fuses and circuit breakers, which cut off the flow of power when the current increases beyond a certain threshold.
In some sense, the grid behaved exactly as it was supposed to on Aug. 14, 2003. A spike of demand in a particular area (possibly Niagara) brought current flooding in, burning out a couple of transmission lines in Ohio, and the system responded by shutting down circuit breakers, which then increased demand on other nearby lines and switches, which also shut down. This domino effect sounds crazy, but in fact, any system has its failure point, beyond which it simply will not operate. Once you reach this point, your choices are: (a) an ugly shutdown mode where everyone’s stuff gets fried, or (b) a graceful one where the system shuts itself down, containing the physical damage to as small an area as possible.
And, of course, there is nothing new about massive blackouts. This may be the largest one in world history, but it’s not so terribly different, in its causes and effects, from the ones in 1965 (northeastern U.S. and Canada), 1977 (New York) and 1996 (Oregon-California-Texas). But given that North America’s power consumption is 230 percent higher today than it was in 1965, we can, in some sense, pat ourselves on the back that the system is not really any worse now than it was then.
Our sin, if we have one, is in running too close to the failure point, too much of the time.
Unfortunately, this is not an easy problem to solve. It requires the investment of a lot of money, to build new wires, new switching stations, new power plants. Whether this money comes from the government or from private companies is immaterial: The consumer pays the price either way, in the form of higher taxes or higher utility bills. How popular is that? And power plants are a keg of worms unto themselves, because coal and gas plants (where most North American energy comes from) pollute our air and consume our irreplaceable fossil fuels. Wind farms are expensive and prone to breakdown and, as we’ve seen in community after community, unsightly enough that people still don’t want them in their backyards. Meanwhile, solar energy is grossly inefficient in anything but a desert, has high up-front costs, frequently relies on toxic materials and disrupts the normal heat and light of the area where it’s used. (We may all live to see a day when the roofs and even walls of our buildings are dead black and cool to the touch, covered with hyperefficient solar cells drinking in every photon of energy the sun can throw at them. This may be efficient, but it sure ain’t beautiful.)
And then there is nuclear power. The waste products of this process are rods of heavy metal so toxic and radioactive that simply picking one up for a few seconds could be enough to kill you. Radiation is invisible and intangible, it does not have a smell, and it causes ailments ranging from radiation sickness to chromosome damage, birth defects to cancer. This understandably makes it unpopular, and in the wake of the 1986 Chernobyl accident, which killed dozens of people immediately and will probably (if slightly) shorten the lives of thousands more, it has become politically all but impossible to build a nuclear power plant. This is partly a reflection of public ignorance, since the “Triga” design of a modern reactor causes the nuclear reaction to stop if the fuel rods get too warm. If you shut off the coolant–even if you beat the core to pieces with a crowbar–the reactor will simply shut down. Barring some external (and very large) source of power, a meltdown is literally impossible–actually forbidden by the laws of physics. But if people don’t want nuclear power, it’s probably unwise to force it down their throats.
And don’t get me started about hydrogen-burning power plants. Hydrogen is a wonderfully clean-burning fuel, but unlike wind and sunlight and oil it does not bubble up from the ground or rain down from the sky. Some planets, like Jupiter and Saturn, are made of pure hydrogen, but here on Earth all the hydrogen is embedded in complex molecules like water, methane and petroleum. Extracting it as a pure gas requires–you guessed it–energy, and the “cracking” process is not too terribly efficient. So whatever you may have read in the newspaper, hydrogen is not an energy source at all. Rather, it’s an inefficient means of storing energy from other sources, and transporting it around in trucks and bottles. Like the batteries you buy at the grocery store, it’s basically a way of exporting pollution. If I’ve done the math correctly, that MP3 player of yours produces about a gram of coal smoke an hour–somewhere else. Sadly, AA batteries are not the answer to our problems, and neither is hydrogen.
Still, we do have to have some kind of power, from some kind of source, resulting in some kind of pollution in somebody’s backyard. And this is an unpopular truth, ignored whenever possible by politicians and the general public alike. As a result, our newly deregulated utility companies, through some combination of greed and regulatory helplessness, have managed to avoid building enough surplus capacity into the system. Anyone who’s seriously concerned about this is, of course, free to leave the grid, roofing their home with shiny blue solar panels and filling their backyard, and perhaps their front yard, with windmills and heat pipes, generators and wires. You’ll need about a ton of batteries in your basement as well, and all this takes space and charm away from your home. It will also set you back tens or even hundreds of thousands of dollars. Sound like more trouble than it’s worth? Most people seem to think so, and that, in a nutshell, is why we had a blackout.
The other answer is, of course, even more appalling: We could use less electricity. The choice, like so many others in life, is ours to make.
Wil McCarthy is a rocket guidance engineer, robot designer, science-fiction author and occasional aquanaut. He has contributed to three interplanetary spacecraft, five communication and weather satellites, a line of landmine-clearing robots and some other “really cool stuff” he can’t tell us about. His short writings have graced the pages of Analog, Asimov’s, Wired, Nature and other major publications, and his book-length works include the New York Times notable Bloom, The Collapsium and most recently The Wellstone and a related nonfiction book, Hacking Matter.