Hi,
This is a tricky question. The Sun, as most things, has many different types of energy: 1) motion energy, also called kinetic energy, of the gas, 2) energy stored in the magnetic or electric fields, called magnetic potential energy, 3) the source of all the energy in the Sun is the nuclear fusion energy where hydrogen atoms collide and become helium atoms, 4) the light energy, otherwise known as electromagnetic radiation, and 5) we could consider all the mass to be energy (since as Einstein showed, the energy of an object can be its mass times the speed of light squared).
Since the source of the energy that the Sun has is really the gravitational potential energy and the nuclear fusion (and since the mass mostly stays as mass and does not turn to energy) we could approximate the amount of energy that the Sun has as the energy from nuclear fusion and the gravitational potential energy. Unfortunately I do not have time right now to make an approximate calculation of the energy from these two sources. Perhaps one of my colleagues will. But at least you see that your question is not a trivial one!
Laura