* Hydropower Energy*



The History of Hydropower*

Of the renewable energy sources that generate electricity, hydropower is the most often used. It accounted for 7 percent of total U.S. electricity generation and 75 percent of generation from renewables in 2004.
It is one of the oldest sources of energy and was used thousands of years ago to turn a paddle wheel for purposes such as grinding grain. Our nation’s first industrial use of hydropower to generate electricity occurred in 1880, when 16 brush-arc lamps were powered using a water turbine at the Wolverine Chair Factory in Grand Rapids, Michigan. The first U.S. hydroelectric power plant opened on the Fox River near Appleton, Wisconsin, on September 30, 1882. Until that time, coal was the only fuel used to produce electricity. Because the source of hydropower is water, hydroelectric power plants must be located on a water source. Therefore, it wasn’t until the technology to transmit electricity over long distances was developed that hydropower became widely used.
The Greeks used water wheels to gring wheat into flour more than 2000 years ago. In the early 1800s, American & European factories used water wheels to power machines.
In the 19th century, the force of falling water was used to generate electricity. The first hydroelectric power plant was built at Niagara Falls in 1879. At its height in the early 1940s, hydropower provided 33 percent of the country's electricity.




Production:Where does It come From?*

Understanding the water cycle is important to understanding hydropower.
Hydropower plants capture the energy of falling water to generate electricity. A turbine converts the kinetic energy of falling water into mechanical energy. Then a generator converts the mechanical energy from the turbine into electrical energy. The water flows through a pipe, or penstock, then pushes against and turns blades in a turbine to spin a generator to produce electricity. The electricity is then transported to huge transmission lines to a local utility lines. The amount of electricity we get depends on the rainfall. Hydro plants produce from 8 to 11 percent of the electricity produced in this country.

















Is Hydropower A Good Energy Source?*


Some people regard hydropower as the ideal fuel for electricity generation because, unlike the nonrenewable fuels used to generate electricity, it is almost free, there are no waste products, and hydropower does not pollute the water or the air. However, it is criticized because it does change the environment by affecting natural habitats. For instance, in the Columbia River, salmon must swim upstream to their spawning grounds to reproduce, but the series of dams gets in their way. Different approaches to fixing this problem have been used, including the construction of "fish ladders" which help the salmon "step up" the dam to the spawning grounds upstream.
Along with being almost free and non-polluting, it's clean and is renewed yearly by snow and rainfall. Hydropower facilities also offer a range of additional benefits. Many dams are used to control flooding and regulate water supply, and resevoirs provide lakes for recreational purposes, such as boating and fishing. Futhermore, hydroplants don't emit pollutants into the air, because they burn no fuel.





Future of Hydropower*

Hydropower is the cheapest way to generate electricity today. No other energy source, renewable or nonrenewable, can match it. In 1998, it cost about 1 cent per kWh(kilowatt hour) to produce electricity at a typical hydro plant. I believe that it will be a energy source used greatly in the future. Hydro plant operations may also affect water quality, increase silting, change water temperatures, and lower the levels of dissolved oxygen. But these problems can be managed by dredging the silt, and carefully regulating plant operations.

So far, we've been learning about different galaxies and all the amazing things within these galaxies. Some of the things we have been studing are the zodiac signs, some of the North Circumpolar Constellations, and the life cycle of stars.
It was interesting learning about all the zodiac sgins, because u learn about yours, and the signs that belong to the people around you, like Scorpio and Cancer. I found a few good sites that i thought gave helpful information about the zodiac signs. A lot of good information came from www.astro.uiuc.edu/~kaler/celsph.html, which was the most helpful, to me. It gave good and helpful information about the signs, what they mean, and their origin. The other two websites were:www.homepage.mac.com/kvmagruder/bcp/zodiacal/zoo.htm and
www.enchantedlearning.com/subjects/astronomy/stars/zodiac.shtml. I would say they both had helpful and important information, that would be interesting or helpful for people to learn about.
Next, we learned about the North Circumpolar Constellations, which kind of went into detail. The ones that were in the North were the ones that we rarly hear about. Out of the three i found about the North Circumpolars,www.geocities.com/Heartland/fields/8616/circumpolar.html, would be the most helpful.It explains the relationships and the five different North Circumpolar Constellations. There are two other good sites where you can find helpful imformation on the circumpolar constellations: //homepage.mac.com/kvmagruder/bcp/diurnal/circumpolar.html , and
www.science-teachers.com/space/circumpolar_constellations.doc.

And last, we explored the the life cycles of stars. one of the best sites to find out about these cycles would be: // sunshine.chpc.utah.edu/labs/star_life/starlife_main.html. It shows pictures and explains the life of the stars and things. Some other good sites to visit would be: www.telescope.org/pparc/res8.html and
www.duke.edu/~teb/stars/index.html .