Journal : Mitigation and Adaptation Strategies for Global Change (2007) 12: 573–608

consideration in the 1990s. However, two major government-sponsored research programs in Japan

and the USA concluded that the requisite technology was not feasible, and those programs were

terminated after investing US$117 million and US$25 million, respectively. We report here on the

results of a privately funded US$20 million program that has engineered, built, and successfully

operated a commercial-scale (2 ha), modular, production system for photosynthetic microbes. The

production system couples photobioreactors with open ponds in a two-stage process – a combination

that was suggested, but never attempted – and has operated continuously for several years to

of biofuel production from plantations of terrestrial “energy crops.” The maximum production rate

that prevail in the existing production system. At this rate, it is possible to replace reliance

By comparison, most projections of biofuels production from terrestrial energy crops would require

in excess of 80% of surplus arable land. Oil production cost is estimated at $84/bbl, assuming no

improvements in current technology. We suggest enhancements that could reduce cost to $50/bbl or

less.