Charcoal is a nonrenewable resource because it comes from coal, which is a fossil fuel. Coal is formed from the remains of plants that died millions of years ago and were buried under sediment. Over time, the heat and pressure from the sediments turned the plant matter into coal. Charcoal is made by burning wood or other organic materials in a low-oxygen environment. This process creates charcoal, which is mostly carbon.
While charcoal itself is not renewable, it can be used to generate electricity through a process called pyrolysis. In pyrolysis, high temperatures are used to break down the coal into its component parts: carbon dioxide, water vapor, and hydrogen gas. The resulting gases can then be combusted to generate electricity.