Comparison of Well-to-Wheel energy efficiency between combustion vehicles and electric vehicles

The amount of energy required by the transport sector is largely based on fossil fuels, but it is a finite source of energy. The use of these fuels results in the emission of pollutants such as greenhouse gas. As an alternative to reducing pollutants in the transport sector, there is the alternative of replacing the fleet with electric vehicles. However, if the electrical matrix depends on non-renewable energy sources, the objective of reducing pollutants may not be achieved, in addition to interfering with the efficiency of energy use. As a way of evaluating the energy efficiency of different vehicular propulsion, a well-to-wheel (WTW) efficiency analysis was performed considering vehicles with internal combustion engine (ICE) based on gasoline, compressed natural gas, diesel and ethanol. For electric vehicles, hybrid electric vehicles (HEV) operating with gasoline and diesel, and battery electric vehicles (BEV) were considered. As an evaluation tool, calculations with WTW efficiency values were performed. The values referring to the weel-to-tank (WTT) and tank-to-wheels (TTW) stages were obtained from the literature. For the production of electricity, non-renewable sources of energy (natural gas, diesel and nuclear generators) and renewable sources (hydroelectric, solar and wind) were considered. The results obtained indicate that among the ICE category, diesel-powered ICE is the category that has the highest WTW efficiency. In addition, the lowest efficiency of ICE is represented by vehicles powered by ethanol. For electric vehicles, it was observed that the best WTW general efficiency values are obtained when renewable energy sources are used as electrical energy supply to the BEV.