Algae Fuel Passes Another Crucial Test

By Mary Rosenthal | October 07, 2013

The big test of any advanced biofuel is whether it can be produced cost competitively, in a way that reduces greenhouse gases and delivers more energy than it requires, while its inputs such as land, water and nutrients can be provided sustainably. For years, we have known that algae is one feedstock that can theoretically meet all those requirements.

In August, the theoretical gave way to real-world data, and the news is even better than expected.
For the first time, researchers conducted a life-cycle analysis (LCA) of pilot-scale operations at an algae-to-fuel facility, and found substantial reductions in greenhouse gases over petroleum and a sustainable energy return. They also found that algae-based fuels from the pilot plant are on par with commercial-scale, first-generation biofuels. It concluded that greenhouse gas reductions and energy returns are set to increase even further once economies of scale in production take hold.

This latest peer-reviewed LCA, published in Bioresource Technology, examines the cultivation and hydrothermal liquefaction technologies at Sapphire Energy’s Green Crude Farm. This report reinforces a clear trend in the algae industry: During the past few years, the environmental and energy performance of algae-derived fuels has continued to get better. 

In 2011, the U.S. EPA qualified algae under the advanced biofuel provisions of the renewable fuel standard after finding that algae-based biodiesel could reduce emissions by more than 50 percent compared to conventional fuels.

Last fall, the National Research Council report on the sustainability of algal fuels in terms of land use, water and other factors definitively concluded that sustainability concerns are not a barrier to future growth.

The big advantage of this latest analysis is that it addresses one significant drawback of previous studies. Up until now, most peer-reviewed research relied on theoretical production estimates or data available only in the public sphere. Now, a look at one of the first real world operations has given us proof that algae-derived fuels can indeed be produced sustainably and competitively.

Meanwhile, the energy return on petroleum fuels has been getting worse. Decades ago, you could expect petroleum to yield 100 times the energy it took to extract the stuff. Today, gasoline will yield as low as four to five times the energy, and prices are near 10-year highs. Furthermore, given that finding new sources of oil is increasingly energy intensive, we can expect the energy return to steadily decrease. Talk about diminishing returns.

What does this mean? When the benefits of algae-derived fuel and other advanced biofuels are getting better and the benefits of fossil fuels are being eroded to record lows, you know change is coming.
The pilot-scale demonstrations of algae-to-fuel technologies we see today will give way to full-scale production in the next couple of years. Nobody expects fossil fuels to become easier to extract, or to somehow become carbon neutral. And nobody expects gas prices to fall. It all points to a competitive future for advanced biofuels.

We know it’s not a question of “if,” and we can see that the “when” is getting closer every day.

Author: Mary Rosenthal
Executive Director, Algae Biomass Organization


1 Responses

  1. Cliff Claven



    The real news in this study is the EROI (energy return on investment) that the researchers found possible for algae-based fuels. The range was between 1:1 and 3:1. A minimum of 6:1 is necessary to fuel the post-industrial economy of a modern developed nation like the USA. EROI can be understood as the fraction of a nation's GDP that must be dedicated to producing the energy needed to run its economy and produce that GDP. Whenever that fraction has exceeded 10% (i.e., an EROI less than 10:1) in the past, the US economy has entered recession or depression. A 6:1 EROI represents a tipping point between survival at current quality of life and regression to a lower quality of life. A 3:1 EROI (1/3 of the economy purely dedicated to producing new energy) represents the cutoff where modern civilization cannot sustain itself and begins to starve and collapse. A nation's economic health and quality of life are directly correlated to the EROI of its primary energy sources. Algae and corn ethanol with energy balances barely above break-even and with no hope to achieve EROIs exceeding 3:1 can only support pre-industrial civilizations. This study proves that modern civilization will starve to death on algae fuel. As to petroleum fuels, they are today delivering EROIs generally between 10:1 and 20:1 depending upon location and technology being employed. Petroleum EROI has not monotonicaly declined over time, but rather has waxed and waned in response to fitful cycles of capital investment and technological innovation. Recent calculations of the EROI of shale gas range from 60:1 to 150:1. Even if one believes the EROI or economic viability of fossil fuels is about to plunge, it does not make EROI-handicapped biofuels any more of an alternative. The offramp to biofuels is a dead end. We need to find another path.


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