Algal biofuels worse than corn on GHGs, water and energy consumption

In Virginia, researchers at the University of Virginia's Department of Civil and Environmental Engineering, writing in Environmental Science & Technology, have concluded in an algae lifecycle analysis, that algae biofuels production "consumes more energy, has higher greenhouse gas emissions and uses more water than other biofuel sources, such as switchgrass, canola and corn."
"Given what we know about algae production pilot projects over the past 10 to 15 years, we've found that algae's environmental footprint is larger than other terrestrial crops," said lead author Andres Clarens.

"Before we make major investments in algae production, we should really know the environmental impact of this technology. 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."
"It's sour grapes," one biofuels industry professional commented. "They didn't get DOE funding for their wastewater path, and now they're trying to scare people into funding more wastewater research."

The researchers propose siting algae production ponds behind wastewater treatment facilities to capture phosphorous and nitrogen, and the research team is investigating demonstration projects for the wastewater production methods. The team is also developing research on the economic lifecycle of algae compared to other bioenergy feedstocks.
"The large environmental footprint of algae cultivation is driven predominantly by upstream impacts," the researchers write, "such as the demand for CO2 and fertilizer. To reduce these impacts, flue gas and, to a greater extent, wastewater could be used to offset most of the environmental burdens associated with algae".

To demonstrate the benefits of algae production coupled with wastewater treatment, the model was expanded to include three different municipal wastewater effluents as sources of nitrogen and phosphorus.
Each provided a significant reduction in the burdens of algae cultivation, and the use of source-separated urine was found to make algae more environmentally beneficial than the terrestrial crops.