We explain what energy sources are, how they are classified and the difference between renewable and non-renewable energy sources.
What are energy sources?
The energy sources are natural phenomena capable of generating usable energy for economic or biophysical uses. These sources can be varied, physical or chemical. They generally involve human intervention to transform and redirect their energy, to dispose of it at will, in the form mainly of electricity, movement or heat.
Energy cannot be created or destroyed, but only transformed. In the universe, it is essential to start, sustain or stop certain processes, including life.
Endless reactions, systems and all living beings require energy to exist, which we obtain from different sources: food (chemical energy), the sun (solar energy), electromagnetism (electromagnetic energy), etc., releasing other forms of energy in exchange, such as caloric, kinetic, etc.
But in the case of the energy sources of planet Earth, they are mostly natural processes whose own dynamics can be exploited or replicated by humanity. Depending on the case, they usually have very different characteristics, such as their renewability, their environmental impact and their efficiency (amount of energy generated).
According to their origin, these energy sources can be classified into:
- Primary When they come directly from a natural phenomenon and have not been transformed or intervened by humanity, such as sunlight, wind, etc.
- Secondary When they are the result of some intentional transformation process of a primary energy source, such as electrical energy, chemical energy, etc.
Another important classification is the one that distinguishes between renewable and non-renewable, and which we will see separately below.
See also: Energy in physics
Renewable energy sources
Renewable energy sources, or simply renewable energies, are those whose use and consumption do not significantly reduce their reserves within a foreseeable time scale.
That is, their natural replacement dynamics are fast enough to replace what has been consumed, or that they do not generate any long-term change in the natural mechanism that produces them.
Renewable energies usually have a lower environmental impact than non-renewable ones, which does not mean that they are totally clean or ecological energies. But at the same time, they are not usually as efficient, that is, they do not usually produce the same amount of energy as non-renewable ones.
Examples of renewable energy sources are hydroelectric energy, tidal energy, wave energy, wind energy, solar energy, etc.
Non-renewable energy sources
Non-renewable energy sources are those whose exploitation substantially reduces their reserves. Consequently, they may become scarce in the not too distant future, which would prevent their continued and sustained exploitation.
On the other hand, this type of energy tend to have a greater environmental impact and greater energy effectiveness than its renewable variants, which is why they are largely responsible for the ecological damage that humanity has caused to the planet since the beginning of the Industrial Revolution.
Examples of non-renewable energy sources are oil and its numerous derivatives (gasoline, diesel oil, kerosene, etc.), natural gas, mineral coal, radioactive heavy metals, etc.
Continue with: Alternative energies
References
- “Energy source” on Wikipedia.
- “Energy sources” in ICT Resources of the Spanish Ministry of Education.
- “Energy sources” in Add2.
- “What are the energy sources?” at ENSA (Panama).
- “Energy and energy sources” in Educational Corner.
- “Energy Source” in The Encyclopaedia Britannica.