A little over 3 years ago I discussed high oil algae, noting that it's one of the very few biofuel ideas that made any sense. However, there's still no output.

But after all the hype—and there's been plenty of it—the fact remains that nobody has yet proven they can cheaply and reliably transform the stuff from a thick, green slurry to a finished fuel capable of making a dent in America's 870 million–gallon-per-day petroleum habit.

"I get a lot of people telling me that they've got thousands of gallons, but when I actually ask for a sample I can get maybe two," says Jennifer Holmgren, director of the University of Phoenix (UOP) renewable energy and chemicals division, which is working to refine jet fuel from feedstocks that include algae.

"Google some of the numbers, and you've got people claiming that right now they're producing 35,000 gallons per acre per year, and they'll be producing 100,000 gallons—and that's just impossible," says Solix Biofuels lead scientist Bryan Wilson, a veritable grandfather with two successful years in the fledgling algae industry. "There's probably not more than a few barrels floating around right now."

You're gonna love it when you get it.

A number of pilot plants scheduled to come online in the next several months will likely give the most accurate glimpse of algae's future: how much oil it can produce, how soon and whether it will live up to its promise. GreenFuel, one of the oldest names in algae, already operates a pilot plant in Arizona, where it houses algae in large, clear plastic bags. Solix will break ground this summer on a new plant in Colorado, growing algae in what are essentially 230-ft.-long, 5-ft.-high freezer pops, suspended vertically in shallow pools; a smaller array, with eight 65-ft.-long bioreactors, has entered production in recent weeks. HR BioPetroleum, which signed a deal with Shell last year to produce biodiesel from algae, is currently building a pilot plant in Hawaii using a "hybrid system"—growth begins in long, clear, horizontal tubes before being dumped into open ponds to multiply further. Blitzing the ponds with algae for a short time has the advantage of rendering species invasion a nonissue, the company says.

"The jury is out on all of them—nobody has fully demonstrated that their system is going to be affordable and scalable, and be robust in terms of operations and maintenance and the ability to produce a large amount of oil routinely," says Ron Pate, a researcher at Sandia National Laboratories who evaluated algal oil in conjunction with DARPA's jet fuel project last year. "There are a lot of naysayers out there, and that's fine. It's good to be skeptical. But at the same time, I think there's enough promise with algae that it needs to be given a better shot than what's been done in the past."

It's worth researching further. I'd like to see some more detailed discussion of the systems. Nothing (yet) grows on just air, sunlight and water, there has to be a nutrient supply. What is being used? How efficient is the process. Do the algae carcasses have other uses after the oil etc. is wrung out.

Got any links?