Electric cars (EVs) are generally being marketed as clean, economical, and convenient, and there’s no real cause for argument with most of the promises made at this moment in time, bar the known critical problems with range anxiety. If fossil fuel cars were marketed with range on a full tank as a deal-clincher, the EC official figures for distance on a tank of fuel would be exposed as just as over-optimistic as those for electric cars, and that’s all down to the unreality of the EC test cycles used to derive the range figures.

But other negatives are not being fully appreciated, and we’ve a duty to readers to make them aware of some pitfalls of electric car ownership. Firstly, the current UK government subsidy of £5,000 off the purchase price of plug-in cars isn’t going to last forever – probably not beyond the time when 50,000 grants have been given, or 2017, whichever comes first. When such volumes have been achieved (current pure plug-in sales volumes are still only running at around, 6,700 a year), manufacturers may be able to offer volume manufacture savings, although it’s doubtful that savings of anything like £5,000 a car will surface over the next few years. So new plug-in EV prices are quite likely to rise when the subsidy ends, although the government may feel obliged to create a new scheme if total EV sales are still well below 50,000.

Either way though, the rapid first year depreciation of pure electric cars is a serious matter. Based on figures for a Renault Zoe and Nissan Leaf, you’ll lose around £6,000 over six months and a thousand miles, although you can find plenty of pre-registered very low mileage 2014 cars with huge discounts. But the used electric vehicle market is not good and, if you find that you are not able to live with your electric car for any of a number of possible reasons, your experiment will undoubtedly hit you hard in the pocket.

Then there’s the green factor. Let’s not get too deep into the calculations, but whilst the electricity is indeed totally clean at the point of usage (zero carbon dioxide emissions from the car), the generation of that electricity does create significant carbon dioxide emissions. At present that’s around 400 to 450 grams of carbon dioxide for every kiloWatt hour of electricity. A typical medium sized plug-in electric hatchback will cover around three miles per kWh, making its real life carbon dioxide emissions somewhere around the 85 to 90g/km mark, which is equivalent to a diesel car doing 80mpg plus. Impressive, at city speeds, and great to keep our cities clean, but definitely not the answer for motorway cruising, where the emissions rise rapidly with speed to match (or exceed) those of many diesel cars.

But what about the future of government tax income from motoring? When the government of the time sees plug-in electric cars sales climbing fast, the purchase subsidies will rapidly disappear and government returns from fuel excise duty and VAT will start falling rapidly. Nearly £30 billion is raised annually from road fuel taxation, and it would be totally out of character for any government to look elsewhere than to motorists to replace the disappearing tax income, as diesel and petrol sales decrease. So treating vehicle charging electric power as almost something that you can give away is not something that’s sustainable, and motorists will end up paying the lost taxation in some other way. So electric vehicle purchasers need to be aware then that the current attractive low running costs may not actually be sustainable long-term.

But there is seemingly a severe lack of joined-up thinking at government and industry level. Plug-in electric vehicles are most suitable and environmentally beneficial when used in the urban setting, where range anxiety is far less of a problem, with short low speed journeys and wide availability of charging points. So why are financial incentives for electric vehicles and other alternative fuel car purchases not being focused at town and city residents, and particularly city car rentals, to generate the high volume sales that surely must eventually bring down the purchase costs? Without them, and with the negative effects of lower diesel and petrol prices, wide adoption of alternative power cars could be delayed another decade. The politicians also need to come clean now on how future motoring taxation will be levied, or at least admit that it is inescapable.