Alternative Energy: Hydroelectric PowerBy Naina Gimadeyeva and Kalil Johnson

General DescriptionElectricity 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

Hydroelectric Power: How it WorksDam are built barrier constructed to control the flow of waterWater flows into tunnels in the damGravity causes the water to flow downWhich turns the turbines that drives the generatorsElectricity is made by the spinning turbines

How it works video

AdvantagesWater provided is

freeNo greenhouse gas

emissions, minimal pollution

Low maintenance costs and operations

More reliable than solar, wind, or wave power

Fuel is renewableIncreases to full

power very quickly

• Reservoirs offer a variety of recreational opportunities

Disadvantages of Hydropower Expensive to constructFlooding can disrupt the plant and animal life

Effects fish population-reducing access to spawning groundsDams causes soil erosionHydrology is dependent on precipitation- can be effected by droughtWater quality- low dissolved oxygen levelsPower plants in tropical regions produce a high amount of methane

and carbon dioxide due to decaying plant material

Extra InformationSpecifications

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.

Hydroelectric Power: DamsTwo types of dams:Gravity dam- supported by a bedrock baseArch dam- form a convex arch, supported by lateral walls

Used in narrow canyons with steep sidewallsRisk Factors to the design of a hydroelectric dam: Resistance of dams to earthquakes Permanent inspection Ecological impact – under-oxygenated waters Human impact – relocation of peopleConditions 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

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)

Websiteshttp://discoverer.prod.sirs.com/discoweb/disco/do/artic

le?urn=urn%3Asirs%3AUS%3BARTICLE%3BART%3B0000133825

http://ga.water.usgs.gov/edu/hyhowworks.htmlhttp://www.enviroliteracy.org/article.php/59.htmlhttp://www.tvakids.com/electricity/hydro.htmhttp://home.clara.net/darvill/altenerg/hydro.htmhttp://www.epa.gov/solar/energy-and-you/affect/hydro.

htmlhttp://www.energyrefuge.com/archives/hydro-electricit

y.htmhttp://ga.water.usgs.gov/edu/wuhy.html*

http://www.eia.doe.gov/kids/energyfacts/sources/renewable/water.html

http://www.beyondfossilfuel.com/hydroelectric/ http://www.promotega.org/AAU06004/Hydroelectricity.htm