Power play

It’ll come as no surprise that electric vehicles are near the top of the list of stories we cover on The Engineer. For all sorts of reasons, the development, testing and deployment of all the different varieties of electric vehicles — plug-in hybrid, range-extender, all-electric, fuel-cell powered — is a hot topic, and it’s something we’re following closely.

But whenever we feature an electric vehicle story, we can be sure that one issue above all will be raised: the source of the electricity. While proponents of electric vehicles, especially in government, invariably say that their development is vital if we’re to become a low-carbon economy, it’s completely true that electric power is not, of itself, low carbon. Far from it: you have to generate the electricity somehow, and if, as at the moment, that electricity is generated in a fossil fuel-burning power station, then switiching from petrol to electric power doesn’t reduce emissions at all. It just shifts them somewhere else.

The argument always comes up that money spent on developing electric vehicles is therefore wasted. It’s not solving the problem, therefore the (now scarce, we’re told) development money should go on the root problem: low-carbon electricity (or hydrogen) generation. This week, we’re running a poll on this very subject — go here to register your opinion — and as I write, more than two-fifths of respondents believe that fuel cell development is a waste of time while the environmental cost of hydrogen generation remains high.

This attitude ignores some important factors, however. Most obvious is the advantage of developing both the vehicles and the low-carbon generation of power or hydrogen concurrently: once the technology for one is in place, then the other will be ready at the same time. Leave off the development of the vehicles, and there would be a gap, possibly decades long, until they would be roadworthy. The low-carbon power stations, whatever form they take, would either be over-specified, as they’d be planned to generate power for vehicles that don’t yet exist; or they would be sized for demand that excludes electric vehicles, meaning they’d struggle to catch up. And during the gap, cars would still be running on fossil fuels, increasingly scarce and just as polluting as ever.

There’s also an argument that shifting emissions isn’t necessarily a bad thing. Large point sources of emissions are always easier to deal with than small, diffuse sources. If power stations or hydrogen generation stations were equipped with carbon capture and storage — another technology which needs to be developed concurrently with electric vehicles and low-carbon power — then the emissions from transport would still be reduced; the fuel consumed in engines would effectively be ‘pre-burned’ and the carbon removed, rather than belched out along the length of the motorway system.

The low-carbon generation problem could be solved sooner rather than later, if energy secretary Chris Huhne is correct and the new fleet of nuclear power stations starts to come on-stream in 2018. And other potential large sources of low-carbon power — offshore installations of 10MW+ wind farms, tidal stream turbines in the Pentland Firth — could arrive soon after. But if we don’t keep up development of the vehicles to be powered by that electricity, then we’ll be faced with problems just as big as the ones we have now.

Technologies that generate, transmit and consume energy are linked together in a complex web; you can’t change one without affecting the others. Assigning funding to developing the various different aspects of this web is a tricky business. But it’s difficult to see how one area can be prioritised over another. It has to be done together, and it has to be coordinated.