What is hydropower? Where does it come from? Humans learned how to use the energy of water a long time ago. A water wheel was widely used back in the 3rd century BC – it was the predecessor and the prototype of the contemporary water turbines. Water wheels were used to produce energy in watermills, forges and sawmills.
WE WILL NEED
- Plastic bottle
- Plastic card you no longer need
- Wine cork
- 2 toothpicks or skewers
- Kettle with water
Cut out the top of a bottle. Then, cut out small fragments of plastic on the opposite sides of the bottle. They should be 2cm long and 3mm wide. Cut a plastic card into 4 identical parts. Then, make 4 deep cuts on a wine cork and press the 4 pieces of the plastic card into the created spaces. Now you have the rotor of your water turbine which spins under the pressure of water. Next, press toothpicks or skewers into the edges of the cork. Now you can place your rotor in the previously cut plastic bottle. You’re ready to slowly pour the water from a kettle on the rotor blades. The rotor will start to spin because of the pressure of water. This is how the mechanical energy of water is converted into rotational motion.
This system is mainly used in hydropower plants. Simply, they are dams in which the flow of water is channelled to turbines. Turbines start to spin and then generators convert this movement into electricity. Surprisingly, most of the contemporary hydropower plants still use the gravity flow water supply system well known in the past, although there are much more efficient systems now.