Hydroelectricity?

Question

I have to do a project for school so if you people could tell me some pros and cons or/and some websites about it that would be grate so tks for the Help ppl

Ps. dont critisize me for using tks adn ppl

Answer 1

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

this is the best site

Answer 2

can i "critisize" u 4 using "adn"?

pros- clean energy,

cons- can interfere with ecosystem, unless landscape is effectively altered, few places where dam-type plants can be placed, hard to incorporate into other areas of high current ( but still feasible)

http://www.usbr.gov/lc/hooverdam/

Answer 3

Pros- like Silver Fox said, it's clean energy, in that it doesn't pollute the air or emit green house gasses like burning fossil fuels does.

Cons- unfortunately, there seem to be a lot of cons.

Displacement of people is one (such as Native Americans in the south western United States and villagers in rural China); people either have to move because the land they live on is going to be flooded, or they can't maintain their way of life because fish runs are blocked or their supply of water for agriculture is diminished.

Then there are the environmental impacts, ranging from the fact that dams block fish runs to the fact that the reservoirs that form behind them are giant lakes that weren't there before; imagine the loss of habitat. Animals and ecosystems downriver are also affected--dams regulate the amount of water that makes it downriver, so seasonal changes are less apparent (as far as I understand it). Often dams play a part in stopping flooding, but the seasonal flooding of various rivers is what can make the land around them so fertile (think the Nile river).

There are also major safety issues. If properly maintained dams aren't dangerous, but in China there have been instances where dams have broken and killed tens of thousands living downstream. And now there's the added threat of terrorism.

Dams are also not great as long term solutions to energy needs--silt builds up behind them, eventually creating a waterfall and rendering the dam useless as a source of power. There are varying reports on how long this could take, but some say it could happen in as little as a century.

The water stored behind the dams in reservoirs can also be problematic. Often it is used in irrigation, but this creates an increased demand which during dry years cannot be adequately fulfilled. The water itself often proves to be unusable for irrigation, as resevoirs over salt deposits leach the salt up into the water.

Obviously I'm much more versed in the disadvantages in hydroelectric power, and I'm sorry I don't have any more in terms of pros. I suggest that you check out http://www.greywaterguerrillas.com/ if you're curious about any of this, or if you have time to go to the library, check out their book "Dam Nation: Dispatches from the Water Underground." That's where I got most of this from, and while it isn't balanced (you won't find them listing any pros), it is a very interesting read.

Answer 4

The Democratic Comprehensive Energy Plan To Lower Gasoline Prices





               This is how we will do it. And this why we will do it.







       This country has so much under used industrial capacity in our Auto Plants, Airplane Plants, Steel Plants and Electronics Plants to make America Energy Independent in 2 to 5 years. We can build enough windmills and solar power and wave generation energy plants to replace 90% of all of the electricity generated by COAL and NATURAL GAS.



      The Coal and Natural Gas saved by Green Replaceable Elecrrical Generation can now be used to make fuel for cars, trucks, busses, boats and airplanes, and or plastics, chemicals, fertilizers and pharmacuticals.



If we build 400,000 windmills for $400 Billion we could save 90% of all of the oil and Natural Gas used to generate electricity.

      We need a comprehensive plan that puts America back to work in endeavors that benefit 99% of America.



                                      Howard Scott Pearlman



                                                   and



                                            Tony Mullen

Answer 5

Hydroelectricity is a form of hydropower, and is the most widely used form of renewable energy. It produces no waste, and does not produce carbon dioxide (CO2) which contributes to greenhouse gases. Hydroelectricity now supplies about 715,000 MWe or 19% of world electricity (16% in 2003), accounting for over 63% of the total electricity from renewables in 2005.

Although large hydroelectric installations generate most of the world's hydroelectricity, small hydro schemes are particularly popular in China, which has over 50% of world small hydro capacity. Some jurisdictions do not consider large hydro projects to be a sustainable energy source due to human and environmental impacts, though this judgment depends on the definition of sustainability used.Most hydroelectric power comes from the potential energy of dammed water driving a water turbine and generator. In this case the energy extracted from the water depends on the volume and on the difference in height between the source and the water's outflow. This height difference is called the head. The amount of potential energy in water is proportional to the head. To obtain very high head, water for a hydraulic turbine may be run through a large pipe called a penstock.

Pumped storage hydroelectricity produces electricity to supply high peak demands by moving water between reservoirs at different elevations. At times of low electrical demand, excess generation capacity is used to pump water into the higher reservoir. When there is higher demand, water is released back into the lower reservoir through a turbine. Pumped storage schemes currently provide the only commercially important means of large-scale grid energy storage and improve the daily load factor of the generation system. Hydroelectric plants with no reservoir capacity are called run-of-the-river plants, since it is not then possible to store water. A tidal power plant makes use of the daily rise and fall of water due to tides; such sources are highly predictable, and if conditions permit construction of reservoirs, 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 such as undershot waterwheels.

A simple formula for approximating electric power production at a hydroelectric plant is: P = hrk, where P is Power in watts, h is height in meters, r is flow rate in cubic meters per second, and k is a conversion factor of 7500 watts (assuming an efficiency factor of about 76.5 percent and acceleration due to gravity of 9.81 m/s2, and fresh water with a density of 1000 kg per cubic metre. Efficiency is often higher with larger modern turbines and may be lower with very old or small installations due to proportionately higher friction losses).

Annual electric energy production depends on the available water supply. In some installations the water flow rate can vary by a factor of 10:1 over the course of a year.

For More Information go to:

- http://en.wikipedia.org/wiki/Hydroelectr...

- http://www.energyrefuge.com/archives/hyd...

- http://www.electricityforum.com/hydroele...

- http://www.eas.asu.edu/~holbert/eee463/H...

For More Information go to google and search (Hydroelectricity)