Several posts (see Lose-Lose for a recent one) have excoriated bio-fuels since they are produced from crops, adding more pressure to an already troubled world agricultural system that must double its production in the next few decades to feed a couple of billion more people and raise the nutrition of a billion food insecure people already here. The continuing degradation of environments from industrial agriculture and the biodiversity losses from expansion make it pretty clear that "dirt burning", as bio-fuel use is sometimes called, is self-punking. This cure for the various symptoms of fossil fuel use is as bad or worse than the disease.

Philip points to a possible exception.

At heart, biofuels are a form of solar energy, as plants use photosynthesis to convert solar energy into chemical energy stored in the form of oils, carbohydrates, proteins, etc.. The more efficient a particular plant is at converting that solar energy into chemical energy, the better it is from a biofuels perspective. Among the most photosynthetically efficient plants are various types of algae.

The Office of Fuels Development, a division of the Department of Energy, funded a program from 1978 through 1996 under the National Renewable Energy Laboratory known as the "Aquatic Species Program". The focus of this program was to investigate high-oil algae that could be grown specifically for the purpose of wide scale biodiesel production. The research began as a project looking into using quick-growing algae to sequester carbon in CO2 emissions from coal power plants. Noticing that some algae have very high oil content, the project shifted its focus to growing algae for another purpose - producing biodiesel. Some species of algae are ideally suited to biodiesel production due to their high oil content (some well over 50% oil), and extremely fast growth rates.

This is misleading happy talk to some extent that glosses over the need for nutrient feedstocks. If solar energy was all that was needed then the deserts would bloom continuously. But the article addresses many of the issues by proposing establishment of such algae ponds as waste treatment systems, recycling urban, industrial and agricultural wastes.

As with all solar energy systems yield depends on location. Much more area would be needed in cloudy or higher latitudes, and a frozen algae pond produces no biomass, but the idea has legs. It could produce significant quantities of plant oils without degrading the environment unacceptably.

There are other issues. Biodiesel refining is an industrial process that consumes energy and resources, not least of which is that 10% of the volume of biodiesel is ethanol. But the net benefit to society after fully accounting for costs still seems positive.

Little thought seems to have been given to operational issues in the article. For example, it mentions establishing algae ponds in the Sonoran desert near the Salton Sea to harvest the intense sunlight and nutrients from the tail water of the extensive croplands in that irrigated desert. The history of the Salton Sea provides some useful insights into unanticipated evolution of altered landscapes. See Rhetorical Rubble and Yellow Science for some of the specific issues with the Salton Sea.

Briefly, the ponds would not be a set-it-and-forget-it solution since they are open to the environment. Like the Salton Sea itself, an artificial lake accidentally created by a diversion of the Colorado river gone horribly wrong 100 years ago, ecosystems will develop to exploit the ponds. Nature will see such ponds as an open buffet that will attract hungry travelers as well as squatters and homesteaders. In short order the ecology of the area will change greatly and I'll bet dollars to donuts there will be enviro-weenies suing to prevent harvest of the algae since it will impact the artificial ecology that has developed.

There are good points and bad points as well as unknowns, but the use of specialized algae to produce plant oils usable for fuel can be added to the very short list of sensible bio-fuel sources.

» Qualified Win from Crumb Trail
See Bio-Fuelish @ M&M for further discussion of the problems with bio-fuels noted in Lose-Lose, as well as a candidate for honors. The Office of Fuels Development, a division of the Department of Energy, funded a program from 1978......[read more]
Tracked: May 27, 2005 01:14 PM