The sun's energy is released from the nuclear fusion of hydrogen atoms that are inside the star. These mergers generate an immense amount of heat energy, which affects all the planets. Of the total energy that reaches the Earth, 78% comes from sunlight. If this persists, the planet would become a dark, frozen rock mass. Solar energy enables plants to make the process of photosynthesis, by which synthesize carbohydrates to kick off the food chain. Air circulation in the atmosphere is basically a consequence of solar energy.
Although the Sun could meet all the energy needs of man, he has just started to use your energy. The main obstacle is the lack of means to collect it. With the scientific and technical progress, new methods are emerging to take it.
Solar energy, unlike the atomic or based on fossil fuels, is clean, ie does not pollute the environment.