What electrical energy is and how it is generated

This version of is not compatible.

Non-compatible browsers, in addition to preventing you from using all of the webpage’s features, are slower and present security risks.

We recommend that you update your version of your browser now, or that you access the page using another compatible browser .

Go to content
Press enter to display the menu content Press enter to display the language options Press enter to display the font size options

Main Home

Page saved correctly as favourite

What electrical energy is and how it is generated

electrical energy

Content offered by


Turning on a computer, lighting up our home or keeping food fresh in our fridge are everyday actions that we can perform thanks to electrical energy. This form of energy is the most commonly used by humans in their daily routine, but , do we know what is it, where does it come from and how is electrical energy generated?

Electric power is produced by the movement of electrical charges (positive and negative electrons) inside conductor materials. Therefore, every time a lamp is switch on, an electric circuit is closed and electron movement is generated through metal cables, such as copper. In addition to the metal, for this transport to exist and the light bulb to be turned on, a generator or battery is needed to drive electron movement in a given direction.

electrical energyFollowing the principle of energy conservation that states that it is not created or destroyed, but only transformed from some forms into others, it is explained that electrical energy can be transformed into light, mechanical and thermal energy. To this it must be added how easily it is generated and transmitted. However, despite being one of the energies most commonly used by humans due to its application in a diverse range of products and everyday devices, this energy shows the difficulty of storing electricity. This disadvantage causes that supply must be equal to the demand. As a result of this, both coordination in the production of electrical energy and between the decisions taken to make an investment in generation and transmission of this commodity are necessary.


How is electrical energy generated?

1. Generation. Electrical energy is obtained at generation plants, which are determined by the sources of energy used to move the engine. Furthermore, these energy sources can be renewable or not. The group of renewables includes hydraulic plants (making use of the mechanical strength of water) wind farms, solar (sun) and biomass plants (burning organic compounds of nature as fuel). Each of these sources can be regenerated naturally or artificially.

In contrast with these, there are power plants using energy sources which are not renewable. That is, those with an unlimited use in the plant and where the consumption rate is higher than the regeneration rate. This second formation groups thermal power plants (producing electricity from limited resources, such as coal, oil, natural gas and other fossil fuels) and nuclear power plants (through nuclear fission and fusion).

2. Transmission. Once the electrical energy has been generated by some of the above techniques, the transmission stage starts. For this, energy is sent to the substations located in the generation plants by means of transmission lines, which can be overhead (if located in support towers) or underground. This high-voltage lines transmit high quantities of energy and are deployed along very extended distances.

3. Supply. The last step before obtaining electricity at homes is that of supply. This electricity supply system has the function of supplying energy from the supply substation to the end users.


Environmental problems

Today, transport, supermarkets, companies, industries and most households all over the world depend on the electrical energy supply. However, meeting this global demand is beginning to take its toll on the global environment. Generation of electrical energy is still obtained largely by burning fossil fuels (oil, gas and coal). This combustion is releasing pollutant gases to the atmosphere, such as carbon dioxide, which many scientists consider to be responsible for global warming. This same group of non-renewable energy sources includes nuclear power plants, which still raise significant concern over the long-term waste storage, as well as the possibility that accidents occur that involve releasing radioactive agents to the environment. Examples such as Chernobyl (Ukraine) and Fukushima (Japan) have warned about the serious consequences that they can have for the environment and the community. With this regard, it is increasingly frequent that the governments from different countries start to be committed with the development of renewable energies such as wind and solar.

More articles in -The Endesa energy efficiency website.-
hydraulic energy Water fall from a given height by natural resources or building dams is known as hydraulic energy. Discover how hydraulic plants work and how they use this energy.  Go to the article in twenergy.com
renewable energy The cleanest option for the environment is renewable energy. We talk about each of the different types of renewable energies existing today.  Go to the article in twenergy.com
marine currents Did you know that tidal energy generates energy from the movement of marine currents? From a simple mechanism, it is able to produce one of the cleanest renewable energies existing.  Go to the article in twenergy.com