Hydroelectric power

Group 3

Leader - Jerald Kiew 12

Members Chu Yuan 3 Leom Sheng Teng 13 Gregory Loh 15 Wong Choon Pin 24

The Team

Contents

• How it produces electricity• Contribution to world fuel

consumption• Advantages & Benefits• Problems and challenges

How it WorksA few different ways:

-

-Most used method of generating hydroelectricity

-Potential energy of dammed water driving a water turbine and generator

generates electricity.

-The power extracted from the water depends on the volume and on the

difference in height between the source and the water's outflow.

-The amount of potential energy in water is proportional to the height

difference.

-A large pipe delivers water to the turbine where the electricity is generated.

Conventional - Damn

Pumped Storage

Run-of-the-River

Tide

How it Works

-Produces electricity to supply high peak demands by moving water between reservoir at different elevations.

-Low electrical demand: excess generation capacity is used to pump water into the higher reservoir.

-Higher demand: water is released back into the lower reservoir through a turbine to produce electricity.

Pumped Storage

-Small or no reservoir capacity

-Water coming from upstream must be used for generation at that moment, or must be allowed to bypass the dam.

Run-of-the-River

-Makes use of the daily rise and fall of ocean water due to tides

-Highly predictable

-Can also be dispatchable to generate power during high demand periods.

-Less common types of hydro schemes use water's kinetic energy or undammed sources

-Tidal power is viable in a relatively small number of locations around the world due to need of specific conditions.

Tide

Underground-Makes use of a large natural height difference between two waterways (e.g. Waterfall, Mountain Lake).

-Underground tunnel is constructed to take water from the high reservoir to the generating hall built in an underground cavern

-Built near the lowest point of the water tunnel

-A horizontal tailrace taking water away to the lower outlet waterway.

Contribution to world fuel consumption

• Most widely used form of renewable electricity

• Accounts for 7% of global energy consumption in 2012- energy, not fuel as hydroelectric energy does not use fuel

- it lessens world fuel consumption

• 12,340 PJ (petajoules) of electricity production in 2010

Problems & Challenges● Economic Challenges

• Environmental Impact

The construction and maintenance of the structures that help to produce the power is very high. The high costs of building and maintenance can undermine the overall production of electricity.

a. Average cost to build a dam on a river - $3.4 billion

b. Annual maintenance cost - $2 million

Economic Challenges

Flooding land for a hydroelectric reservoir has an extreme environmental impact as it destroys forest, wildlife habitat, agricultural land, and scenic lands.

Environmental Impact

The formation of the reservoir increases the water level. Animals are displaced from their natural habitats and these habitats are sometimes destroyed.

Impact on Wildlife

The dam blocks the way for upstream fish to lay eggs and migrate. For example in North America the salmon have been greatly affected by the damming of major rivers.

Impact on Marine Life

The stagnant water in the reservoirs produces substantial amounts of greenhouse gases like methane and carbon-dioxide.

Greenhouse Emissions

Social ImpactThe lives of people living on the river banks and whose income is closely tied with the river will be greatly affected.

1. Fishing and agriculture would be affected due to the environmental effects of this power production

2. Entire communities have to be relocated to higher grounds or to places further away from the dam.

The Tehri dam in India was well known for its controversy. Due to the construction of the dam, the people had to be relocated. This caused social unrest among the people because they

had lost the agricultural land that they had owned and passed down from generation to generation.

Tehri Dam - India

Referenceshttp://en.wikipedia.org/wiki/World_energy_consumption#Hydroelectricity

http://jisibhlphysics.wikispaces.com/Problems+with+hydroelectricity+and+their+solutions

http://envirometl.com/leed.html

http://www.illustrationsof.com/10132-royalty-free-dollar-sign-clipart-illustration

http://childrenssermonstoday.blogspot.sg/2012/02/noahs-noisy-ark.html

http://en.fotolia.com/id/8715535

http://www.fotosearch.com/photos-images/greenhouse-emissions.html

http://economictimes.indiatimes.com/slideshows/infrastructure/tehri-dam-holds-ganga-and-saves-rishikesh-haridwar/strong-currents-of-the-river/slideshow/20812832.cms

Thank you!Any questions?