Things you know that ain’t so” – electric cars

Breaking Views | 2 April 2015

“Things you know that ain’t so”: “electric cars have a bright future”

No. The reality is that electric cars are a solution in search of a problem. Electric cars exist because they have attract large subsidies for their development and for tax rebates and grants on the sale price. The subsidies paid in the USA, UK, Germany, Norway and other countries are costing taxpayers billions of dollars.

Governments decided to subsidise electric cars because they had been told that they could lead to a substantial reduction in carbon dioxide emissions, they would reduce air pollution in cities and they would conserve our dwindling supply of fossil fuels.

On the carbon markets, carbon credits can be bought for $7.50 per tonne and substantial savings can be made at no cost at all simply by switching from coal to gas-fired generation or by encouraging nuclear power. Emission savings arising from electric cars cost more than $1000 per tonne.

Most electric cars are in countries where coal and gas-fired generation provides a large proportion of the demand. The additional demand of every electric car is met by increasing the output of these-stations. On average, US power stations produce about 700 g kg of carbon dioxide per kWh generated. A typical electric car uses 44 kWh/100 miles producing about 42 kg of CO2 while a typical petrol driven car uses 3.8 gallons/100 miles and emits 34 kg of carbon dioxide. So, in the US at least, electric cars increase carbon dioxide emissions. (These calculations are based on information from the US Environmental Protection Agency.)

Electric cars can cause serious problems with electricity supply. In general, most people will charge them when they get home from work and this is will substantially increase the household electricity demand over the critical system peak demand period. In the USA, where each transformer supplies four or five houses, a couple of electric cars could burn out the distribution transformer.

Some people claim that the electric car batteries could be used to support the grid during peak demand periods. Peak demands occur in the early evening in colder regions when the battery will be significantly discharged and in the early afternoon in hotter regions  when the car is unlikely to be parked at home. The cost of battery storage is also high because, for instance, a Nissan Leaf battery stores 24 kWh, costs $15,000 and lasts for about 1000 charge/discharge cycles. The cost of one cycle is $15 or 62 cents/kWh – three or four times the cost of power from the US grid.

So we are left with the fact that their only substantial advantage is the reduction in emissions. But, as motorcars become cleaner and cleaner their emissions reduce to harmless water vapour and vegetation enhancing carbon dioxide. So even that advantage is small and declining.

In spite of government encouragement and subsidies and the fact that many people regard the ownership of an electric car is evidence of their “clean and green” credentials, the uptake of electric cars has been very slow. In the US, it was predicted that 1 million would be on the road by now: the actual figure is about 200,000. Most of them are in the warmer south and west because heating electric cars is a heavy drain on the battery.

It is highly likely that when the day comes that you can use your cell phone to call up a driverless shuttle car to provide personal transport it will be electrically driven because it will be quiet, reliable, convenient and it can take itself to the nearest recharging station whenever necessary.

So, as with almost everything involved with the belief that man-made carbon dioxide causes dangerous global warming, the huge subsidies for electric cars are based on bad science, even worse economics and place a large extra burden on the hapless taxpayer and electricity consumer.

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