Section: Introductory Concepts of Energy and Power | Alternative and Appropriate Technologies

Select activity Lecture 4: Thursday August 25

Lecture 4: Thursday August 25
Select activity Human Domination of the Biosphere: Rapid Discharge of the Earth-Space Battery Foretells the Future of Humankind
Human Domination of the Biosphere: Rapid Discharge of the Earth-Space Battery Foretells the Future of Humankind File
URL/Ref: Schramski, Gattie, and Brown. "Human Domination of the Biosphere: Rapid Discharge of the Earth-Space Battery Foretells the Future of Humankind", PNAS 112(31), August 4, 2015, pp. 9511-9517 (read entire article).

Study Questions

What is the PNAS (in the bibliographic citation)?

How is energy defined in the paper?

What is meant by "low quality" and "high quality" energy?

What is the relationship between photosynthesis and respiration?

What was a key turning point in human civilization with respect to expanding human energy consumption beyond the hunter-gatherers?

What is meant by "recoverable" and "non-recoverable" energy?

What is "net primary production" and how large is it?

What are the two main types of organic chemical compounds that supply energy for human civilization?

Verify the following calculations:

p. 9514, column 1: 74.6x10⁹J/person/yr is equivalent to 2,370 W (1W = 1J/s)

p. 9514, column 1: total annual energy consumption (per person) is 0.53 ZJ (1ZJ = 10²¹J = 10¹⁵MJ)

p. 9514, column 1: 2000 Cal = 8.4 MJ (consult http://www.onlineconversion.com/energy.htm)

p. 9514, column 1: the metabolic rate is 100 W (8.4 MJ/day)

p. 9514, column 2: the average human power demand is 24 times that of the ancient hunter-gatherer (divide one of the above numbers by another - do you see which ones?)

Do the authors make any predictions about the future of human civilization and the earth?
Select activity The Toaster Challenge: Robert Förstemann

The Toaster Challenge: Robert Förstemann URL
Select activity The Toaster Challenge: Ida Ingemarsdotter

The Toaster Challenge: Ida Ingemarsdotter URL
Select activity Energy Unit Conversion Calculator

Energy Unit Conversion Calculator File

Here is a good energy unit conversion calculator. The spreadsheet provided is a simplified version for some common units.
Select activity Introduction to Energy and Power

Introduction to Energy and Power File
Select activity Lecture 5: Tuesday August 30

Lecture 5: Tuesday August 30
Select activity Slow Electricity: The Return of DC Power?
Slow Electricity: The Return of DC Power? File
URL/Ref: DeDecker. "Slow Electricity: The Return of DC Power?", Low Tech Magazine, April 27, 2016. Read entire article

Study Questions

What are the main factors that make DC systems attractive again?

What is the relationship between power loss due to cable resistance and current?

List at least 4 Native DC Power sources or devices (that naturally produce DC power or DC loads)

Besides a hybrid DC-AC system for high power appliances, what is the other alternative presented?
Select activity Optional: How to Calculate Power from Wind Turbine

Optional: How to Calculate Power from Wind Turbine Page
Select activity Optional Reading: Energy and Equity

Optional Reading: Energy and Equity File

From Iván Illich. Electronic link
Select activity Resources RE Calculating Energy Use

Resources RE Calculating Energy Use Page

Please check out this article from Low-tech Magazine. It may form the basis of a future assignment. Other sources will be added later.
Select activity The Oil in your Oatmeal

The Oil in your Oatmeal URL

How much energy goes into producing and delivering your food, compared with the energy that you actually derive from the food? I.e., how efficient is our food system? Also, check out the comment about 'truth in packaging'.

Section outline