Most people are used to analyzing the economy of a car starting from the calculation of consumption. In the case of fuels of fossil origin (petrol, diesel and LPG) the parameters usually observed are the ratio km/litre or litres/100 km (L/100 km). For methane, on the other hand, the km/kg factor is considered (the theoretical energy yield of 1 kg of methane corresponds to around 1,675 liters of petrol). The advent of electric cars has introduced a new reference unit: kWh/100 km. It therefore becomes important to identify an equivalence criterion between the energy contained in a liter of petrol and that which the battery of an electric car can store.
The American EPA (Environmental Protection Agency) has done this by associating the energy of 3,785 kWh to one gallon of petrol (33,7 litres). That is, 1 liter of petrol contains about 8,9 kWh of energy. At this point it may be interesting to observe the consumption of a widespread model such as the Volkswagen Up, declined according to three different engines. The figures declared by the car manufacturer are respectively 4,3 L/100 km for the 48 kW petrol version, 2,9 kg/100 km for the 50 kW methane version (both values are calculated in the combined cycle) and 14,5 kWh/100 km for the electric configuration with 61 kW power (WLTP standard). The consumption of the model with the battery can thus be converted into 1,6 L/100 km of petrol equivalent.
Moving on to the economic calculation of the aforementioned mileage for the three versions, we obtain these numbers: 6 euros for the petrol model and 2,83 euros with the methane propulsion. For the electrical equipment, on the other hand, multiple refueling options must be taken into account. In the case of recharging via public infrastructure, for example, Enel X offers a rate of €0,40/kWh using AC alternating current. This value drops to around 0,20 €/kWh using a domestic recharging system (taking into consideration a domestic contract residing in the enhanced protection service). It is therefore necessary to shell out 5,8 euros or 2,9 euros. But spending can be further lowered by selecting specific plans from energy operators in the free market, or in the case of self-production of energy through photovoltaic panels, until it becomes free under certain conditions (as occurs with Tesla Superchargers and in shopping centres, for example hypermarkets Iper). Not to mention the lower maintenance costs and tax breaks in favor of battery-powered machines compared to their "cousins" with an internal combustion engine.
However, another element to examine is also the environmental quality of the fuel used to power a vehicle. Electric cars already have a great advantage today: they can in fact be recharged with energy from totally renewable sources. These also represent the main component in the national average mix used for the production of electricity (40,83%), as confirmed by the 2018 GSE report. And the quantity is destined to grow in the future to achieve the objectives set in the NECP (Integrated National Plan for Energy and Climate) for 2030.
In short, similarly to the agri-food sector, in which organic and biodynamic products are causing radical transformations in intensive production chains, electric vehicles can help redesign the energy scenario in the world of transport, making it progressively independent from hydrocarbons. Italian motorists therefore hold the keys to their future in their hands.
