Author: Megan Ouyang
Introduction:
Since we were young, we’ve seen movies, TV shows, and books set in futuristic worlds with technology that seem a whole universe away. And yet, those ideas are much closer than we believe! As Tesla improves on their self-driving and electric cars, other brands move forward to join the race and put forth their own electric cars. This brings up the question: what will transportation look like in the future?
To fully understand the impacts, we must first understand how electric cars work and weigh the pros and cons of using them.
How do electric vehicles work?
Electric Vehicles (EVs) run on electricity instead of gasoline. They get their power from charging stations or units and storing that energy in a battery. This energy is then harnessed to power motors that turn the wheels. EVs contain 90% less parts than an ICE (Internal Combustion Engine) vehicle. Let’s explore some parts of electric vehicles:
Battery (all-electric auxiliary)
Stores AC (alternating current) power.
Made of cells grouped into modules.
A traction battery pack stores electricity to be used by the electric traction motor
Inverter
Converts DC (direct current) power to AC power used by motor
Can change speed at which motor rotates by adjusting AC frequency.
Can also increase or decrease power or torque of the motor by adjusting signal amplitude.
Electric Traction Motor
Power to rotate wheels
DC/AC types both exist, but AC is more common
Transmission (electric) transfers mechanical energy from the traction motor to power the wheels
Some vehicles use motor generators to do drive and regeneration functions
Controller
Manages all the parameters
Controls the charge rate, using battery info
Adjusts speed in the inverter by translating pressure on the accelerator pedal
Controls speed and torque of the motor
Battery Charger
Converts AC power to DC power to be stored in the battery
Controls the battery cells’ voltage level by adjusting the charge rate
Monitors the temperature, voltage, current, and state of the cells
Charging Cable
Used for charging.
Three different types of chargers: three pin plug, socketed, and tethered
Charge Port
Charges the battery pack by connecting to an outside power source
Thermal System
Maintains proper temperature of all the parts of the vehicle
There are a few different types of electric cars. Pure electric vehicles run solely on electricity while hybrid electric vehicles can also run on gasoline. Plug-in electric vehicles run only on electricity and get all of their power from charging, so they don’t produce any emissions since they don’t need any gasoline.
Plug-in hybrids run mainly on electricity, but have a fuel engine (so they can run on gasoline). When the car runs out of charge, it switches to gasoline. It will produce emissions, but only when running on gasoline. Hybrid-electric vehicles run mainly on fuel but have a battery which can be recharged through regenerative braking, which is where the car converts and stores thermal energy from the brakes and tires’ heat friction to be reused in powering the car.
Now that we’ve covered some of the basic knowledge about electric vehicles, it’s time to look at the advantages and disadvantages of using them.
Disadvantages of Electric Vehicles:
Even though electric vehicles are better for the environment than gas-powered vehicles when they’re running, they typically use lithium-based batteries. These batteries require raw materials like cobalt and other rare earth metals, which are linked with serious environmental and human rights issues. Extracting metals from ores requires a process called smelting, which can produce sulfur oxide and other harmful air pollutants. Making these batteries also takes a lot of resources, sometimes even taking away from the people who live around the area.
Because of the cost of making the battery, EVs are considerably more expensive than traditional cars. Buyers might pay at least $10K more for an electric car than they would for the same type in a gas model.
Recharging the vehicle takes time as well. Filling up a gas tank might take up to three minutes, but recharging can take up to 20 hours to fully charge. Newer models may take less time but it’s still a good amount greater than the three minutes. In addition, EVs have a shorter range than traditional cars. They can get between 60-100 miles on full charge, while some gas-powered cars can make up to 400 miles on a full tank of gas.
Advantages of Electric Vehicles:
Although EVs still need to be improved a great amount, they provide many benefits already. In comparison to traditional cars, EVs have a near-instant torque, or turning force, so they have faster acceleration and a “lighter” feel than traditional cars, making them quieter as well. Because EVs don’t need gasoline, they don’t have any of the parts associated with gasoline like the fuel tank, pump, or tailpipe, and they don’t emit any pollutants while running. This can help us have fewer greenhouse gases and cleaner air. Electricity can be renewable, but gasoline cannot. We can power EVs naturally by renewable resources like solar, wind, and water.
EVs require less frequent maintenance. Without the necessity of fuel, this means no oil changes and no need for maintenance associated with a traditional engine. EVs are also easier on brakes, so there’s less brake replacements. EVs are also more efficient than traditional vehicles. They minimize wasted energy by turning off the car when stopped (“idle-off”) and charging the battery when braking (“regenerative braking”). All-electric vehicles convert over 77% of energy from grid to power vehicle. On the other hand, gas-powered vehicles only convert about 15% of energy in gasoline.
Conclusion:
As technology further develops, people will rush to get the newest and improved versions of things. Transportation is, and always will be, an important part of people’s lives. It’s also necessary for us to understand the appliances we use and if they’re worth it.
Electric vehicles still have a ways to go before they replace traditional gas-powered vehicles, but automakers have already made long strides in that department.
Author: Megan Ouyang
Megan is a rising junior in high school. She’s interested in biology, engineering, computer science, and psychology. In her free time, she loves to bake, draw, play tennis, and spend time with her friends and family.
References
1. Hearst Autos Research. “Electric Cars: Pros and Cons.” Car and Driver, 2021, https://www.caranddriver.com/research/a32758614/electric-cars-pros-and-cons/. Accessed 20 March 2021.
2. Lane, Charles. “Opinion: Electric vehicles won’t fix our carbon dilemma without some hard choices along the way.” The Washington Post, 16 March 2021, https://www.washingtonpost.com/opinions/electric-vehicles-wont-fix-our-carbon-dilemma-without-some-hard-choices-along-the-way/2021/03/16/c8759c6a-8665-11eb-bfdf-4d36dab83a6d_story.html. Accessed 20 March 2021.
3. Moses, Marta. “How do electric cars work?” Energywise, 8 January 2020, https://www.edfenergy.com/for-home/energywise/how-do-electric-cars-work#:~:text=Electric%20cars%20function%20by%20plugging,they%20feel%20lighter%20to%20drive. Accessed 20 March 2021.
4. Sustainable Energy Authority of Ireland. “How Electric Vehicles Work.” Electric Vehicles, 2020, https://www.seai.ie/technologies/electric-vehicles/what-is-an-electric-vehicle/how-electric-vehicles-work/. Accessed 20 March 2021.
5. Tabuchi, Hiroko, and Brad Plumer. “How Green are Electric Vehicles.” The New York Times, 2 March 2021, https://www.nytimes.com/2021/03/02/climate/electric-vehicles-environment.html. Accessed 20 March 2021.
6. U.S. Department of Energy. “How Do All-Electric Cars Work.” Alternative Fuels Data Center, https://afdc.energy.gov/vehicles/how-do-all-electric-cars-work. Accessed 20 March 2021.
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