PNNL

Abstract

To reduce U.S. dependence on foreign oil, the Energy Independence and Security Act (EISA) of 2007 targets the production of 36 billion gallons of renewable fuels per year by 2022, of which at least 21 billion gallons must be advanced biofuels such as microalgae. Algae consume CO2 as a nutrient and have a much higher yield potential for oil than other terrestrial biomass feedstocks. We present a national assessment of open pond microalgae production at a 480-ha spatial scale and a 1-hour temporal scale consistent with the dominant physical processes that influence growth. The results show microalgae production has the potential to meet both EISA renewable fuel targets using about 134,277 km2 of land and 24,075 BL/yr of water, equivalent to 3% of current cropland and 14% of freshwater withdrawals for irrigation. Total microalgae production potential is estimated at 402 BL/yr, rough 88% of current imports for transportation fuel, however, water requirements would be nearly twice that used for irrigation.