The Sun the Sun is the nearest star to our planet, is a star type dwarf, with a diameter of 690 000 Km and a mass equal to 300,000 planets like ours, the average distance of the Sun to the Earth is called the astronomical unit and has a value of 1.5 X 10-11 m. Solar energy comes from nuclear fusion reactions that take place at its core, where atoms of hydrogen, combined between whether to form atoms of helium atoms of hydrogen combined with helium atoms to form atoms of lithium, etc. at the same time, a small part of the mass of these atoms is converted into energyin accordance with the equation Einstein = mc2.In the solar core is estimated that the temperature is on the order of 10 to 7 degrees Kelvin and is where 90% of the energy that flows toward the solar surface is generated. The Sun radiates its energy in the form of electromagnetic waves with a wide range of wavelengths, which scroll across space at a speed of 300 000 kilometers per second, or speed of light. The Sun radiates every second a quantity of energy of 4 X 10 to the 26 Joules which generates a power of 4 X 10 to the 23 Kw, to give us an idea of the enormous amount of energy that this amount represents, suffice it to say that world a year energy consumption is estimated at 3.25 X 10 20 Joules or 3.25 X 10 power 17 KwThis means that in one second the Sun generates more energy, than the consumed in a year around the world. The solar constant, solar energy is radiated into space in all directions, this energy is distributed in a hypothetical spherical surface whose center is the Sun and whose RADIUS grows at the same speed as the own filing.