I was wondering the same thing a few weeks ago. This site will tell you everything you need to know. Biofuel is very useful. Biofuel is defined as solid, liquid or gas fuel derived from recently dead biological material and is distinguished from fossil fuels, which are derived from long dead biological material. Theoretically, biofuels can be produced from any (biological) carbon source; although, the most common sources are photosynthetic plants. Various plants and plant-derived materials are used for biofuel manufacturing. Globally, biofuels are most commonly used to power vehicles and cooking stoves. Biofuel industries are expanding in Europe, Asia and the Americas.