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

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, but it
flows in a one way path
What are the 2 major laws???
- 1st and 2nd Law of thermodynamics
What are the 6 major forms?
- light, chemical, nuclear, mechanical, electrical, heat
Energy Resources
• Renewable Energy
–
–
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–
–
–
Hydroelectric
Wind
Solar
Biofuels
Hydrogen fuel cell
Geothermal
• Nonrenewable Energy
–
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–
–
Oil
Coal
Natural gas
Nuclear
What was
the US’s
principal
energy
source…
in 1875?
In 1910?
In 1960?
What is your guess?
Fossil fuel power
Nuclear power
Wind / solar power
Hydroelectric power
1. Out of the energy sources above, which is used
the most worldwide? Least?
2. Guess what percentage each source contributes
to the world’s energy supply.
3. Create a graph.
Worldwide energy sources
7% 2%
7%
fossil fuel
nuclear power
hydroelectric
power
wind and solar
power
84%
Can you make it work?
• What is causing the ball to light up?
• Where is the power coming from?
Can you light the lightbulb?
• Make a circuit = energy CIRCLE
What is electricity?
• The movement of
electrons.
• Created by moving wires
(electrons) through a
magnetic field.
Energy is needed to make electricity
• Where does the supply of electrons come from?
http://www.youtube.com/watch?v=HBu9LZa8Yrk
• Can you list the steps to create electricity?
Electricity Production
•
Coal/oil/natural gas fired power plants
1. Burn fossil fuel to make heat.
2. Heat boils water to make steam.
3. High pressured steam turns a turbine.
4. Moving turbine spins a magnet within wires (generator).
5. The magnet creates a flow of electrons = Electricity!
6. Moving electrons sent through wires to houses, schools,
etc.
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
Can you make 2 observations regarding energy and
electricity generation?
Extra Resources
2nd set of notes on Energy:
Usage & Quality
Net Energy
Energy Quality
Energy Efficiency
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
– How much net energy available?
• 2 units
Energy Quality
• Second Law: In any energy conversion, you
will end up with lower quality (less usable)
energy than you started with.
• QUALITY = The measure of the energy’s
ability to be used to produce mechanical or
electrical energy
• Low temperature heat has the LOWEST quality
Energy Efficiency
• Amount of energy that gets converted to
useful energy.
What’s the difference?
Light bulb
or heat
bulb?
Two sides to everything.
Take old
bulbs to
Lowe’s
or Home
Depot!
http://www.mnn.com/earth-matters/translating-uncle-sam/stories/cfl-vs-incandescent-battle-of-the-bulb
How can
changing a light
bulb reduce
greenhouse
gases?
Matter Cycles, Energy Flows
Global Warming
Acid Rain Smog
Burning Coal = CO2 + SO + H20 + Ash +
(CxHxSxOx)
Light + Noise + Heat
Example of the Laws of Conservation of Matter and Thermodynamics
Cartoon: https://www.youtube.com/watch?v=OqVyRa1iuMc
Mini-FBL lesson
Discuss the following questions…
1. What is global warming?...climate change? Are
they the same?
2. What have you heard about it?
3. Do you think it’s “real?”
Climate change vs. Global warming
• Climate change - major changes in climate
(temperature, rainfall, snow, or wind patterns)
lasting for decades or longer.
• Global warming - average increase in
temperatures near the Earth’s surface and in
the lowest layer of the atmosphere.
– One form of climate change
Global warming
• In specific terms, an
increase of 1 or more
Celsius degrees in a period
of 100 – 200 years would
be considered global
warming.
• Over the course of a single
century, an increase of
even 0.4 degrees Celsius
would be significant.
Byproducts of electrical generation
• Burning coal
Air: Mercury, CO2, SO2, NO2, fly ash
Water: thermal pollution, acid rain
Ground: bottom ash
Simple Solutions…
What processes involve the transfer of
carbon?
Carbon Cycle Drawing
• Make your own, UNIQUE, drawing
of the carbon cycle (both land and
ocean). Include the following:
– Photosynthesis, decomposition,
respiration, combustion, diffusion,
(LABEL ALL)
– Include yourself somewhere in the
cycle
– Point out where humans
interfere/alter the carbon cycle
How Fossil Fuels Are Formed
How Fossil Fuels Are Formed
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.
Do you have
any vampires in
your house?
What if I left my computer on every night…
How much energy would it consume?
Assume 14 hours
• In “sleep” mode, the computer draws 4 watts/hour
How much would it cost the district per day? Per
year?
• 1 kWh costs $0.15
What if all computers at the school were left on?
Energy consumed? Cost to district?
• Around 200 computers at UDHS
• Sources of
electricity
http://www.ted.com/initiatives/aws/soccket.html
Matter cycles, energy flows
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
No matter
what our
decision…
Ask:
• How much will be available in the
next 15 years? the next 30 years?
longterm?
• What is the source’s net energy
yield?
• How much will it cost to develop,
phase in, and use this energy
resource?
• How will extracting, transporting,
and using the energy resource
affect the environment?
• Can this energy source help us
sustain the earth?
• 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)