Hydroelectricity

1
Hydroelectricity
http//ehpnet1.niehs.nih.gov/qa/105-10focus/focus.
html
2
Method of Using Hydroelectricity

• Dams trap river water in a reservoir
• The moving water turns turbines
• Electricity is produced by generator

3
Hydroelectricity
http//wwwga.usgs.gov/edu/hyhowworks.html
4
Impacts of Hydroelectricity (1/3)

• Atmosphere
• Greenhouse gas from decay of biomass in reservoir
• More for shallow reservoirs
• Vegetations removal ? less CO2-O2 Exchange
• Bodies of water change climate
• Lithosphere
• Water causes changes in landscape
• Silting up of reservoirs
• Less deposition in lower river

5
Impacts of Hydroelectricity (2/3)

• Hydrosphere
• Slows water movement
• Reduce flow of water
• Affects temperature of water
• Water level fluctuate with electric demands

6
Impacts of Hydroelectricity (3/3)

• Biosphere
• Prevents fish from spawning
• Creates and destroys habitats
• Reservoir may promotes water related disease
• Provides usable water
• Loss of plants

7
To ratify the impact

• Removal of dams
• Build smaller dams
• Divert water through pipes to generator instead
• Fish ladders

8
Examples

• Poorly managed
• Costa Rica
• Balbina Shallow resourvior

9
Tidal Energy
La Rance
10
Tidal Energy

• How It Works
• A dam stretched across a tidal basin allow the
  tide to flow into the basin through a sluice.
• The elevated water in the basin is utilized for
  electricity by producing mechanical energy over
  water wheels.

11
Tidal Energy

• Pros
• Predictable, reliable
• Sustainable
• Widely available
• Few greenhouse gas emissions
• Cons
• Variable power throughout day
• Expensive
• Potential negative impact on estuaries and
  shorelines

12
Tidal Energy

• Effects on Biosphere
• Interruption of ocean wildlife
• Potential destruction of estuaries
• Effects on Atmosphere
• Less gas exchange if marine plants affected
• Effects on Lithosphere
• Potential to change shorelines
• Effects on Hydrosphere
• Disruption of water flow

13
Tidal energy
14
Solar Energy
http//www.eren.doe.gov/pro/images/femp.jpg
15
Method of Using Solar Energy

• Photovoltaic cells
• Makes up of semiconductors
• Produces energy when sunlight hits its surface

16
Solar Thermal Electricity

• Uses mirror to reflect sunlight to a central
  receiver
• Heat is used to generate electricity
• Fluid circulated to drive a generator

• http//www.solardev.com/SEIA-makingelec.php

17
Solar Thermal Heater

• Solar collector absorbs heat from sunlight
• Solar collector then heats the air or water

http//www.irish-energy.ie/abouten/main3l.html
18
Impacts of solar energy

• Atmosphere
• No impacts
• Lithosphere
• No impacts
• Hydrosphere
• No impacts
• Biosphere
• No impacts

19
Indirect cost of solar energy

• Battery production
• Panel production uses up resources
• Uses of land spaces

20
Wind Energy
21
Wind Power-How it is generated

• Turbine blades rotate when wind hits them which
  causes a rotor to turn and then drives an
  electrical generator

22
Wind Power-Impacts

• Atmosphere
• NONE, Wind power does not polute the atmosphere
• Lithosphere
• Wind turbines have to be anchored to the ground
  which could impact soil structure

23
Wind Power-Impacts

• Hydrosphere
• None
• Biosphere
• The building of wind turbines could result in
  less habitat for animals and plants

24
Wind Energy

• Wind Energy is a renewable source of energy
• Wind energy is the fastest growing energy source
  on earth

25
Management of Wind Energy

• Wind turbines should be used where there is
  plenty of wind
• More wind turbines should be built because the
  resource is currently not being used as well as
  it could be

26
Wind Energy Poorly Managed

• The United States has the wind energy potential
  to supply one and a half times the current
  electricity consumption but only a very small
  amount electricity is generated by wind

27
Wind Energy-Well Managed

• In Europe wind energy capacity has increased by
  40 in the last six years and there is currently
  enough wind electricity to meet the needs of 5
  million people and by 2010 there should be enough
  for 75 million

28
Geothermal Power
29
Geothermal Power-How It Works

• Water travels through pipes deep into the Earths
  surface where the temperature is hotter, the
  water than turns to steam which drives the turbine

30
Geothermal Power -Impacts

• Atmosphere
• geothermal plants emit carbon dioxide
• Lithosphere
• geothermal plants require pipes to be dug through
  soil and rock to get deep into the earths surface

31
Geothermal Power-Impacts

• Hydrosphere
• Geothermal plants require the use of water in
  order to produce electricity
• Biosphere
• The Building of geothermal plants could result in
  less habitat for animals

32
Management of Geothermal Energy

• Buil geothermal plants in areas where heat from
  magma is closer to the surface of the earth so
  that it is easier to generate electricity

33
Geothermal Energy-Well Managed

• In the Philippines geothermal power provides 27
  of the nations total electrical generation

34
Nuclear Energy
Three Mile Island
35
Nuclear Energy

• How It Works
• Uranium atoms are bombarded with neutrons causing
  fission.
• Neutrons from the split uranium atoms collide
  with other atoms
• The energy from fission heats water
• Hot water is used to spin turbines

36
Nuclear Energy
37
Nuclear Energy

• Benefits
• Few greenhouse gas emissions
• High energy yield compared to fossil fuels
• Consequences
• High cost of repairing aging plants
• High cost of plant shutdowns
• Radioactive waste

38
Nuclear Energy

• Effects on Biosphere
• Accidents may expose living things to radiation
• Effects on Atmosphere
• None
• Effects on Lithosphere
• None
• Effects on Hydrosphere
• Water diverted to plant for harnessing energy