3. ENERGY SOURCES

3. ENERGY SOURCES.

Energy sources are natural resources that we can use to generate different forms of energy. Then we can transform that energy for various purposes.
We can classify energy sources into two general categories: renewable and non-renewable.

3.1. Non-renewable energy sources.

Non-renewable sources come from natural resources that are limited and can be exhausted. At the moment, the most commonly used energy sources are non-renewable. They include fossil fuels (oil, coal and natural gas) and nuclear energy, which uses radioactive materials, such as uranium.

                                                                                                                                            
       Coal                        Uranium    

Gas tanks    
                   Pretroleum extractor





3.2. Renewable energy sources.

Renewable energy sources come from natural resources that we cannot use up completely. These include hydroelectric, solar, marine, geothermal and biomass resources, as well as energy that we can produce from solid urban waste.