Take Your Algae Biofuel News With a Grain of Salt

A study released this week says Algae fuels may not be worth it. But critics point out that the study’s data were old – some more than ten years old.

It’s a picture-perfect example of how when it comes to arguments over renewable energy, it’s always good to check your sources.

The Study

Bearing the difficult title “Environmental Life Cycle Comparison of Algae to Other Bioenergy Feedstocks”, the study concluded that Algae for biofuel isn’t as good for the environment as other potential fuel-crops such as switchgrass, canola and corn.

(“What’s that?” you say. “Isn’t corn ethanol bad?” Keep reading…)

One of the study’s lead authors was Andres Clarens, an assistant professor of civil engineering at the Civil and Environmental Engineering Department of the University of Virginia. The New York Times had him explain his findings:

The main reason for this is that fertilizers have to be directly delivered to the pool of water that algae is growing in… And fertilizers are very energy intensive to produce.
Corn and switchgrass can draw nitrogen from soil, which reduces the overall amount of fertilizer required, he said. In addition, crop rotation can help replenish soil nutrients.
“Nutrients are going to be the limiting factor,” Dr. Clarens said. “We’re humans. We need to eat dinner, and you can’t expect to have algae that provides a bunch of energy without feeding it nutrients.”

And it’s true that fertilizers – mostly petrochemical-based – have a nasty carbon footprint. That’s why, for instance, corn-based biofuels have turned out to be such a carbon disaster. But… algae?

Critics cry “Foul!”

The Algal Biomass Assocation responded,

“...We expect such research to be based on current information, valid assumptions and proven facts. Unfortunately, this report falls short of those standards with its use of decades old data and errant assumptions of current production and refining technologies.”

Where’s the issue? Older studies did indeed use fertilizers, but these were small-scale pilot projects. Current plans for large-scale operations call for using wastewater, which is full of nutrients, instead of taking clean water and adding nutrients.

Riggs Eckelberry, chief executive of the algae biofuel company Origin Oil, told The New York Times,

“Identifying wastewater is a homerun for algae production, probably the best there is,” he said. “There are lots of nitrates, and algae love dirty water — they can remove toxins, such as medical drugs from that water.”

And it gets even better: energy is currently used treating wastewater, so using it to grow algae saves that CO2 as well.

The Happy Ending

The authors of the study complained that many of today’s algae companies use proprietary processes – they say that with everybody keeping trade secrets, they shouldn’t be blamed for using ancient data (and in the algae field, 10 years back is practically the dark ages).

It appears Mary Rosenthal of the Algal Biomass Association is talking with Clarens about cooperating on a follow-up study. That should make everybody happy - and provide everyone with accurate and up-to-date science.

(Originally appeared at Tenthmil.com)