What type of energy is classified as renewable?

The classification of energy as renewable is based on its source and the ability of that source to naturally replenish over time. Energy that is derived from resources such as sunlight, wind, rain, tides, waves, geothermal heat, and biomass is considered renewable because these resources are replenished naturally and can be harnessed without depleting them on a human timescale. This characteristic is critical for sustainability, as it supports an energy system that reduces dependence on finite resources and limits environmental impact.

In contrast, energy produced from fossil fuels is drawn from resources that take millions of years to form and are considered non-renewable due to their depletion over time. Similarly, energy generated by nuclear power relies on uranium, a finite resource, and while it produces low emissions during operation, it does not fit the definition of renewable energy. Lastly, energy sourced from destructive extraction processes often entails significant environmental damage and depletion of resources, further distancing it from the renewable classification.