Friday, November 04, 2011
Over the last several weeks we have been trying to pin down the yield claims of the various algae-based biofuel producers. Most of our calls have gone unanswered. While waiting for the phone to ring, we decided to try another tack.
Yields are not the only issue for biofuel producers hoping to squeeze oil from these simple organisms. Environmental issues plague algae much like any of the other renewable fuel alternatives such as corn-based ethanol. Although the accommodations need not be prime, arable land, growing algae requires space. Then there are power and water requirements to create the specific living conditions favored by algae.
A recent study by the University of Virginia looked at the environmental impact of algae production and came to some decisive conclusions. Their findings suggest it will make a difference if algae are used for direct combustion or anaerobic combustion. Direct combustion for electric production generally outperformed systems involving anaerobic digestion and biodiesel. Direct combustion of aglae generated four to fifteen times as many vehicle kilometers traveled per hectare as switch grass or canola.
However, when it came to energy requirements, water and greenhouse gas emissions, comparisons for algae came in mixed. The authors made it clear that not all algae systems are created equal and that from an environmental standpoint, the right choice of cultivation and conversion process must be made to avoid making more environmental damage than we are trying to clean up by using less fossil fuel.
Results like these are likely to cause a bit of angst among investors who have made big bets on algae as the replacement for fossile fuel. I have not abandoned the idea that algae is superior as a feedstock to land crops. It make sense that the land use burden will be lower than even the non-food feedstocks such as switch grass. However, there appears to much more to be learned reach the right algae system.