Lithium

Those who saw last night’s report on TV One about the lithium reserves in Bolivia might be forgiven for thinking that this is a magic new energy source that the Bolivian president is sitting on. Describing it as ‘the new oil’ is somewhat misleading.

The application at hand is of course lithium ion batteries, which will be well suited to electric cars. (Though note that it is not the only technology that is possible here – don’t discount super capacitors that are growing ever smaller.) But a lithium ion battery is not a source of energy as such – rather it is a store of energy.  You would have to plug in your electric car, which charges the batteries (in other words, stores the energy that you have taken from the national electrical grid) and then this energy is converted to the kinetic energy of your car as you drive. Now, overall this would be a reasonably efficient process, because you don’t waste energy idling your engine in traffic as with a petrol engine, and your electric car doesn’t pump out nasty gases into the atmosphere (not directly, anyway) thus keeping the city cleaner,  but, you still need to use energy. And where does this energy come from?

In order to accommodate large scale ownership of electric cars, there is going to have to be massive improvements in the electricity distribution grid, and building of new power stations. And where will the energy come from for these power stations?  The easy answer is coal. The nice, clean, greenhouse-gas-free electric car doesn’t look so brilliant after all.  That’s not to say it’s not the way to go, but just don’t let yourself think that because it doesn’t appear to be polluting, that it isn’t. It’s only greenhouse-gas-free if it’s powered by a non-fossil-fuel power station.

N.B. Really efficient energy storage is one thing that is holding back solar power. It’s one thing to have solar panels everywhere, but they will generate the most power on a clear summer’s day, when (in NZ anyway) the power demand is probably pretty low. But on a freezing winter’s night, when you want that power, don’t expect your solar panels to be giving you any. If we can store it effectively, with not much loss, we can get around this problem.

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