Intermittency challenges of wind and solar and one storage solution for each.

• A. Wind and solar are continuous; storage options include nuclear and geothermal.
• B. Wind and solar are intermittent; wind storage example: pumped hydro; solar storage example: lithium-ion battery storage.
• C. Wind energy is intermittent, solar is continuous; storage for wind is flywheels, for solar is molten salt.
• D. Both are non-intermittent; no storage is needed.

Answer: (B)

The main idea here is that wind and solar do not produce a steady, controllable output; their generation varies with weather and time of day, creating intermittency that storage helps balance. For wind, pumped hydro is a classic, scalable solution: when wind is abundant, excess electricity is used to lift water to a higher reservoir, storing energy as gravitational potential. When wind drops, the water is released through turbines to generate electricity, providing several hours of storage and large capacity. For solar, lithium‑ion batteries are a common storage choice because they can quickly absorb daytime excess and release it later in the evening or during cloudy periods, with high efficiency and modular, scalable deployment. The other options don’t fit the scenario as well: nuclear and geothermal aren’t storage methods, solar isn’t inherently continuous, and saying no storage is needed ignores the real-time variability these resources introduce.