Here is How Energy Are Formed, All The Information you Should Know

Energy is present everywhere in our environment, in human beings, objects, animal and plant species. There are multiple forms of energy in the world and are used in our daily lives through a process of transformation to heat, feed and move around. How does energy manifest? What are the differences between a source and a form of energy?

Energy is present everywhere in the world and is defined as the capacity of a system to modify its state or that of another system, and to produce a visible effect . More concretely, energy can be found in different natural sources, and manifest in different forms through a process of transformation or conversion.

For example, the Sun, through the radiation it emits, is an energy source which produces thermal energy (solar thermal) and electrical energy by conversion (photovoltaic energy).

It is appropriate to distinguish the source of energy from the different forms of energy , even if intrinsically these two concepts are linked.

Thus, an energy source can be defined as a natural or artificial phenomenon directly exploitable for the production of usable energy (useful energy) by man. These energy sources are primary energies, such as fossil fuels from raw materials (coal, oil, gas, uranium) and renewable energies from the sun's rays, wind, water, biomass, from the natural heat of the earth...

Energy forms are manifestations of different energy sources . There are mainly 7 forms of energy used by humans to produce final energy (consumable by humans) through a process of transformation or conversion:

mechanical energy;

thermal energy;

radiative or light energy;

chemical energy;

electrical energy;

nuclear energy.

The different forms of energy on Earth

The manifestation of energy can take different forms resulting from a process of transformation. Note that these forms of energy contribute independently or jointly to other forms of energy on the principle of the law of conservation of energy. In fact, energy is not destroyed, it changes form from one system to another via a transformation process. Let’s discover these different energies.

Mechanical energy

It combines two other forms of energy, the kinetic energy of an object and the potential or gravitational energy contained in an object. Kinetic energy is associated with movement, knowing that the greater the speed of the object, the more kinetic energy it has. Potential energy only manifests itself in association with kinetic energy. Example: the water contained in a hydraulic dam has potential energy (gravity or gravity) which can be visualized when the water falls (force or kinetic energy).

Thermal energy

It is the manifestation of heat under the influence of movements of atoms and molecules in a solid, liquid or gaseous body . The more this kinetic energy increases, the more temperature and therefore heat there is. Heat manifests itself on an object through different changes of state which can be converted into directly usable energy, such as electrical energy. Example: thermal energy produced by the combustion of raw materials (coal, gas, wood, biomass) is used in a flame-fired thermal power plant to heat water and produce water vapor, which itself will actuate the movement (mechanical energy) of a turbine and an alternator to produce electrical energy.

Radiative or light energy

It is contained in the electromagnetic waves of the Sun's radiation . The visible part of these waves manifests itself as light, like that emitted by the Sun to illuminate us. In his daily life, man has succeeded in recreating radiant energy via the microwave oven in operation to heat a dish, or the light of an electric bulb. Solar energy is a form of radiant energy, which can produce thermal energy (solar thermal) or be transformed into electricity (photovoltaic panels).

Chemical energy

It manifests itself when the bonds of the atoms of molecules contained in an object are transformed or broken . This transformation or chemical reaction releases energy, used as is, or transformed in turn into another form of energy. For example: the combustion of raw materials such as wood or coal is a release of chemical energy, producing heat (thermal energy) or electricity. On an industrial scale in a cogeneration plant, the heat produced by the combustion of wood is injected into the heat networks of a community or is used to produce electricity via the classic process of a thermal power plant (heating from water ➔ produce steam ➔ operate a turbine ➔ produce alternating current via a transformer ➔ be transported on the electricity network).

Electric energy

It comes from the movement of electrons in a conductor. This involves the movement of electrical charges (also called energy transfers) between two systems. The conversion of electrical energy thus manifests itself concretely between two types of systems: generators (or suppliers) and receivers (or receivers).

A lamp then produces heat (thermal energy) and light (radiant energy).

Nuclear energy

It is born from the nuclear reaction produced by the fission of the atom of uranium 235 or hydrogen ( not to be confused with nuclear fusion ). This nuclear reaction creates heat (thermal energy) used in particular in France to produce electricity in a nuclear power plant. Nuclear energy in France is predominant and represents nearly 69% of the total energy mix.

Forms and sources of energy: process of transformation into secondary energy

The classification of forms of energy can be complex, as there are so many energy transformation and conversion processes. By general consensus, we mainly distinguish the different types of energy (and their forms) between primary energies and secondary energies, which make up fossil fuels and renewable energies.

Primary energies

Primary energies are energy sources extracted directly from nature. These raw energies do not come from transformation processes or storage. Among these primary energies, there are two types of energy:

fossil fuels ( or stored energy), such as natural gas, oil and coal, the combustion of which produces thermal or chemical energy, and fissionable fuels , such as uranium used to produce energy nuclear ;

renewable resources ( or flow energies), such as solar energy (radiant energy), the force of water (mechanical energy), biomass energy (organic waste), the heat of the Earth ( geothermal energy ).

Primary energies cannot be used as is for consumption, and must follow a transformation process in order to be converted into secondary energy.

All primary energies consumed in our territory (whether fossil or renewable) make up the French energy mix , also called energy distribution or energy mix.

