03021 Laws of Thermodynamics

There ain't no such thing as a free lunch. --- Robert A. Heinlein, The Moon is a Harsh Mistress

This is a lay person’s general summary of the topic from the viewpoint of someone working on a permaculture design for his or her life.

Thermodynamics is about heat, energy, and work.

The laws of thermodynamics are observations of concrete and unavoidable limitations on human action. Thermodynamics studies the effects of work, heat, and energy on a system.

They apply to everybody and everything, without any exceptions. They are indifferent to social and economic status, location, ethnicity, culture, religion, politics, or nationality. Political and economic theories are irrelevant when it comes to thermodynamics.

In the Permaculture Design Manual, Mollison quotes Kenneth Watt —

All energy entering an organism, population, or ecosystem can be accounted for as energy which is stored or leaves. Energy can be transferred from one form to another, but it cannot disappear, or be destroyed, or created. No energy conversion system is ever completely efficient. — Principles of Environmental Science

Here is an easier to understand summary —

  1. You can’t win (because energy cannot be created or destroyed).
  2. You can’t break even (because entropy always increases and you never return to your original state), therefore all energy transactions cost energy. In other words — you get less energy out than you put into the deal. Well, if it was a very cold day — with a temperature of absolute zero — you could break even.
  3. You can’t get out of the game (because absolute zero is not attainable). In other words, it doesn’t get that cold.

While energy can be transformed, all such transformations are inefficient — they lose energy.

“Transformation” means I can pour gasoline into an automobile and convert the gasoline into work (moving the vehicle down the road) and heat which fritters away into the atmosphere, lost to us forever. Maybe I get a little use out of some of it via the car’s heater during the winter. The rest of it goes away.

Or I could plug in a mixer and convert the electricity into motion (the whirling of the beaters) to mix a batter. Some of the energy converts into waste heat that dribbles off into the surrounding materials/atmosphere and does nothing further for us. In both situations, we got less work out of the deal than we invested as energy.

That is the pattern for energy — each and every energy transformation without exception from the human viewpoint yields work plus waste. We always get less energy out of an energy process than goes into it in the first place.

Because energy transformations always lose energy, if you want 1000 BTUs of work, you need more than 1000 BTUs of energy to do that much work.

This leads us to what Mollison calls the “Law of Return”:

Whatever we take, we must return, or “nature demands a return for every gift received,” or “the user must pay.” — Permaculture Design Manual

The “on the street” version of this law is — “There ain’t no such thing as a free lunch,” the acronym for which is TANSTAAFL.

We ignore these scientific realities to our mortal peril. Understanding the laws of thermodynamics should lend an urgency to our work. It illustrates (among many examples that could be cited) the inherent limitations of alternative energy sources such as wind and solar, when compared with the power of fossil fuels.

Let’s belabor these realities a bit —

When it comes to energy —

  • You can’t win.
  • You can’t break even.
  • You can’t get out of the system.

Why? Because energy transformations always lose energy.

What does this have to do with real life?

Fossil fuels are important precisely because of the “fossil” nature of their origin. The original energy investment was millions upon millions of years ago, in the form of solar energy converted to carbon-based plants and animals which, in time, in the depths of the Earth, changed into petroleum and natural gas.

Considered on a full life-cycle basis (that is, from its beginning millions of years ago to present-day gasoline in my tank), making gasoline from petroleum is an energy-losing activity.

But that doesn’t matter in the present, because the original energy investment was millions upon millions of years ago in the form of the sun shining down upon plant and animal life. That is a done deal, a sunk investment, we don’t have anything to do with that. We dig a hole, pump out the crude oil or the gas, refine it, and voila! Behold the fossil fuel era! Let’s party!

The problem with the party is that fossil fuels are a finite resource. When they are gone, they are gone and then we will have to account in the present for all of our energy transactions. Another way of describing fossil fuels would be “archeological fuels.”

Contrast this with the situation for alternative energy systems. Wind, solar, water, biofuels must be 100% accounted for in the present. The “energy return on energy invested” for all of the alternative fuels and gee-whiz energy gizmos on the market these daze is much less than that of petroleum.

What will happen over the next few decades is that the hard rock of fossil fuel depletion will meet the irresistible force of soaring demand.

Demand for fossil fuels soars each year. There are about 2.5 billion people in China and India and every one there wants a car and gasoline to power it. We already compete with them for energy supplies which is one of the reasons why gasoline has become expensive these past few years. We can expect their consumption to race ahead in coming decades as more of their people are able to afford and buy cars.

This will be a clash of enormous magnitude that will create a tremendous amount of danger for humanity worldwide. Historically, human societies, when faced by resource constraints of this magnitude, resort to war.

Managing the decline in fossil fuel availability, the soaring demand, and the low energy return on energy invested of renewable fuels is a major challenge for permaculture design. No one can, at this point in time, predict how that will work itself out or whether permaculture design can be deployed extensively enough to peacefully manage that decline. Everyone can make a serious contribution to this critical need by beginning permaculture design of their own individual lives and households.

There are three utter necessity energy realities of the future —

  • Do more with less,
  • Do less with less, and
  • Full stop on some activities. War would be a good activity to put first on this list, followed by genocide and ethnic cleansing.

How much fossil fuel energy does it take you to cook a roast? We’ll talk later about accounting for that, but for now — in the future coming at us, and is already here for some — if you have a non-fossil fuel alternative, you will want that to cook your roast. The price of the hydrocarbons will be such that you might not be able to afford conventional energy.

You’ll want something like a solar oven, or an outdoor bread oven, or a retained heat cooker, all of which can work without hydrocarbon energy, so you can have a hot meal instead of going hungry. For some of us, there won’t be a choice. It’s use a non-fossil fuel energy, or go without energy.

I’m not saying fossil fuel energy won’t be available. While oil and gas will be pumped for a long time, they will become more expensive. We have found and exploited all of the cheap oil. The oil that remains is not cheap oil. It is expensive to produce and refine.

So as you go through your design process, your essential testing questions are —

Can I do this without any hydrocarbon energy?

If not, then — how can I do this with less hydrocarbon energy?