Energy and Electricity ES 303. The lifetime of a resource depends on… 1.How much we have 2.How...
-
Upload
evelyn-walters -
Category
Documents
-
view
217 -
download
0
Transcript of Energy and Electricity ES 303. The lifetime of a resource depends on… 1.How much we have 2.How...
What resources does the US have?
• Fossil fuels = – Oil– Coal– Natural Gas
• Why are we depleting our resources (running out)?– http://www.npr.org/news/specials/climate/video/
Energy is…
– The ability to do work.
IMPORTANT ENERGY CONCEPTS1. Energy is neither created or destroyed.2. Energy is lost as heat as it gets transferred
or changes form.
Energy Resources
• Renewable Energy
– Hydroelectric– Wind – Solar– Biofuels– Hydrogen fuel cell– Geothermal
• Nonrenewable Energy
– Oil– Coal– Natural gas
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=AbUjieMLFSo• 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 turns the generator (magnets and wires).
5. The magnet creates a flow of electrons = Electricity!
6. Moving electrons sent through wires to houses, schools, etc.
•Can you order the pictures correctly?
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
• 1 kWh = one kilowatt of electricity over 1 hour
It takes energy to get energy
Before it’s useful…
Oil must be 1. Found2. Pumped3. Transported4. Refined5. Transported6. burned
Net energy
• DEFINITION: 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
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
Two sides to everything.
http://www.mnn.com/earth-matters/translating-uncle-sam/stories/cfl-vs-incandescent-battle-of-the-bulb
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
Example of the Laws of Conservation of Matter and Thermodynamics
Global WarmingGlobal Warming
Acid RainAcid Rain SmogSmog
Burning Coal = CO2 + SO + H20 + Ash +(CxHxSxOx) Light + Noise + Heat
2nd Energy Concept
• When energy changes form, some useful energy is always lost as heat.
• EX: Only 5-10% of the electricity flowing through an incandescent light bulb is converted to light energy (the rest is heat).
Example of the Matter and Energy LawsExample of the Matter and Energy Laws
Global WarmingGlobal Warming
Acid RainAcid Rain SmogSmog
Burning Coal = CO2 + SO + H20 + Ash +(CxHxSxOx) Light + Noise + Heat
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 your guess?
Fossil fuel power Wind / solar powerNuclear 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
84%
7%7% 2%
fossil fuel
nuclear power
hydroelectricpower
wind and solarpower