1. Alternative Energy: Hydroelectric Power
By Naina Gimadeyeva and Kalil Johnson

2. General Description Electricity is generated by hydropower
Hydropower is the gravitational force of falling water
The force of water drives the water turbine and generator to create electricity

3. Hydroelectric Power: How it Works
Dam are built barrier constructed to control the flow of water
Water flows into tunnels in the dam
Gravity causes the water to flow down
Which turns the turbines that drives the generators
Electricity is made by the spinning turbines
How it works video

4. Advantages Water provided is free
No greenhouse gas emissions, minimal pollution
Low maintenance costs and operations
More reliable than solar, wind, or wave power
Fuel is renewable
Increases to full power very quickly
Reservoirs offer a variety of recreational opportunities

5. Disadvantages of Hydropower
Expensive to construct
Flooding can disrupt the plant and animal life
Effects fish population-reducing access to spawning grounds
Dams causes soil erosion
Hydrology is dependent on precipitation- can be effected by drought
Water quality- low dissolved oxygen levels
Power plants in tropical regions produce a high amount of methane and carbon dioxide due to decaying plant material

6. Extra Information Specifications Limited locations due to
Swift flowing rivers or streams
Mountainous regions
Heavy rainfall
Limited locations due to
Space requirements
Areas needed with heavy rainfall
Need to displace the people
Building costs
Least common compared to others
Supplies 9% of the United States’ electricity
Accounts for 49% of all renewable energy used by the U.S.

7. Hydroelectric Power: Dams
Two types of dams:
Gravity dam- supported by a bedrock base
Arch dam- form a convex arch, supported by lateral walls
Used in narrow canyons with steep sidewalls
Risk Factors to the design of a hydroelectric dam:
Resistance of dams to earthquakes
Permanent inspection
Ecological impact – under-oxygenated waters
Human impact – relocation of people
Conditions for building a dam
Topographical location – detailed features
Geographical location – natural features, populations, industries and etc.
Hydrological conditions - the science dealing with occurrence, circulation, distribution, and properties of water

8. Hydroelectric Energy: Dams Contd.
Hoover Dam (Boulder Dam): built in the 1930s in the Black Canyons of the Colorado River
Construction deaths of 112 workers were due to
Rock slide
Explosion
Drowning
Health Prostration
Construction of the dam:
Groundwork- construction of cofferdams were constructed to prevent flooding
River diversion- built diver tunnels through canyon walls to reroute water in construction site
Rock clearance- men suspended removed rock with dynamite and jackhammers
Concrete- built in trapezoid columns to reduce stress and built cooling coils to cool the concrete
Construction cost approximately $49 million ($736 million adjusted for 1936 to 2008)
Hoover dam (google map)

9. Websites *