The world market for electric-powered vehicles is expanding and should grow further in the upcoming years. The number of electric vehicles in the world surpassed the mark of 2 million units in 2016, an increase of 60% over the previous year, according to the International Energy Agency. Although they still represent a small percentage of the world’s fleet, Morgan Stanley’s projection is that by 2030, electric cars make up about 16% of the fleet of vehicles.
The expectation of this growth is largely related to regulatory changes that are being adopted around the world to reduce emissions of pollutants related to global warming and the greenhouse effect. Smoke emitted by vehicles with internal combustion engines is the main cause of pollution in large urban centers and accounts for a fifth of all carbon dioxide emissions, a major greenhouse gas.
The Paris Agreement, an international treaty to combat global warming signed in 2015, set targets for reducing greenhouse gases. Aligned to thes objectives, countries such as the United Kingdom and France have recently announced that internal combustion vehicles will no longer be produced after 2040. Germany, Netherlands and India also announced that they should ban the commercialization of combustion vehicles starting from 2030.
In countries that rely heavily on thermoelectric power, the decrease of pollution promoted by electric vehicles can be compromised, at least in part, by the increase in pollution generated in the production of electricity. In Brazil, there is a very favorable scenario in this sense, since our energy matrix is based on clean and renewable energy, predominantly from hydroelectric sources.
Besides reducing pollution, since electric motors do not emit gases, electric mobility promises to bring other benefits, such as reducing dependence on oil products and, perhaps most noticeably, reducing customer expenses on fuel. According to results released by Emotive, a research project of CPFL Energia, the cost per kilometer of a combustion car is R$ 0.31, while that of an electric vehicle is R$ 0.11, that is, something around three times smaller.
Brazil is also aware of these transformations and the benefits that the introduction of electric vehicles can bring to the country. Of course, in addition to the benefits, there will also be challenges to make this new technology viable. Among these challenges are the impacts that electric vehicles can bring to the electric power system.
Pure and hybrid electric vehicles
Electric vehicles can be classified into pure electric vehicles (vehicles that only have electric motors) and hybrid electric vehicles (which are both electric motors and conventional internal combustion engines).
The pure electric vehicles store energy in banks of batteries that must be recharged through the electric network. Hybrid electric vehicles, on the other hand, can be fueled with conventional fuels (such as gasoline and diesel). In these vehicles, the kinetic energy generated by the motor in the combustion is used to recharge the bank of batteries that feeds the electric traction. The plug-in hybrid electric vehicles also have the possibility of recharging the batteries directly through the electric network.
The recharging of the batteries of an electric vehicle (pure or hybrid plugin) can be done in supplying electricity stations or even in homes. The electrotropics usually use a charging system that allows fast recharge. This type of recharging allows the supply of 80% of the battery charge in 30 minutes. Conventional recharge, which can be done by people directly in their homes, can take more than 8 hours.
The fast-supply station facilities are already being installed in the public supply network, malls and companies. Some roads in Brazil, such as the Presidente Dutra Highway and the Bandeirantes Highway, already have quick supply station facilities.
In addition to the consequent increase in energy demand for battery recharging, the refueling characteristics of electric vehicles (considerably slower than the supply of conventional fuels) should define how people will recharge their vehicles and, consequently, in what way this demand will impact the electricity grid.
Impacts on the Brazilian electrical system
Contrary to the opinion of some experts, recent research results point out that the Brazilian electric system is prepared to absorb the growth of demand for electric power coming from the expansion of the number of electric vehicles in operation in the country.
Studies by CPFL Energia predict that by 2030 electric vehicles in Brazil should account for around 3.8% of the total fleet (both pure electric vehicles and hybrid plugins were included). According to CPFL, considering a share of electric vehicles between 4% and 10% of the fleet, the increase in energy consumption would be between 0.6% and 1.6%. CPFL studies show that this additional load could be absorbed by the capacity of the current electrical system.
CPFL’s research also indicates that the impacts on energy distribution networks would also be small. In the tests made by CPFL, for a penetration of up to 5% of the electric vehicles in the total fleet, 80% of the distribution networks have presented no problem. That is, these distribution networks would not need new investments to meet this new demand.
