To be a viable source for fuel, algae must be dried completely, but the most common way of doing so -- spinning it in a centrifuge -- is costly and inefficient and often damages the plant particles. Algaeventure Systems, founded by Ross O. Youngs in Marysville, Ohio, in 2008, has developed a more efficient drying system based on osmosis and other natural processes. After algal solution is placed on the AVS Harvester, a moving screen pulls the plant particles in one direction as a conveyor belt pulls the water in the other. The resulting thin algal deposit dries using natural evaporation and electric heat before flaking off into a container. The flakes can be processed in a variety of ways to create things such as fuel and food. Algaeventure, which received a $5.9 million grant from the U.S. Department of Energy in October, sold its first harvester to energy firm General Atomics last summer. It plans to target the alternative fuel and food markets in the next two years.

Locally grown

The algae is grown in a greenhouse-like structure next to Algaeventure's Marysville, Ohio, headquarters.

Flaking out

The harvester is 6 feet long and 30 inches wide. It can process 500 liters of algal solution per hour.

The bottom line

It costs about $2 to process a ton of algae using the harvester, compared with $3,400 a ton using a centrifuge, according to research by Algaeventure Systems and Wageningen University in the Netherlands.