Electric cars are already a reality in our streets, however, we are still confronted by doubts when we think about buying or to renting one. How much will my car consume during the journey? How much will it cost me to charge the batteries?

First of all, it is important to know that the majority of factors affecting the consumption of an electric car are exactly the same as those which affect any other car: those related to its own shape and technology and others related to external road factors and your own driving style. The difference with conventional vehicles is that instead of talking about litres, we talk about kWh.

 

Electric car models

We will start by analysing the most popular models currently on the market, obviously in the knowledge that it would not make sense to compare the consumption of a Smart ED with the consumption of a BYD e6 without bearing in mind that one is a small, lightweight vehicle and the other is comparable to a large SUV. Some manufacturers have made enormous efforts to reduce the weight of their electrical vehicles and improve the performance of the batteries and engine, for example the new Renault model, the ZOE 240. Also noteworthy is the work BMW have put into developing their electrical version of the i3, its sleek outline, designed with light materials like carbon fibre contribute to significantly reducing the energy consumption without diminishing safety.

The theoretical consumptions of the following electric cars in test conditions are:

  • BMWi3 -12, 9kWh / 100km
  • Renault ZOE 240 -13, 3kWh / 100 km
  • Renault ZOE – 14, 6kWh / 100km
  • Nissan Leaf – 15kWh / 100km
  • Smart ED -15, 1kWh / 100km
  • Tesla Model S 85 kW -16, 9kWh / 100km
  • BYD e6 -20, 5kWh / 100km

The real consumption, other than in test conditions, average 30-35% more than those indicated by the European Cycle (NEDC).

 

What factors affect the consumption of electric cars?

We would like to emphasise the influence of external factors on consumption. The orography, the speed, the driver’s style and the use of the air-conditioner are all factors which make a difference to the consumption of electric cars. In contrast to conventional cars, electric vehicles are able to non-consume or even generate energy when braking or descending. We will not go into the details of efficient conduction now, but it is an important feature to bear in mind because although we can talk about average consumptions in real conditions, when we plan a route which includes undulating terrain or high-speed motorway driving, we need to be more prudent in our forecasts.

To avoid high consumption, especially on motorways, many manufacturers have chosen to limit the maximum speed of their electric models, for example the BMWi3 is limited to 150km/h and the Nissan Leaf to 145km/h. This, however, is not the case of the Tesla factory, whose Model S, for example, allows speeds of up to 250km/h with a similar philosophy to that of a sports car.

 

How much does it cost to charge the batteries?

Now that we have looked at the influencing factors on consumption, when considering the most popular electric cars on the market, we might conclude that the average consumption of an electric car would be between the 16kWh/100km and 25kWh/100km depending on the model. These theoretical calculations are confirmed by users, although most people who become accustomed to driving an electric vehicle, considerably reduce their consumption thanks to a more efficient driving style.

If we take into account that battery charging has approximately 90% efficiency, we arrive at electrical consumption figures of 18-27 kWh/100 km. This data demonstrates that the cost of an electric car at the current price of energy would be around 3€/100 km at standard rates, going down to 1€/100km with special fares which would be expected for consumers who have a charging point.

Remember this data!

In our next post we will talk about the autonomy of electric cars, or in other words: Am I going to reach my destination?