Hydrogen Highways

Tweet I wasn't really surprised by the story earlier this week that the proposed hydrogen highway through South Wales was 'little more than hot air'. I thought at the time that it was announced that Peter Hain was over-hyping the proposal. Sadly, that's not the first time – and I'm sure that it won't be the last time either – that he has over-stated his case and raised false expectations as a result.

But there's a danger that we go too far and 'under-hype' the idea, as well. I think that hydrogen has a serious role to play in our future fuel economy, and the idea of further research and development is fundamentally sound. The problem is that it's nowhere near as ready to roll out as a practical solution as the original announcement seemed to imply. Politicians are sometimes too keen to present a solution to a problem, before the solution is really fully worked through.

There are a number of technical challenges to be overcome before we see mass production of hydrogen powered vehicles, but I'm confident that there are no insoluble issues on that score. The really big question for me is where the hydrogen itself comes from. There are only two practical solutions at present.

The first is to extract it from hydrocarbons – natural gas mostly – but that leaves us with a waste product - called carbon dioxide. Unless we have a practical and safe way of storing that CO2, then turning the natural gas into hydrogen isn't likely to be any greener than burning it directly.

And the second is to use electricity to split water into hydrogen and oxygen. It's green and clean, but there is inevitably a loss of energy in the process – the electricity generated when the hydrogen is combined with oxygen again in a fuel cell is significantly less than that used to split the water in the first place.

It still makes sense, however, if we are using off-peak electricity from renewable sources. The intermittency, or propensity to produce electricity outside the peak hours when it's most needed, of sources such as wind, sun and tide is much less of a problem if we have a means of 'storing' electricity. Hydrogen can provide precisely that.

What the story highlights though is that energy policy needs to be joined up and planned in a way which simply isn't happening at present, because hydrogen makes most sense as part of an integrated energy policy, not as another stand-alone initiative.