Glen Kertz is excited about algae. But it’s not just because he’s a plant physiologist. Kertz’s enthusiasm about the photosynthetic organisms stems from their ability to both provide a source of energy and absorb greenhouse gases.
With an influx of federal dollars and tax incentives, biofuel facilities are on the rise. While corn, soy, and palm are perhaps the most common base for biofuel today, the folks at Valcent and a handful of other companies—including Solix Biofuels in Fort Collins, Colorado, and California-based LiveFuels—believe that algae will play an increasingly prominent role.
Up to 50 percent of algae’s body weight is oil, which can be extracted and converted into biodiesel—which is much cleaner than petroleum-based fuel. The other byproduct, starch, could be fermented to produce ethanol.
Unlike other biofuel feedstocks, algae reproduce quickly and can be harvested daily. Experts predict that some algae will produce impressively high fuel yields—as much as 20,000 gallons of oil per acre of algae. One acre of corn typically produces 20 gallons of oil per acre, and palm oil trees yield about 600 gallons, researchers have found.
The idea of producing algae-based biofuel is not a new one. For nearly 20 years, scientists at the National Renewable Energy Laboratory (NREL) in Golden, Colorado researched the process.
Though they found that algae had great potential, they also identified major technological hurdles to overcome. The program shut down in 1996 because “the belief was that we’d be able to make biofuel from any kind of biomass for 50 cents per gallon,” says Al Darzins of NREL’s bioenergy center. Algae didn’t seem worth investing in if cheaper alternatives were available.
The recent resurgence of algae came about because companies have found that biofuel costs more to produce than they expected. Additionally, says Darzins, “the [algae] technology has just grown tremendously.”
Algae are attractive for other reasons, too. “They don’t require freshwater, and they don’t require soil,” says Michael Pacheco, director of the NREL’s bioenergy center.
Yet challenges remain. The process is still expensive. Algae need sunlight to grow, but too much will kill them. They don’t reproduce in overcrowded environments. And, if grown in an open pond, other algae can move in and take over the specific strain a company is cultivating.
According to Kertz, Valcent is getting around these obstacles by growing algae in a photobioreactor instead of in ponds. One of these systems is typically 4 feet wide by 10 feet tall, and consists of a several closely spaced vertical sheets of thin film membranes that allow high levels of light to penetrate.
“Bioreactors allow us to have a totally closed loop system, so we control what goes in and what comes out,” says Kertz, adding that they also use less water than a typical pond.
Though the process is still expensive, Kertz hopes to sell his product for $35 per barrel.
Still, researchers say it is unlikely algae alone will ever replace petroleum.
“We use 6.5 billion barrels of oil,” per year says Pacheco. “There is no silver bullet. The final solution may be a combination of fuel sources.”
Story by Alisa Opar. This article originally appeared in "Plenty" in June 2007.