Algae: Power Plant of the Future?

A microscopic green algae -- known to scientists as Chlamydomonas reinhardtii, and to regular folk as pond scum -- was discovered more than 60 years ago to split water into hydrogen and oxygen under controlled conditions. A recent breakthrough in controlling the algae's hydrogen yield has prompted a Berkeley, California, company to try to be first to commercialize production.

Energy experts -- who disagree on the when, but not the if, of the eventual depletion of fossil fuels -- are predicting that within decades the world will switch to a utopian hydrogen economy, where energy will be abundant, inexpensive and nonpolluting.

Hydrogen is used by fuel cells to generate electricity without generating those nasty greenhouse gases.

Hydrogen can be extracted from fossil fuels, but currently it's more expensive than directly using oil or natural gas, so this method is only a temporary fix. Water can be split into hydrogen and oxygen through electrolysis, but that requires electricity generated from fossil fuels, or from renewable sources such as wind or solar that are even more costly.

The potential of algae to be used as microscopic power plants was first discovered by Hans Gaffron, a German researcher who fled the Nazi party and came to the University of Chicago in the 1930s. Gaffron observed in 1939 that the algae would for a then-unknown reason sometimes switch from producing oxygen to instead creating hydrogen, but only for a short period of time.

For 60 years, researchers tried to harness the power potential of algae, without success.

A breakthrough came in 1999 when University of California at Berkeley professor Tasios Melis, along with researchers from the National Renewable Energy Lab, discovered that depriving the algae of sulfur and oxygen would enable it to produce hydrogen for sustained periods of time.

Melis was working on research for the U.S. Department of Agriculture, investigating how plants repaired themselves when damaged by conditions such as lack of sulfur, an ingredient necessary to make proteins.

Melis found that algae must eventually be supplied sulfur to survive, but he was able to repeatedly switch hydrogen production on and off by changing the algae's environment.

Melis launched a company, Melis Energy, in 2001 to try to commercialize a technique that harnesses algae's ability to turn sunlight into hydrogen. In the fall of 2001, the company built a bioreactor containing 500 liters of water and algae that can produce up to 1 liter of hydrogen per hour. A siphoning system extracts the hydrogen, which is stored in its gaseous state.

The company is continuing to refine the process and improve its reliability, while also searching for investors so that it can increase production volume.

Melis was tight-lipped about projecting a date when the technology could be used for mass production.

He said that his team of researchers at Berkeley has thus far only been able to achieve 10 percent of the algae's theoretical production capacity, but in the near future he will publish an advancement for peer review.

Once the process reaches a 50 percent yield, Melis said it would be cost-competitive with fossil-fuel energy.

Because the algae require ample sunlight, Melis said the Southwest United States would be a likely region to build production facilities.

Being able to cost-effectively produce hydrogen from a renewable source "would grow demand for hydrogen extensively," said T. Nejat Veziroglu, president of the International Association for Hydrogen Energy.

Veziroglu said that if the United States had a Manhattan Project-like commitment to developing hydrogen production, it could create the necessary infrastructure within 20 years.

"If half the money being spent on terrorism was spent on hydrogen production, we'd have a permanent solution to terrorism," Veziroglu said, referring to the link between some oil-producing countries and terrorist activities.

Melis is one of many researchers around the world vying to reach hydrogen nirvana. Projects are also underway in England, Germany, Russia, France and New Zealand.