# Is the solar energy Infinite?

Is the solar energy coming from the sun infinite and will continue to be radiated to our earth forever? (discarding any outer factors) what's the sun's fuel?

When you mention solar power, it makes me think you are thinking about photo-voltaic power or power extracted from solar panels. The power put out by the sun is about $3.95*10^{26}W$ per second. But solar panels can only capture a fraction of that energy. Even so, in 2008 humans used about $4*10^{13}W$ per second which is many orders of magnitude less than the sun puts out.

The suns life cycle will last billions of years fusing hydrogen, then helium and slowly working its way down to a white dwarf star.

As the temperature and radius changes of the sun, it's power output will fluctuate. But it will always put out more power than humans could use until the Earth is heated greatly during the red giant phase.

Considering homo sapiens have only been around 200,000 years and the Sun won't expand for another ~7,000,000,000 years that is approximately infinite in terms of human life spans which are about 80 years. What will exactly happen during this red giant phase is still under debate, but it is a long long time from now.

"Is the solar energy coming from the sun infinite?" Obviously not. If it were so, that would be a disaster for us. The number of protons and the ${}^{12}_{6}C$ nucleus are finite inside the sun and energy released by the corresponding processes (in each cycle) are also finite . Thus a finite amount of energy is generated inside the sun and is radiated.