Review & Extra Resources

Hello again, Dr. hall here.

So you've finished lesson. two on energy supply and demand and again we've made a review sheet to help you identify some of the key components of this lesson to better prepare yourself for the quiz.

So one of the first points is gross domestic product. You may have seen this in an economics class but we're introducing this so you understand the relationship between productivity and nations and how that relates to energy use.

Another important concept is energy intensity so you can get a sense for how much each citizen in the world uses energy and how that varies across the globe. So because we're talking about national and global energy consumption and production, the units of energy that we're using are extraordinarily large. So we talk about quads or quadrillion BTUs which is 10 to the power 15 BTUs. That's right, so that's a lot of energy. A tremendous amount compared to how much we need to power our bodies in the day.

Right so the given amount of calories we consume or about 2,000 and comparing that to how many btus we use to do everything else in our life it's quite extraordinary what the differences are.

So we also covered world energy consumption and some of the trends that we've seen in the past and what we expect again the best of our knowledge what we expect they will look like in the future.

And there are some key points that you can learn from this. So number one oil is one of the most utilized energy resources across the world and it seems like it'll stay that way from 2020 on to 2050. Another fact that we're coming to terms with is energy consumption across the globe will likely continue to increase from 2020 on to 2050. In terms of the u.s, we have an extraordinary amount of fossil fuels in particular coal. But like much of the rest of the world what we use regularly the most is still oil and it looks like it will remain that way for a long time in the future.

Another thing that seems to be a constant is that the consumption of all different energy sources both renewable and non-renewable appear today will increase to meet our growing energy demand. Uh as you'd expect or what you you'd probably be familiar with in your real life. most of our use of petroleum and oil is in the form of transportation and that's why it's so high is we we move many things in this world and a lot of that relies on petroleum-based products. And in the U.S. we use so much of this that we regularly have to import this petroleum from somewhere else because we don't produce as much as we would need in order to satisfy the demand. And lastly the U.S. not only has a lot of coal in terms of itself but even in terms of the world we have about one fourth of the resorts overall.

Another interesting thing to consider is the doubling time ,right. This was important concept that we covered that helps us understand the role of growth and consumption how that relates to uh the supply of energy and the consumption that we have of it.

Uh when we talk about energy in terms of non-renewable sources. We have what's called reserves and resources and each of these represent two distinctly different qualities that we have in an energy resource. So when we look at those we can also do some rather straightforward math to see how long we expect those reserves to last. But in an ever and changing world where our relationship with energy keeps changing we can always estimate how long those reserves last but innovations sometimes improve how much we we have in terms of resources and reserves and it also changes our relationship with how we use them. Right so for example the emergence of renewable energy and electric cars that changes how long those reserves are last because it changes our our rate of consuming them.

So uh again uh i'm glad that you finished lesson two. I hope that you take into account each of these points uh review. Be sure to practice the practice questions and good luck on the quiz alright.

Thanks everyone.