Which energy source is not renewable?

Coal is classified as a non-renewable energy source because it is a fossil fuel formed from the remains of ancient plants and animals that have been subjected to heat and pressure over millions of years. This process leads to a finite supply that cannot be replenished on a human timescale. Once coal is extracted and used for energy, it cannot be replaced within a reasonable timeframe, making it unsustainable as an energy resource.

In contrast, wind, hydro, and solar energy are all renewable sources because they are constantly replenished by natural processes. Wind energy harnesses the power of moving air, hydro energy utilizes flowing water, and solar energy captures light from the sun, all of which are readily available as long as the natural systems that produce them are intact.