at 50% cost reduction, that's about $10/gallon (noted elsewhere that it costs $20/gal from algae fuel). With time, the cost could go down some more while gasoline prices increases. It will be equally priced soon.

http://i.i.com.com/cnwk.1d/i/bto/20080610/algaepond.bmp.jpg
An algae farm. (Credit: U.S. Department of Energy)

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