Electricity Out of Thin Air? Huc Yes!

Generating cheap, abundant electricity has been a dream of scientists and inventors for decades. With the increasing demand for energy and rising environmental concerns, researchers and inventors are working hard to find new and innovative ways to produce electricity that is affordable, sustainable, and accessible to everyone.

One promising area of research is the development of renewable energy sources, such as solar, wind, and hydropower. These sources have the potential to provide electricity at a lower cost than traditional fossil fuels and with less negative environmental impact. Solar panels, for example, have become more efficient and cost-effective in recent years, and the installation of solar panels around the world is growing.

However, technologies presently in use to harvest renewable energy are far from ideal. One of the primary challenges of renewable energy sources is their intermittency. Solar and wind power, for example, are dependent on weather conditions and are therefore subject to fluctuations in output. Energy storage technologies such as batteries can help to smooth out these fluctuations, but they are currently expensive and may not be able to store enough energy to meet demand during periods of low energy output.

To meet the world’s future energy demands, it is clear that new technological advances are needed. This realization has led a team at the Monash University Biomedicine Discovery Institute to ask the question: what if we could harvest energy from thin air? Well, we certainly cannot do that (pesky laws of thermodynamics!), but this group has pulled off the next best thing. For the first time, they have elucidated how certain types of bacteria are able to generate electricity from atmospheric hydrogen. Further, they also believe that this mechanism can be reproduced in vitro. If their techniques could be scaled up in the future, the implication is that this method could be leveraged to produce virtually endless clean energy.

It has been known for some time that certain types of bacteria, especially those that live in harsh environments, like in Antarctic soils, volcanic craters, or the ocean’s depths, are able to produce energy from minute quantities of environmental hydrogen. Exactly how this happened, however, had been a mystery until now. The researchers found that an enzyme called Huc is responsible for converting hydrogen gas into an electrical current.

The Huc enzyme was extracted from Mycobacterium smegmatis for further analysis by the team. As is often the case with nature’s machinery, it was discovered that this enzyme was incredibly efficient. It is capable of generating electricity from even minute amounts of hydrogen — even at concentrations far, far lower than are present in the atmosphere.

It was discovered that this incredible efficiency is due, in part, to the fact that the Huc enzyme is largely insensitive to the inhibition of hydrogen catalysis by oxygen, which normally poisons the process. Not only is this property extraordinarily rare for a hydrogenase, but it is also a requirement for any mechanism to efficiently interact with atmospheric hydrogen.

Powering a single cell and a city are worlds apart, of course, so there is still much work to do before the Huc enzyme can provide the energy to power much of anything. It was found, however, that it is possible to grow large quantities of this enzyme, because the bacteria that produce it are very common and simple to grow in culture. And once produced, Huc is highly stable and can be stored for long periods of time. Even after being frozen or heated up to high temperatures, it was shown that Huc still retains its ability to efficiently generate energy.