Why Blue Energy needs trading When fossil fuel is traded as commodity in global market, do you think you can do something about the energy you consume everyday? While writing this webpage, ABC television aired Dick Smith's own documentary production - Ten Bucks a Liter. In this show, Mr. Smith made no discussion on engine efficiency. He failed to point out many important "attributes" that differentiate fossil energy and renewable energy. Both factors are important to understand why the world could eventually have petrol price at (or more than) $10/L, if we don't address many important issues, such as, heat engine efficiency.