Energy cannot be created or destroyed, it can only be transformed from one form to another.
In our world the most popular energy is the electrical energy, which is generated in various power plants.
In our early years we generated electric energy from burning fossil fuels e.g. coal.
Today not so many things changed, there are still many countries, where fundamental method for obtaining electric energy is from coal.
Thus there are alternatives such as:
The scientists are also researching another possible source of energy: nuclear fusion, some called it the Sun on the Earth.
