One clever plant

A U.S. company has designed an unusual source of diesel

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Henry Ford, the father of the modern assembly line, predicted a future where fuel would be mass-produced from natural materials like fruit, weeds, or even sawdust—renewable alternatives to finite fossil fuels. Still, one energy technology being developed by Joule Unlimited, a company in Cambridge, Mass., might have surprised even him: a plant that sweats diesel.

Plants use the sun to convert carbon dioxide into energy, but Joule has designed tiny, gene-altered organisms (essentially single-celled plants) that use the photosynthetic process to create liquid fuel. Stored in brackish water enclosed in glass panels, they grow for a few days before a genetic switch is flipped, diverting their energy toward fuel production. The diesel, which they pump out continuously, is circulated away to a separator, where it’s extracted and sent to a storage tank. After several weeks, the plants are flushed away and the process starts over again. These microscopic organisms can be genetically engineered to secrete diesel or other chemicals the company plans on commercializing; president and CEO Bill Sims calls the technology an “above-ground oil well.”

While exact details are still closely guarded, Joule says the system—which won a spot on MIT’s Technology Review magazine’s top 10 most important emerging technologies of 2010—is the first of its kind. Unlike biofuels made from corn, say, it doesn’t require biomass, but rather turns sunlight directly into fuel. The only inputs required are sunlight and carbon dioxide, the company notes, making it cost-efficient and productive: one 10,000-acre facility could create an astonishing 150 million gallons in a year, it estimates. “Because our process is free of the land and resource constraints that hinder biofuels, we’re able to meet or beat the costs of fossil fuels,” a spokesperson said over email. “We expect to deliver diesel for as little as $30 per barrel.”

Joule, which employs about 45 people, recently raised $30 million to build a plant in Leander, Texas; it’s planning to start commercial production as early as 2012. If the company’s predictions are right, Technology Review reports, “biofuels could become an alternative to petroleum on a much broader scale than has ever seemed possible.” For some, that can’t happen fast enough.