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The energy stored in hydrogen gas is enormous, but the challenge is how to release that energy in a controlled way.

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Hydrogen holds great promise as a clean renewable fuel for the future because the only waste product of using it as a fuel is water.

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There's already a growing fleet of hydrogen powered cars and buses on the roads in London and a growing network of hydrogen fuelling stations.

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So what is it that holds us all back from having a hydrogen powered vehicle?

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One of the big challenges in using hydrogen as a fuel is how to split apart the two atoms of the hydrogen molecule to release the energy.

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Currently, the best way to do that is using platinum.

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But the problem is that platinum is very expensive, more expensive than gold, and it's a limited resource.

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We are looking into the natural world to find ways of splitting hydrogen, using cheaper metals.

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Bacteria all around us use hydrogen for energy.

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These are bacteria found in all sorts of environments, in the soil, in lakes, even in our own stomachs.

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And they're able to split hydrogen using large molecules called enzymes.

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And these enzymes split apart the hydrogen using special metal sites very deep inside the enzyme.

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And these metals are cheap, readily available metals, nickel and iron.

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Here at the University of Oxford, I'm working with my colleague, Dr Philip ECHE to study how these enzymes from bacteria are able to split hydrogen.

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Dr. Ash is now going to tell us more about how he's studying these enzymes.

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Enzymes have shown us that it's possible to split hydrogen gas using cheap and abundant metals,

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nickel and iron, but we really don't know what makes them so efficient at doing this.

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One of the problems that we face when we're studying these enzymes is that all the chemistry

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takes place at a tiny metal site within a very large enzyme molecule here in Oxford.

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We've developed a technique that uses Infra-Red light to take snapshots of the metals inside the enzyme as they split the hydrogen gas.

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There's still a lot of fundamental research needed here,

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but what we're learning from studying how bacteria in the natural world are able to use cheap metals to extract energy from

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hydrogen brings us a step closer to the reality of affordable vehicles running on hydrogen as a clean renewable fuel.