A GIS Cost Model to Assess the Availability of Freshwater, Seawater, and Saline Groundwater for Algal Biofuel Production in the United States

A key advantage of using microalgae for biofuel production is the ability of some algal strains to thrive in waters unsuitable for conventional crop irrigation such as saline groundwater or seawater. Nonetheless, the availability of sustainable water supplies will provide significant challenges for scale-up and development of algal biofuels. We conduct a partial techno–economic assessment based on the availability of freshwater, saline groundwater, and seawater for use in open pond algae cultivation systems. We explore water issues through GIS-based models of algae biofuel production, freshwater supply (constrained to less than 5% of mean annual flow per watershed) and costs, and cost–distance models for supplying seawater and saline groundwater. We estimate that, combined, these resources can support 9.46 × 107 m3 yr–1 (25 billion gallons yr–1) of renewable biodiesel production in the coterminous United States. Achievement of larger targets requires the utilization of less water efficient sites and relat...