Ultimately, nearly all  of the energy on Earth, including most of the energy humanity uses, comes from the Sun.  (The other energy on Earth is nuclear energy.)  All fossil fuels are solar energy that has been stored away by life and geology over hundreds of millions of years.

The surface of the Sun has a temperature of around five-thousand-five-hundred degrees Celsius.  That high surface temperature is why it radiates heat and light as it does.  At a distance of one hundred and forty seven million kilometres, we only get a tiny proportion of all of the light and heat that that the Sun transmits.  Nevertheless, Earth’s surface receives more energy from the Sun in an hour than humanity uses in a year; in fact, Earth's surface receives more energy from the Sun in a year than is stored in all of our non-renewable energy sources, including all fossil fuels. 

The core of Earth is hotter that the surface of the Sun, at around six thousand degrees Celsius.  Most of the heat at the centre of Earth  is derived from naturally occurring nuclear fission; the rest is primordial heat from when Earth formed.  If we could tap this giant nuclear reactor we would solve our energy problems! 

The only energy that doesn't come from the Sun  is nuclear energy.  

Fission nuclear energy comes from uranium and plutonium, which were made in long dead stars that exploded billions of years ago, providing some of the material from which our solar system was made.  When the nuclei of uranium or plutonium are split, energy is released.

Fusion energy comes from hydrogen, which came into existences near the very beginning of the Universe.  When the nuclei of hydrogen atoms are combined together, energy is released.

We get some of our energy from nuclear processes in nuclear reactors.  Some other life forms also use nuclear energy.  These life forms live in deep oceans around hydrothermal vents (underwater geysers.)  At the bottom of their food chain bacteria get energy from hydrogen sulphide from the vents rather than sunlight as most other life does.  The hydrogen sulphide is created in chemical reactions that are driven by the heat from within Earth .  That heat is derived mostly from naturally occurring nuclear fission in Earth's core, although some of it is primordial heat left over from when Earth formed with the rest of our solar system, over four billion years ago.  We also use that energy when we get energy from geothermal sources.

This page is linked from:

energy security

Agree? Disagree? Make a comment!  (Comments are moderated)