What is renewable energy
The name Renewable Energy is given to an energy which is obtained from natural sources that are virtually unlimited, some because of the immense energy they contain and others because they have the ability to naturally regenerate. Energy is the effort a person makes when pedalling a bicycle. Energy is also the continuous movement of water in a river or the heat given off by coal when it is burned.
Man has always used the sources of energy available to him to do a job or create heat. First using his own physical strength or that of domestic animals. Then using the energy of the wind or the water. Later, we saw the arrival of fossil fuel (coal, natural gas and oil) and then nuclear energy. It is quite possible that new sources of energy will appear in the future, but whatever the source, the availability of energy has always been essential for humanity. As essential as drinking water for example.
From among these different sources of energy, renewable energy sources are those that are continuously produced and are unlimited on a human scale, although for sources such as biomass, this can only be said if natural cycles are respected.
The sun is the origin of all renewable energies because its heat causes the differences of pressure on the Earth which in turn cause winds, a source of wind power. The sun governs the water cycle, it causes evaporation which then leads to the formation of clouds and, therefore, rain. As such, hydraulic power also comes from the sun. Plants use the sun for photosynthesis, for living and growing. All of this plant mass is biomass. Finally, the sun is directly used in both thermal and photovoltaic solar power.
The main sources of renewable energy are wind, solar thermal and solar photovoltaic, biomass and biofuels, hydraulic, geothermal, energy from the sea, hydrogen and fuel cells.
Hydrogen is not a source of energy, just as electricity isn't, but it is undoubtedly the clean fuel of the future and one day it will be produced mainly from renewable sources.
