Most algae companies are either growing algae in open ponds or bioreactors.

Startup Plankton Power says it will combine the two. But first it needs $20 million to prove it.

The Wellfleet, Mass.-based company potentially can produce 100,000 gallons of biodiesel per acre with proprietary system that combines open ponds and closed bioreactors, according to CEO Curt Felix. The company has gotten some prominent partners in the project – Woods Hole Oceanographic Institution and the Marine Biological Laboratory, which will help in researching new strains of algae, he said. 

Still, the claim may well garner skepticism among watchers of the algae-to-biofuel race now underway (see Green Light post). After all, the 53 algae biofuel startups covered in an April report by Greentech Media analyst Eric Wesoff have yet to produce commercial-scale quantities. The report did not include Shell, which has inked research deals with some algae companies, Targeted Growth and Genifuel (see A New Use for Algae: Natural Gas). That makes 56 and there are undoubtedly more out there.

Exxon, which just said it would invest $600 million into algae biofuel research, half in partnership with genetic engineering firm Synthetic Genomics, has put a goal of 2,000 gallons per acre on algae, according to the New York Times (see Green Light post).

And Henrik Scheller, director of cell wall biosynthesis at the Joint BioEnergy Institute at U.C. Berkeley, has said that 4,400 gallons per acre per year is a limit for algae-based biofuels, given the plant's ability to capture sunlight – a limit that Plankton, along with other startups, says it can overcome (see Green Light post).

Plankton Power in the midst of raising $4 million that it hopes to combine with about $16 million in Department of Energy funding to get the pilot plant built at a National Guard site in Bourne, Mass., Felix said Tuesday.

It plans to use carbon dioxide from a source such as a power plant to feed non-genetically modified strains of algae that have a greater than usual lipid, or fat, content, of up to 65 percent, he said. That's the claim to fame of other algae biofuel startups, including Targeted Growth (see Green Light post).

But the key to what Plankton Power says it can achieve is its system of combining open ponds and closed bioreactors to boost growth about sixfold compared to natural growth, he said.

The National Renewable Energy Laboratory's Aquatic Species Program, a 20-year research effort, determined that open ponds were the most cost-effective way to grow algae. But proponents of closed bioreactors say they've found ways to make them work more cost-effectively (see Can Solix Cut the Cost of Making Algae by 90%?).

Felix said Plankton Power's system circulates algae-filled water between an open pond and a bioreactor system that lies on top of it. That increases the number of light-dark cycles the algae are exposed to, which makes them grow faster, he said.

"Imagine having a solar collector on the roof of your pond," he said. "We're circulating through something that's more equivalent of a solar collector, and controlling our light levels that way." That requires some clever engineering to keep the energy needed to move the water to a minimum, he said.

Then, Plankton Power has also developed a process to separate the algae from the water it grows in for harvesting through a continuous screening process, he said.

From there, the company has a process to fracture the algae cell walls and remove and purify the oil within, which can be converted to biodiesel with a minimal cost, he said.

Whether Plankton Power will get the public and private funding it seeks to build its pilot plant and prove its technology remains to be seen. Certainly algae biofuel companies have been collecting large sums from venture capital investors in recent quarters.

Solazyme last month raised $57 million to push commercialization of its unusual process of growing algae in the dark and feeding it industrial and biomass byproducts (see Solazyme Snags $57M to Make Algal Oil for Cars and Salad).

At the same time, funding is no guarantee of success. Algae biofuel pioneer GreenFuel Technologies, after raising more than $70 million from venture capital firms, shut its doors earlier this year and is now seeking a buyer of its intellectual property (see Green Light post).

Tags: algae, exxon, genifuel, GreenFuel, greenfuel, plankton power, solazyme, Solazyme, solix, synthetic genomics, targeted growth