This new natural power source pulls electricity out of the air

Scientists say they’ve discovered a way to create electricity out of thin air. And their process might some day power your watch, your smartphone or possibly your laptop.

Using a common soil bacterium that consumes small amounts of hydrogen from the air to help power its metabolism, researchers at Monash University in Melbourne have managed to isolate the enzyme that enables it to do so. (Enzymes are substances produced by living organisms that help them carry out certain biochemical actions.)

The researchers showed that this enzyme — going by the decidedly ignoble name of Huc — was able to turn even the smallest amounts of atmospheric hydrogen into an electrical current.

Though it’s still in the proof-of-concept stage, the discovery raises exciting possibilities, says the study’s co-author, Rhys Grinter, laboratory head in the microbiology department at Monash.

The bacterium from which the enzyme is extracted, Mycobacterium smegmatis, is nonpathogenic, grows quickly and is easy to work with in the lab. The extracted enzyme, Huc, is stable and long-lasting — it can endure temperatures up to 80 degrees and down to -80 Celsius and still retain its ability to generate electricity. It has continued that activity for several days at a time — and it is absurdly efficient, says Grinter.

“We managed to put it into a small electrochemical circuit and show that it can make electricity down to (minute) atmospheric concentrations — so the 0.00005 per cent of hydrogen in the atmosphere, it can turn into electricity.”

So far, says Grinter, they’ve grown the bacteria in the lab in relatively small batches — five to 10 litres. The next step is to scale up the operation — 1,000- or 10,000-litre batches — and engineer the enzyme to increase its stability and longevity.

Because it draws on hydrogen from the air, theoretically a battery based on Huc could last indefinitely, or at least as long as the enzyme does — they’re hoping to engineer it to last for years.

But Huc isn’t about to about to replace windmills or solar cells any time soon; when there is a need for large-scale centralized electricity generation, says Grinter, there are more convenient ways to achieve it. Instead, he and his colleagues visualize Huc — when fully developed — as the basis of a small-scale, long-term power source.

“The real niche for this technology are things that need a sustained, relatively low amount of power, and it’s not convenient to have a battery which charges them all the time,” he says.

“Things like biometric devices, implanted medical implants or potentially a remote sensor which is difficult to access and that needs to have power 24/7.”

But there’s another intriguing possibility. They’ve discovered that when they put Huc in a circuit, the more hydrogen they feed it, the more electricity it produces. That may prove a promising route for engineers to develop ways to integrate the enzyme into hydrogen-based fuel cells — the kind that might power an electric car.

Those days are still well in the future, however. Although Grinter and colleagues have managed to isolate the enzyme and prove that it can convert atmospheric hydrogen into electricity, they have yet to devise the machinery to take advantage of that.

But, says Grinter, other researchers’ work with other enzymes shows that they can work in the kind of circuit he and his colleagues envision for turning Huc into a practical power source.

“We have proof of concept on both ends, but we still need to connect in the middle and that’s going to be our work going forward,” he says.

The Australian research opens up the window for an astonishing amount of further study. While his team’s research is the first to isolate an enzyme with such great efficiency in converting atmospheric hydrogen to electricity, Grinter notes that bacteria everywhere in the world are removing hydrogen from the air to power their metabolic functions — he says something like 80 billion tonnes of atmospheric hydrogen are removed by soil-based bacteria annually.

Therefore, it’s likely that other researchers will follow their path, using different bacteria.

Grinter described the moment he and his colleagues managed to isolate their enzyme for the first time and view it with an electron microscope: “They’re really striking in appearance — like a little cloverleaf shape. And to a structural biologist like myself that looks really beautiful.

“When we’d seen that, when we knew that we spent four years of hard work and we’d finally done it, we cracked a bottle of champagne and were incredibly excited.”

The Monash research was published in the journal Nature on March 8.