In this third and final part of my series on a long-term energy solution for our nation (see also Part 1 and Part 2), I take an in-depth look at the prospect of algae-based biofuels. Regardless of whether you believe that we should pursue alternative fuels because supplies of fossil fuels are finite, or because it is in our strategic interest to become less dependent on the rest of the world for our energy supplies, or because the continued build up of greenhouse gases in our atmosphere requires that we take action to turn the tide now — or for any other good reason — much time and money are today being poured into the effort.

Even the Department of Defense has jumped into the act. At the end of 2008, DARPA awarded contracts to teams led by General Atomics ($19.5 million) and SAIC ($14.9 million) to develop economical methods for making JP-8 jet fuel from algae. Next summer tests will begin on a Navy F/A-18 Super Hornet fighter aircraft burning a mix of conventional jet fuel and biofuel. And in a speech last week to the San Diego Military Advisory Council, Navy Secretary Ray Mabus declared that the Navy intends to use renewable energy sources for half of its energy needs by 2020. It is anticipated that a significant portion of these renewable fuels would be algae-based biofuels, although other biofuels are also in the running. As Secretary Mabus pointed out, “If the Navy has a demand for it, the technology will come.”

The future is now, and there is no turning back.

The Current Situation

Biofuel is fuel derived from biomass — plant-based organic matter available on a renewable basis. Biofuels include such things as ethanol derived from corn, sugar cane, and other crops; reclaimed vegetable oils; biodiesel; algae-based biofuels, and more. As I noted in the second part of this article, Department of Energy statistics rank bioenergy second to hydropower in renewable U.S. primary energy production, accounting for 3 percent of the primary energy production in the United States today. It is my belief that these sources of bioenergy — and others yet to be developed — will one day directly replace the majority of liquid and gaseous fossil fuels used today.

But it is algae-based biofuel that is gaining much of the attention today, and for good reason. In a cover story in the October 19, 2009 issue of The Wall Street Journal, reporter Michael Totty listed Five Technologies That Could Change Everything. Fifth on the list (which includes space-based solar power, advanced car batteries, utility storage, and carbon capture and storage) is next-generation biofuels. While this category includes a variety of different biomass sources such as lumber and crop wastes, garbage, and inedible perennial plants, according to Totty, “…the most promising next-generation biofuel comes from algae.” Why? Says Totty, “Algae grow fast, consume carbon dioxide, and can generate more than 5,000 gallons a year per acre of biofuel, compared with 350 gallons a year for corn-based ethanol. Algae-based fuel can be added directly into existing refining and distribution systems; in theory, the U.S. could produce enough of it to meet all of the nation’s transportation needs.”

This Wall Street Journal reporter is not alone. Today, many organizations are placing their biofuel bets on algae.

In July 2009, Exxon Mobil announced that it was investing $600 million in a venture with Craig Venter’s company Synthetic Genomics to produce renewable liquid transportation fuels from algae. BP and Royal Dutch Shell have also jumped on board the algae bandwagon, funding their own research efforts into the promising biofuel.

These huge oil companies are being joined by other large companies. The 2009 Algae Biomass Summit — organized by the Algal Biomass Organization (ABO), and held in San Diego from October 7-9, 2009 — was sponsored by such companies as Airbus, FedEx, Raytheon, Boeing, Sapphire Energy, and Invitrogen. According to Mark Allen — a former SAIC employee from the ’80s and founding board member of ABO — the event was expected to attract more than 1,000 scientists, engineers, venture capitalists, and industry executives. Mark is also a co-founder of A2BE Carbon Capture, which is working on closed photobioreactors (PBR) for the cultivation of algae on an industrial scale. Other ABO corporate members include Air New Zealand, Virgin Atlantic, EPRI, General Atomics, Siemens, Waste Management, and many more.

Why Algae? Why Now?