Increase of demand at peak times
The peak time (or peak hours) of electricity consumption occurs between 18h and 21h. In that period, the electricity consumption is higher than in the rest of the day, as we have more electric charges running simultaneously. In addition to the factories, which continue to operate, in this period we have a greater use of energy in homes and public lighting.
The increase of energy demand caused by the insertion of the electric vehicles can bring risk of overloading the electric system at peak times. i.e., imagine a scenario which all or most people who own electric vehicles, after returningn home from work, put their cars to recharge. This scenario is not unlikely, especially if we consider that the full recharge of the batteries of an electric vehicle can take several hours.
To avoid the high costs of planning the energy infrastructure to meet peak demand, companies may use differential tariffs to encourage users to consume energy outside of that period. In Brazil, the so-called White Tariff already promotes energy consumption outside of peak hours through cheaper tariffs. Currently, the white tariff option is available to consumers with a monthly average consumption of over 500 kWh, but the option will be extended to other consumers.
The use of off-peak differential tariffs allows operators to have some control over the distribution of energy demand, helping to establish a more uniform load throughout the day. This scenario becomes even more interesting when this management demand is performed automatically by the grid.
Smart grids, which have become common around the world and are already being tested in some cities in Brazil, make use of a smart meter. This meter records the consumption of electricity and sends the data directly to the utility through a communication infrastructure. The same communication infrastructure can be used for the company to send data to consumers. This data may contain useful information for the user, such as current energy expenditure. This communication channel can also be used to send control information that promotes actions to increase energy efficiency.
The charging system of the electric vehicles could make use of this mechanism of communication so that the concessionaire could manage the load of the grid. Imagine a scenario in which the customer connects his/her electric vehicle to a fueling terminal (which could be in his/her home) and triggers an economical charging option. In this charging mode, the consumer would be authorizing the concessionaire to carry the load of the vehicle at the most appropriate time, and in return, the energy tariff would be cheaper.
This concept has been called smart charging and can allow the management of utility demand for electric vehicles by companies. For customers, it would also be interesting, since they would not need to directly control the refueling of the vehicle.
Another challenge that companies should face in the coming years is the imbalance of the network caused by the growth of distributed energy sources, such as solar and wind. These energy sources are typically intermittent, that is, they are not able to generate energy evenly throughout the day. For example, photovoltaic cells generate energy only during the day. Thus, at the end of the day, at the moment of peak demand, the companies can not count on the generation of solar energy. This problem should increase in the coming years, as there is greater participation of distributed generation in the electric system.
One possible solution to the problem would be for utilities to invest in energy storage technologies, for example using battery banks. In this way, the energy generated by these intermittent energy sources could be stored for use in times of increased demand.
In this scenario, electric vehicles can be understood as a huge bank of batteries for storing solar and wind energy. This concept is known as V2G (Vehicle to Grid) and has been studied around the world as an alternative for utilities to bring more stability to the power grid. With this technology, owners of electric vehicles could recharge batteries during periods of low demand and subsequently resell the power to the grid in periods of peak demand. For users, this would represent an opportunity to further reduce the cost of refueling electric vehicles.
The Brazilian government recently presented the approval of the “Rota 2030” program, which will bring new incentives to enable the introduction of electric vehicles in Brazil. In addition to tax incentives for the import and manufacture of electric cars, the program should also promote research and development of new technologies in the sector.
Companies and concessionaires in the electric power sector should also continue to invest in research to better understand the impacts of these transformations in the electric power sector, as well as to the maturation of technologies such as smart charging and vehicle to grid that still need to be developed.
Electrical mobility, along with other trends such as the distributed generation of wind and solar energy, is one more factor that must change the panorama of the electric system in the near future, bringing opportunities and challenges for the companies and companies of the sector.
- International Energy Agency: Global EV Outlook 2017 (link)
- Morgan Stanley, Batteries May Power the Future of Auto Industry (link)
- FGV: Recarga de veículos elétricos: o que esperar quando o combustível dos nossos carros for a eletricidade? (link)
- CPFL: Veículos elétricos trazem economia de até 84% nos gastos com combustível (link)
- CPFL Energia propõe criação de estratégia nacional para impulsionar crescimento de mobilidade elétrica no Brasil (link)
- CPFL Energia e Rede Graal instalam novo eletroposto para veículos elétricos na Rodovia dos Bandeirantes (link)