The Crash Course - Chris Martenson [70]
The more energy density something contains, the more useful it is. This is why the fossil fuels—oil, natural gas, and coal—are so desired and desirable. They represent concentrated forms of energy that are capable of doing a lot of work. Without them, our economy would be a pale shadow of its current bright self. Given the importance of energy to the continued smooth functioning of our economy, we owe it to ourselves to understand the ideas and the data that underlie the sources and amounts of energy that course through our economic arteries.
Energy Budgeting
To help us on this journey, let’s take a quick tour through the concept of energy budgeting. If you have a household budget or have ever run the numbers for a business, this will be an easy topic.
Imagine that at any given time there is a defined amount of energy available for us to use as we wish. This will be our budget to spend as we see fit, but instead of dollars, this budget will consist of units of energy. Let’s put every source of currently existing energy into this budget: solar, wind, hydro, nuclear, coal, petroleum, natural gas, biomass, and so on.
This list represents our total energy to use any way we please; it’s our “energy budget.” Our first mandatory expenditure from this budget will be the energy that we need to use in order to ensure that we’ll have more energy next year. Consider it an unavoidable energy tax. A certain amount of energy must be used to maintain our existing energy infrastructure—all the dams, pipes, and power plants—and an additional amount must be expended to find more energy to replace that which we use up. Along with this, we must also invest some energy in building and maintaining the capital structure that allows us to collect and distribute energy and maintain a complex society. Things like roads, bridges, electrical grids, and even our buildings go into this category. Together, all of this can be considered our mandatory energy expenditures, meaning that they are unavoidable.
Once we’ve subtracted all of the mandatory energy expenditures from our budget, the remaining energy can be used for consumption. Part of this must go toward procuring our basic living needs, such as water, food, and shelter, leaving the rest for truly discretionary things like vacation trips to the Galapagos, selling hula hoops to Eskimos, and attending concerts. All of this has been diagrammed in Figure 15.1.
Figure 15.1 Energy Budgeting
In this energy budget, a certain amount must be reinvested (darkest arrows), leaving the rest to be consumed by basic living and fully discretionary uses.
Image: Jeanine Dargis
To further simplify this story, we can divide energy up into two big buckets: (1) energy that must be reinvested to maintain existing energy flows, buildings, and basic living needs (“mandatory”), and (2) energy that we can more or less choose what to do with (“discretionary”). Using our prior terminology, the discretionary bucket becomes the surplus energy that we can either apply toward growth or prosperity, but not both (unless there is surplus). But our surplus energy is shrinking, for two reasons: Every year there are more people placing more “mandatory” demands on the energy we have, and every year we’re getting less and less energy back from our energy investments.
Net Energy
This is the most important concept of this chapter and one of the most important concepts of the book. I want you to ignore how much energy costs in money terms, because the cost is actually irrelevant (especially when your money is printed out of thin air). Instead, I want you to focus on how much energy it takes to get energy, because, as I’m going to show you, this is even more important to our current and future well-being than the raw amount of energy that we can produce each year. The concept is straightforward, and it’s called “net energy.”
Because it takes energy