The Second Law of Thermodynamics means energy will always be degraded—with profound implications for notions of "sustainable development."
By William Ophuls
In a previous essay on complexity, I said that the anti-ecological Titanic created by industrial civilization will not achieve sustainability by recycling the deck chairs, feeding the boilers with biofuels, installing hybrid winches and windlasses or the like. In other words, technology cannot save us from having to make fundamental, even radical changes in our way of life.
Why is this?
In brief, the laws of thermodynamics, among the most basic known to science, forbid infinite technological improvement. This is due to shadow costs and diminishing returns.
Using technology, we humans turn matter and energy from one form into other forms that are more useful to us. But every such transformation incurs losses—that is, it has a shadow cost. There may be just as much energy in the system after the transformation as before, but the quality of that energy is poorer.
To put it another way, all technological transformations cause matter and energy to move inexorably downhill from a more useful or concentrated state to one that is less useful or concentrated. This movement is called entropy, and the overall effect of human civilization—especially an industrial civilization—is to expedite entropy by manufacturing various forms of depletion, decay, degradation and disorder along with the desired goods and services.
An example will illustrate the point concretely and also make clear why technology cannot forever overcome thermodynamic limits. When coal is burned to produce electricity, only about 35 to 40 percent of the energy in the coal is converted into electrical energy. The rest becomes waste heat, various gases (such as carbon dioxide), various chemicals (such as sulfuric acid), particulates and ash. Even the electricity dissipates into the environment as waste heat once it has done its work.
From the physicist’s point of view, the books are balanced – there is just as much matter and energy in the system as before – but what remains is significantly lower in quality. So for every unit of good that man creates using this particular technology, he manufactures two units of bad—and even the good is ephemeral.
Could we improve on this? Yes, but not as much as we might like. Improvement in engineered systems soon encounters diminishing returns (which means that it takes a leap to an entirely new technology to make substantial progress). For instance, generating electricity from coal-fired plants is a mature technology, so any thermodynamic gains would likely be modest.
However, even a magic wand would be of little use in this case. Perfect efficiency is impossible, for that would be tantamount to perpetual motion, which the entropy law forbids. But even if we were able to raise useful output to the thermodynamic maximum of 77 percent, this only represents a doubling of efficiency.
Tech Innovations Increase Thermodynamic Costs
Moreover, ironically, technological innovations often increase thermodynamic costs. Take the substitution of the automobile for the horse. To make a horse requires a modest investment in pasture, water, and fodder for the two to three years it takes from conception until the horse can work.
But to make a car requires not only many direct inputs—steel, copper, fuel, water, chemicals and so forth—but also many indirect ones such as a factory and labor force as well as the matter and energy needed to sustain them.
To use a technical term, the “embodied energy” in the car is many times that in the horse. And the thermodynamic cost of operating the car is far greater. A horse needs only a modicum of hay, water, and oats procured locally without too much difficulty. But the auto requires oil wells, refineries, tankers, gasoline stations, mechanics’ shops, and so on—that is, a myriad of direct inputs that are difficult and expensive to procure, as well as a host of indirect costs.
So the substitution of auto for horse may have brought many advantages, but at a heavy thermodynamic price.
Technology Not a Source of Energy
The technological leap represented by the computer is no different. Its partisans may believe that it will be the instrument of humanity’s final liberation from the tyranny of nature, but a quick glance at the enormous quantity of embodied energy in each computer and in the systems that support it, plus the major energy requirements needed to operate networks and servers, testify otherwise.
The idea that technology will allow us to do ever more with ever less is a delusion.
It is vital to understand that technology is not a source of energy. That is, it is not a fuel in its own right, only a means for putting fuel to work or for transforming one resource into another.
Thus, for example, coal can be converted into gasoline—but at a high thermodynamic price, because much of the potential energy in the coal is lost in the process. Or technology can make the conversion of energy more efficient—but, as we have seen, only up to a point. Similarly, technology can make new energy resources available—but only by first expending energy to find and exploit them.
So technology does not make energy out of thin air. On the contrary, technology is always ultimately dependent on the supply of energy. If the quantity or quality of energy resources dwindles, the power of technology declines along with them.
Technology Depends on Energy Density
Above all, technology depends critically on energy density. The total amount of available energy is staggering, but very little of it is available in concentrated form.
That is the beauty of fossil fuels. They are the energy-dense residue of past solar energy in the form of buried organic matter that has been subjected to eons of geological heat and pressure. With such a concentrated source of energy, technology can perform wonders, because it is, in effect, traveling thermodynamically downhill from dense to diffuse—from coal to electricity and waste heat, instead of vice versa.
By contrast, dispersed energy can do much less work and therefore limits what technology can do. Solar rays will make hot water for a household but do not easily lend themselves to running a multi-megawatt power plant that supplies power on demand.
Energy Return on Investment
One of the best ways of understanding the relationship of energy, entropy and technology is by examining economic systems in terms of net energy—that is, how much energy remains after subtracting the cost of effecting the transformation. The technical term is energy return on investment or EROI.
For example, it used to be that it took the energetic equivalent of only one barrel of petroleum to obtain a hundred barrels—that is, an EROI of one hundred to one. But this ratio has now declined to roughly fifteen to one and is destined to fall even further, because the remaining resources are on the whole more difficult, dangerous and expensive to extract and refine.
Hence the mere quantity of a resource is not what is important. A billion barrels of oil in the ground may sound like a lot, but if it costs five hundred million barrels to extract and refine, then the net energy is only five hundred million barrels, and the EROI is just two to one.
Peak Quality Is the Problem…
Because quality, not quantity, is the critical issue, the debate over so-called peak oil is often incoherent. The real concern for a civilization critically dependent on fossil fuels is not really the moment in time when the maximum rate of petroleum extraction is reached, after which production enters terminal decline, but rather the inexorable trend toward lower net energy and higher costs, both monetary and environmental.
New discoveries and improved techniques may boost production in the short term, but to hail them as refutations of peak oil while ignoring the long-term trend toward lower net energy makes no sense.
Low net energy is why most of the schemes for replacing fossil fuels with one or another form of ambient solar energy on a scale that would satisfy current demand, much less future growth, will come to naught; the EROI will be marginal, and the capital costs exorbitant.
Thermodynamic Vicious Circle
To reiterate, unless it is a matter of simply scooping up found wealth, technology is not a panacea. It is dogged at every step by the laws of thermodynamics.
Civilization is trapped in a thermodynamic vicious circle from which escape is well nigh impossible. The greater a civilization becomes, the more the citizens produce and consume—but the more they produce and consume, the larger the increase in entropy.
The longer economic development continues, the more depletion, decay, degradation, and disorder accumulate in the system as a whole, even if it brings a host of short-term benefits.
Depending on a variety of factors – the quantity and quality of available resources, the degree of technological and managerial skill and so forth – the process can continue for some time but not indefinitely. At some point, a civilization exhausts its thermodynamic “credit” and begins to implode.
Adapted from the author’s Immoderate Greatness: Why Civilizations Fail, CreateSpace, 2012.
About the Author:
William Ophuls is the pen name of Patrick Ophuls. He served for eight years as a Foreign Service Officer in Washington, Abidjan and Tokyo before receiving a PhD in political science from Yale University in 1973. In addition to Immoderate Greatness, he has published three books on the ecological, social and political challenges confronting modern industrial civilization. www.ophuls.org