With Prehistory the man used fire to heat and work metals without realizing that it was energy. With Antiquity the people of the sea were the first to use the energy of the wind to drive the ships and, later, the wings of the windmills.

Then, the man discovered the force of the water of the rivers to make function the water mills. They were there its independent sources of driving energy until the end of the XVIIIe century.

During most of the XVIII E S., where the principal machines were the pumps of the mines, wood remained very much used and the coal was employed only in the areas where it was particularly accessible. However, towards the end of the century, the growing number of the steam engines and the development of metallurgical industries reflect in obviousness the essential economic role of the coal of which the availability conditioned, for a great part, industrial rise (ten-fold multiplication of the production of coal of 1850 to 1900).  

Contemporary time

The thermal electricity of origin started to play a considerable part as from 1875 with the invention of the dynamo, the industrial engines and lighting. The discovery of the electric transformer (1881), which widens considerably the ray of distribution (lines with high voltage), and that of the steam turbine, higher than the alternate machine for the electrical production, did nothing but reinforce the demand for coal, which became increasingly difficult to satisfy. Two other forms of energy arrived then in reinforcement: oil and hydroelectricity. Oil, almost exclusively North-American at the origin (1860), initially used mainly for lighting, extended little by little its field of application. Become, as from 1880, the equal one of coal for many industrial and thermal applications, it took, with the advent of the spark-ignition engine and the car, its place of fuel par excellence, easy to store, distribute, use. From 1900, its importance did not escape anybody and it became the object of an intense prospection, accompanied on a worldwide scale by political efforts to control the production of it.  

The hydroelectricity, born towards the end of the XIX E S., was supported by the reduction in the offer out of coal and the appearance, around 1895, of the water turbines which proved to be an excellent means of training of the generators electric, but handicapped by the importance of the investments necessary for the construction of the stoppings and by the limited number of exploitable sites. The coal, the oil (to which its derivative will be added, the natural gas, after 1945) and the hydroelectricity will remain the three pillars of industrial development until 1960, from where their name of conventional energies.  

If the possibilities of exploitation of the nuclear energy of fission to the fine civil ones are interviews as from 1940, the first semi-experimental industrial exploitations made their appearance later only fifteen years, proving the interest which already the governments of the industrialized countries carried to him, interest which will be being reinforced with the increase in the energy dependence with respect to oil. Nuclear energy, calorific in the beginning and making it possible to provide very hot vapor, is especially used for the electrical production and, very incidentally, for the district heating. Its applications to the engines are limited to the submarines and the boats because of the heavy shieldings necessary. Progress of the technology of the nuclear plants makes today of it an energy less expensive than that of fossile fuels and rather abundant (taking into account the terrestrial thorium and uranium reserves) to meet the world foreseeable needs during a few centuries, in so far as one uses to produce it the breeder reactors, approximately 60 times more profitable than the engines for the first generation (with pressurized water or natural uranium).  

Humanity now seems to be about to lay out, with the thermonuclear energy of fusion, of a virtually inexhaustible source of energy, founded on a reaction identical to that which occurs in the Sun. Theoretical work shows plausibility of it; however, it appears that, in spite of certain encouraging experiments, the control of the very high temperatures necessary will still take decades.  

Since 1973, date on which the oil price passed arbitrarily from simple to triple, the States whose economy depends largely on this resource were concerned with find alternative energies in the short or medium term, from where an renewed interest for certain expensive forms of energy, but whose exploitation is likely to reduce the dependence with respect to fossile fuels: solar energies, geothermic, thermics of the oceans, the plants, the wind, etc Generally, they can play an auxiliary considerable part.