Where does your energy come from?

Mary SavinaCarleton CollegeCLEAN webinarApril 12, 2011

Seminal moment for me•Science Museum of Minnesota•Mid 1980s/early 1990s•Northern States Power (now XCEL) interactive graphic•Assumes ~70% coal, 30% nuclear•10 kwh/day

http://www.peakoil.org.au/news/index.php?does_nuclear_energy_produce_no_co2.htm

These quantities represent my recollections – not necessarily truth!

Some teaching activities

• Where Does Your Energy Come From? (SERC – Cutting Edge; Mary Savina)

• The Big Energy Gamble (CLEAN: Jeff Lockwood – NOVA teachers)

• From Grid to Home (CLEAN: Marie Johnson)• Any number of Carbon Footprint calculators

and exercises in the CLEAN collection, many using the EPA emission calculator

Context for use

• Introductory geology, including introductory environmental geology)

• Class size 18-48 • Typical class: students from a dozen or more states and at least

a few foreign countries. • Near the start of a unit on energy, whose other components

might include reading, debates, a lab exercise on nuclear waste disposal, and drafting of an ideal energy policy

• Unit comes about 3/4 of the way through the course.• Students asked at start of course to get a copy of a recent

energy bill.

Basics of assignment

• Acquire, read, and analyze a utility bill from your home.

• Trace the sources for your electricity, heating and cooling, and other components of energy use.

• Compare energy sources from different states and countries.

• Discuss energy sources, including their environmental, societal and economic advantages and disadvantages.

Presentation possibilities

• Class discussions that culminate in each student writing a short essay that's evaluated as part of the course work (the teaching materials linked from this page assume this model) OR

• Part of a larger project on hometown environmental health. In this case, energy sources and uses are part of a series of topics (also including drinking water sources, watershed/water bodies, pollution and waste, natural hazards, and cancer rates) that students explore throughout the trimester and then write about as the course final exam.

Goals

• Analyzing energy use data, including making conversion among units, and developing comparisons for different sources (quantitative skills).

• Calculating personal contribution to the energy expenditures of humans.

• Researching (and comparing) on-line and written documentation from government and utility sources.

• Summarizing and synthesizing the societal, economic and environmental costs and benefits of energy use.

Questions for studentsBefore you start: Locate the utility bill from your home for a recent month. Start your research by answering these questions:• Where do you live?• How many utilities (or other sources) supply you with energy? What are

their names?• What does your utility do to provide you with energy (e.g. burn coal for

electricity)? Is it the same sources for all types of energy?• What is the cost per kwh of this electricity? • What is the cost per day of other forms of energy (e.g. heating)? Convert

these amounts into kwh to get a comprehensive picture of your total energy use.

• Where does the energy come from? (Where is the coal mined, the oil extracted, the uranium ore found?)

The student handout linked from the assignment web page has more detail.

Sources of information for students

• US Government Energy Information Administration web sites

• State energy agencies web sites• Utility web sites• CO2 calculators

What students share

• While students do calculate and write individually about the total energy used by their household, they share mainly the information about cost per kwh, BTU or whatever units the utility uses and the utility's energy sources. These data go into a spreadsheet that's available to the students as they write their summaries.

Sample spreadsheetName Home-

townCountry Elec.

Util. Elec. source

Elec. Cost/KWH

Heat Utility name

Heat Source

Heat cost

Other Util.

Source Origin

Mary Savina

Northfield MN

USA XCEL/3/11bill

50% coal; 24% natural gas; 12% nuclear; 14% “green”

$0.063650 (energy charge - winter); $0.090474 (with fuel cost and env. Improvement)

XCEL Nat. Gas 0.7507therms

N/A coal: Montana and Wyoming; natural gas: Rocky Mountain, Anadarko, Permian, Western Canada basins; nuclear: uncertain, stay tuned

Sample - Comparative information

State/Country Energy source Price per KWH

Minnesota 50% coal; 24% natural gas; 12% nuclear; 14% “green”

$0.063650 (energy charge - winter); $0.090474 (with fuel cost and env. Improvement)

Washington State 41% hydro; 36% coal; 20% natural gas; 3% “other”

$0.085544 Per KWH (for first 600 KWHS)

Qingdao, China 99% coal 0.52 China Yuan (about $ 0.0778)

Los Angeles, CA 52% coal; 26% natural gas; 11% nuclear; 6% hydro

$0.12 per KWH

New York City, NY 30% coal; 21% nuclear; 20% natural gas ; 19% hydro; 10% oil

Tulsa, OK 0.0006510 Per KWH

A kinesthetic exercise

• Students calculate the cost of electricity per kwh

• Students line up in order of that cost. • Students observe the wide variation within

the U.S. (and abroad) in the cost of electricity. We can then explore some of the reasons, historical and otherwise, for these variations.

Focus on energy sourcesState/Country Energy source Price per KWHMinnesota 50% coal; 24% natural gas;

12% nuclear; 14% “green”$0.063650 (energy charge - winter); $0.090474 (with fuel cost and env. Improvement)

Washington State 41% hydro; 36% coal; 20% natural gas; 3% “other”

$0.085544 Per KWH (for first 600 KWHS)

Qingdao, China 99% coal 0.52 China Yuan (about $ 0.0778)

Los Angeles, CA 52% coal (From Utah); 26% natural gas (local – from LA Basin); 11% nuclear (local – prob. from Canyon Diablo); 6% hydro (from Colorado River)

$0.12 per KWH

New York City, NY 30% coal; 21% nuclear; 20% natural gas ; 19% hydro; 10% oil

Tulsa, OK0.0006510 Per KWH

Common Sources of confusion

• Variety of energy sources used for electricity, heating and cooling

• Usage amounts depend on mix of sources (e.g. electric heating/cooling vs. gas/oil/propane heating/cooling)

• Units – electric units (e.g. KWH), thermal units (e.g. therms, BTU) One can convert among these units (1 kwh = 3412.14 BTU according to http://www.aps.org/policy/reports/popa-reports/energy/units.cfm; an American Physical Society site with an excellent discussion of energy units). More quantitative skill building!.

More sources of confusion

• Utility bills – Challenging organization– Separate “charges” that need to be added

• Utility websites– Variable in amount of information

• Students from co-operative or other shared housing may not have bills

Discussion questions for students

Consider these questions (for class discussion and as part of your written assignment):

• How do the energy sources for your hometown compare (in cost and type) with the sources used by others in the class?

• What effect do the energy sources (including locations of power plants, mines, etc.) have on the environmental health of your hometown? Of the country?

• What did you learn from this exercise about your own energy use that was unexpected? What actions might you take in light of this knowledge?

• Frame and answer an additional question about energy use that arises from your research.

A new book you may not have encountered yet

• James J. Farrell (St. Olaf College - American Studies, History, Environmental Studies), 2010, The Nature of College: Minneapolis, Milkweed Editions, 336 p.

Jim Farrell links environmental principles with higher education and the student experience in his characteristically funny and engaging way. David Orr (Oberlin College) calls this "the first book every college student [should] read.”