User:NL Audena Garcia Kempf

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My name is Audena.

· Is it expensive?


There is usually a large one off initial capital outlay, for example to build a dam. After that the electricity produced is almost zero cost

You will usually be sued also, but it is too clean to turn down.

http://wiki.answers.com/Q/Is_using_hydroelectric_power_expensive_or_cheap

9/1/1012

It can be expensive build a dam, but wen it begins to produce energy it compensates the money used in the dam.

Hydroelectric1.jpg


· What is the effect on the environment?

Hydropower does not pollute the water or the air. However, hydropower facilities can have large environmental impacts by changing the environment and affecting land use, homes, and natural habitats in the dam area.


Most hydroelectric power plants have a dam and a reservoir. These structures may obstruct fish migration and affect their populations. Operating a hydroelectric power plant may also change the water temperature and the river's flow. These changes may harm native plants and animals in the river and on land. Reservoirs may cover people's homes, important natural areas, agricultural land, and archeological sites. So building dams can require relocating people. Methane, a strong greenhouse gas, may also form in some reservoirs and be emitted to the atmosphere.

http://ga.water.usgs.gov/edu/wuhy.html

9/1/2012


"Everyone thinks hydro is very clean, but this is not the case,"


Hydroelectric dams produce significant amounts of carbon dioxide and methane, and in some cases produce more of these greenhouse gases than power plants running on fossil fuels. Carbon emissions vary from dam to dam. But we do know that there are enough emissions to worry about.


This is because large amounts of carbon tied up in trees and other plants are released when the reservoir is initially flooded and the plants rot. Then after this first pulse of decay, plant matter settling on the reservoir's bottom decomposes without oxygen, resulting in a build-up of dissolved methane. This is released into the atmosphere when water passes through the dam's turbines.

http://www.newscientist.com/article/dn7046-hydroelectric-powers-dirty-secret-revealed.html

9/1/2012

· Are you depended of other countries/people when you want to generate eslectricity with this energy source?


· How much electricity is generated in one plant?

Really there is no a fixed quantity, basically it depends on the flow and the pressure of the water, in general it is considered a small head office that it are the one that produces less than 25 Mw and big one as the Hoover in the USA comes to 2074 Mw

http://espanol.answers.yahoo.com/question/index?qid=20080327113524AAx3RvN

9/1/2012


· What are the advantages and disadvantages of this energy souce?


  • Adventages

They use up valuable and limited natural resources

They can produce a lot of pollution

Companies have to dig up the Earth or drill wells to get the coal, oil, and gas

For nuclear power plants there are waste-disposal problems


  • Disadvantages

High investment costs

Hydrology dependent (precipitation)

In some cases, inundation of land and wildlife habitat

In some cases, loss or modification of fish habitat

Fish entrainment or passage restriction

In some cases, changes in reservoir and stream water quality

In some cases, displacement of local populations

http://ga.water.usgs.gov/edu/wuhy.html

9/1/2012

· Is it sustainable?

Yes, in most cases. Wherever the natural water cycle continually replenishes the water source, power can be continually generated. There is no need ever to discover, mine, produce, or transport any additional water to the higher elevation from which it can generate energy as it moves under the effect of gravity through the generator turbines to a lower elevation.

http://wiki.answers.com/Q/Is_hydroelectric_energy_sustainable

9/1/2012



   How does it works?


The water of the dam flow past there at almost 60km/h, it is a very good design. We can use waterfalls, rapids, rivers...

The water of the river go throught a tunel and down to arrive to the turbine that is conecteded at the generator and it moves. Inside the generator it’s produce de energy and it go to our homes. Then, the water go out, again to the river,to continue with the cycle.

There are many tipes of turbines like the impulse, the reactions and other variations.

Some types of hydroelectric power are:

Convetional:

It’s form by dammed water and when it comes out it move a turbine and a generator, the power extracted from the water depends on the volume and on the difference in height between the source and the water’s outflow.This difference is called head. Run- of-the-river:

There are those with small or no reservoir capacity, so that the water coming from upstream must be used for generation at that moment.


http://home.clara.net/darvill/altenerg/hydro.htm

http://en.wikipedia.org/wiki/Hydroelectricity

13/9/2011


   Where can you find plants of this source an why?


You can find hydrolectric plants in rivers and in water falls, becase the turbines need the water moviment and the water moves in the river and in the water falls.



   Can be used in Spain?

Yes:

Producction in Spain: 800 plants

20 produce 50%, there are big centrals like Villarino in Salamanca, Aldeávila in Salamanca, Estany-Sallente in Lérida...

The others 780 produce the other 50%, there are medium and small centrals like Gabantes in Málaga, Urdiceto in Huesca, Pintado in Sevilla...


Situation:

Nordwest mountains and Pirineus constructed for the Catalán industry in XX century.

Mountains in the interior of the peninsula

In Duero and Tajo rivers

In the border with Portugal.


Conclusion: There are many hydroelectric centrals in Spain because is a country whith many mountains, an is easier to do a dam when a river goes though a mountain, that when it goes through a valley, and because if is through a valley you need to sink part of the valley. But many of the hydroelectric plants are very small, and I think that is not necesary to do so small centrals.