Shockwave can be considered responsible for the origins for energon on earth. His foresight led to shooting rockets with the energy source for all cybertronians into space on to multiple planets that he felt would sustain the element so it could be harvested later on.
Starscream found a new form of Energon on Earth. It is called Ore-13 or Ultra-Energon
Forms of Energon
Dark Energon: A corrupted version of Energon that is the life essence of the Chaos Bringer "Unicron". This version that supercharges any Cybertronian who ingests it, making them stronger, faster, more powerful...and more aggressive. It turns pain into pleasure, rendering any blows inflicted on a user futile and heals their wounds as well. However, it also acts as a powerful narcotic, filling the user with thrilling, dark sensations and causing addiction. Dark Energon withdrawal turns the user into a raving brute desperate to do anything for more. If the craving is not satisfied, the user devolves to a beast-like state and eventually dies. It is also capable of bringing deceased Cybertronians back from the dead as Terrocons mindless feral creatures that destroy anything in their path. If a powerful user has Dark Energon in their bodies are capable of controlling Terrocons.
Red Energon: Introduced in the Prime series, Red Energon is an extremely volatile and rare type of energon. When it is refined into fuel, it provides the user with the power of hyperspeed as well as some measure of increased strength.
Synthetic Energon : Introduced in the Prime series and also known as Synth En, is a manufactured version of Energon that supercharges the users physical attributes and reflexes. But also makes the user increasingly aggressive, arrogant and ruthless.
Tox-En: Introduced in the Prime Series. An extremely poisonous version of energon. Exposure creates the opposite effect of regular energon, causing the efflicted to become nauseous and weak. Prolonged exporsure will paralyze and eventually extinguish a Transformer's spark.