Which energy source is considered nonrenewable?

Which energy source is considered nonrenewable?

• A. Wind energy
• B. Hydroelectric power
• C. Coal
• D. Solar energy

Answer: (C)

Coal is considered a nonrenewable energy source because it forms over millions of years from the remains of ancient plants and animals buried under layers of earth and subjected to heat and pressure. This lengthy geological process means that coal reserves are finite and cannot be replenished on a human timescale once they are depleted.

In contrast, wind energy, hydroelectric power, and solar energy are renewable sources because they can be replenished naturally in a relatively short period. Wind and solar energy are derived from natural phenomena that are inexhaustible in the human time frame, while hydroelectric power relies on the natural water cycle, which continuously renews the water resources used to generate electricity. Thus, coal's finite availability and the lengthy time required for its formation distinguish it as a nonrenewable energy source.