What does it mean to say that something is a sustainable energy source?

A sustainable energy source is one that meets current energy needs without compromising the ability of future generations to meet theirs. It typically comes from renewable resources, such as solar, wind, or hydroelectric power, which are naturally replenished and have minimal environmental impact. Sustainable energy sources also promote energy efficiency and reduce greenhouse gas emissions, contributing to a healthier planet. Overall, they play a crucial role in combating climate change and fostering ecological balance.