To be a green wizard you have to understand energy flow and do away with the concept that energy is infinite.
Green Wizardry (New Society Publishers, 2013) is a comprehensive manual for today’s green wizard-in-training. From basic concepts of ecology to a plethora of practical techniques, author John Michael Greer offers a solid tech toolkit for anyone concerned about decreasing our dependence on energy. This excerpt is from part one, “Principles.”
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It’s not accidental that the appropriate tech movement of the 1970s was brought into being by the experience of energy crisis, or that tools and insights having to do with energy played a central role in that movement. In the most pragmatic of senses, understand energy and you understand the whole art of appropriate technology. In the broadest of senses, understand energy and you understand the predicament that is looming up like a wave in front of the world’s industrial societies, and you also understand what we can and cannot expect to get done in the relatively short time we have left before the pressures unleashed by that predicament crest, break, and wash most of the modern world’s certainties away.
Important as it is, though, energy doesn’t stand alone. Two other concepts join the concept of energy to provide the central triad of principles that undergird this book and the perspectives and practices it explores. The first of these additional concepts is matter; the second is information. These three—energy, matter, and information—flow constantly through every whole system, in nature or in human society. Understand these flows and you understand the system. Each of the three, though, follows its own rules, so we’ll explore them one at a time.
We can start with some basic definitions. Energy is the capacity to do work. It cannot be created or destroyed, but the amount and kind of work it can do can change. The more concentrated it is, compared to its surroundings, the more work it can do; the less the difference in its concentration and the background level of energy around it, the less work it can do. Left to itself, it moves from more concentrated to more diffuse forms over time, so everything you do with energy has a price tag, measured in a loss of concentration. These are the groundrules of thermodynamics, and everything a green wizard does comes back to them in one way or another.
Some examples will help show how these rules work. In energy terms, for instance, a garden bed is a device for collecting solar energy by way of the biochemical dance of photosynthesis. Follow a ray of sunlight from the seething thermonuclear cauldron of the sun, across 93 million miles of hard vacuum and a few dozen miles of atmosphere, until it falls on the garden bed. About half the sunlight reflects off the plants, which is why the leaves look bright green to you instead of flat black; most of the rest is used by the plants to draw water up from the ground and expel it as water vapor into the air; a few percent is caught by chloroplasts—tiny green disks inside the cells of every green plant—and used to turn water and carbon dioxide into sugars, which are rich in chemical energy and power the complex cascade of processes we call life.
Most of those sugars are used up keeping the plant alive. The rest are stored for the plant’s future needs, though a percentage of them get hijacked if some animal eats the plant. Most of the energy in the plants the animal eats gets used up keeping the animal alive; the rest get stored until another animal eats the first animal, and the process repeats. Sooner or later, an animal manages to die without immediately ending up in something else’s stomach, and its body becomes a lunch counter for all the creatures—and there are a lot of them—that make a living by cleaning up dead things. By the time they’re finished with their work, the last of the energy from the original beam of sunlight that fell on the garden bed has been lost to the food chain.
What happens to it then? It turns into diffuse background heat. That’s the elephant’s graveyard of thermodynamics, the place useful energy goes to die. When you do anything with energy—concentrate it, move it, change its form—a price has to be paid in diffuse heat. All along the chain from the sunlight first hitting the leaf to the last bacterium munching on the last scrap of dead fox, what isn’t passed onward is turned directly or indirectly into heat so diffuse that it can’t be made to do any work other than jiggling molecules a little. The metabolism of the plant generates a trickle of heat; the friction of the beetle’s legs on the leaf generates a tiny pulse of heat; the mouse, the snake, and the fox all turn most of the energy they take in into heat, and all that heat radiates out into the great outdoors, warming the atmosphere by a tiny fraction of a degree, and slowly spreading up and out into the ultimate heat sink of deep space.
That’s one example. For another, let’s take a solar water heater, the simple kind that’s basically a tank in a glassed-in enclosure set on top of somebody’s roof. Once again we start with a ray of sunlight crossing deep space and Earth’s atmosphere to get to its target. The light passes through the glass and slams into the black metal of the water tank, giving up much of its energy in the form of heat. Inside the metal is water, maybe fifty gallons of it; it takes a fair amount of heat to bring fifty gallons of water to the temperature of a good hot bath, but the steady pounding of photons against the black metal tank will do the trick in just a few hours.
