Potential for biofuel production from algae based wastewater treatment in California: Can algal biofuels be cost-competitive with traditional petroleum based diesel?

Neither the use of algae to clean wastewater, nor the use of photosynthetic organisms to generate biodiesel, are new concepts on their own. By combining these two processes, algal-based wastewater treatment with algal biofuel production, additional benefits can be derived, among which could be a cost-savings. In California the average estimated base production cost per gallon for algal biodiesel is $5.98/gallon. Compared to the adjusted production cost of petroleum-based diesel of $1.53/gallon, biodiesel is not cost-competitive. Coupling wastewater treatment and algal cultivation reduces the net energy use of the two processes separately and, if accounted for, greatly reduces the production cost of algal biodiesel. When adjusting the production costs for some of the many co-benefits of this combined process and fuel, such as wastewater treatment cost offsets and carbon credits, the fuel becomes much more competitive with an average production cost of $0.56/gallon. As this production process develops, technological optimization, particularly improvements in algal lipid content and productivity, will further reduce the cost of algal biodiesel.