Sources of Energy

Wind

- Wind has provided energy for thousands of years.
- Wind is a renewable energy source, it never runs out.
- Wind is moving air.
- Wind farms in California make use of moving wind to turn the blades of turbines. The turbines are connected to a generator that creates electricity.
- The turning sails of windmills used to drive machines help people grind corn. The sails of the windmills are pushed around by the wind. Then they turn the wheel inside.
- Some modern cargo ships reduce fuel costs by using the wind to blow large rectangular sails. The sails are mechanically operated. They do not need large crews to work them as they did on the old sailing ships.
- The blades of the windmill spin the fastest if they are facing straight into the wind.

Advantages
- using wind to create electricity does not cause air pollution like burning of fossil fuels.
- It is a renewable source of energy and doe not run out. It can be used for a long time.


Disadvantages
- There is lack of wind in some countries. Some countries do not have wind strong enough to turn the turbine, to create electricity.
- It costs money to build the wind turbines.
- The building of wind turbines require a lot of space. Some countries have very little land.


COMMENT by Group

In future, wind will be one of the world's main sources of energy because it is safe, cheap and clean.


HYDRO-POWER

- We use the power of water to make electricity by building huge dams across rivers.
- The rushing water turns the blades of a turbine. This drives a generator, which produces electricity.


Advantages

- Water is everywhere. It will never run out. Water can be used to work for us.
- It will not cause water pollution


Disadvantages
- It occupies a lot of space.
- It may upset the eco-system