Energy. on this world and elsewhere. Instructor: Gordon D. Cates Office: Physics 106a, Phone: (434)

Transcription

1 Energy on this world and elsewhere Instructor: Gordon D. Cates Office: Physics 106a, Phone: (434) Course web site available at click on classes and find Physics or at August 27, 2013

2 The World s energy infrastructure is huge

3 Energy: the defining issue of the 21st Century Society s rapid growth has been fueled by cheap energy. Energy is becoming more expensive as fossil fuels are depleted. Even if fossil fuels remain relatively affordable, they are fundamentally altering our planet. It is likely that future generations will judge us according to how we deal with the challenge of meeting our energy needs.

4 A slide I showed in 2011 We face very immediate issues Domestic production of crude oil has long since peaked and is in decline. We face a very real scarcity of liquid fuel for transportation

5 Primary energy sources: 2005 vs /0'.-,+*)('!%&%$#"!! (# 90+/ ($ 7+4*-+/28+6!# )*+,-.//.01234* 9-*,:2;./<!$ # ( 78?C D $ 123)+'4)5)6789)':5)+;0 &!"#$!"%$!"&$!"'$!""$ ($$$ ($!$ E 28:04F:-5+/G260/+-HIF040J0/4+.=G2+1,2@.1,K L0*-=:M22N+O/:2!K(K2 Domestic oil production is on the rise again, but is that an entirely good thing?

6 CO 2 concentration over ten thousand years Whatever you end up concluding about global warming, there is no question that we have increased the carbon dioxide levels in our atmosphere by something like 35% since the beginning of the industrial revolution.

7 Pre-clicker question How much has the temperature risen since the beginning of the industrial revolution? About 1 C Correct answer, rounded to the nearest degree About 3 C About 5 C

8 A few important questions... What are the sources of commercial energy? What does physics tell us regarding future sources of energy? What can we do to insure a secure future?

9 So what do we do? It is clearly desirable to move away from fossil fuels. The energy infrastructure, however, is huge. Even minor interuptions of energy supply have dramatic disruptive effects on society, including recessions, and even the loss of life.

10 Energy from a physicist s perspective While physics has its limits, it brings a valuable perspective to the subject. Physics can help us understand what is and is not possible. Physics can empower us with a new and more critical perspective on the ongoing public discussion of energy issues.

11 Example of the types of questions you will learn to answer If we had the technology, and we could store large amounts of energy in a practical manner, could we power all of our nation s needs for electricity using solar power?

12 Area needed to generate ALL the nation s electricity using solar power 83.4 mi. x 83.4 mi., area needed to produce (on average) all electricity currently used (assuming 200 W/m 2 ). (assumes 13.5% efficiency)

13 Make numerical concepts real by relating them back to things that are familiar. 441 million acres devoted to cropland (for comparison) mi. x 83.4 mi., area needed to produce (on average) all electricity currently used (assuming 200 W/m 2 ). 118 mi. x 118 mi. (twice the above mentioned land area).

14 Does this mean we should generate all of our electricity using solar power? If it takes more energy to build the solar farms than the energy we will ultimately collect from them, no! Financially, is it even feasible? Is it competitive? What are the environmental impacts? It takes lots of nasty chemicals to manufacture photovoltaics!

15 Why is it important to educate ourselves about energy?

16 Why is it important to educate ourselves about energy? Because in a democracy, we need to make certain that our leaders are doing a good job.

17 Why is it important to educate ourselves about energy? Because in a democracy, we need to make certain that our leaders are doing a good job. Because at UVa, many of the people that go through this class will BE future leaders in both politics and industry.

18 Why is it important to educate ourselves about energy? Because in a democracy, we need to make certain that our leaders are doing a good job. Because at UVa, many of the people that go through this class will BE future leaders in both politics and industry. Because there are many personal choices that we can make that will make a difference.

19 Don t take my word for it...

20 Don t take my word for it... Thomas Jefferson, 1789

21 Don t take my word for it... Thomas Jefferson, 1789 Library of Congress

22 Goals of the course Develop a common language with which to discuss energy issues. Better understand how energy is produced in our society. Better understand how energy is consumed. Use basic physics to quantitatively analyze energy issues - and better understand the challenges and opportunities.

23 Course Structure Lectures (important!) - Lecture notes - Homework Quizzes Exams All lecture slides are posted on the course website. Passed out in class, not available online. Readings from various sources

24 Books The Character of Physical Law - (will be made available online) Energy for Future Presidents Physics and Technology for Future Presidents Beyond Smoke and Mirrors The High Frontier

25 Working from source materials

26 Course Content

27 Course Content

28 Approximate Grading Scheme (probable, but not guaranteed range) Class participation 10-15% In-class quizzes 10-15% Homework 20-30% Midterm 15-25% Final 30-40%

29 The golden rule of Physics 1110 Every class-related issue you have is important to me, so...

30 The golden rule of Physics 1110 Every class-related issue you have is important to me, so... ALWAYS FOLLOW UP CONVERSATIONS on something important with an .

31 The golden rule of Physics 1110 Every class-related issue you have is important to me, so... ALWAYS FOLLOW UP CONVERSATIONS on something important with an . That should have Physics 1110 in the subject line, as well as one keyword, i.e. clicker, quiz, homework, etc.

32 Defining Energy Not as easy as it might seem!

33 Defining Energy

34 Energy can be transformed into different forms, but is never lost Gravitational potential energy Kinetic Energy

35 Generating electricity using waterfalls

36 Different types of energy Kinetic energy Potential or stored energy Gravitational potential energy Mechanical potential energy Electrical potential energy Nuclear energy Chemical energy

37 More types of energy Thermal energy Pure energy in the form of radiation

38 Homework Read today s handout. Review the course information from the website. Come to class on Thursday!

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