1. Renewable Energy
Chapter 18

2. Solar cooker lab
You will be building a solar cooker in class Wednesday and Thursday, Friday will be cooking day.
All materials must be natural (nothing electronic)
Some examples but not limited to:
scotch tape
black duct tape
1 box, any kind, any size, remember larger the box, the more space has to be heated
3-4 feet of aluminum foil
Cellophane wrap
scissors; must be strong enough to cut corrugated cardbaord if utility knives are not used
(optional) glue
3-4 pieces of black construction paper
ruler
Pan/plate to cook on
food item to be cooked on metallic pan with box, such as Break and Bake Cookies (pre-made cookie dough), Bagel Bites, etc...; best if the items are pre-cooked and only require warming
Thermometer (I provide)
oven mitts (can share among groups)
graph paper

3. Solar cooker continued
You will need to bring in the supplies to build in class
It is highly recommended that you research solar cooker plans tonight!!!!
Lab grade will be based on the following:
20 points for basic construction
60 points for write up (all the basics steps and purpose of lab should be here, standard type of lab write up)
20 points for cooking (basically did you get it hot enough to warm up item)

4. Hydroelectric Energy
Electricity that is produced from the energy of moving water.
Anything that has mass, and moves, has kinetic energy.
Harnessing moving water is a clean, readily available source of energy.
Has been around for centuries (water wheels)
Roughly 20% of the worlds electricity is generated by flowing water.

5. How it works:
water, behind the dam, is directed towards turbines.
Water pushes against the blades, causes it to spin “run”
This motion is transferred to coils of wires in generators
Coils spin through a magnetic field
Produces electricity

7. The pro’s and con’s of Dam’s
Renewable
Green
Reliable
Flexible
Safe
Flood control
Recreation

8. Cons:
Environmental consequence's
Fish migrations
Habitat destruction
Relocation (includes humans)
Drastic temperature changes
Expensive to build
Droughts

9. Other water sources:
Tides
Tidal surges are a great source of electricity (where available)
Pro’s: renewable, very clean, not typically disrupting normal flow (migrations),
Con’s: limited locations available, eye sore, affect benthic community.
Waves
Movement (up and down) waves create can be used to make electricity
Pro’s: renewable, clean, mostly anywhere
Con’s: expensive and difficult to harness, eye sore

13. Home work!! A1’s Read “A Super Efficient Home” page 458-459
Answer questions 1 and 2 on page 459
Also:
In 2-3 sentences, explain whether or not this is a feasible solution to energy/water crisis found through out the world.
A11’s
Walk/drive around your neighborhood and list as many sources of biomass fuel as you can find. Answer:
Are any large enough to be used as a fuel source?
List 2 each; advantages and disadvantages of biomass as a fuel source.
How many people do you think take advantage of fireplaces in the wintertime (guesstimate the approx. number of houses with fireplaces in your neighborhood)
List 2 each; advantages and disadvantages of home fireplaces.

14. Solar Energy
Energy from the sun (which technically is the source for hydro and wind power as well)
Thermonuclear fusion (where the suns energy comes from)
High temps (on the sun) cause hydrogen nuclei to fuse creating helium nuclei
As helium forms, a loss of mass occurs, which is converted into heat and light energy.
We actually receive a miniscule amount of the energy that is created by the sun.
This energy can be harnessed and used to generate electricity.

15. 7.Many Applications
Pros
8.Shared Solar
1.Renewable
9.Silent
2.Abundant
10.Financial Support from Government/State
3.Sustainable
4.Environmentally Friendly
11.Low Maintenance
12.Technology is Improving
5.Good Availability
6.Reduces Electricity Costs

16. Cons
1.Expensive
2.Intermittent
3.Energy Storage is Expensive
4.Associated with Pollution
5.Exotic Materials
6.Requires Space

17. Active and passive solar energy: devices are used to collect, store, and circulate heat produced from solar energy.
In active systems
Tubes, tanks, fluids, pumps, fans, and other stuff are used to collect and distribute
Can be used after the sun sets as well
Make use of collectors (ex. Solar panels)
In passive systems (collected, distributed, and stored naturally)
Relies more on the positioning of the house and windows
Oriented so open facing areas (windows) typical face south

20. Photovoltaic Cells: uses thin wafers of semiconductor material to produce electricity directly from the solar energy
Also called the solar cell
Produces electricity directly
Made of elements like silicon and/or selenium
Two layers, of the semiconductor, sun strikes it, causes electrons to move back and forth…viola electricity.
Very common today, signs, watches, etc…

23. Wind Power
Use of the wind to turn a source to generate electricity. Called aerogenerators.
Same basic pro’s and con’s of solar
Not as constant or steady though
and elaborate storage devices are typically required
Two basic types:
Horizontal axis (traditional)
Vertical axis (can be used in lower wind environments)

26. Geothermal
Heat energy generated within the earth.
Generated by the decay of radioactive elements
Hot enough to melt rock (magma)
Water trapped nears surface create steam (geysers)
Geo is used in areas where this source of heat is closer to the surface
Most of Iceland used geothermal to heat homes
Green houses take advantage of the heat to grow produce all year long
Several countries use it to produce electricity.

27. Pro’s and Con’s
Pro’s
Renewable
Con’s
Not available everywhere
Air is often polluted with toxic hydrogen sulfide in areas where is available
Mineral waste, salts, and toxic metals, tend to corrode pipes and boilers
Often a lack of water in these areas.

29. Ocean thermal energy Conversion (OTEC)
Makes use of the extreme temp difference in ocean levels
Water is boiled in a vacuum chamber (very low temp when in a V. Cham.)
Turns water to steam, etc…

30. Hydrogen fuel
See text