Anthony, I don’t know how you can group algae with all other technologies.  From what I have read, algae biofuels are being produced at pilot and demonstration scales which are necessary before commercialization occurs. Your claim that algae is just another long-shot technolgy is refuted by the fact that the Navy just ordered 20,000 gallons of algae jet fuel from Solazyme. http://www.biofuelsdigest.com/blog2/2009/09/25/solazyme-receives-algae-based-jet-fuel-order-from-us-navy/

Do you think open ponds or PBRs (or fermentation) will end up being the winner?  What do most companies use now?

Great article. I have thoroughly enjoyed both the content and the writing of this series.  GOOD should do more of these multi-part series.  One question: I have read that invasive species are the biggest problem with open ponds. That is, competing organisms come into the pond and try to steal the nutrients designated for the algae.  How much of a problem is this and what is being done to solve it?

excuse me, i meant 33% of our corn crop, not cropland

Johnsonj, I think you make some interesting points about land use but am not entirely sold that corn ethanol is making any significant dent in our petroleum consumption. 33% of our cropland to displace 5% of our gasoline does not seem worth championing corn ethanol as our savior.  With regard to our economy, while it is good to have american farmers growing crops and american companies manufacturing and distributing ethanol, it is not entirely clear whether ethanol could survive without the generous subsidies that congress gives to the corn ethanol industry in the form of blenders and production credits and the import tax on brazilian ethanol.  While I don’t like imported petroleum either, I am concerned that as congress increases the mandates for corn ethanol (expected to reach 15 billion gallons in the coming years from 9 billion in 2008),  we will continue using up massive amounts of our cropland for a crop that displaces only a marginal amount of imported petroleum.  A better use of the subsidies would seem to be to invest in the advanced biofuel technologies that are not commercial.

I take issue with your claim that “ethanol has up to 2.2 to 1 energy return and half the ghg of gasoline.”  According to who?  where do you get this information?  Before attacking my response as a “joke” why don’t you source your information?According to the U.S. Congressional Research Service, “studies suggest that the amount of energy needed to produce ethanol is roughly equal to the amount of energy obtained from its combustion.” http://alternativeenergy.procon.org/viewanswers.asp?questionID=1261 With regards to greenhouse gas emissions.  The California Air Resource Board (CARB) conducted a comprehensive lifecycle analysis earlier in the year of corn ethanol’s greenhouse gases.  The CARB found that when you calculate the carbon associated with the forests that have to be cut down in other parts of the world to make new cropland to compensate for the cropland used in the United States to grow corn for biofuel, that corn ethanol is less carbon friendly than extracting, refining, and burning a gallon of gasoline. If you want to actually learn about this issue (rather than pretending you know anything about it), go to: http://wwwp.dailyclimate.org/tdc-newsroom/ethanol/california-takes-on-king-cornYou ask about alternatives?  What about the advanced biofuels mentioned in this article?  why not grow algae or cellulosic crops?

Corn for ethanol uses limited cropland that could be used to grow other crops.  That is why it competes with food supplies. Corn ethanol is a joke supported by large agriculture businesses.  Scientists don’t even know if more energy and C02 goes into producing it than what is saved

Anthony, I don’t know how you can group algae with all other technologies.  From what I have read, algae biofuels are being produced at pilot and demonstration scales which are necessary before commercialization occurs. Your claim that algae is just another long-shot technolgy is refuted by the fact that the Navy just ordered 20,000 gallons of algae jet fuel from Solazyme. http://www.biofuelsdigest.com/blog2/2009/09/25/solazyme-receives-algae-based-jet-fuel-order-from-us-navy/

Do you think open ponds or PBRs (or fermentation) will end up being the winner?  What do most companies use now?

Great article. I have thoroughly enjoyed both the content and the writing of this series.  GOOD should do more of these multi-part series.  One question: I have read that invasive species are the biggest problem with open ponds. That is, competing organisms come into the pond and try to steal the nutrients designated for the algae.  How much of a problem is this and what is being done to solve it?

excuse me, i meant 33% of our corn crop, not cropland

Johnsonj, I think you make some interesting points about land use but am not entirely sold that corn ethanol is making any significant dent in our petroleum consumption. 33% of our cropland to displace 5% of our gasoline does not seem worth championing corn ethanol as our savior.  With regard to our economy, while it is good to have american farmers growing crops and american companies manufacturing and distributing ethanol, it is not entirely clear whether ethanol could survive without the generous subsidies that congress gives to the corn ethanol industry in the form of blenders and production credits and the import tax on brazilian ethanol.  While I don’t like imported petroleum either, I am concerned that as congress increases the mandates for corn ethanol (expected to reach 15 billion gallons in the coming years from 9 billion in 2008),  we will continue using up massive amounts of our cropland for a crop that displaces only a marginal amount of imported petroleum.  A better use of the subsidies would seem to be to invest in the advanced biofuel technologies that are not commercial.

I take issue with your claim that “ethanol has up to 2.2 to 1 energy return and half the ghg of gasoline.”  According to who?  where do you get this information?  Before attacking my response as a “joke” why don’t you source your information?According to the U.S. Congressional Research Service, “studies suggest that the amount of energy needed to produce ethanol is roughly equal to the amount of energy obtained from its combustion.” http://alternativeenergy.procon.org/viewanswers.asp?questionID=1261 With regards to greenhouse gas emissions.  The California Air Resource Board (CARB) conducted a comprehensive lifecycle analysis earlier in the year of corn ethanol’s greenhouse gases.  The CARB found that when you calculate the carbon associated with the forests that have to be cut down in other parts of the world to make new cropland to compensate for the cropland used in the United States to grow corn for biofuel, that corn ethanol is less carbon friendly than extracting, refining, and burning a gallon of gasoline. If you want to actually learn about this issue (rather than pretending you know anything about it), go to: http://wwwp.dailyclimate.org/tdc-newsroom/ethanol/california-takes-on-king-cornYou ask about alternatives?  What about the advanced biofuels mentioned in this article?  why not grow algae or cellulosic crops?

Corn for ethanol uses limited cropland that could be used to grow other crops.  That is why it competes with food supplies. Corn ethanol is a joke supported by large agriculture businesses.  Scientists don’t even know if more energy and C02 goes into producing it than what is saved