Most of what makes building a solar water heater complex is a matter of keeping that relatively concentrated heat in the water where it belongs, instead of letting it leak out as—you guessed it—diffuse background heat. The glass in front of the tank is there to keep moving air from carrying heat away, and it also helps hold heat in by way of a clever bit of physics: most of the energy that matter absorbs from visible light downshifts to infrared light as it tries to escape, and glass lets visible light pass through it but reflects infrared back the way it came. (This is known as the greenhouse effect, by the way, and we’ll be using it later on in this book, not least in the context of actual greenhouses.) All the surfaces of the tank that aren’t facing the sun are surrounded by insulation to keep heat from sneaking away, and the pipes that carry hot water down from the heater to the bathtub and other uses are wrapped with insulation. Even so, some of the energy slips out from the tank, some of it makes a break for it through the insulation around the pipes, and the rest of it starts becoming background heat the moment it leaves the faucet.
There are five points I’d like you to take home from these examples. The first is that both the plant and the solar heater function as a result of the same process: the flow of energy from the sun to Earth. Start looking at everything that goes on around you as an energy flow that starts from a concentrated source—almost always the sun—and ends in diffuse heat. If you do this, you’ll find that a great deal of the material in this book is simply common sense—and a great many of the habits that are treated as normal behavior in our society will suddenly reveal themselves as stark staring lunacy.
The second point to take home is that natural systems, having had much more time to work the bugs out, are much better at containing and using energy than most human systems are. The solar water heater and the house with its natural gas furnace take concentrated energy, put it to one use, and then lose it to diffuse heat.
A natural ecosystem, by contrast, can play hot potato with its own input of concentrated energy for a much more extended period, tossing it from one organism to another for quite a while before all of the energy finally follows its bliss. The lesson here is simple: by using existing natural systems to do things, green wizards can take advantage of two billion years of evolution, and by paying close attention to the ways that natural systems do things, green wizards can get hints that will make human systems less wasteful.
The third point is that energy doesn’t move in circles. In the next lesson, we’ll be talking about material substances, which do follow circular paths; in fact, they do this whether we want them to do so or not, which is why the toxic waste we dump into the environment ends up circling back around into our food and water supply. Energy, though, follows a trajectory with a beginning and an end. The beginning is always a concentrated source, which again is almost always the sun; the end is diffuse heat. Conceptually, you can think of energy as moving in straight lines, cutting across the circles of matter and the far more complex patterns of information gain and loss. Once a given amount of energy has followed its trajectory to the endpoint, for all practical purposes, it’s gone; it still exists, but the only work it’s capable of doing is making molecules vibrate at whatever the ambient temperature happens to be.
The fourth point is that while energy is the capacity to do work, it can’t do work in a vacuum. To make energy do whatever work you have in mind for it—whether that work consists of growing plants, heating water, or anything else—matter, information, and additional energy have to be invested. The plant needs carbon dioxide, water, and an assortment of minerals, as well as the information in its DNA and a stock of energy stored up in sugars from previous sunlight, in order to turn each new photon into useful energy. The solar water heater has equivalent requirements. Far more often than not, these secondary requirements impose limits that are far stricter than the limits imposed by the energy flow itself.
The fifth and final point, which follows from the third and fourth, is that for practical purposes, energy is finite. It’s common for people these days to insist that energy is infinite, with the implication that human beings can walk off with as much of it as they wish. This is an appealing fantasy, flattering to our collective ego, and it plays a central role in backing our culture’s myths of perpetual technological progress and limitless economic growth. As ecologist Garrett Hardin pointed out quite a while ago, though, it’s also nonsense. In his useful book Filters Against Folly (which should be required reading for any student of green wizardry), Hardin showed that words such as “infinite,” “limitless,” and “boundless” are thoughtstoppers rather than useful concepts because the human mind can’t actually think about infinity.4 When people say “X is infinite,” what they are actually saying is “I refuse to think about X.”
Still, there’s a more specific sense in which talk about infinite energy is nonsense. At any given place and time, the amount of energy that is available in a concentration and a form capable of doing any particular kind of work is finite, often distressingly so. Every ecosystem on Earth has evolved to make the most of whatever energy is available, whether that energy takes the form of equatorial sunlight shining down on the Amazon rain forest, chemical energy in sulfur-laden water surging up from hot springs at the bottom of the sea, or fat stored up during the brief Arctic warm season in the bodies of the caribou that attract the attention of a hungry wolf pack.
Thus it’s crucial to recognize that useful energy is always limited, and it usually needs to be coaxed into doing as much work as you want to get done before it gets away from you and turns into diffuse background heat. This is true of any whole system, a garden as much as a solar hot water system, a well-insulated house, or any other project belonging to the field of appropriate tech. Learn to think in these terms and you’re well on your way to becoming a green wizard.
Reprinted with permission from Green Wizardry by John Michael Greer and published by New Society Publishers, 2013.