An Introduction to "Thinking In Systems" - Part Two: The First of the Three Inputs - "Energy"

  • Posted on: 23 January 2019
  • By: dtrammel

In the first part of this introduction to the valuable Green Wizardry principle, "Thinking In Systems", we saw how simple things like a bathroom shower are in fact an organized and adaptive mechanism, one with a desired "output", in this case "getting a hot wash".

This "output" is affected by three broad "inputs" which we call Energy, Matter and Information. They each influence the overall system in different ways, and can be tweaked to make the system perform in various ways, both good and bad. Understanding how to optimize those inputs to achieve the best performance at the least cost, is key to using Green Wizardry.

A Closer Look at the First of the Three Inputs - "Energy"

When you think of Energy in a System, it is important to understand its primary characteristic:

"Energy will always follow a one way path from a concentrated source to a diffused state."

You can not re-concentrate energy. There is no process by which you can take a diffused source of energy and put back into a concentrated one. There may be systems and equipment which appears to do that, but if you look at the entire system in total, there is always a less than 100 percent efficiency.

That is to say, that there is always a loss of energy in any process in a system. We can simply add more energy to make up for that loss or we can find ways to minimize those losses. Since we have entered a time when energy will be more and more scarce, and that which we can access is more and more expensive, finding and using the best ways to cut those losses and make our systems more efficient will be critical.

First let us look at the ways energy losses concentration.

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Conduction, Convection, Radiation

When considering how energy in a system diffuses you must look at the boundary layers where a concentrated energy source comes in contact with a diffused source. Basically where a hot substance meets a cold substance. Science divides these types of boundaries into three names, Conduction, Convection and Radiation. They are related to how dense the material in a boundary layer is. That density affects the speed at which the diffusion takes place.

Think of it like this analogy.

Suppose you have a large auditorium. You are on one side and your friend is on the other. You want to get a bag of coins to them, It would be easy enough to just walk across to them and hand them the bag. And it wouldn't take much time either.

Lets make the task a bit more challenging.

The first rule we will introduce is that if there is another person between you and your friend, you must hand the bag to them, and then they will hand it to your friend but if there are two people between you, then you must divide the coins and give each half, they in turn will give their half to your friend. Increase the number of people and the bag gets further and further divided, and takes more and more time for the transfer to be completed.

Notice something, the total amount of coins, though divided, doesn't decrease. Energy can't get destroyed but it can get so diffused as to be useless. If all those people eventually handed their few coins to your friend, and he then handed them off to the third friend in the next room, the total coins (aka energy) would be the same.

If we let each person keep one coin as they transferred them, then the resultant energy handed to your friend would in fact be less.

But it becomes more complicated.

Suppose that we don't have just one bag. Instead we get one every ten minutes. We keep handing them off, and if we let each person keep one coin, at some point, all the people in the room will have a full bag of coins. If we make a rule that you can't keep more coins that I have at the start, then we will reach a point of equilibrium.

No more energy can be transferred.

It is complicated how energy goes from concentrated form to diffused but you must remember this simple thing, there is always some loss.

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In a material that is dense, like metal or other solids and like that filled up auditorium, energy diffuses slowly. We call that process "Conduction". In a less dense material, like a liquid or gas, we call it "Convection". And in a vacuum, we call it "Radiation".

Whatever you call it though, it is still energy going from being a concentrated source to a diffused one. The important thing to remember is putting a dense material between those two, extends the time the process takes to work.

You can see this in our shower example when you consider the copper pipes which carry hot water from the water heater to your shower. Bare copper pipes are thin and the energy in the hot water inside of them will easily cross the boundary of that metal, and then begin to diffuse to the surrounding air. Put a foam insulator around the pipe and you can see that the energy will take a much longer time getting out.

Shortening the distance from the water heater and the shower can also be thought of as an insulator. Cutting the distance in half will cut the loss of energy in half.

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Time As Energy

Energy can be thought of as "Stored Work". The kind of work it can do varies according to its concentration.

You can think of it in the comparison between a man with a shovel and a colony of ants. The shovel allows a man to move dirt in large amounts in a short amount of time. Ants too move earth, and while each ant moves a tiny amount of dirt in compared to that shovel, given enough ants, or enough time, that colony of ants can move just enough if not more than the man.

Another example, relating to our bathroom shower. That electric water heater uses a very concentrated source of energy to heat that tank of water in a short period of time, but we could get the same result if we took a large tank, painted it black and set it where the Sun could warm it all day. Both processes result in the same output, hot water. One just takes longer to do it.

We can therefore lower the energy requirements of a system, if we are willing to modify the time frame that we wish the system to perform in.

You can also use Time as a helper. If you use a solar hot water system, like that black tank, to preheat the water, then have a smaller tankless electric water heater, to bring the preheated water up to the desired hot temperature, then you save on the energy needed.

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Understanding how energy in a system finds ways to diffuse and coming up with ways to slow it down, is important to a Green Wizard and their mastery of "Thinking In Systems".

We will look at the second Input, Matter, next week.