Solar Prime was once one of the foremost scientific minds on Cybertron. Working with fellow scientist Skyfire, he had been on the brink of a marvelous discovery: a special coating of micro-chips which when applied to a Transformer would allow them to draw energy from the sun, thus eliminating the need for Energon. However, when Skyfire was lost on an expedition with Starscream who joined up with the emerging Decepticon army shortly after, Solar Prime blamed Starscream for the loss of their mutual friend. Solar became one of the most vocal supporters of wiping out the Decepticons. When the Autobot high Council, not expecting the Decepticons to do more than make minor trouble, brushed aside his concerns, he left, taking all of his research with him. Now, in the midst of the latest stage of the Great War, Solar Prime has returned. His Solar Coating Technology perfected, he has a near limitless supply of energy to power himself and his weapons. He rarely misses a chance to point out his power or to inform those around him that he saw the Decepticon threat for what it was from the begining. He fully believes that had he been listened to, countless lives would have been spared over the millenia. His main weakness is his over confidence and out right arrogance. While he has energy to spare, it does not make him invincible. His attitude also alienates him from potential friends and comrades, though Skyfire, happy to see his old friend, is only too eager to look past Solar's shortcomings. Solar Prime is able to transform into an Earth Styled truck with his new armor becoming a trailer. He carries a machine gun, a laser rifle, and a fusion cannon. The fusion cannon, a greatly improved and more powerful version of the weapon Megatron wields, can only be wielded when Solar Prime is in his battle armor. The amount of energy it generates would short him out without the added buffer.