Energy in Our Rivers

when Bruce and Larry fixed an old water wheel to turn a grindstone so that they could sharpen their Scout axes they were doing what people have been doing for thousands of years using the energy in our rivers to do work this is called a current or under shot wheel because the current moving underneath pushes against the paddles which turn the wheel in an overshot wheel the water moves over the top producing more power than in the under shot because the weight of the water pulls the blades down still another kind is the breast wheel as with the undershot wheel the water passes underneath but it also pulls down on the blades as with the overshot type the turning wheel must be connected directly to the machine so factories using water power had to be located along stream but at the turn of the century the electric generator made it possible to transform this energy and send it over wires to drive machinery and so another type of waterwheel was developed the hydroelectric turbine the machine is called hydroelectric because it uses water to generate electric current inside huge protective cases the turbines and generators spin day and night and here's how they work pressure of the water stored behind the dam forces water through a large pipe called a pen stock this water pushes through the turbine and striking the turbine blades makes them turn rapidly the turbine is connected to a generator which produces electricity of course these generators can't be installed just anywhere there must be a supply of falling water such as at a natural waterfall at niagara falls on the Niagara River the first power plant was installed more than 50 years ago but there are few natural waterfalls in this country so we have created our own waterfalls for hydroelectric energy by the construction of high concrete dams such as Grand Coulee Dam on the Columbia River in the state of Washington this dam built by the United States government is longer than nine city blocks and as high as a fifty story building many such hydroelectric projects have been built in North America but notice how many of them are near mountains why are so many in the West and Northwest in the East coal is plentiful and is used widely to generate electrical energy for homes and industries from the coal fields to the steam plants of the East and Middle West is a short economical hall but in the rapidly growing West coal is not plentiful and mountains are so more hydroelectric projects are being built because western mountains and rivers are well adapted to water power development to understand why this is so look first at a river in flat country from Mississippi could it be used to spin turbines not very well it is a lazy slow-moving stream for most of its course with low banks that would flood if a high dam were built the Mississippi drops only sixteen hundred seventy feet in the 2500 miles from its source in Minnesota to the Gulf of Mexico that's only about eight inches to the mile on the other hand the Colorado River drops more than 8,000 feet between its source in the Rocky Mountains and the Gulf of California only about 900 miles away over 100 inches per mile in addition to rapid flow the Colorado River has many steep banks and narrow rocky gorges such as this one in Arizona where Hoover Dam has been built under federal sponsorship Hoover Dam supplies electric energy to Arizona California and other southwestern states and also water for irrigation so the first requirement for a hydroelectric project is the fall of the river to higher and more direct the fall the greater the power of electricity produced rugged Western mountains are naturally excellent sites providing plenty of fall volume of water is another factor affecting the development of hydroelectric energy the more water available the more electricity can be generated great western rivers such as the Columbia furnish vast quantities of water to operate such hydroelectric projects as Bonneville there is still a third requirement for a hydroelectric project since electricity can't be stored there must be a steady year-round supply of water to keep the turbines spinning in addition to creating a waterfall a damn builds up a huge lake water stored in this lake can be used to run the turbines at times when there may not be enough water coming down the river Western streams are kept flowing by melting snow on the mountain peaks and abundant rainfall spread throughout the year heavy litter on the forest floors and on the mountain slopes acts as a huge sponge soaking up rains and feeding the water to the mountain streams sparkling mountain streams provide clean water free from mud and debris which might damage the power plant and clog the turbines all these factors combine to provide a steady flow of water water that runs down the rivers to the hydroelectric plants water that spins the turbines day and night 365 days a year generating electric energy energy sent along wires for hundreds of miles to make life easier and more pleasant for everyone to run industries such as the manufacture of aluminum to run the machinery of huge factories to speed trolley cars and buses along the streets to light our homes and operate household appliances we're so accustomed to the uses of electricity that modern life would be disorganized if the turbines were to stop for even a few minutes imagine what it would be like if the current were turned off for a moment even this film would stop besides generating electric energy hydroelectric projects are valuable in many other ways improved navigation above the dam and flood control in the valley below are two benefits derived from these projects and lakes created by such dams are valuable additions to our country's Park and Recreation resources arid deserts provided with irrigation water from the dams become productive farm lands one of our most serious national problems is the conservation of our national resources on a shovel full of coal is burned it is gone forever as a source of energy but the energy in our rivers is an inexhaustible resource when water from behind the dam has spent its force run to the sea its usefulness to man is not over thanks to the neverending cycle of nature water evaporated by the Sun returns to the land in the form of clouds and falls as rain or snow finds its way to the larger rivers and is once more ready to generate electricity electricity which has made our modern civilization possible and which will continue to work for us in an endless variety of new ways just as water worked for Bruce and Larry when they fixed up the old waterwheel to grind their Scout axes