Which energy source is most dispatchable due to storage options?

• A. Wind energy
• B. Solar PV
• C. Hydroelectric power with reservoir storage
• D. Biomass energy with small-scale digesters

Answer: (C)

Energy sources that can be stored and released on demand are highly dispatchable. Hydroelectric power with reservoir storage fits this best because water can be kept behind a dam and released quickly to spin turbines, giving fast, reliable control over output. The reservoir acts like a large energy bank, enabling rapid ramp-up for sudden load increases and smooth ramp-down when demand falls. Wind and solar PV depend on weather and daylight; without dedicated storage, their output is intermittent and not easily dispatched on demand. Biomass with small-scale digesters can be turned on or off to some degree, but its availability and response time are limited by feedstock supply and digestion dynamics, making it less dispatchable than hydro with reservoir storage.