Is Joule’s Renewable “Liquid Energy” Far More Efficiently Produced Than Biofuel?


Joule Unlimited, a startup that produces solar fuels, says it can generate renewable diesel fuel at up to 15,000 gallons per acre annually. In comparison, biodiesel produced from algae fuel generates 3,000 gallons per acre.

Joule has made some lofty claims over the past few years. In 2009, the startup announced that it had figured out how to engineer microbes that require only sunlight and CO2 to produce ethanol, diesel, and other hydrocarbons. In 2010, the company revealed the patent for its engineered cyanobacteria, which can supposedly produce “Joule liquid energy,” a biofuel-like ethanol or diesel replacement, in a single step.

Now Joule says it can far exceed the production capacity of any other biofuel manufacturer. An article recently published in the peer-reviewed Photosynthesis Research journal by Dan Robertson, Senior Vice
President of Biological Sciences at Joule, analyzes Joule’s capacity.

Among the article’s claims: The conversion efficiency of Joule’s diesel, ethanol, and chemical production process is
between five and 50 times greater than biomass-dependent processes, and the company can achieve a photosynthetic conversion efficiency of over 7% relative to the solar energy that hits the ground each year.

We will know soon enough whether or not Joule’s claims can live up to the hype. The company says it will begin commercial production in 2012.

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