What is Energy?
Energy can take many forms
• Thermal or calorific energy
• Chemical energy
• Radiant or light energy (solar Energy)
• Nuclear energy
• Electrical energy
• Mechanical energy in two forms:
1. kinetics, if the bodies are moving (water falling from a dam)
2. potential, if the energy is in reserve (the water stored behind a dam)
Solar energy is truly inexhaustible and abundant energy. In 12 hours, for example, the solar energy arriving on earth is greater than the total of known and predictable fossil fuels. To set another order of magnitude, the solar energy arriving on the ground is 10,000 times greater than what the world consumes today.
It would be a shame not to use such a jackpot
! However, solar energy now accounts for 0.04% of energy consumption.
The most direct use is for heating homes and water. It is estimated today at 50% the possible gain on domestic heating (water and housing) by using solar panels
thermal. Coupled with good insulation, a 10 to 20% saving in fossil fuels would be possible.
Heating a fluid at high temperature (several hundred degrees) with solar energy can also generate electricity. This type of power plant can be combined with heat tanks to ensure the continuous production of electricity between day and night.
There are also devices that directly convert light into electricity. This “photovoltaic” device has truly remarkable properties:
it has no moving parts, no liquid flows!), it does not wear out and its longevity can be counted in decades. The efficiency of this photoelectric conversion is relatively large: around 15 to 20%
in the laboratory, and 10 to 15% in production.