Renewable resources are natural resources that can be replenished, such as plants, animals, wind, water, and geothermal energy. Humans use renewable resources for food, energy, and power. There are several types of renewable energy including solar energy from solar cells, wind energy from wind turbines, hydroelectric power from dams, geothermal energy from hot underground rock, and nuclear energy from splitting atoms. Each renewable energy source has advantages and disadvantages related to factors like costs, land needs, and pollution levels.

1. RENEWABLE RESOURCES 8SCIENCE: Wed. Jan. 12/Thurs. Jan. 13

2. What are renewable resources? Renewable resources are natural resources that can be recycled or replaced by the environment E.g.: Cotton plants to make clothing i.e. jeans can be planted again each year Examples Plants and animals Wind Geothermal Nuclear Water (hydro)

3. How do we use renewable resources? Humans use renewable resources as a source of food (plants and animals) to help us survive We also use renewable resources to provide energy and power Examples: Solar energy: solar cells Wind energy: wind farms Water energy: dams

4. SOLAR ENERGY Solar energy is energy from the sun It is trapped in solar cells and turned into electric current Sunlight hits cells covered with silicon (Si) layers, changes the light and a stream of electrons is created Solar cells can be small and easy to use Expensive to generate largeamounts of electricity

5. WIND ENERGY Electricity can be produced on wind farms Wind turbines are placed on the land Need lots of open space No pollution is produced

6. WATER ENERGY Called hydroelectric power Electricity created from the energy of flowing water by building dams Earth’s water cycle continually replaces the water and it is non-polluting

7. GEOTHERMAL ENERGY Used and found in locations with lots of volcanic activity Energy from an eruption comes from hot rock under the Earth’s surface Thermal energy (heat energy) is used to generate electricity

8. NUCLEAR ENERGY Huge amounts of energy are stored in the nucleus of an atom When this nucleus is split, the energy released is used to generate electricity water is heated by this energy and turns to steam which turns turbines to produce electricity Examples: - uranium (U)

9. Questions to consider: Which renewable energy is ‘best’? Which renewable energy type is a good alternative to burning fossil fuels (using non-renewable resources) ? Which renewable energy type produces little pollution? Which renewable energy type costs little money? Which renewable energy type requires little land and people to manage it?