ExxonMobil just torpedoed a shareholder resolution that would have forced the company to disclose risks from climate change. In the main, the company remains committed to fossil fuels. Beyond the boardroom, however, Exxon is hedging its bets, investing in a host of breakthrough green technologies that could replace oil, including — believe it or not — algae.
Algae absorbs atmospheric carbon dioxide, like plants. It can survive in saltwater and wastewater. It can be cultivated in shallow pools built and maintained in regions spare of arable land. It grows quickly, needs little fertilizer and requires no pesticides.
Critically, algae can provide climate-friendly alternatives to other sources of energy, whether fueling airplanes or feeding cattle.
Algae can power cars, ships and planes.
Microalgae,a single-celled form of algae, can be turned into biofuel, just like corn, sugarcane and sorghum. Biofuel is nearly carbon neutral, meaning it adds little additional carbon to the atmosphere. Algae fixes atmospheric CO2 during photosynthesis. Burning algae fuel returns that CO2 to the skies.
San Francisco biotech firm Solazyme produces algae-based diesel fuels that can be used in cars, trucks and Navy vessels. Solazyme also manufactures an algae-based jet fuel that, according to the company’s website, promises greater range, reduced emissions and lower maintenance cost than conventional fuels.
Jet fuel remains a huge source of carbon pollution. Soon, algae could be could provide a viable alternative. Boeing is currently working with Japanese airlines and the Japanese government to provide algae-fueled flights to the 2020 Olympic Games in Tokyo.
Algae can feed animals (and people).
Once the oils needed to make biofuel are squeezed from microalgae, producers are left with a protein- and carbohydrate-rich byproduct. That substance can by dried and turned into feed for livestock, replacing soy as a source of protein for chickens, cows and pigs. Crucially, this would ease demand for arable land. In the next few decades the global population will round the corner on 9 billion souls just as climate change renders fertile regions dry and barren.
A 2015 study showed cows could live on a diet of up to 45 percent algae meal. Cows didn’t object to the taste (as judged by watching them chow down), and algae didn’t harm the health of the animals or degrade the flavor of the meat.
Brian Walsh, a researcher at the International Institute for Applied Systems Analysis, and his colleagues modeled the effect of replacing 35 percent of animal feed in the United States with algae. The move would free up millions of acres of farmland that could be converted to forests or used to grow biofuels — both of which would help combat climate change.
Humans can also cut out the middleman, turning algae into a protein supplement. The oily component of algae used in biofuels can be turned into a replacement for butter, oil and egg yolks. Solazyme produces an butter substitute that contains less saturated fat than the real thing. Sold under the brand AlgaVia, the lipid powder can be used in bread, pasta sauce and all manner of baked desserts.
Before long, algae foodstuffs may be cheap enough to compete with eggs, milk and palm oil. This would be a win for the climate. Animal agriculture is a huge source of carbon pollution, much of it from cows and other large mammals belching heat-trapping methane. Palm oil is driving deforestation in Malyasia and Indonesia, where growers are burning forests to clear land for palm tree plantations.
Algae still faces numerous hurdles.
Algae still incurs high costs for several reasons.
- Algae need a lot of CO2. Algae can’t trap carbon dioxide quickly enough to support large-sale commercial operations. One solution is to build algae farms near of abundant sources carbon dioxide, like coal-fired power plants. But, since those are going out of style, producers would do better to genetically engineer strains of algae that could more efficiently absorb CO2.
- Photosynthesizing algae do not produce enough lipids to make biofuels or butter substitute. Producers like Solazyme get around this by raising algae in a darkened fermentation tank, suppressing photosynthesis. Instead of providing sunshine and carbon dioxide, growers feed algae sugar, which is then converted to oil. Fermentation negates many of the environmental benefits of algae, because farmers need land, water and energy to produce sugar cane. UCLA bimolecular engineer James Liao says that, instead of raising lipid-rich algae in fermentation tanks, producers should grow protein-rich photosynthetic algae that can be fed to microorganisms that produce ethanol.
- Producers lack institutional knowledge. Humans for been harvesting plants since the dawn of civilization. Algae represents a new frontier. Scientists are producers are still experimenting with the best way to grow, harvest and process algae as they work to reach economies of scale.
Once growers surmount the technological challenges of growing algae, the species could prove a game changer for everything from food to flight, giving new meaning to “going green.”