So, why all of the interest in algae? And why now? Algae grow rapidly and can develop a high energy content. According to the Department of Energy, some algal strains double their mass several times a day, with more than half of that mass comprising lipids or triacylglycerides. These are the basic ingredients of common vegetable oil. The lipids and triacylglycerides produced by algae can be turned into biodiesel, green diesel, green gasoline, and green jet fuel. The Department of Energy has pinpointed five key benefits of algae-based biofuels (PDF):

• Impressive Productivity: Microalgae, as distinct from seaweed or macroalgae, can potentially produce 100 times more oil per acre than soybeans — or any other terrestrial oil-producing crop.
• Non-Competitive with Agriculture: Algae can be cultivated in large open ponds or in closed photobioreactors located on non-arable land in a variety of climates (including deserts).
• Flexible on Water Quality: Many species of algae thrive in seawater, water from saline aquifers, or even wastewater from treatment plants.
• Mitigation of CO₂ During photosynthesis, algae use solar energy to fix carbon dioxide (CO₂) into biomass, so the water used to cultivate algae must be enriched with CO₂. This requirement offers an opportunity to make productive use of the CO₂ from power plants, biofuel facilities, and other sources.
• Broad Product Portfolio: The lipids produced by algae can be used to produce a range of biofuels, and the remaining biomass residue has a variety of useful applications:
  • combust to generate heat
  • use in anaerobic digesters to produce methane
  • use as a fermentation feedstock in the production of ethanol
  • use in value-added byproducts, such as animal feed

Research by Dr. Oliver Hemmers — director of strategic energy programs at University of Nevada Las Vegas — indicates that production of algae-based biofuels could top 15,000 gallons per acre in warmer areas of the United States. And in colder areas, algae ponds could be coupled with coal-burning power plants, using CO₂ produced by the power plants (which, on average, produce more than 5 million metric tons of CO₂ a year) to feed the algae. According to Hemmers, a coal-burning power plant combined with an algae-pond system could produce 156 million gallons of biodiesel a year.

Of course, while the promise of algae-based biofuels is great, we are still in the early stages of research and development. It will be a number of years before algae becomes an economically viable alternative to petroleum. According to Emil Jacobs, vice president for research and development at Exxon Mobil’s research and engineering unit, large-scale commercial plants to produce algae-based fuels are at least five to ten years away.

Much to Be Done

There are still a number of challenges to overcome before algae-based biofuels can move from the test tube to the filling station. For one thing, the technology is still in its early stages, and the price of algae-based biofuel will not be competitive with conventional petroleum fuels until significant production facilities and refineries are brought on line. That said, progress is being made. According to the General Atomics team, they have already been able to cut the cost of algae-based biofuel from $30 a gallon to a range of $6-7 a gallon. However, this figure needs to get closer to $1 a gallon says David Hazlebeck, General Atomics’ program manager.

There is much debate about which approach to growing algae is best, with much of this debate centering on open ponds versus closed vessels. Open ponds are far more cost effective, but environmental conditions within closed vessels can be controlled much more precisely. Eventually, I believe that the most cost-effective approach that offers a reasonable amount of control will win out. As Stephen Mayfield — professor and associate dean of graduate studies in the Department of Cell Biology at the Scripps Research Institute here in La Jolla — noted on this blog on April 21, 2009, the capital expense of building closed bioreactors (vats) is prohibitive. According to Stephen, “Fuel, even at $4 gallon is still only $0.60 a pound, and it’s tough to get that cost of goods out of a facility that contains [expensive] bioreactors…For those of us that think about fuels retained in the algae, then open ponds are the only way cheap enough to work.”

But surmounting these challenges will undoubtedly be of great benefit to our nation, and I believe that unlocking the secrets of algae-based biofuel is a smart investment of both time and money. According to David Hazlebeck at General Atomics, doing so will create “trillions of dollars in economic activity” for our economy while reducing our dependence on foreign sources of oil.

Whatever happens in the future, I am certain that algae-based biofuels will be an important part of our nation’s alternative fuel portfolio, and one that cannot be ignored. Follow the money, and you’ll see that the prospects for renewable algae-based biofuels are brighter than ever.