Secondary energies

The transformations of primary energies make it possible to create secondary energies whose specificity is to be more or less storable to be transported to the different points of consumption. Electricity, heat and fuels or biofuels are representative examples of secondary energies, the production methods of which use various energy sources.

Fossil fuel sources

Fossil fuels come from primary fuels such as gas, oil or coal. Through their combustion, fossil fuels contribute to:

the production of electricity via thermal power plants (coal and gas);

heat production via cogeneration plants, gas boilers, or via direct distribution on the national gas network (GRDF);

the production of fuels, via the transformation of crude oil (kerosene, fuel oil, butane and propane).

Fossil fuels, although coming from natural resources, create significant environmental damage and are considered non-renewable resources . Their uses in the production of secondary energy generate greenhouse gas (GHG) emissions, mainly carbon dioxide CO 2 , responsible for current global warming.

Furthermore, their resources are not inexhaustible over time. In this way, they are opposed to energy from renewable resources , the development of which in France and around the world actively contributes to the energy transition.

Renewable energy sources

Secondary energies from renewable resources are mainly green energies: green electricity, green gas or biomethane, biofuels, renewable heat. Their production is part of an approach to promoting the renewable energies from which they come. These renewable energies stand out from fossil energies in several aspects, including their inexhaustible stock in constant renewal and their reduced impact on the environment (low GHG emissions).

Energy from renewable resources

We thus distinguish 6 main energies from renewable resources:

Solar energy produces radiation (radiant energy) and heat (thermal energy). The recovery of solar energy makes it possible to produce electricity via photovoltaic panels, and heat via solar thermal power plants;

hydraulic energy comes from the exploitation of the force of water (kinetic energy) of rivers, rivers and streams, to create mechanical energy (action of a turbine) and finally electrical energy . Hydroelectricity represents the 1st renewable energy in France and the 2nd source of electricity production out of total installed capacity (all energies combined in the energy mix);

Wind energy comes from the force of the winds (kinetic energy) and is used mainly to produce electrical energy. The wind creates movement which activates the blades of a wind turbine, then a turbine and an alternator to produce electricity. The operation of a wind turbine makes it possible to produce 100% green electricity and clean energy. However, the installation of wind turbines encounters some opposition among local populations: advantages and disadvantages of wind energy, opinions differ. Wind energy is the 2nd source of renewable energy in France;

Tidal energy also uses the kinetic force of water like hydraulic energy to produce mechanical energy (starting a turbine) and then electricity. Installed at sea, tidal turbines are part of a specific category of renewable energies: marine energies;

Geothermal energy comes from the exploitation of thermal energy (heat) from the Earth's subsoils. The development of the geothermal sector in France makes it possible to produce mainly heat (heating and domestic hot water), electricity, and cooling ( via a reversible heat pump and a climatic well). Note that like geothermal energy which uses the Earth's calories to generate heat, aqua thermal energy uses those contained in groundwater and aerothermal energy uses those contained in the air;

biomass energy exploits different organic materials (food, industrial waste, etc.) and plant materials (wood and its derivatives, green and agricultural waste, etc.) to produce electrical energy, heat, and biofuels. The process of exploiting biomass to produce energy is based on the form of chemical energy: combustion of wood, degradation of matter via mechanization, and mixing of plant materials and oil to produce biofuels. In France, biomass energy represents more than 55% of the total production of energy from renewable sources.

The sea is a fantastic resource for producing energy

Other forms of energy, less developed to date, rely on this gigantic resource that constitutes seawater:

Tidal energy exploits the phenomenon of tides. The world's first power plant was inaugurated in 1966 in Brittany: the Rance Dam;

Wave energy is the energy contained in the movement of waves. Although several prototypes have been created, there is currently no large-scale production plant;

Tidal energy exploits the temperature difference between surface waters and those at great depths. It is particularly suitable in intertropical zones;

thalassotherapy recovers the calories contained in seawater to power a heat pump producing heat (heating, domestic hot water) or cold (air conditioning) ;

finally, osmotic energy (or blue energy) is the energy released when salt water and fresh water meet, thanks to the phenomenon of osmosis.

These energies from the sea are, without a doubt, part of the energies of tomorrow, alongside carbon-free hydrogen, bioluminescence, and even thorium.

Nuclear energy

Nuclear energy comes from a fissile fuel, uranium. However, it is not considered a fossil energy, but a carbon-free energy almost free of greenhouse gas emissions. Nuclear energy occupies a central place in national electricity production in France. The share of nuclear power represents nearly 69% of total electricity production in 2021 (RTE report).

Nuclear power plants spark lively debates in France and face numerous detractors concerning the radioactive material used and its dangers, as well as the recycling of the nuclear waste produced.

From secondary energy to final energy and useful energy

Final energy is energy directly usable by final consumers. We can therefore consider that secondary energy is a form of final energy before transport to places of consumption. For example, electricity, natural gas, green gas, fuel oil, and gasoline are all types of final energy made available for the consumption of individuals, businesses, and communities via a subscription with an energy supplier.

Measuring the energy used by the user is particularly interesting for making energy savings and thereby reducing their electricity or gas bill. This key concept is called useful energy. It is defined as the energy actually used to obtain the desired effect. For example, the consumption of the final energy necessary to light an incandescent bulb represents a derisory amount of useful energy: 5% of the energy consumed is actually used for lighting, and the remaining 95% is lost in thermal energy (heat).