Question

while researching a topic, a student has taken the following notes:

• vanadium redox flow batteries (vrfbs) store energy in external tanks of liquid electrolytes rather than in solid electrodes.
• standard lithium - ion batteries often degrade after 1,000 to 5,000 charge cycles, losing significant capacity over time.
• vrfbs can be cycled tens of thousands of times over 20 years with virtually no loss in storage capacity.
• because the energy is stored in liquid tanks, vrfbs are much easier to scale up; one simply needs larger tanks to increase the amount of energy stored.
• a drawback of vrfbs is that they are much bulkier than lithium - ion batteries, making them unsuitable for mobile devices like phones.
• vrfbs are increasingly used for \grid - scale\ storage, helping to stabilize energy flow from wind and solar farms.

27 mark for review
the student wants to explain an advantage of vrfbs for large - scale energy storage. which choice most effectively uses relevant information from the notes to accomplish this goal?
a vrfbs are advantageous for large - scale energy storage because their compact size makes them ideal for use in mobile devices while also supporting long - term grid applications.
b unlike lithium - ion batteries used in mobile devices, vrfbs store energy in external liquid tanks rather than in solid electrodes.
c vrfbs are less prone to degradation than lithium - ion batteries, but they are too bulky for use in small electronics.
d vrfbs are ideal for stabilizing wind and solar farms because they can be easily scaled up by increasing tank size and can last for decades without losing capacity.

Explanation:

To determine the best choice, we analyze each option:

• Option A: Claims VRFBs have a compact size, but the notes state they are bulkier than lithium - ion, so this is incorrect.
• Option B: Only mentions the energy storage method, not an advantage for large - scale energy storage.
• Option C: Focuses on their bulkiness (a drawback) and not an advantage for large - scale storage.
• Option D: Combines two relevant points from the notes: they can be easily scaled up (by increasing tank size) and have a long lifespan (last for decades without losing capacity), which are both advantages for large - scale energy storage (like stabilizing wind and solar farms).

Answer:

D. VRFBs are ideal for stabilizing wind and solar farms because they can be easily scaled up by increasing tank size and can last for decades without losing capacity.