Energy Water Power Science Project Idea

What is the Source of Energy of Water Power?

What is the source of this energy which may be used in running water wheels or turbines, whose energy in turn may be transformed into heat, light, electrical and mechanical energy? We know that falling bodies exert energy, but no more than is put into them in raising them to the point from which they fall. The pile driver exerts energy in driving piles into the earth, but an engine must be used to pull the weight up to the place from which it is dropped.

In country houses, running water is frequently supplied from an elevated tank. The energy possessed by the running water may be demonstrated by permitting it to run a water motor, which in turn may run a sewing machine, a churn, or a washing machine. Energy, however, usually supplied by a windmill or the burning of fuel in an engine must be used to pump the water into the tank.

Diagram of a Power house:

Water passing through A turns the water wheel B. At D the energy of motion is changed by a dynamo into electrical energy.

Thus the energy set free by the windmill or by the burning of the fuel is transformed into the energy possessed by the water because of its position. We can understand now, that energy, or the power of doing work, exhibited by water in rivers and streams on their way to the ocean, must have been given to it in some way. The following suggestions may lead you to an understanding of the source of the energy of water power:

(a) What was the original location of the water concerned?

(6) What is happening to water on the surface of oceans and lakes?

(c) What is the relation of evaporation to heat?

(d) What is the source of the heat used up in changing the water into invisible water vapor, a gas?

(e) Just as steam, which is invisible water vapor, possesses energy, so this water vapor which results from the ordinary evaporation of water by the sun's rays has been given the energy which was used in changing the water into vapor.

(f) Because of the energy which it possesses, the water vapor is able to overcome the force of gravity (the force which draws things to the earth) and to move away from the surface. It is assisted in its movement by the currents of air and winds, which you will recall, are caused by the heat of the sun.

(g) When condensed into drops of water, the energy which the vapor possessed as a gas is changed largely into energy of position which is changed into the energy of water power, as the water travels in streams toward the ocean again.

In your own language, explain how water power depends upon the energy of the sun.

The energy of the water power developed at Niagara Falls, from the Mississippi River at Keokuk, Iowa, and in the streams which flow from the higher regions of the Appalachian Mountains, upper portions of the Great Lakes region, and the Rocky and Sierra Mountains, can be changed into electrical energy and be transmitted many miles to cities where it may be used to run mills and trains, and to furnish light and heat.

In order to make use of the water power of a river in which there are no falls but only a gradual slope of the river bed, dams are built which raise the surface to a higher level. By this means artificial falls are produced which may represent the natural fall of the river for several miles above the location of the mill or factory which is run by its power. Thus we may understand how water power can be developed from any stream in which there is an appreciable current. Even in parts of the country which are relatively level, the mill dams from which power is developed to run flour or saw mills are common. With the great demand for electricity there is need for the larger development of this source of power.