Ethanol is a clean-burning, high-octane fuel that is produced from renewable sources. Because it is domestically produced, ethanol helps reduce dependence upon foreign sources of energy for most countries in the world.

Many macroalgae species are rich in carbohydrates and cellulose and hence could make a more suitable feedstock for ethanol than microalgae. This chapter tells us how ethanol from algae is made possible by converting the starch (the storage component) and cellulose (the cell wall component). Put simply, lipids in algae oil can be made into biodiesel, while the carbohydrates can be converted to ethanol. Algae may be the most suitable source for second generation bioethanol due to the fact that they are high in carbohydrates/polysaccharides and thin cellulose walls.

1. Algae could be the optimal source for second generation bioethanol due to the fact that they are high in carbohydrates/polysaccharides and have thin cellulose walls.
2. Most attempts at producing ethanol from algae have been using macroalgae rather than microalgae as the starting feedstock.
3. Ethanol can be produced from either the algae biomass or from algae cake. The later option gives rise to the interesting possibility of producing both biodiesel and ethanol from the same biomass.
4. There are no large commercial projects currently underway that explore algae as a feedstock for cellulosic ethanol production as of Apr 2010, though there are species of algae that have reasonable cellulose content (between 7-30%).
5. As of Apr 2010, there are about 10 companies that are attempting production of ethanol from algae.Companies such as Solazyme plan to combine cellulosic ethanol and algae biodiesel production technology, which they think provides a more positive energy balance than either one alone.