Hi Doctor Diesel.
Just a few ramblings from me about the economics of electric cars! Many of the electric cars have quoted running costs of about 5p per mile for electricity (4.75p before tax) when charged from home. My petrol MINI First costs are 11.24p per mile including fuel tax, or 4.28p per mile if you take the tax off. A Renault Zoe costs 11.31p per mile for a 10,500 miles a year contract, plus the cost of electricity. Finally, Mercedes-Benz says that 72.6kWh of electricity are needed to put 63kWh into an EQC battery. Now the questions! Do car magazines quote electricity used by the vehicle, or the amount used to charge the battery, as it seems there could be a 15 per cent difference. How long before the government find a way to charge a tax on car charging ñ I have read that smart meters could facilitate this. If you take the environment out of the equation, the only financial benefit of electric cars is due to little or no taxation, with PHEVs even more so!
How very perceptive of you! Not many people bother to explore the taxation rip-off of diesel and petrol prices. An untaxed 50p litre of diesel costs you £1.30 at the pumps. Not that this seems to dissuade quite a lot of people driving like morons and wasting fuel though! By the way, from your calculations, I deduce that you are getting 53 to 55mpg from your petrol MINI ñ not bad!
To your questions: In fact many electric cars are advertised as delivering as little as 3p a mile, which may be somewhat over-optimistic. Enough cars have been tested in real motoring to suggest that smaller EVs will cover 4 miles on a kWh, in favourable weather conditions, larger EVs maybe only 3 miles. This only applies to the modest mainstream pure EVs, and bigger and heavier machines like Teslas, and the Jaguar I-Pace. drop to more like 2.5 miles per kWh.
But you asked how magazines measure the electricity used. Some do actually measure the charge energy, rather than the used energy, which as you correctly point out could show as much as a 15 per cent difference, depending on where you are actually measuring the energy input ñ i.e. which side of the necessary AC/DC transformer. It has been quite clearly established that, using a typical 7kW home charger, you will need to pay for 12 to 15 per cent more electricity than the battery actually gains in charge energy. The Mercedes-Benz figures that you quote confirm this, but very few manufacturers have been as honest as them, and tend to gloss over the charging losses. They also gloss over the fact that the faster you charge up, the higher the energy losses, which can be as much as 20 per cent.
We might also wish to consider the likely efficiency of “Grid Connected” EVs, where the grid will take energy out of your battery at times, and then give it back to you later (hopefully before you need to set off with a full charge) where we may imagine the losses then, at say, 15 per cent each charge/recharge… 100 x 0.05, x 0.85 x 0.85 = 61 per cent efficiency, or nearly 40 per cent of the electricity dispersed/wasted as heat.
If you think there may be some cunning plans regarding smart meters, you are entirely on my wavelength. I obviously don’t know what sort of tariffs will develop with time, but this “grid connected” system obviously needs a smart meter that will measure not only what energy you use, but how much they borrow from you, and so on. I have seen some very fancy figures for how much they might pay you to “borrow” a few kWh of your car’s charge, which tends to indicate how desperate the electricity suppliers are to avoid having to build more and more power stations to cope with the demands of electric car charging. But such smart meters would, no doubt, make it quite easy to charge tax on vehicle charging electricity at a different rate from other domestic electricity… and I don’t imagine that it will be cheaper!
I think that “the gaff has been blown” on the fraud of PHEVs that are never, or rarely, charged up. It’s just another case of misguided taxation. I am beginning to think that the issue of global warming versus city pollution was very poorly refereed, in our case by the EU, and has led to this awful situation with diesel car sales. History will not judge governments kindly on this issue. But will history judge a panic conversion to electric road transport any better? Consumers will certainly not judge their governments with any generosity and understanding if, in five to ten years time, they find they are paying as much, or more, of their personal income in personal transport fuel costs, as is more than likely.
Many thanks for your provocative letter!
Best regards, Doc Diesel