The choice for eletric cars na pencil tip

Novel models evaluate economic scenarios and the costs of ownership and generation of solar energy.

Finding electric cars on the streets has become increasingly common in Brazil. In 2025, more than 223 new electric or hybrid vehicles were sold, according to data from the Brazilian Electric Vehicle Association (ABVE). The increase recorded in the last ten years is impressive: more than 26.000% — in 2015, only 846 new electric vehicles were registered. Several factors contributed to this... treeAmong these factors are the entry of the Chinese company BYD into the national market, encouraging other automakers to invest in the sector, increases in fuel prices, the expansion of vehicle use for work, such as in app-based transportation, and incentives for electricity generation.

Even with their virtuous growth, electric cars still seem a mystery to consumers—if not the vehicles themselves, then the various factors that influence the choice. First comes the price, as the cheapest car currently in the country, the Renault Kwid e-Tech, costs R$ 100, a still high price—currently, the cheapest combustion engine models on the market are around R$ 75. Maintenance costs, resale value, and probably the main question—whether swapping gas stations for charging stations or using a garage outlet is a more economical option—also come into play.

A doctoral research study conducted at the Faculty of Mechanical Engineering (FEM) of Unicamp, in partnership with the Instituto Superior Técnico of the University of Lisbon, concludes that, in many cases, it is worthwhile to switch from combustion engine vehicles to electric vehicles. Some contexts prove more advantageous than others, especially when the owner is able to recharge at home, taking advantage of the benefits of distributed microgeneration of photovoltaic solar energy, that is, when the consumer generates their own electricity through solar panels. To evaluate the different scenarios, Nathalia Hidalgo Leite, author of the study, developed mathematical models to calculate the interference of various factors, both in the cost of vehicle ownership and in the generation of electricity. The thesis was supervised by professors Luiz Carlos Pereira da Silva, director of the Paulista Center for Energy Transition Studies (CPTEn) at Unicamp, and Hugo Gabriel Valente Morais, from the University of Lisbon, and co-supervised by Cindy Paola Guzman Lascano, from the Institute of Computer Systems Engineering (INESC-ID), in Lisbon.

How much?

This study relates two distinct but complementary analyses: the viability of photovoltaic solar systems, considering different credit compensation rules for consumers, and the attractiveness of electric vehicles compared to combustion-powered vehicles, through the calculation of the total cost of ownership (TCO). The models also took into account possible economic variations and subsidies for the sectors. The conclusion is that even with lower compensation to consumers for the photovoltaic energy generated, the TCO of electric vehicles varies little, ranging from a 1,8% reduction to a 6,3% increase in its cost of ownership.

Until 2023, consumers who generated photovoltaic energy received 100% compensation. With Law 14.300/2022, it was established that the compensated amount would be progressively reduced, causing the financial return on investment to fall by an average of 5,77%. "What changed was the period of..." payback"The return on investment time has lengthened. However, it remains a viable option," explains the engineer. According to Leite, recent changes in the electricity sector should not impact the long-term choice of electric vehicles. According to the research, other factors have a greater influence on the TCO calculation in Brazil. "Most combustion engine vehicles in Brazil today are flex-fuel, making it possible to fuel them with ethanol as well. This was taken into account in the mathematical models," she details.

Considering four vehicle categories—entry-level, compact, mid-size, and luxury—and the various compensation rules, the researcher outlined 23 scenarios comparing the Total Cost of Ownership (TCO) of electric and combustion vehicles. In 12 of these scenarios, there was a tie; in two, the cost of electric vehicles was higher; and in nine scenarios, combustion vehicles had a higher TCO. Among the different factors, the one that most impacts the TCO calculation for electric vehicles is the initial value of the vehicles, especially compact ones.

Leite highlights aspects specific to the Brazilian context that should be considered in studies of this type and that show how much energy recharging conditions affect the cost. One of them is the still reduced number of charging stations in the country. ABVE counts 16,8 charging stations, a ratio of 20,9 vehicles for each station. “With the growing demand from people buying electric and hybrid vehicles, the price [of energy] at charging stations tends to be higher.” Another factor is cultural: according to the researcher, studies in the area show that few owners of hybrid vehicles... plug-in — which allow for refueling and recharging — have a habit of recharging them. “Most of the time, they are carrying extra weight on the batteries and consuming more fuel because of it. That's not efficient,” he comments.