1. Chapter 21: New renewable Energy Alternatives

2. Renewable Energy sun wind geothermal oceans hydrogen

3. Solar Energy conversion of hydrogen (H) to helium (He)
each m2 of area receives about one kilowatt of solar energy= seventeen 60 watt light bulbs
therefore each house has enough roof area to generate all it needs using solar panels
passive and active solar energy collection

4. Passive Solar Energy Collection
design of buildings
construction materials are chosen to:
maximize direct absorption of sunlight during winter
keep the interior cool in summer by:
south facing windows
planting vegetation for shade during summer
overhangs to block sun in summer
heat-absorbing construction materials
straw, brick or concrete for example

5. Passive Solar Energy Collection

6. Active Solar Energy solar panels solar cookers photovoltaic cells

7. Active Solar Energy solar panels
few on the roof of a house or building
collection of mirrors
power tower with molten salt creating steam that moves the generator
tubes with oil which creates steam that move turbines

8. Active Solar Energy photovoltaic cells
collect sun's energy converting it to electrical energy using semiconductors.

9. Benefits of PV cell quiet safe require little or no maintenance
no moving parts
no turbine or generator required
each unit lasts years

10. Active Solar Energy
allows families to cook without having to gather fuel wood
lessens daily workload
helps reduce deforestation
helps relieve social and environmental stress

11. Benefits of Solar Power
inexhaustible as energy source
enough energy to power earth as long as technology develops
allows decentralized control over power
producing many new jobs
does not pollute

12. Drawbacks of Solar Power
localization

13. Drawbacks of Solar Power
costs

14. Wind Energy wind turbines
windmills have been used for more than 800 years in Europe
drain wetlands
irrigate crops
grind grain into flour

15. Wind first wind turbine was created in the late 1800s
rural electrification act 1935 killed its development promoting dams and coal plants
not until the oil embargo of 1973 that the idea was brought back and funding for research was given
low costs
kinetic energy converted into electric energy
different turbines are designed to work at different wind speeds
faster the wind the more energy it generates

16. Wind: fast growing energy sector

17. Offshore Wind Turbines
more expensive
more productive
shallow areas
maintenance

18. Benefits of Using Wind Power
cleaner
under optimal conditions it is much more effective than any other conventional energy source
small to large scale usage
farmland can lease a small area and still be productive
once built, the costs are only for maintenance
as efficiency increases the cost of electricity decreases

19. Downsides of Wind Power
wind is intermittent and unpredictable
good resourses are mostly away from populations
grid has to be built and that costs money
conspicuous
people object to farms due to aesthetics
not-in-my-backyard syndrome
threat to birds and bats

20. Geothermal Energy generated deep within Earth
from an area of volcanic activity along two tectonic plates

21. Benefits and Limitations
reduces emissions relative to fossil fuels
other pollutants it produces are in very small quantities
filters help control pollutants
Limitations
can produce other pollutants like CO2, CH4, NH3
sources may not be truly sustainable
limited to area where tectonic plates meet
water used for energy corrodes equipment shortening lifetime of the plant
chemicals in the water may pollute the air

22. Ocean Energy Sources
tides
waves
currents

23. Tides rising and fallen of the ocean level twice each day
erecting dams across the outlets of the tidal basins
outgoing tide will pass through the turbines generating electricity
no pollution
high impact on the ecology of estuaries

24. Hydroelectricity from Tidal Waves
La Rance- France

25. Wave Energy converting mechanical energy to electricity
harness the motion of wind-driven waves at the ocean surface
greater energy is found in deeper ocean sites NY

26. Wave Energy Generator

27. Currents marine kinetic energy
essentially like underwater wind turbines
are now been tested in Europe

28. Hydrogen Benefits Drawback
storage of energy generated by sustainable energy is a problem, hydrogen fuels cells are promising
Hydrogen is the fuel and it is abundant
clan, bonds H2 and O2 making water as final product
Drawback
to make the fuel (H2) energy is required and carbon based pollutants are produced
possible risk of depleting ozone from stratosphere if H2 leaks

29. Bloombox or Bloomenergy
stack of silica plates covered with patented solutions on both sides
it converts oxygen into energy with a minute use of energy (gas, electric, biodisel, etc)
one "box" is required for every European home, 2 for every American home
no need of the grid
several companies are already using it in California
EBay
Google
FedEx
CBS 60 minutes 2/21/2010
The End