Vehicle-to-grid (V2G) concept in Power Electronics - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the sentence to explain what V2G means.

Power Electronics

Vehicle-to-grid (V2G) technology allows electric vehicles to [1] energy back to the power grid.

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

Astore

Bblock

Cignore

Dsend

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'store' because vehicles do store energy, but V2G focuses on sending energy back.

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

2fill in blank

medium

Complete the sentence to describe a benefit of V2G.

Power Electronics

One benefit of V2G is that it helps [1] the electricity grid during peak demand times.

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

Aignore

Boverload

Cstabilize

Ddisconnect

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'overload' which would make the problem worse.

V2G helps stabilize the grid by providing extra energy when demand is high.

3fill in blank

hard

Fix the error in the description of V2G operation.

Power Electronics

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

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

Areceive

Bsend

Cblock

Dignore

Attempts:

3 left

💡 Hint

Common Mistakes

Choosing 'send' which is what the sentence incorrectly claims they cannot do.

The error is that vehicles do not only receive energy; they can also send it back to the grid.

4fill in blank

hard

Fill both blanks to complete the V2G energy flow description.

Power Electronics

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

Cstore

Dblock

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up the direction of energy flow for charging and discharging.

Vehicles receive energy to charge and send energy back to the grid when needed.

5fill in blank

hard

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

Power Electronics

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

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

Avehicle_id

Bcharge_level

Dbattery

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'battery' as a key or loop variable which is undefined here.

This comprehension creates a dictionary with vehicle_id as keys and their charge_level as values, for vehicles with battery level above 20.

Practice

1. What is the main idea behind the Vehicle-to-grid (V2G) concept?

easy

A. Electric vehicles can send stored energy back to the power grid.

B. Electric vehicles only charge from the power grid.

C. Electric vehicles use gasoline to generate electricity.

D. Electric vehicles cannot interact with the power grid.

Solution

1. Step 1: Understand V2G basic function

   V2G means electric cars can both receive and send electricity to the grid.

2. Step 2: Identify correct description

   Electric vehicles can send stored energy back to the power grid correctly states that vehicles can send stored energy back to the grid, unlike the other options.

3. Final Answer:

   Electric vehicles can send stored energy back to the power grid. -> Option A

4. Quick Check:

   V2G = bidirectional energy flow [OK]

Hint: V2G means two-way energy flow between car and grid [OK]

Common Mistakes:

• Thinking V2G only means charging cars
• Confusing V2G with gasoline vehicles
• Assuming no energy flows back to grid

2. Which of the following best describes a key benefit of V2G technology?

easy

A. It prevents electric vehicles from charging during peak hours.

B. It allows electric vehicles to run without batteries.

C. It increases gasoline consumption in vehicles.

D. It helps balance electricity supply and demand on the grid.

Solution

1. Step 1: Identify V2G benefits

   V2G helps the grid by sharing stored energy from vehicles to balance supply and demand.

2. Step 2: Match benefit to options

   It helps balance electricity supply and demand on the grid correctly states this benefit. The other options are incorrect or unrelated.

3. Final Answer:

   It helps balance electricity supply and demand on the grid. -> Option D

4. Quick Check:

   V2G supports grid stability = It helps balance electricity supply and demand on the grid. [OK]

Hint: V2G supports grid by sharing stored energy [OK]

Common Mistakes:

• Thinking V2G removes need for batteries
• Confusing V2G with fuel use
• Believing V2G stops charging at peak times

3. Consider this scenario: An electric vehicle with a 60 kWh battery is connected to the grid using V2G. If the vehicle sends 10 kWh back to the grid during peak hours, how much energy remains stored in the vehicle's battery?

medium

A. 50 kWh

B. 70 kWh

C. 10 kWh

D. 60 kWh

Solution

1. Step 1: Understand initial battery capacity

   The vehicle starts with 60 kWh stored energy in its battery.

2. Step 2: Calculate remaining energy after sending 10 kWh

   60 kWh - 10 kWh = 50 kWh remains in the battery.

3. Final Answer:

   50 kWh -> Option A

4. Quick Check:

   60 - 10 = 50 kWh [OK]

Hint: Subtract sent energy from total battery capacity [OK]

Common Mistakes:

• Adding instead of subtracting energy
• Confusing kWh with kW
• Choosing unchanged battery value

4. A user claims that V2G technology only allows electric vehicles to charge from the grid but not send energy back. What is wrong with this statement?

medium

A. V2G only works with gasoline cars.

B. V2G allows two-way energy flow, so vehicles can both charge and discharge.

C. Electric vehicles cannot connect to the grid at all.

D. V2G prevents vehicles from charging.

Solution

1. Step 1: Review V2G functionality

   V2G means vehicles can both receive energy from and send energy to the grid.

2. Step 2: Identify error in statement

   The claim ignores the 'to-grid' part, which is key to V2G's two-way flow.

3. Final Answer:

   V2G allows two-way energy flow, so vehicles can both charge and discharge. -> Option B

4. Quick Check:

   V2G = bidirectional energy flow [OK]

Hint: Remember V2G means two-way energy exchange [OK]

Common Mistakes:

• Thinking V2G is one-way only
• Confusing V2G with non-electric vehicles
• Believing V2G stops charging

5. A city plans to use V2G technology to reduce peak electricity demand. If 1000 electric vehicles each with 40 kWh battery capacity send back 5 kWh during peak hours, how much total energy is supplied to the grid? What is the main advantage of this approach?

hard

A. 40000 kWh; it prevents vehicles from charging.

B. 20000 kWh; it increases gasoline use in vehicles.

C. 5000 kWh; it reduces the need for extra power plants during peak times.

D. 500 kWh; it only benefits vehicle owners.

Solution

1. Step 1: Calculate total energy sent to grid

   Each vehicle sends 5 kWh, so 1000 vehicles send 1000 x 5 = 5000 kWh.

2. Step 2: Understand main advantage

   Sending stored energy reduces peak demand, lowering need for extra power plants.

3. Final Answer:

   5000 kWh; it reduces the need for extra power plants during peak times. -> Option C

4. Quick Check:

   1000 x 5 = 5000 kWh; peak load reduction [OK]

Hint: Multiply vehicles by energy sent; peak load reduction benefit [OK]

Common Mistakes:

• Multiplying battery capacity instead of sent energy
• Confusing benefits with fuel use
• Underestimating total energy contribution