1. What it is & What it isn’t
RENEWABLE ENERGY
What it is
&
What it isn’t

2. Vocab Buzz Sustainable  Renewable  NonRenewable  Organic  Green 
Clean 
B: Students brainstorm and construct lists. Best answers are put on the board. Throughout class, stress that none are necessarily synonymous, although green and sustainable are likely the best pair for the energy movement.

4. Energy Waste & Inefficiency What’s the moral of this story?
Conservation vs. Efficiency
84% of commercial energy in US is wasted
41% due to entropy
(2nd law of thermo)
43% unnecessary; inefficiency
$570,000/min
Look at unnecessary waste vs petrochemicals. Sure they’re nonrenewable, but stupidity is our greatest hurdle.

5. How does energy get wasted?
Net Energy Yield
Net Energy Efficiency
Combine efficiencies of all steps in energy conversion for the entire system
Every hour the sun beams onto Earth more than enough energy to satisfy global energy needs for an entire year.
the solar energy hitting the earth exceeds the total energy consumed by humanity by a factor of over 20,000 times.
How does energy get wasted?

6. Every hour the sun beams onto Earth more than enough energy to satisfy global energy needs for an entire year.
Why is solar our best transition option?

7. Solar Energy

8. Passive Solar Heating and Cooling
How does it work?

9. Passive Solar Heating

10. Thick walls & insulation on north side.
Passive Solar Heating
SOUTH FACING
Venting in summer
Thick walls & insulation on north side.

11. Passive Solar Heating ADVANTAGES DISADVANTAGES HIGH net energy yield
Free energy
No pollutants
Moderate cost
DISADVANTAGES
Is there enough available sunlight in all areas?
Need 60% of the time
Needs correct orientation
Need heat storage or backup

12. Solar Cooling Super-insulation Block summer sun  trees, awning, etc.
Good ventilation
Earth Tubes
Soil ~5-13ºC
Moves cool, dry air in
Inexpensive
Light colored roof
Reflective foil in attic
Earth sheltered building

13. Active Solar Water Heating

14. Active Solar Heating Solar collectors on roof
Heat stored in insulated tanks of water, rocks, heat-absorbing chemical
Used for heating and hot water

15. Active Solar ADVANTAGES DISADVANTAGES No pollutants
Moderate net energy
Free after initial installation
DISADVANTAGES
Unattractive
Is there enough available sunlight in all areas?
Needs correct orientation
Requires a backup hot water source
Pump requires energy, maintenance

16. Solar cooker

17. Solar Thermal Plant

18. Parabolic (U-shaped mirrors) concentrate the sun’s rays onto a black pipe containing molten salts or oil. This produces steam to turn a turbine and generator.

19. Pros and Cons PROS CONS Non-polluting, no carbon emissions
High efficiency (~15%)
Operating costs are low
Takes up a lot of land – 1 sq. mile or more
Not always reliable
Slightly more expensive than PV cells
New technology involved
Heavily location dependent

20. Why do we waste so much? Fossil fuels cheap Few gov’t incentives
Inaccurate pricing
Inequitable subsidies
What are the benefits to reducing?

21. Photovoltaic (Solar Cells)
Good description of batteries and link to how solar energy can recharge them

22. Photovoltaic Cells Sunlight strikes semi-conductor Electrons move
Life is carbon-based for a reason
Silicon atoms have the same capabilities
When a sufficiently strong photon of sunlight hits the cell, it can knock an electron free. Since PV cells have electromagnetic fields, the electrons are propelled out of the cells, forming an electric current Read more: How Do Photovoltaic Panels Work? | eHow.com
Sunlight strikes semi-conductor
Electrons move
Energy can be stored in battery
(1:07 mins)

23. Solar Cells ADVANTAGES DISADVANTAGES No pollutants Safe Expen$ive!
Need large surface area
Unattractive
Is there enough available sunlight in all areas?
Requires a backup electricity source

24. Hydrogen Fuel Cells How it Works: Combines H with O to produce energy
Can be fueled by anything with H in it
Natural gas, alcohol, gas
Gives off water
Set-up demo before showing video, let run during video, then light on fire after video is complete
(5:53 mins)
Fuel Cell Flash Animation
Bill Nye video
(12:49 mins)

25. Hydrogen Fuel Cells ADVANTAGES DISADVANTAGES H is abundant
Non polluting
DISADVANTAGES
Not very efficient to produce
Takes electricity to split water and produce H
Expensive
Needs to be stored at high pressure

26. Energy Types: Can you match and discuss the +/- ?
Chemical
Electrical
Mechanical
Light (EM)
Nuclear
Heat
Clean
Renewable
Sustainable
Wind
Hydrothermal
Active Solar
Biomass
Passive Solar
Coal, Oil, Natural Gas
Hydrogen Fuel Cells
Hydroelectric
Tidal
Would do this as part of the review after all the presentations are completed

27. Slide Bank

29. Use renewable energy!
Benefits of shifting to local, renewable energy sources
More reliable source
Improve national security
Reduce trade deficits due to importing oil
Reduce greenhouse gases and other air pollution
Creates jobs
Saves $ in the long run

30. Hybrid, Plug-in hybrid, Electric
Hybrid Car Flash Animation
Prius Hybrid Synergy Drive
GM Volt (2010)
The EV-1
The Tesla

31. More on Batteries Carbon-Zinc – 1st Duracell Lead-Acid – Car batteries
Nickel Cadmium – consumer electronics
Nickel-Metal Hydride
Lithium Ion – notebook computers
Lithium polymer – newest development

32. 3 types of Heat Transfer

33. 33

34. TRADE-OFFS Passive or Active Solar Heating Advantages Disadvantages
Energy is free
Need access to sun 60% of time
Net energy is moderate (active) to high (passive)
Sun can be blocked by trees and other structures
Quick installation
Environmental costs not included in market price
No CO2 emissions Very low air and water pollution
Need heat storage system
Figure 16.11
Advantages and disadvantages of heating a house with passive or active solar energy (Concept 16-3). Question: Which single advantage and which single disadvantage do you think are the most important? Why?
Very low land disturbance (built into roof or windows)
High cost (active)
Active system needs maintenance and repair
Moderate cost (passive)
Active collectors unattractive 34

35. What IS a Battery? Energy Storage System!
As easy as a clock spring or a log
Is that potential or kinetic?
Have magnets for simple demo and discussion of negative and positive
Great history and construction of battery site; bottom pic is Duracell battery;

36. What IS a Battery? -aka cell
Changes chemical energy to electrical
Voltaic cells (cells that can transfer voltage)
Electrons collect on the negative terminal of the battery
Flows between the positive and negative terminals if a conductor (or wire) is present

37.
Battery video

38. What is Energy? “The Ability to do Work”
The world is made up of MATTER & ENERGY.
Which one cycles and which one flows?
The 2 classes are Potential & Kinetic
The 6 types are:
Chemical, Mechanical, Nuclear, Light (EM), Heat, Electrical

39. What’s the bridge to get there?
Where are we now?
Coal Gasification
Where might we go?
Hydrogen Fuel Cells
What’s the bridge to get there?
Photovoltaic Cells
Do coal gasification demo and then jump into discussion of net energy – low due to the many steps