Thursday, 25 February 2010

Hydrogen Highways

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.


Plaid Whitegate said...

THis caught my eye yesterday

Maybe Hydrogen power is closer than we think as a viable alternative.

John Dixon said...

The technology for using Hydrogen is probably the easiest part. IT's been known in principle for many years, and the technology will be developed.

The hard part is producing and distributing the hydrogen, and doing so in a clean way. I suspect that's still a way off.

MH said...

Couldn't agree more, John. In fact I may just have said the same thing myself once or twice ;-)

Since the key is the "excess" from renewable sources, deciding the location of the highway (which is a good idea) is going to depend on where those sources are. The latest offshore wind developments (Round 3) include two zones near Wales. The smaller Bristol Channel zone is set to bring electricity ashore in Somerset, but the Irish Sea zone north of Môn is set to bring huge quantities of electricity to land on the north Wales coast. The plan is for 3.6GW capacity ... more than the nuclear station at Wylfa has ever produced.

I think that makes the A55 a much better option to develop as a hydrogen highway than the M4. If we don't develop a way of storing the excess electricity at or near the point it comes ashore, the only other alternative is to restrengthen the grid, something that is bound to involve additional power lines across north Wales.

However, if we want to introduce the technology more gradually, an intermediate answer would be to power buses by hydrogen. Most buses are on defined routes and return to the same depot for refuelling, that means the infrastructure need only be at the depot rather than strung out along a highway. Larger hydrogen-powered buses have been successfully run in London (they're not cheap, but they are green) and small minibus-sized buses have been developed by the University of Glamorgan.