World-Of-Algae - Algae Life Cycle Study

Algal Biomass Organization Questions Accuracy of
University of Virginia Algae Life Cycle Study

ABO believes that reliance on obsolete data and faulty assumptions undermines all conclusions

WASHINGTON, D.C. (January 25, 2010) - The Algal Biomass Organization, today challenged the conclusions of a published report in Environmental Science and Technology claiming that “conventional crops have lower environmental impacts than algae in energy use, greenhouse gas emissions and water.” The report was based upon obsolete data and grossly outdated business models, and overlooked tremendous improvements in technology and processes across the production cycle. ABO strongly believes that these obsolete data and faulty assumptions seriously undermine the credibility of the study’s conclusions.

“We appreciate and support the interest in algae among the scientific community, and agree that examination of the life cycle impacts of algae for fuel processes is important,” said Mary Rosenthal, executive director of ABO. “However, 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.”

Assumptions about algae growth systems. The report uses a first generation, raceway-style pond system as its benchmark. Many leading algae companies abandoned that approach years ago and have a variety of more advanced cultivation systems, some of which are unrelated to the methods the authors sought to assess.

Assumptions about co-location. By assuming the production facility is not co-located with a large CO2 emitter, calculations for sourcing CO2 are flawed, resulting in a higher attribution of CO2 for algae plants. Most commercial-scale algae projects are being developed alongside major emitters in order to beneficially reuse CO2 that will take the place of equivalent carbon emissions from petroleum fuels.

Assumptions about water use. The study assumes fresh water and non-potable salt water are equal. A sustainable industrial algae production model uses non-potable, non-agricultural water in the process of making liquid fuels.

Assumptions about nutrient use. Because the report does not look at the full algae fuel cycle, ignored is the opportunity to consider the ability of algae producers to recycle nutrients and avoid such a substantial burden.

Assumptions about energy use. Because the authors admittedly did not consider the full algae fuel cycle, which allows energy reuse through biodigester biogas combustion coupled with the carbon recycling from all of the aspects of biodigestion, the report errantly gives a higher emissions burden.

Assumptions about purchase of CO2 and fertilizer. The base case assumes algae farmers will purchase CO2 and fertilizer, yet such an approach is so prohibitively expensive it would never happen in reality. Yet those inputs are the major drivers of the negative impacts in the study.

Lastly, the authors make it very clear that their approach is “stochastic.” ABO believes the results of any stochastic study, defined as “of or pertaining to a process involving a randomly determined sequence of observations each of which is considered as a sample of one element from a probability distribution,” should not be given the same weight as studies and analyses based on facts and other measurable data.

“Even with the scientific shortcomings of the survey, it shows that with a few improvements, algae is much better than terrestrial plants as a fuel source,” said Dr. Stephen Mayfield, director of the San Diego Center for Algae Biotechnology. “The truth is that the algae industry is already well beyond the obvious improvements these authors suggest, and as we add these new efficiencies algae will become much more environmentally beneficial.”

In general, the Algal Biomass Organization firmly believes life cycle assessments are critical to the development of the industry, given the need to accurately assess and quantify the environmental impact of algae-derived energy. Its membership supports the development of robust LCAs, but believes that the process should include input from a multitude of stakeholders, including algae technology companies, NGO’s and other scientists. ABO has published a set of guidelines for LCA on its website and is working with a cross section of industry leaders to develop a definitive LCA framework for algal biomass systems.