The ecological transition of mobility is the subject of frequent discussions on the many still unsolved problems of the electric car. Among these is the question of how to meet the enormous energy and power needs generated by the recharging of battery-powered vehicles without huge investments in national electricity grids. However, research by the Massachusetts Institute of Technology shows how careful spatial and temporal planning of top-ups would reduce the load on the network. Indeed, MIT researchers argue that iThe renewal of the car fleet towards electricity would not automatically require an upgrading of the power plants for energy production.
Transportation
Politecnico di Milano: “Using technology to solve mobility problems”
by Vincenzo Borgomeo
Two different needs
To fully understand the problem, it is first necessary to distinguish between two different needs. The energy requirements indicates the energy absorbed by the electricity grid over a prolonged and well-defined period of time. The diffusion of the electric car will inevitably increase the national energy needs, but the real problem lies in the power requirement. Indeed, this indicates theenergy absorbed instantly by the network, a demand whose growth could only be satisfied by upgrading existing plants or building new ones. However, the MIT research proposes a strategy aimed at satisfying the greater energy needs of an electric vehicle fleet, without necessarily increasing the demand for instantaneous power.
The study was published in the journal Cell Reports Physical Science and was written by Dr Zachary Needell, from the postdoctoral student Wei Wei and by the teacher Jessica Trancik from the MIT Institute for Data, Systems, and Society. In support of the research also some organizations of the old continent, among which theEuropean Regional Development Fund Operational Program for Competitiveness and Internationalizationil Lisbon Portugal Regional Operation Program and the Portuguese Foundation of Science and Technology. The researchers conducted surveys of the cities of New York and Dallas. In detail, the anonymous recordings of data on board the vehicles were collected, while in parallel surveys were carried out on the population to reconstruct the driving habits and movements of citizens. It was thus possible to reconstruct the number of cars in circulation and the average time of daily use, taking into account the periods of the day and the movements between the various areas: residential, commercial, industrial and administrative.
Mobility
NASA technology to recharge electric cars in 5 minutes
by Dario d’Elia
Smart charging
MIT research describes the reduction of the demand for power from the electricity grid as a priority. In fact, without interventions, drivers would tend to recharge their cars at the same time as the end of the day, overloading the network. It is estimated that this would lead to a 20% increase in power requirements, which would require large investments for the construction of new energy plants. A problem not only of an economic nature, since, even if the new plants produced energy using renewables, this would then be wasted during the other times of the day, as there is no proportionate demand or means of storage. The study of Massachusetts Institute of Technology instead shows how spreading the recharging of cars during the day would help not only to contain the power requirement in the evening, but also to reduce the energy waste of the current network. The research cites the example of solar power plants, but in general also other renewable plants, such as wind and hydroelectric plants, are not always exploited to their maximum capacity. This is because in times when the demand for power is low, as there are no means of storage, the energy produced is wasted. Electric cars could thus be recharged precisely with the energy surplus during the day, avoiding instead adding to the high demand in the evening which would overload the grid.
The study therefore proposes theinstallation of charging stations in workplaces, which moreover could work with slow rather than ultra-fast charging cycles. However, MIT also underlines the importance of home recharging stations, not limited to personal garages, but also in public car parks, shopping centers and various parts of the city. The idea is to avoid a single bulk top-up in the evening, dividing it into several mini-top-ups during the day. A spatial distribution of the columns would therefore help to spread the recharge even over time.
Mobility
Electric cars: Ewiva arrives, the largest high-power charging network in Italy
by Vincenzo Borgomeo
Smart charging
The analysis of Massachusetts Institute of Technology lastly, he proposes a last logistical precaution which would help to contain the increase in the demand for power from the electricity grid. With the aim of managing the critical evening phases, MIT proposes to preset the recharge so that it does not start at the exact moment of inserting the plug. The idea is delayed-start charging to relieve peak demand on the grid, timed to deliver the fully charged vehicle to the driver exactly when he needs it at the start of the next day. Professor Jessica Trancik explains: “It’s essentially about incentivizing people to start charging later. This can be pre-programmed into the chargers. You encourage people to delay the start of charging by a bit, so that everyone is not charging at the same time and the peak demand is dampened.”
A careful distribution of the columns and a temporal planning of the recharge would therefore help to mitigate the impact of an electric car fleet on the network. Not only that, but the cars themselves would also reduce energy waste linked to the unpredictability of renewable sources. Professor Trancik summarizes: “I think one fascinating thing about these discoveries is that, with a strategic approach, you can avoid building physical infrastructure that you would otherwise need. Electric vehicles can alleviate the need for stationary energy storage and it is also possible to avoid expanding the capacity of energy plants, thinking of where to place the columns as a tool to manage demand where and when it arises.
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