How Good Is Algae Fuel At Fighting Climate Change? Totally Depends

The idea of using algae to produce fuel for vehicles has been the blockbuster topic of the summer. Major deals have recently been done by heavyweights like Exxon, and Synthetic Genomics, Sapphire Energy and Bill Gates’ Cascade Investments, and more funding is in the pipeline from the U.S. government. But does that mean that algae-powered cars are going to significantly help fight global warming? Not necessarily, but maybe — it seems that, as with most types of biofuels, the overall carbon emissions reductions we could get by swapping out gasoline for algae fuels totally depends on the production process.
Here’s the rub of algae fuels: algae absorbs CO2 as it grows, and this CO2 can come from, say, power plant emissions, thus providing a productive way of recycling the carbon emissions. But when algae fuel is burned in an engine, guess what — the carbon dioxide is released. As Robert Rapier, chemical engineer, former Engineering Director for Accsys Technologies, and blogger at R-Squared Energy Blog, explained in an email to me, “carbon is only briefly sequestered until the algae are turned into fuel and burned. . . If an efficient process is worked out, what you could say is that it is at best carbon neutral, unless you are burying the algae.”

Of course a truly carbon neutral fuel would be great, compared to gas being burned by internal combustion engines, but another problem with algae is that finding an efficient way to grow and collect the algae, and then extract the oil is proving difficult. That’s part of the reason why costs are so high for the industry, and why companies like GreenFuel have struggled to make the economics work. While we don’t have the data to know for sure, it’s possible that some of these processes from startups and big oil firms could actually result in more carbon emissions than some of the fossil fuels they’re supposed to replace, if you take into account the large amount of electricity required (and thus carbon emitted) to harvest the algae from the water and then the oil from the algae.

Earth2Tech