Energy > Forms, conservation of energy and energy transfer > Energy Sources
An energy source is any physical or artificial system able to produce energy. Energy sources can be renewable (like solar energy) or non-renewable (like petroleum). They may have a low conversion efficiency (like coal or gas) or a high one (like hydropower).
Connection to Big Idea about forces: Energy sources can only be exploitable through the action of forces that allow the transformation of energy. Energy sources are used to produce mechanical work and thus usable energy.
Connection to Big Idea about the universe: Stars are one of the dominant energy sources of the universe. It seems that there tremendous amounts of energy able to cause the Universe’s accelerated expansion. The source of that energy is unknown and thus called “Dark Energy”.
Connection to Big Idea about particles: Chemical bonds store energy, that can be released and used through chemical reactions. The nuclear fusion and fission of atomic nuclei releases tremendous amounts of energy which humanity uses (or attempts to use) for its needs.
Connection to Big Idea about Earth: There are numerous energy sources available on Earth some of which are renewable (solar energy) and some not (fossil fuels are buried geological deposits of plants and dead organisms that we burn in order to generate energy). Earth's energy budget accounts for the balance between energy Earth receives from the Sun, and energy Earth radiates back into outer space. The absorbed energy is distributed throughout the components of Earth's climate system powering the so called “Earth’s heat engine”.
Subjects related: Biology, Chemistry, Environmental Sciences, Physics