Not so, since researchers have been able to use a bacterial enzyme that conducts hydrogen to create electricity, literally out of thin air.

The discovery promises to open up a new field of clean energy that would take on all kinds of sci-fi forms.

Recent work by the team at Monash Biomedicine Discovery Institute at Monash University, Australia, has shown that many bacteria use hydrogen from the atmosphere as an energy source in nutrient-poor environments.

"We've known for some time that bacteria can use the trace hydrogen in the air as a source of energy to help them grow and survive, including in Antarctic soils, volcanic craters, and the deep ocean," said Monash Univ. Professor Chris Greening. "But we didn't know how they did this, until now."

In their discovery paper published in Nature, the researchers extracted the enzyme responsible for using atmospheric hydrogen from a bacterium called Mycobacterium smegmatis. They showed that this enzyme, called Huc, turns hydrogen gas into an electrical current.

"Huc is extraordinarily efficient," notes co-author Dr. Rhys Grinter. "Unlike all other known enzymes and chemical catalysts, it even consumes hydrogen below atmospheric levels—as little as 0.00005% of the air we breathe."