Under the 2007 Energy Independence and Security Act signed by President George W. Bush, Americans are mandated to fill their gasoline tanks with 36 billion gallons of biofuels by 2022. To further that goal, the U.S. Department of Energy just announced $78 million in grants this week for R&D on algae-based biofuels. But are such algae-based fuels "sustainable" to use that popular environmentalist buzz-word? Perhaps not. A press release reporting the results of a new study by researchers at the University of Virginia notes:
The U.Va. research, just published in the journal Environmental Science & Technology, demonstrates that algae production consumes more energy, has higher greenhouse gas emissions and uses more water than other biofuel sources, such as switchgrass, canola and corn.
The researchers suggest that using wastewater from sewage plants might make fuels produced from algae more environmentally friendly. The press release continues:
"Before we make major investments in algae production, we should really know the environmental impact of this technology," Clarens said. "If we do decide to move forward with algae as a fuel source, it's important we understand the ways we can produce it with the least impact, and that's where combining production with wastewater treatment operations comes in."
As an example of the importance of completing the environmental life cycle study, Clarens points to the 2008 ethanol boom which created a spike in corn prices worldwide and raised complex ethical issues that could have been avoided by producing separate crops for food and fuel.
"People were investing in ethanol refineries, but then we realized that it takes a lot of petroleum to grow corn and convert it to ethanol," Clarens said. "By the time you get done, you've used almost as much petroleum to make ethanol that you would have if you just put the oil straight into your car.
In addition, other researchers found that producing ethanol from corn could actually increase greenhouse gas (GHG) emissions as farmers cleared more land to grow fuel crops. One such study found:
… that corn-based ethanol, instead of producing a 20% savings, nearly doubles greenhouse emissions over 30 years and increases greenhouse gases for 167 years. Biofuels from switchgrass, if grown on U.S. corn lands, increase emissions by 50%.