Is Tesla's Model S really a 'greener' alternative?

London - They are marketed as being among the world’s most environmentally friendly vehicles.

But Teslas may be as bad for the planet as their petrol and diesel equivalents, it was claimed recently. Analysts found the amount of greenhouse gas used in building a Tesla and generating the electricity to charge it was no different to that generated by building and running petrol cars.

Battery-powered cars such as the Tesla are charged with electricity from power stations, and half of Britain’s power comes from coal and gas. Even more so in a coal-dependent country like South Africa.

Tesla disputed the research by Engaged Tracking, a London-based firm that analyses the sustainability and green credentials of companies for potential investors.

Studies in the US had suggested its cars were greener than petrol or diesel equivalents – if measured over the life cycle of the vehicle.

But Engaged Tracking analysed the amount of greenhouse gas generated in building and running a Tesla Model S.

Its chief analyst Jonathan Harris told the Sunday Times: "Teslas are not cleaner to run than the average car in the UK. The annual emissions of a UK car is 1.5 tons of carbon dioxide, based on an average of 12 550km a year.

"Both the Tesla Model S vehicles we analysed have the same emissions as an ordinary petrol car of 1.5 tons of CO2 per year." Mr Harris said the BMW i3 electric car, which is smaller, had an annual emission equivalent of 1.3 tons of CO2, making it 15 percent more efficient than the Tesla Model S. Tesla said the comparison between the Model S and an average car was not fair, because the Tesla was much larger.

A comparison between the Model S and an equivalent vehicle, the Mercedes S-Class S500, showed the Mercedes produced nearly 300 percent more emissions, the firm claimed.

Tesla insisted its smaller car, the Model 3, was a more appropriate comparison to the BMW i3, and said it was 15 percent more efficient than that.

A spokesman said: "The Engaged Tracking data has been cherry-picked, and is not a valid analysis to demonstrate the cleanliness and efficiency of the Model S. It makes no sense to compare Model S to the average annual emissions figure for cars in the UK, because that average includes a lot of smaller models that are dissimilar to Model S.

"Any fair analysis shows that electric vehicles like Model S and Model 3 generate far less CO2 per mile than any comparable gas-powered car."