The microscopic green spheres above may not seem like a significant source of energy, but their potential might be surprising. The spheres above are actually individual algae cells and can range in color and size: from tiny protozoa in ponds, to giant seaweed floating through the ocean. The small size of most algae actually becomes quite beneficial in saving space because they are capable of producing large amounts of energy in that small amount of space. They are especially more efficient when compared to other sources of biofuel, which will be discussed later. The most difficult part of the search for algae biodiesel was the search for the proper type of algae. Scientists had to test the more than 100,000 different types of microscopic plants that exist in the algae family (Newman). After more than three decades of research, scientists across the nation came to the conclusion that the best type of algae to use was, surprisingly, a microalgae known as common pond scum (Newman).
The diagram above shows how the algae cell works. The cell draws in water-based nutrients and carbon dioxide and is able to efficiently convert those into energy for the cell through photosynthesis and fermentation. Because plants produce oxygen and use carbon dioxide, they use the opposite process from humans and living things in the Animalia Kingdom. Creatures that are not plants use respiration and the byproduct is carbon dioxide, but plants use fermentation and often (and in the case of algae) produce ethanol alcohol as the byproduct of the production of energy (Newman). Although the ethanol is an important component, the most important substance harvested is the lipids that the algae produces, also called triglycerides (Algal Biofuels II). This oily substance is the true base of biodiesel, as it is much more abundant than the ethanol produced by the algae.
