http://ehpnet1.niehs.nih.gov/qa/105-10focus/focus.html

Hydroelectricity

Method of Using Hydroelectricity

• Dams trap river water in a reservoir

• The moving water turns turbines

• Electricity is produced by generator

http://www.energy.ca.gov/education/story/story-html/chapter06.html

Hydroelectricity

http://wwwga.usgs.gov/edu/hyhowworks.html

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

Impacts of Hydroelectricity (2/3)

• Hydrosphere– Slows water movement

– Reduce flow of water

– Affects temperature of water

– Water level fluctuate with electric demands

http://ehpnet1.niehs.nih.gov/qa/105-10focus/focus.html

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

To ratify the impact

• Removal of dams

• Build smaller dams

• Divert water through pipes to generator instead

• Fish ladders

Examples

• Poorly managed– Costa Rica– Balbina Shallow resourvior

Tidal Energy

La Rance

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.

Tidal Energy

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

shorelines

Tidal Energy

Effects on Biosphere:• Interruption of ocean wildlife

– Potential destruction of estuaries

Effects on Atmosphere:• Less gas exchange if marine plants affectedEffects on Lithosphere• Potential to change shorelinesEffects on Hydrosphere• Disruption of water flow

Tidal energy

http://www.eren.doe.gov/pro/images/femp.jpg

Solar Energy

Method of Using Solar Energy

• Photovoltaic cells– Makes up of

semiconductors

– Produces energy when sunlight hits its surface

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

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

Impacts of solar energy

• Atmosphere– No impacts

• Lithosphere– No impacts

• Hydrosphere– No impacts

• Biosphere– No impacts

Indirect cost of solar energy

• Battery production

• Panel production uses up resources

• Uses of land spaces

Wind Energy

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

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

Wind Power-Impacts

• Hydrosphere– None

• Biosphere– The building of wind turbines could result in

less habitat for animals and plants

Wind Energy

• Wind Energy is a renewable source of energy

• Wind energy is the fastest growing energy source on earth

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

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

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

Geothermal Power

Geothermal Power-How It Works

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

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 earth’s surface

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

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

Geothermal Energy-Well Managed

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

Nuclear Energy

Three Mile Island

Nuclear Energy

How It Works:Uranium atoms are bombarded with

neutrons causing fission.Neutrons from the split uranium atoms

collide with other atomsThe energy from fission heats waterHot water is used to spin turbines

Nuclear Energy

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

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