Electric cars are a great idea and they’ll save the earth, right? Well, sorry, but it’s going to be a whole lot harder to handle large numbers of electric cars than we hoped.
The whole point of electric cars is that they’re powered by clean, far-away electricity generators instead of petrol engines putting out that dirty carbon dioxide which dangerously heats our planet.
We would prefer to gently erect some pretty windmills or softly lay delicate and lovely solar panels to generate electricity non-intrusively, without antagonism and free of violence to our beloved Mother Earth.
But no matter what we might prefer, if we eliminate all those wonderful, rumbling newtons (known to Jeremy Clarkson as horsepowers) from petrol we must make them up from somewhere else. Ok. Simple question: can we make it up with electricity?
A New Zealand study
A long time ago, in 2008, the CCG published NZ sustainable energy supplies, a paper by local engineer Gary Kendall. Also, incidentally, one of the original members of the CCG.
He examined renewable energy options for New Zealand and the potential load on the national grid of recharging substantial numbers of electric cars. After four years the numbers will need revising as battery capacities and engine specifications will have changed, but what did he find then?
First, Gary made a conservative assumption that private car owners might decide to convert ten per cent of our national fleet to electric vehicles (300,000 cars).
To charge them all at night would require, depending on the choice of vehicle, extra generation capacity equivalent to over 10,000 medium wind turbines, 6.75 Huntly coal stations or 12 Benmore hydros. That’s only while wind speeds stay below half a gale, we’d still need backup thermal generation for when the wind’s too strong or dies down, and there’d still be 90% of our national fleet to convert.
That gives us a working definition of impossible.
United States experience
Now, in Electric Car Owners All Plug In at Once, Scientific American gives the first objective confirmation that Gary was on the right track. If we put too much faith in electric cars, we’ll be brewing a heap of network trouble.
“The utilities are worried that if too many people in a community charge their vehicles at the same time of day, that synchrony would create spikes in power demand that could force the power suppliers to turn on expensive “peak generators” such as gas turbines — costs the utilities would rather avoid, and would ultimately pass on to consumers.”
Experience from a new, “sustainable” community in Austin, Texas, shows that “once 15 to 20 per cent of residents in a neighborhood own electric cars… utilities could have real trouble meeting peak demand.”
If that’s likely in the largest industrial society on the planet, it’s highly likely in ours, too.
What can we do about it? Should we go nuclear and provide all the electricity we could ever want, or wait until battery technology makes some amazing breakthrough, or forget about electric cars and go for hydrogen or fuel cells or something else?
Because one thing’s blindingly obvious: we can’t replace even 10 per cent of our cars with electric versions (quite beside the personal cost) without a substantial investment in electricity generation – which we’re selling off (perhaps we shouldn’t be doing that?).
But it’s all right – the Greens will tell us to plant more windmills.