Even after decades of development, a global market that is already fairly consolidated, and a near-consensus that the future of transportation is electric, the great dilemma of these vehicles still has no easy solution.

Until a little over a decade this was not possible, but today some models guarantee an autonomy equivalent to or even superior to that of “conventional” combustion engine cars. A welcome relief to driver anxiety, who can plan longer trips without fear of being in the middle of the road and with less dependence on charging stations rare in Brazil and still scarce even in developed countries.

The problem is that in order to go further on the same charge, the car needs very large and expensive batteries. In addition to affecting the final price, extra weight requires even more from engines and requires more efficiency. In addition to paying more per kilometer, a more solid mechanical package ends up giving you the privilege of going 600km or more for a luxury car-only fee, at least for now.
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The most “popular” trams – being very flexible in this definition – usually rely on lighter batteries and more efficient kits to make it easier for the consumer, who leaves less money at the dealership and spends less per kilometer.

The cost in this case is to spend more time on the car connected to the charger and, depending on how limited the autonomy is, to leave this beautiful holiday trip with electricity only a dream.

Autonomy or economy?

So what’s the best choice? Go further with the same fee, paying dearly for it, or lighten your pocket with more visits to outlets and exclusive urban use?

The technology being tested in Sweden promises to make this complicated balance equation a thing of the past. After all, why do you need a huge battery if the car can be charged while driving?

Charge on the go, no cables or rails

Don’t worry, these are nothing but “trolleybuses”, electric buses with pantograph booms that rely on cables supported by poles at the top of the track, which have even appeared in some Brazilian cities, but probably due to a lack of flexibility that imposes the need for physical contact with the power grid have never been very successful.

Now the focus is on electromagnetic induction charging, which has been a reality in the world of smartphones for several years and has recently begun to be used in static chargers for electric vehicles.

The test site was a road on the island of Gotland, located in the Baltic Sea between Sweden and Latvia. The 1.6 km section connecting the city of Visby with the regional airport was equipped with a system created by the Israeli company ElectReon Wireless, which inductively charges passing vehicles. Trials with the same technology are also in their early stages in Germany.

The installation, costing 11 million euros, consisted of placing a series of coils under the asphalt, to which electricity is supplied. When an electric vehicle equipped with a compatible coil passes there, its battery is constantly charged.

Initially, the project focused on public transport and taxis, but the goal is to make charging available to all compatible vehicles.

Sweden bets on expanding the model

With one of the highest percentages of electric vehicles in the world in its fleet, the Scandinavian country is really confident in the results and ready to bet big on wireless charging.

By 2025, another 21 km section of the E20 road between Halsberg and Örebro will be equipped with a system similar to the one tested in Gotland, but this time on a permanent basis. The focus will be on encouraging the use of electric trucks to transport goods from the railway station in Hallsberg, one of the most important in the country, to the port of Örebro.

This technology is still in its infancy and has some challenges to solve, but its mass adoption could eliminate the need for large battery modules in electric vehicles, greatly improving their efficiency and leading to significant reductions in manufacturing and marketing costs. A big step in mass production of these vehicles, which are still significantly more expensive than their fossil fuel counterparts.

Is there free lunch?

While the technology issue has already been mastered enough, charging electric vehicles in motion by induction runs into a problem that seems much simpler, but which could bury the possibility of its mass adoption. So far, there is no established way to measure and mainly charge for the consumption of each vehicle.

In a conventional charger, everything is very simple. All you need is a system that ensures that the electrons only go down the cable to the car when the driver pays up front, or measure consumption and charge at the end, like a fuel pump.

In the case of “electric roads”, the process is a little more complicated.

Physicists, forgive me, but it turns out something like a radio station. It is necessary that the coils remain energized at all times, which means that the magnetic field is also available to anyone who wants to use it, in the same way that radio waves can be tuned by any device within its reach, without the station knowing for sure. who is listening.

In Sweden, one of the countries that most encourages the use of electric vehicles, this may be the way it works, but in the rest of the world it may be different.

The Question of Efficiency

Anyone who has ever connected their computer or console to the Internet via a cable to try and improve Internet performance in an online game already knows that going wired is no doubt very convenient, but performance can be impacted.

In a project of the scale of an electric road, this certainly does not leave the minds of engineers.

Find out how induction chargers work and see if they are worth it for you.
We tested three wireless chargers and recorded the results

The good news is that the spacing between the car and road coils allows the current to alternate at the resonant frequency, greatly increasing the transfer efficiency, which can reach over 90% under ideal conditions.

Not only is this more than the average of about 60% achieved by inductive charging in cell phones, which cannot use the “bonus” given by the resonant frequency due to the heat generated, it also outperforms even the use of household wired chargers. .

In theory, everything is perfect, but what about in practice?

The problem is that the real world does not belong to the physics of ENEM, where you can ignore gravity, friction, heat loss and everything that complicates the calculation. These ideal conditions require, for example, perfect alignment between the coils, which is much more difficult to achieve in a moving car than in a telephone on a table.

Another important factor for maximum efficiency is the perfect match between road and car coils, which must have the same resonant frequency. This means setting industry-wide standards that seem almost impossible in the tech world.

Even wired chargers already have many different connectors, making it difficult to share chargers. Attempts to rectify the situation run into the refusal of some companies to adopt a single standard. One of the largest electricity producers in the world, Tesla, for example, uses its own standard in its cars and charging stations.

However, there are adapters on the market today that make systems interoperable, and some regulators are pressuring companies to set a “standard” for the entire industry, so there is hope that the issue will be resolved in the future.

It’s not magic, it’s technology

British writer Arthur C. Clarke, author of several science fiction classics such as 2001: A Space Odyssey, established as his third law that “any sufficiently advanced technology is indistinguishable from magic.” This certainly applies to induction charging.

A car’s battery can be recharged while driving at high speed by touching the ground with just four rubber tires, the infamous insulator. Doesn’t it feel like magic?

Moreover, the pedestrian who eventually crossed this road would not only not get electrocuted, but would probably never think that there was anything different from a normal road on it.

History of the fundamental principle

Although its use for recharging batteries is relatively recent, the phenomenon of electromagnetic induction has been known since the 19th century.

In the 1820s, electromagnetism pioneer Hans Christian Oersted noticed that a conductive wire caused the needles of a compass to move when an electric current was applied. Thus, he discovered the connection between electricity and magnetism, establishing that electric currents can create magnetic fields.

In 1831, Michael Faraday, famous for his Faraday cage, discovered that relative motion between a magnet and a coil was capable of producing an electric current, establishing the principle of electromagnetic induction. His discovery was absolutely fundamental for the development of electronics and is the basis for the production of electricity to this day.

Nikola Tesla, once again claiming his status as a botanist idol, was the main proponent of electromagnetic induction, using a principle very similar to electrical “mains” to control alternating current in a coil and light bulbs connected to another without making any contact. between them. This principle also underpinned one of his major inventions, the three-phase induction motor, which is still in use today.

Source: Elektreon, SmartCitySweden, Business Wire

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