Can Electric Cars Convert Kinetic Energy Back into Electrical Energy?

In summary, the conversation discusses the concept of using regenerative braking in electric cars to convert kinetic energy back into electrical energy. The idea is that this would increase energy efficiency, but the experts explain that the extra load of the generator would actually slow down the car and it is not worth the trade-off. They also mention the use of KERS in Formula 1 racing cars and how it is more efficient than traditional brakes. Overall, the conversation concludes that while there are ways to improve energy efficiency in electric cars, it is important to consider the trade-offs and focus on reducing drag instead.
  • #1
hwall95
16
0
Just out of curiosity, electric cars produce movement through converting electrical energy into kinetic via magnetic field and magnets, etc; would it not be possible to convert the kinetic energy back into electrical energy while the car is moving. I know the Law of Conservation of Energy says that all sums of energy must be the same both before and after, but if a generator were to be placed to use the kinetic energy acting upon to car to convert it to electrical energy could you not convert most of the kinetic energy back into electrical energy while the car still moves. Sorry i don't know if I've explained it very well. Basically I am asking unless the generator slowed the rotational force placed upon the axle down how come you can't double the energy?
 
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  • #2
Yes, that is how regenerative breaking works in today's hybrid cars. Except you can't increase the energy, you always get back less than you put in.
 
  • #3
So the act of using the rotational force of an axle like generator slows it down? What about if they were to channel air through a car and use the force and pressure of the air to spin a generator would they be able to recover the kinetic energy spent in moving the car forward and gather it up again? Sorry if i sound stupid, I'm just trying to think of ways that we could like use energy more efficiently.
 
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  • #4
Using a windmill to extract energy from the air passing through/over a car would increase drag, meaning more energy is required to push the car through the air. More energy than you capture with the windmill. There would also be losses in the generator. Overall you are better off not using a wind mill and concentrating on reducing drag.

There are times when you want to slow down. A cars brakes waste all the KE the car has gained by turning it into heat. However instead of brakes you can connect a dynamo to the wheels and collect the energy...

http://en.wikipedia.org/wiki/Kinetic_energy_recovery_system

a.k.a. KERS See also Formula 1 racing cars

The extra load of the dynamo/generator acts like a brake and slows down the car.
 
  • #5
hwall95 said:
So the act of using the rotational force of an axle like generator slows it down? ... Sorry if i sound stupid, I'm just trying to think of ways that we could like use energy more efficiently.
Yes, it slows it down, as does any means of extracting KE. However, it is more efficient than throwing the energy away in the brakes. That is why all hybrid vehicles use the idea.
 

1. How long does it take to fully charge an electric car?

The time it takes to fully charge an electric car depends on several factors, such as the size of the battery, the type of charger being used, and the current charge level of the battery. On average, it takes anywhere from 4-8 hours to fully charge an electric car with a Level 2 charger, which is the most common type found in homes and public charging stations.

2. How often do electric cars need to be charged?

The frequency of charging an electric car depends on the individual's driving habits and the range of their vehicle. Most electric cars have a range of 200-300 miles, so they typically need to be charged every 2-3 days for average daily use. However, some drivers may need to charge their car more frequently if they have a longer commute or use their car for longer trips.

3. Can an electric car be charged at any electrical outlet?

No, electric cars require a specific type of charger, and not all electrical outlets are compatible. Level 1 chargers, which use a standard 120-volt outlet, can be used in a pinch, but they are much slower and less efficient than Level 2 chargers. Level 2 chargers require a 240-volt outlet, similar to what is used for large appliances like dryers, and are the most common type of charger used for electric cars.

4. Is it safe to leave an electric car charging overnight?

Yes, it is safe to leave an electric car charging overnight. All electric cars have built-in safety features to prevent overcharging, and modern charging stations also have safety mechanisms in place. However, it is always recommended to follow manufacturer guidelines and to have a licensed electrician install the charging station to ensure proper safety measures are in place.

5. Can electric cars be charged using renewable energy sources?

Yes, electric cars can be charged using renewable energy sources, such as solar or wind power. Many electric car owners choose to install solar panels at their home to charge their car, reducing their carbon footprint even further. Additionally, some public charging stations also use renewable energy sources to power their chargers.

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