Step 2

PRESENTER: In Step 2 of the Capstone Project here, we have to make some decisions about the mix of different fossil fuels that we're going to use as our carbon-based energy. And so, the model comes with this little pie diagram, it's showing the present-day distribution of coal, natural gas, and oil. So those are the percentages, or fractions really. And so, you can change this. You can keep this the way it is, or you can reduce it. But if we reduce it, we can maybe get this fossil fuel energy intensity number little bit higher. So, this is the number of exajoules of energy you create per gigaton of carbon emissions. Remember, we've already sort of set, we've determined, in this graphical converter what the carbon emissions are going to be.

And so, the question is, well, how much energy can we get from that, that amount of carbon emissions? That, this is in gigatons of carbon. So, this fossil fuel energy intensity value, the bigger this is, the more energy you get from that. And depending on, because they cost different amounts per unit of energy, we're going to end up with a different fossil fuel unit cost. So, you can see presently it's 18 dollars and 5 cents, not dollars and five cents but it's in, its billions of dollars per exajoule of energy, let’s say. We're going to make some changes here. We’re going to make these changes by sliding these little yellow, or these white circles around, like that. We can, so we can make natural gas a bigger part of this.

Now I'm going to do something radical here and say, I'm gonna just kinda cut coal out entirely. There, I've cut coal to zero. Natural gas I’ve got that at 73. I'm going to bump that up to closer to 80. That's close enough. Now, if I run the model, you will see the unit cost and the fossil fuel energy intensity change. So, we’ll just run the model. You see those values change. So sure enough, I got this up higher, close to the, theoretically this could be as high as 59.

So, I'm quite close here. I've kept some oil here in the mix and it's just because the products of oil, so, gasoline, diesel, kerosene, jet fuel, things like that. Those are, those are pretty useful. They're very portable forms of energy. So, we might want to still have some use of oil, but for most of the other carbon energy, we're going to rely on natural gas, which is cleaner. And sure enough, that brings the cost down quite a bit to $12.91.

We make that change and then that's going to affect how much energy we produce with this amount of carbon emissions. And then we'll look at that a little bit later. But as a product, as a deliverable from this step, you're going to want to take a little screenshot of this pie diagram after you've run the model. You’ve got the new fossil fuel energy intensity and the unit cost here. You can go back to the start here by hitting this little undo button, return button. And there we go, back to the original.