When a source of energy is described as non-renewable, it means that it cannot be naturally replenished or regenerated within a reasonable time frame. Non-renewable energy sources are finite and limited in quantity, making them unsustainable in the long run. These sources take millions of years to form and are consumed much faster than they can be replenished. Examples of non-renewable energy sources include fossil fuels like coal, oil, and natural gas, as well as nuclear fuels. Once these resources are depleted, they cannot be easily replaced, leading to concerns about energy security and environmental impact.
