Non-renewable energies are energies generated from non-renewable resources. These types of resources cannot be restored once used because they either do not regenerate or take millions of years to do so.
Non-renewable resources mainly include fossil fuels (coal, oil, natural gas), nuclear fuels and biofuels.
In contrast, there are several types of renewable energy whose resources are considered inexhaustible. Prominent examples of renewable sources are: solar energy, wind energy, hydraulic energy and geothermal energy.
The vast majority of these energy resources have two main purposes: the generation of electricity and the obtaining of mechanical energy.
Fossil energy: the world's first energy resource
Fossil fuels are resources such as coal, oil and natural gas that have been generated from organic matter that has undergone various physical-chemical transformations over millions of years.
Although its origin is natural, it is clear that the consumption of these resources is much faster than the time they need to generate.
Today it is believed that fossil-based resources will be too expensive to process and that humans will have to turn to other sources of energy, such as solar and wind.
Currently, the main source of energy used by man are fossil fuels due to their price and the calorific power they offer. This energy source is mainly used to generate electrical energy in steam power plants and to obtain mechanical work (thermal engines).
The constant use of fossil fuels implies the emission of polluting gases: carbon dioxide and other greenhouse gases, one of the causes of global warming and climate change.
Coal: the king fuel of the industrial revolution
Coal was once the main source of energy used for the industrial production of electricity. It was later replaced by oil which is easier to use and work with. Coal comes from the fossilization of aquatic plants.
The use of coal became a very popular fuel when the first steam engines appeared. The ability to obtain mechanical energy from coal started what we know as the Industrial Revolution.
Oil: the main fuel for engines
Petroleum is a liquid fuel composed mainly of hydrocarbons, that is, substances whose molecules are formed from hydrogen and carbon (derived from the decomposition of organic substances by anaerobic bacteria). Oil is the product of the chemical transformation, which lasts hundreds of years, of animal and vegetable organisms.
This fossil fuel is found in the subsoil and, therefore, it is necessary to proceed to a drilling of the ground, and the characteristics vary according to the reservoir of origin. After its extraction, it needs to be refined for use and is therefore called "crude".
Nuclear energy: the energy of the atom
The use of nuclear technology, which is based on the fission of uranium atoms to obtain energy. Nuclear energy has many applications, but the most important today is the generation of electrical energy in nuclear power plants.
Uranium is element 92 on the periodic table and occurs in relatively low concentrations in nature. Currently, there are 19 countries with uranium mining operations.
At an energy level, large amounts of energy can be obtained for each gram of uranium. However, it is a resource that does not regenerate and uranium mines are not inexhaustible.
Atomic energy does not generate greenhouse gases but it cannot be considered clean energy either because it generates large amounts of radioactive waste.
Biomass and agrofuels
Biomass and agrofuels are fuels that are burned to obtain heat energy that is used in engines or thermal power plants. The biomass comes from vegetables (wood, wheat, etc.) cultivated extensively or from livestock products, which must subsequently be treated industrially.
Sometimes this type of fuel is used mixed with fossil fuels.
Biomass energy is not considered a sustainable and non-renewable energy source on a human scale. Nor can it be considered clean energy because combustion generates greenhouse gases.
Initially, it may seem that if a plant can be cultivated and can grow, we can produce and regenerate this resource. However, it is not a type of renewable energy because there is not enough space on Earth to grow it.
For it to be sustainable, the entire surface of a few planet Earths would be needed just for the biomass crops needed to generate the energy that is currently generated by fossil energy.