Biodiesel is the name given to fuel for Diesel engines created by the chemical conversion of animal fats or vegetable oils. Biodiesel is a clean-burning, renewable fuel made from vegetable oils, animal fats and recycled cooking oil and greases. Biodiesel is a renewable diesel fuel substitute that can be made by chemically combining any natural oil or fat with an alcohol such as methanol or ethanol. Methanol has been the most commonly used alcohol in the commercial production of biodiesel. Algae fuel or algal biofuels is an alternative to fossil fuel that uses algae as its source of natural deposits. Microalgae are currently cultivated commercially for human nutritional products around the world in several dozen small to medium scale production systems, producing a few tens to a several hundreds of tons of biomass annually.