Unit 10: Energy
How do we power our cities? How
should we power our cities?
Agenda
New seats!
DNA
Group quiz
N: Energy use
N: Coal and petroleum
A: Scavenger hunt
Homework
Fracking OR
Fukushima OR BP oil
spill OR Keystone XL
reading on website
Write summary, make
up 3 questions about
your reading to quiz
others
Group
quiz
For each question, a twosentence defense is
required. Answers without
defenses are scored as
incorrect
Groups that are caught
“dividing up the
questions/work” will get a
zero.
All energy
use has
consequences
Nonrenewable energy
accounts for most of
our energy use
Worldwide
energy use
Total world
energy
consumption
by source
(2010)
Worldwide
energy use
Energy use is not evenly
distributed
Energy consumption in the
U.S. in 2007 was 5x greater
than the world average
20% of the world’s people
use 70% of the world’s
energy each year
Worldwide
energy use
Commercial
energy vs.
Subsistence
energy
Commercial energy sources:
bought and sold (ex: coal, oil,
natural gas)
Subsistence energy sources:
gathered by individuals for
immediate needs (ex: wood,
animal waste)
Commercial
energy vs.
Subsistence
energy
Changes in energy demand reflect
the level of industrialization that
is occurring in a country/region
Brainstorm: with your elbow
partner, ID two ways energy
demands reflect industrialization
Energy use
in the U.S.
Make 2 inferences with your elbow partner
Energy use
in the U.S.
Energy use varies regionally and
seasonally
Coal burned in midwest and
southeastern states
Nuclear fuels, natural gas, and
hydroelectric dams in western
and northeastern states
Highly populated areas use less
coal
Energy
types and
quality
Certain forms of energy are best
suited for particular purposes (ex:
transportation prefers gas or
diesel)
Energy efficiency helps us
determine the best source of
energy to use
Energy we use to get the fuel
How efficiently can we use the
fuel
Energy return on energy
investment (EROEI)
Energy
types and
quality
EROEI
example
In order to obtain 100 J of coal
from a surface coal mine, 5 J of
energy is expended… what is
the EROEI?
Energy expanded for different modes
of transportation in the US
Mode
Another
math
question
Air
MJ per passengerkm
2.1
Passenger car
(driver alone)
Motorcycle
3.6
Train (Amtrak)
1.1
Bus
1.7
1.1
Checkpoint
What are three examples of
energy sources used by
humans?
What are some world-wide
trends in energy use? U.S.
trends in energy use?
What are the nonrenewable
sources of energy?
Primary vs. secondary source of
energy
Electricity
Primary: coal, oil, natural gas
Secondary: electricity
40% of the energy used in the
U.S. is used to generate electricity
Conversion losses = only 13% of
the 40% is available to end users
Electricity
generation
Electricity
Fossil fuels
provide
most of the
world’s
energy
Checkpoint: share with the person
across from you 10 things you
know about coal
Coal
Coal
Coal is a solid fuel formed
primarily from the remains of
plant materials that were
preserved 280-360 million years
ago
Largest coal reserves are found in
the US, Russia, China, India
Largest producers of coal are
China, US, India, Australia
Coal
4 types of coal
Coal
Young/new
Less pressure
Less energy
Old
More pressure
More energy
(+) and (-) of
Coal
Advantages
• Inexpensive
• Easy to handle
• Little refining
before burning
• Easy to
transport
Disadvantages
• Miners’ health
impacts
• Impurities
released into air
when burned
• Produces more
CO2 when
burned than oil
or natural gas
Random
coal facts
1,450 coal mines in the U.S.
Ash deposit in Knoxville
Tennessee buried 3 houses!
Coal is 60-80% carbon
Bituminous coal has a higher
sulfur content
Petroleum
Fluid mixture of hydrocarbons,
water, sulfur
Occurs in underground deposits
Petroleum produces fluid
products like gasoline and oil =
ideal for mobile combustion
Petroleum
Petroleum
Petroleum
Petroleum
Liquid petroleum removed from
the grown is known as crude oil
Crude oil can be refined into: tar,
asphalt, gasoline, diesel, kerosene
Depends on the temperature at
which they boil (what temp they
separate from the petroleum)
~150 oil refineries in the U.S.
Keystone XL pipeline wants to
bring oil to US refinery
Petroleum
U.S. is responsible for about 22%
of worldwide petroleum
consumption
US uses more petroleum than any
other fuel – for gasoline and also
for making plastics
Top petroleum-producing
countries: Saudi Arabia, Russia,
U.S., Iran, China, Canada, Mexico
(+) and (-) of
Petroleum
Advantages
• Easy to
transport
• Ideal fuel for
transportation
Disadvantages
• Releases CO2
when burned
• Contains sulfur
and trace metals,
released when
burned
• Oil leak potential
from wellhead,
pipeline or tanker
Random
petroleum
facts
Deepwater Horizon spill
Exxon Valdez spill
1991 Persian Gulf War Spill
ANWR = Arctic National Wildlife
Refuge in Alaska is sitting on
possibly 25million-378 billion
gallons of oil