Fossil Fuels
1. Fossil Fuels
Fossil fuels are energy resources formed from the remains of plants and animals that lived millions of years ago. Over time, heat and pressure deep underground turned these remains into fuels.
Types of Fossil Fuels
Coal
Solid fuel
Formed from ancient plants in swamps
Mainly used in power stations and steel production
Oil (Petroleum)
Liquid fuel
Formed from tiny sea plants and animals
Used for petrol, diesel, plastics, chemicals
Natural Gas
Gaseous fuel
Often found with oil
Used for cooking, heating, electricity
Advantages
Produce a lot of energy
Easy to store and transport
Reliable supply
Disadvantages
Non-renewable (will run out)
Cause air pollution
Release carbon dioxide → climate change
Mining and drilling damage the environment
2. Chemical Energy Stores
A chemical energy store is energy stored in chemicals and released during a chemical reaction.
Examples
Fossil fuels (coal, oil, gas)
Batteries
Food
Biofuels (wood, ethanol)
How It Works
Energy is stored in chemical bonds
When a reaction happens (burning fuel, using a battery, digestion of food), energy is released
This energy can become heat, light, movement, or electricity
Example
In a battery, chemical reactions produce electrical energy
In food, chemical energy is released for body movement and heat
3. Where Energy Came From (Origin of Energy)
Most energy on Earth comes from the Sun.
Main Energy Origins
Solar Energy
Direct energy from the Sun
Solar panels convert sunlight into electricity
Indirect Solar Energy
Wind (caused by uneven heating of Earth)
Water cycle (rainfall creates hydroelectric power)
Fossil fuels (plants grew using sunlight → stored energy)
Nuclear Energy
Comes from splitting atoms (uranium)
Does not come from the Sun
Geothermal Energy
Heat from inside the Earth
Caused by radioactive decay underground
4. Generating Electricity
Electricity is generated by converting other forms of energy into electrical energy.
Common Methods
1. Fossil Fuel Power Stations
Fuel is burned → heats water
Water turns into steam
Steam spins a turbine
Turbine turns a generator → electricity
2. Nuclear Power Stations
Nuclear reactions heat water
Same turbine and generator process
No carbon dioxide during operation
3. Renewable Methods
Wind turbines: wind turns blades → generator
Hydroelectric: falling water spins turbines
Solar panels: sunlight directly produces electricity
Geothermal: Earth’s heat produces steam
Generator Principle
A spinning magnet inside coils of wire
Movement causes electrons to flow
This flow is electric current