The Ways of Water

The Ways of Water

Water covers more than two-thirds of the Earth's surface and is constantly on the move. It rushes along rivers and streams ; it flows into oceans.

This endless movement of water creates energy that can be harnessed. For centuries, people have channeled flowing water into waterwheels that turn to grind grain. Hydroelectric power stations use water in a similar way, but to generate electricity. These enormous concrete constructions are usually found in mountainous regions where there is a high rainfall. Engineers build huge dams across steep-sided valleys. Turbines (modern versions of ancient wooden waterwheels) are placed in the path of the water that gushes with force through the dam. This torrent of water strikes the angled blades of the turbines, which begin to spin and extract an incredible amount of energy from the water. The process of producing hydroelectric power is set in motion.

Control room

The operation of the entire power plant is directed from the control room.

Watering the land

The water for this insectlike irrigation system is coming from the dam of a hydroelectric power station.

Transmission lines

Strengthened electric cables called transmission lines carry electricity away from the power plant.

Way of Water. Photo by Elena.

Spillway

The spillway gates are opened to release water when the level of water behind the dam is too high.

Reservoir

The deep lake that forms behind the dam wall is called a reservoir. The reservoir is built to make sure there is always enough water to operate the generators.

Dam Walls

There are usually curved to withstand the enormous force of water pressing against them. The walls are thicker at the base than the top.

Transformers

Transformers boost the electrical force from the generators to more than 200,000 volts.

Penstock

This channels water from the reservoir through the dam to the turbines

Generators

The spinning turbines are connected by shafts to electricity generators. When the turbines spin, the generators make electricity.

Turbines

Water flowing through tunnels in the dam makes the turbines spin at high speed. Once the energy has been removed, the water flows away through the center of the turbines.

Make Your Own Waterwheel

Cut four pieces of cardboard 1 ½ in x ¾ in and collect an empty thread spool and drinking straw (Step 1) to Glue each piece of cardboard to the thread spool (Step 2) and push the drinking straw through the middle so that your waterwheel can spin easily. Hold the wheel under a running faucet. When water hits the card paddles, the wheel will turn (Step 3).

A Daily Grind

Water-powered hammers are used in Laos in Southeast Asia to grind rice. When the paddles are turned by the flow of the river, the crossbeam at the end of the axle raises the hammer, then releases it to fall on the rice below.