Transcript Energy – Where does it come from and why does it produce waste?

With your closest table mates:
Write the answer to your assigned question.
Remember to show work!
HOMEWORK CHECK
Resources & Reserves
Resources ≠ Reserves
• Resources – amounts of material that are
known/ assumed to exist that can be
extracted NOW or in the FUTURE for a
POSSIBLE profit $
• Reserves – known amounts of material that
can PRESENTLY be extracted for a PROFIT
– “proven”
Changing estimates
• Why do reserves of resources usually last
much longer than most early estimates
predict?
• How does technology influence the estimates of
reserves and resources?
Resource Depletion
static, exponential, real world
Energy –
Where does it come from?
ES 302
Objectives
• What is energy?
• What forms does it come in & how do we use it?
• Understand that ALL sources of energy have costs
and benefits
What is Energy?
• Energy “The ability to do work”.
• Remember:
The amount of energy in the universe is constant.
What are the 2 major laws???
- Laws of thermodynamics
What are the 6 major forms?
- light, chemical, nuclear, mechanical, electrical, heat
Make a circuit
• Circuit = energy circle
What is electricity?
• The movement of electrons
• As electrons move through metal wires, they
rub against the wire – creating friction. This
resistance creates heat and even light!
• But where does this supply of electrons come from?
What is a watt?
• 1 watt = energy to lift 100 g (or 1 Newton) in
1.0 seconds.
• It is a measure of energy over time
Other Units of Energy
• 1 calorie
• 1 Btu (British thermal unit)
• 1 Q (quad) = 1 quadrillion Btu (very large!)
– The U.S. uses ~ 1 quad of energy about every 3.7
days
• 1 kWh = one kilowatt of electricity over 1 hour
How is electricity made?
• http://www.youtube.com/watch?v=AbUjieML
FSo
• Can you list the steps?
• Check it out!
Magnets &
Generators
•
•
•
•
•
•
Energy sources, for example coal, are burned
which boils water, which produces steam
The steam spins a turbine
The turbine spins a magnet
The magnet creates a flow of electrons
This flow of electrons travels from the power plant to
your home!
How can
changing a light
bulb reduce
greenhouse
gases?
1st Law of Thermodynamics
• “Conservation of Energy Law”
– Energy can neither be created nor destroyed.
• Energy in the universe is constant.
• If you can’t destroy energy, you CAN change its form!
– EX: Matches
– EX: Light Bulb
2nd Law of Thermodynamics
• “Energy Quality Law”
– When energy changes form, some useful energy is
always degraded to lower quality, less useful
energy.
• Low temperature heat is the least useful energy form!
• EX: 90% of energy in gas (chemical) is changed to heat!
• Only 5-10% of the electricity flowing through a light bulb is
converted to light energy (the rest is heat).
Energy Quality
Energy in = Energy Out
But the quality is always lower
It takes energy to get energy
•
Before it’s
useful…
Oil must be 
1.
2.
3.
4.
5.
6.
Found
Pumped
Transported
Refined
Transported
burned
Net energy
• Total useful energy available from the
resource over its lifetime minus the amount of
energy used and wasted
• Example:
– 10 units of energy in oil in ground
– Use 8 units to find, extract, process, transport
– 2 units of net energy available
Energy Quality
• The measure of the energy’s ability to be used
to produce mechanical or electrical energy
• Low temperature heat has the LOWEST quality
– You can’t cook with it, you can’t move anything
with it, you can’t even heat with it
– Power plants are designed to release it into space
Did you beat Mrs. Loch?
• You analyzed your (presumed) usage of electricity
– That energy is secondary
• Primary Energy Resources: The fossil fuels(oil, gas,
and coal), nuclear energy, falling water, geothermal,
and solar energy.
• Secondary Energy Resources: Those sources which
are derived from primary resources such as
electricity, fuels from coal, (synthetic natural gas and
synthetic gasoline), as well as alcohol fuels.
How can
changing a light
bulb reduce
greenhouse
gases?
CFL – compact fluorescent lightbulb
life span:
Watts:
Annual $:
Incandescent
1,500 hours
60
$76.65
CFL
10,000 hours
14
$328.60
Over the course of 30 years, having CFL lightbulbs in your
househttp://www.mnn.com/earth-matters/translating-uncle-sam/stories/cfl-vs-incandescent-battle-of-the-bulb
can save you around $20,000!
Two sides to everything.
Byproducts of electrical generation
• Burning coal
Air: Mercury, CO2, SO2, NO2, fly ash
Water: thermal pollution, acid rain
Ground: bottom ash
Example of the Laws of Conservation of Matter
and Thermodynamics
Global Warming
Acid Rain Smog
Burning Coal = CO2 + SO + H20 + Ash +
(CxHxSxOx)
Light + Noise + Heat
CaCO3 (n) [building] + H2SO4 (aq) [acid rain] → Ca2+
(aq) + SO42- (aq) + H2O + CO2
Acids and Bases
Water molecules can react to form
individual ions:
H2O
H+ + OH• In pure water this occurs naturally but
the amount of H+ is always = to the
amount of OH- so water remains neutral
ACID:Any compound that forms H+ ions in solution
BASE: Any cmpnd that forms 0H- ions in solution
Example of the Laws of Conservation of Matter
and Thermodynamics
Global Warming
Acid Rain Smog
Burning Coal = CO2 + SO + H20 + Ash +
(CxHxSxOx)
Light + Noise + Heat
Cartoon: http://www.youtube.com/watch?v=V1O34cqerqs
Mini-FBL lesson
What processes involve the transfer of
carbon?
Carbon Cycle Drawing
• Make your own, UNIQUE, drawing
of the carbon cycle. Include the
following:
– Photosynthesis, decomposition,
respiration, combustion (LABEL ALL)
– Include yourself somewhere in the
cycle
– Point out where humans
interfere/alter the carbon cycle
What is our best immediate energy option?
1. Cut out unnecessary energy waste by
improving energy efficiency
2. Transition to a renewable or solar age
– Sun, wind, flowing water, biomass, geothermal,
hydrogen gas
3. Burn more coal & synthetic gas/liquids
4. Natural gas
5. Nuclear power
Other Units of Energy
• 1 calorie = amount of heat needed to heat 1 g
of water 1 degree Celsius
– 1 cal = 4.187 Joules
• 1 Btu (British thermal unit) = amount of heat
energy needed to raise the temp of 1 pound
of water by 1 degree Farenheit
– 1 Btu = 1,054 joules; 252 calories
• 1 Q (quad) = 1 quadrillion Btu (very large!)
– The U.S. uses ~ 1 quad of energy about every 3.7
days
• http://www.youtube.com/watch?v=1xPjESsHwg&feature=related
– Very slow explanation of current & voltage. Nice
analogy to water (river, lake)
• http://www.youtube.com/watch?v=k7Sz8oT8
ou0
– Cardboard generator constrxn (7:44)