Vehicle-to-grid (V2G) concept in EV Technology - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the sentence to explain what V2G means.

EV Technology

Vehicle-to-grid (V2G) is a system where electric vehicles can [1] energy back to the power grid.

Drag options to blanks, or click blank then click option'

Asend

Bbuy

Cstore

Dignore

Attempts:

3 left

💡 Hint

Common Mistakes

Confusing V2G with just charging the vehicle.

V2G allows electric vehicles to send energy back to the grid, helping balance electricity supply.

2fill in blank

medium

Complete the sentence to describe a benefit of V2G.

EV Technology

One benefit of V2G is that it helps [1] the demand on the power grid during peak hours.

Drag options to blanks, or click blank then click option'

Adelay

Breduce

Cignore

Dincrease

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'increase' because it sounds like adding energy, but V2G actually helps reduce strain.

V2G helps reduce the demand on the power grid by supplying stored energy during busy times.

3fill in blank

hard

Fix the error in the description of V2G operation.

EV Technology

In V2G, electric vehicles only [1] energy from the grid and cannot return it.

Drag options to blanks, or click blank then click option'

Aignore

Bsend

Creceive

Dstore

Attempts:

3 left

💡 Hint

Common Mistakes

Selecting 'send' because it fits the sentence but makes it incorrect.

The statement is incorrect because V2G allows vehicles to both receive and send energy back to the grid.

4fill in blank

hard

Fill both blanks to complete the V2G energy flow description.

EV Technology

Electric vehicles [1] energy from the grid when charging and [2] energy back during high demand.

Drag options to blanks, or click blank then click option'

Areceive

Bsend

Cignore

Dstore

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up 'send' and 'receive' in the blanks.

Vehicles receive energy when charging and send energy back to the grid during peak demand.

5fill in blank

hard

Fill all three blanks to complete the V2G dictionary comprehension example.

EV Technology

v2g_status = { [1]: [2] for [3] in vehicles if [2].battery_level > 20 }

Drag options to blanks, or click blank then click option'

Avehicle.id

Bvehicle

Dvehicles

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'vehicles' as the loop variable instead of 'vehicle'.

Using 'vehicles' as a key or value incorrectly.

This dictionary comprehension creates a mapping from each vehicle.id to the vehicle object for all vehicles with battery level above 20.

Practice

1. What is the main purpose of the Vehicle-to-grid (V2G) concept?

easy

A. To replace gasoline engines with electric motors

B. To increase the speed of electric vehicles

C. To allow electric vehicles to send energy back to the power grid

D. To reduce the size of electric vehicle batteries

Solution

1. Step 1: Understand V2G basic function

   V2G technology enables electric vehicles to interact with the power grid by sending energy back when needed.

2. Step 2: Identify the main goal

   The goal is to help balance electricity supply and demand by sharing stored energy from vehicles.

3. Final Answer:

   To allow electric vehicles to send energy back to the power grid -> Option C

4. Quick Check:

   V2G = energy sharing with grid [OK]

Hint: V2G means cars give energy back to the grid [OK]

Common Mistakes:

• Thinking V2G is about vehicle speed
• Confusing V2G with battery size reduction
• Assuming V2G replaces engines

2. Which of the following is a correct statement about when V2G works best?

easy

A. When cars are parked and plugged in for long periods

B. When cars are moving at high speeds

C. When cars are running on gasoline

D. When cars are charging wirelessly while driving

Solution

1. Step 1: Recall V2G operation conditions

   V2G requires cars to be connected to the grid, which happens when parked and plugged in.

2. Step 2: Identify the best scenario

   Long parking and plugged-in times allow cars to send energy back without interrupting driving.

3. Final Answer:

   When cars are parked and plugged in for long periods -> Option A

4. Quick Check:

   V2G needs plugged-in parked cars [OK]

Hint: V2G needs plugged-in parked cars, not moving ones [OK]

Common Mistakes:

• Thinking V2G works while driving
• Confusing wireless charging with V2G
• Assuming gasoline cars can do V2G

3. Consider this simple code snippet representing V2G energy flow:

energy_in_car = 50  # kWh
energy_needed_by_grid = 30  # kWh
energy_sent = min(energy_in_car, energy_needed_by_grid)
energy_left = energy_in_car - energy_sent
print(energy_sent, energy_left)

What will be the output?

medium

A. 20 30

B. 50 0

C. 30 50

D. 30 20

Solution

1. Step 1: Calculate energy sent to grid

   Energy sent is the smaller of energy in car (50) and energy needed by grid (30), so 30 kWh.

2. Step 2: Calculate energy left in car

   Energy left = 50 - 30 = 20 kWh.

3. Final Answer:

   30 20 -> Option D

4. Quick Check:

   min(50,30)=30; 50-30=20 [OK]

Hint: Energy sent = smaller value; leftover = difference [OK]

Common Mistakes:

• Swapping energy sent and left values
• Using max instead of min function
• Subtracting in wrong order

4. This code tries to calculate energy sent from car to grid but has an error:

energy_in_car = 40
energy_needed = 60
energy_sent = max(energy_in_car, energy_needed)
print(energy_sent)

What is the error and how to fix it?

medium

A. Change variable names to avoid conflict

B. Use min() instead of max() to avoid sending more energy than available

C. Add a loop to repeat energy sending

D. No error, code works fine

Solution

1. Step 1: Identify the problem with max()

   max(40, 60) returns 60, which is more than energy available (40), causing wrong output.

2. Step 2: Correct function choice

   Use min(energy_in_car, energy_needed) to send only available energy or what is needed, whichever is less.

3. Final Answer:

   Use min() instead of max() to avoid sending more energy than available -> Option B

4. Quick Check:

   min() limits energy sent correctly [OK]

Hint: Use min() to limit energy sent to available amount [OK]

Common Mistakes:

• Using max() causes sending too much energy
• Ignoring variable meaning
• Assuming no error in logic

5. A city wants to use V2G to support renewable energy by storing excess solar power in electric cars during the day and sending it back at night. Which of these is the best strategy to maximize V2G benefits?

hard

A. Encourage car owners to park and plug in cars during daytime solar peak hours

B. Require cars to only charge at night when solar power is low

C. Limit V2G use to only emergency power outages

D. Use V2G only for fast charging while driving

Solution

1. Step 1: Understand renewable energy timing

   Solar power peaks during the day, so storing energy then is ideal.

2. Step 2: Match V2G usage to solar availability

   Having cars plugged in during daytime allows storing excess solar energy to send back later.

3. Step 3: Evaluate other options

   Charging only at night misses solar peak; limiting to emergencies reduces benefits; fast charging while driving is not V2G.

4. Final Answer:

   Encourage car owners to park and plug in cars during daytime solar peak hours -> Option A

5. Quick Check:

   Plug in during solar peak = max V2G benefit [OK]

Hint: Plug in cars during solar peak to store energy [OK]

Common Mistakes:

• Charging only at night misses solar energy
• Using V2G only in emergencies limits impact
• Confusing fast charging with V2G