Joule uses genetically modified algae-like microorganisms (it doesn’t like to say what kind) that continuously secrete ethanol. It isn’t necessary to harvest the algae to extract fuel, which is the conventional approach. The company also developed novel containers for the organisms—what it calls solar converters—to ensure that they get the optimal amount of light and nutrients and to minimize water consumption.

The company says the technology allows it to produce up to 15,000 gallons per acre per year—at least in the lab—compared to just a few thousand for conventional algae approaches or about a thousand for producing ethanol from grass or wood chips. Real-world results have been a little less impressive: Joule demonstrated only 8,000 gallons per acre in outdoor tests. Those numbers have to go up quite a bit for the process to be competitive with conventional fuels. Joule says its goal is to more than triple its yields to 25,000 gallons per acre to bring costs down to $1.28 per gallon.

Joule hopes to achieve 10,000 gallons per acre at the new demonstration plant. The plant will use simpler, cheaper solar converters than the ones used at the pilot plant. The original containers were large flat panels mounted on frames that angle them to catch the sun. The new ones are basically long plastic tubes and they lay flat on the ground, the company says.  

Joule says the commissioning of the demonstration plant is an ongoing process. Eventually, the plant will cover four acres, and so be able to produce about 40,000 gallons per year. The plant will be divided into six parts, and so far the company has only installed one of those six sections, which it plans to have producing ethanol in the next few weeks.