Electric cars already cheaper to own and run than petrol or diesel?

So says the Graun. Indeed it claims an Exclusive: Pure electric cars cost less over four years than petrol or diesel cars in the UK, US and Japan, researchers say, but China is set to lead the market. Quite how it can claim an exclusive when this is based on published research (Total cost of ownership and market share for hybrid and electric vehicles in the UK, US and Japan by KatePalmer, James E.Tate, Zia Wadud and John Nellthorp) is a mystery to me; and anyway I'm pretty sure I've seen similar elsewhere. It is a nice headline and points the way to the future but you won't be shocked to learn that there are a few little details in there to be careful of.

The details are all around the fact that while we're all very interested in money, only evil capitalist scum regard money as the bottom line; we of course care about ecological cost. So we need to notice that Pure electric cars receive a sales subsidy of about £5,000 in the UK and Japan and £6,500 in the US. “The subsidies are reasonably expensive at the moment but they are expected to tail off,” said Tate. He estimates that an electric car such as the Nissan Leaf will become as cheap to own and run as a petrol car without subsidy by 2025. Renault expects this to happen in the early 2020s. Unfortunately it isn't easy to add the £5k onto the chart above; but since they use a depreciation rate of a little under 20%, for a simple approximation, add £1k to the Pure Electric, which still (by eye) leaves it a shade under the Diesel.

Further, its kinda odd that the fuel cost for electric is so much lower than for diesel or petrol. If you ignore nuclear and renewables, then electricity is produced by burning things; burning oil is expensive and falling out of fashion but the cost should be comparable to diesel (within a factor of two, perhaps, in some handy-wavy expectation, mixing in the higher efficiency of large-scale combustion with the losses in power lines). And of course it is; the difference is tax: petrol and diesel in the UK are taxed at about 66% whereas electric is essentially tax free (there's a small carbon tax but I think it is significantly smaller than for diesel) so the diesel cost should shrink for comparability. Of course that's true now. In the glorious future when all our electricity is produced fossil-free the electric regains it's pure advantage; so in a sense this is a pointer to the future.

And the big pale blue elephant in the room is depreciation, which is by far the largest part of the cost for any of the types. This is a real financial cost and a real ecological cost, since it represents the cost of the raw materials to make the car, and the cost of the labour etc. to make it. It is reasonable to suggest that electric will come down in the future, since it is a newer thing; and reasonable to hope that electric cars are fundamentally simpler.

Lastly, there's the things we'd need to add onto the diesel (and to a lesser extent petrol) to be fair: costs of particulates and so on. I don't know what those are, numerically.

Prior art from Brian in 2015: EV costs at a tipping point for un-American countries.