Hydroelectric Energy Alisha Kumar

Harry Dakesian

What can this type of energy be used for

• When generated, hydroelectricity is sent to large scale grids, namely houses and businesses.

Can we Renew Hydroelectricity?

• Although water itself is not renewable, in the process of using hydroelectricity, water is not actually lost. It can be sent back through the dam for an unlimited number of times to continuously produce electricity.

This way, building the dam

is a one time process,

and so you have the

electricity for many years.

Cost of Using Hydroelectricity

• The average cost of building a hydroelectric power plant is slightly over one billion dollars. However, building a dam could force people to move away, depending on their location relative to the dam. Also, after years of use, the dam will wear down and become outdated. Because of this, restorations will have to be done to the dam to bring it back to its original state.

Positive Aspects to using Hydroelectric Energy:

• Fuel is not burned so there is minimal pollution

• Water to run the power plant is provided free by nature

• Hydropower plays a major role in reducing greenhouse gas emissions because it produces minimal pollution

• Relatively low operations and maintenance costs (although there is a high startup cost)

• The technology is reliable and proven over time

• It's renewable - rainfall renews the water in the reservoir, so the fuel is almost always there.

• Modern hydro turbines can convert as much as 90% of the available energy into electricity.

• Hydroelectric power is better on the environment than fossil-fuel sources; it provides more than 97% of all electricity generated by renewable resources worldwide.

Negative Aspects to using Hydroelectric Energy:

• High investment costs– Construction costs – Human labor costs – Concluding that the average cost would be around $

250,000• In some cases, loss or modification of fish habitat

– The dams and reservoirs obstruct fish migration.– Due to the hydroelectric power plant, the temperature

can increase and direction of flow in the water can change. This is detrimental to fish habitats.

– How does it change the direction of flow? This is due to the fact that the hydropower plants cause low dissolved oxygen levels in the water

• In some cases, displacement of local populations– Because the hydroelectric pants consume a lot of water

and land, populations are uprooted and people also have to relocate.

Generation of Energy• The most common form of hydroelectric power plants are large

dams. The water is pumped down a tube near the bottom of the dam, propelling a turbine inside of it. The rotation of this turbine turns a shaft inside the generator of the dam, producing power. The energy is stored inside of the

generator, but has power lines

connecting it to outside sources

to provide energy for homes and

buildings. After the water is used,

it can be sent back through for

another use based on the current

electricity demand. However, if the water is not reused, it is sent through into the outflow of the river.

Energy Storage

• The dam creates a reservoir for the water, storing it when not in use. Also, the amount of water sent through the turbine can be controlled based on the demand for energy.

By-products of Hydroelectricity

• Some of the by-products of hydroelectric power include the release of methane into the water, along with a raise in the water temperature. This could cause many problems for the populations of fish living in the river.

Restrictions of Widespread Use

• One of the main reasons that hydroelectric power isn’t being used widespread through the country or even the world is due to the specific needs of the dams. These power plants must be in a

large river that has high

differences in elevation.

Also, a hydroelectric power

plant can run upwards of

one billion dollars.

Yangtze River in China, home of the worlds largest hydroelectric source, the Three Gorges Dam.

When is Hydroelectric Energy expected to be easily accessible to

the general public • - Currently it is already available to general public due to

the large number of reservoirs around the world. Most sites have been developed, so expansion is limited.

• -Hydropower has been available in the United States since 1880

• - Because of the environmental benefits, and reliability, it is a popular source of energy to the general public.

• - hydroelectric energy will be easily accessible to the general public when the large start up cost to create the turbine and power plant will decrease.

-States with low tropic levels do not use hydroelectric energy, but states with high tropic levels use hydroelectric energy for a portion of their energy.

Large Hydroelectric

Power Plant Small scale Hydroelectric Power Plant

Hydroelectric Power Across the World:

Hydroelectric Power Across the United States:

Stories

• In 1932 the Construction Committee of Sun Yat-Sen created the initial plan for a much smaller dam on the Yangtze River. China modeled their plan with US government assistance, and by 1944, the project was referred to as “Chinese TVA.” They believe that the dam would “bring great industrial developments…It will bring widespread employment. It will bring high standards of living. It will change China from a weak to a strong nation.”

• In early 1989, the State Council agreed in March to suspend construction plans because of international pressures. At the same time, Dai Qing, a Chinese journalist and eminent critic of the dam, presented his book “Yangtze! Yangtze!” to the State Council. He was imprisoned for 10 months after he called the Three Gorges Dam “the most environmentally and socially destructive project in the world”

Sources: • http://water.usgs.gov/edu/hyhowworks.html• http://www.tva.gov/power/hydro.htm• http://www.usbr.gov/power/edu/pamphlet.pdf• https://www.mtholyoke.edu/~vanti20m/

classweb/website/history.html• http://www.conserve-energy-future.com/

HydroElectricPlantTypes.php • http://environment.nationalgeographic.com/

environment/global-warming/hydropower-profile/