In many ways, rising fuel demands indicate positive development--a global increase in energy accessibility. But as the threat of climate change from burning fuel begins to manifest, it spurs the question: How can the planet meet global energy needs while sustaining our environment for years to come? While every person deserves access to energy and the comfort it brings, the population cannot afford to stand by as climate change brings about ecosystem loss, natural disaster, and the submersion of coastal communities. Instead, we need a technological solution which will meet global energy needs while promoting ecological sustainability. When people think of renewable energy, they tend to picture solar panels, wind turbines, and corn-based ethanol. But what our society may need to start picturing is that nondescript, green-brown muck that crowds the surface of ponds: algae.
Conventional fuel sources, such as oil and coal, produce energy when the carbon they contain combusts upon burning. Problematically, these sources have sequestered carbon for millions of years, hence the term fossil fuels. Releasing this carbon now increases atmospheric CO2 to levels that our planet cannot tolerate without a significant change in climate. Because fossils fuels form directly from the decomposition of plants, live plants also produce the compounds we normally burn to release energy. But, unlike fossil fuels, living biomass photosynthesizes up to the point of harvest, taking CO2 out of the atmosphere. This coupling between the uptake of CO2 by photosynthesis and the release of CO2 by combustion means using biomass for fuel should not add net carbon to the atmosphere.1 Because biofuel provides the same form of energy through the same processes as fossil fuel, but uses renewable resources and does not increase atmospheric carbon, it can viably support both societal and ecological sustainability.
If biofuel can come from a variety of sources such as corn, soy, and other crops, then why should we consider algae in particular? Algae double every few hours, a high growth rate which will be crucial for meeting current energy demands.2 And beyond just their power in numbers, algae provide energy more efficiently than other biomass sources, such as corn.1 Fat composes up to 50 percent of their body weight, making them the most productive provider of plant oil.3,2 Compared to traditional vegetable biofuel sources, algae can provide up to 50 times more oil per acre.4 Also, unlike other sources of biomass, using algae for fuel will not detract from food production. One of the primary drawbacks of growing biomass for fuel is that it competes with agricultural land and draws from resources that would otherwise be used to feed people.3 Not only does algae avoid this dilemma by either growing on arid, otherwise unusable land or on water, but also it need not compete with overtaxed freshwater resources. Algae proliferates easily on saltwater and even wastewater.4 Furthermore, introducing algae biofuel into the energy economy would not require a systemic change in infrastructure because it can be processed in existing oil refineries and sold in existing gas stations.2
However, algae biofuel has yet to make its grand entrance into the energy industry. When oil prices rose in 2007, interest shifted towards alternative energy sources. U.S. energy autonomy and the environmental consequences of carbon emission became key points of discussion. Scientists and policymakers alike were excited by the prospect of algae biofuel, and research on algae drew governmental and industrial support. But as U.S. fossil fuel production increased and oil prices dropped, enthusiasm waned.2
Many technical barriers must be overcome to achieve widespread use of algae, and progress has been slow. For example, algae’s rapid growth rate is both its asset and its Achilles’ heel. Areas colonized by algae can easily become overcrowded, which blocks access to sunlight and causes large amounts of algae to die off. Therefore, in order to farm algae as a fuel source, technology must be developed to regulate its growth.3 Unfortunately, the question of how to sustainably grow algae has proved troublesome to solve. Typically, algae for biofuel use is grown in reactors in order to control growth rate. But the ideal reactor design has yet to be developed, and in fact, some current designs use more energy than the algae yield produces.5
Although algae biofuel faces technological obstacles and dwindling government interest, many scientists today still see algae as a viable and crucial solution for future energy sustainability. UC San Diego houses the California Center for Algal Biotechnology, and Dr. Stephen Mayfield, a molecular biologist at the center, has worked with algae for over 30 years. In this time he has helped start four companies, including Sapphire Energy, founded in 2007, which focuses on developing algae biofuels. After receiving $100 million from venture capitalists in 2009, Sapphire Energy built a 70,000-square-foot lab in San Diego and a 220-acre farm in New Mexico. They successfully powered cars and jets with algae biofuel, drawing attention and $600 million in further funding from ExxonMobil. Although diminished interest then stalled production, algal researchers today believe people will come to understand the potential of using algae.2 The Mayfield Lab currently works on developing genetic and molecular tools to make algae fuel a viable means of energy production.4 They grow algae, extract its lipids, and convert them to gasoline, jet, and diesel fuel. Mayfield believes his lab will reach a low price of 80 or 85 dollars per barrel as they continue researching with large-scale biofuel production.1
The advantage of growing algae for energy production lies not only in its renewability and carbon neutrality, but also its potential for other uses. In addition to just growing on wastewater, algae can treat the water by removing nitrates.5 Algae farms could also provide a means of carbon sequestration. If placed near sources of industrial pollution, they could remove harmful CO2 emissions from the atmosphere through photosynthesis.4 Additionally, algae by-products are high in protein and could serve as fish and animal feed.5
At this time of increased energy demand and dwindling fossil fuel reserves, climate change concerns caused by increased atmospheric carbon, and an interest in U.S. energy independence, we need economically viable but also renewable, carbon neutral energy sources.4 Algae holds the potential to address these needs. Its rapid growth and photosynthetic ability mean its use as biofuel will be a sustainable process that does not increase net atmospheric carbon. The auxiliary benefits of using algae, such as wastewater treatment and carbon sequestration, increase the economic feasibility of adapting algae biofuel. While technological barriers must be overcome before algae biofuel can be implemented on a large scale, demographic and environmental conditions today indicate that continued research will be a smart investment for future sustainability.
- Deaver, Benjamin. Is Algae Our Last Chance to Fuel the World? Inside Science, Sep. 8, 2016.
- Dineen, Jessica. How Scientists Are Engineering Algae To Fuel Your Car and Cure Cancer. Forbes UCVoice, Mar. 30, 2015.
- Top 10 Sources for Biofuel. Seeker, Jan. 19, 2015.
- California Center for Algae Biotechnology. http://algae.ucsd.edu/. (accessed Oct. 16, 2016).
- Is Algae the Next Sustainable Biofuel? Forbes StatoilVoice, Feb. 27, 2015. (republished from Dec. 2013)