renewability

Renewability is the property of a resource or process that allows it to be replenished or regenerated, often by natural processes, within a timescale that makes ongoing use feasible for humans. In energy and materials contexts, renewability contrasts with resources that are exhausted faster than they are formed.

Renewable energy sources draw on natural flows such as sunlight, wind, and flowing water that are effectively inexhaustible on human timescales, though they may vary by location and season. Common renewable energy sources include solar photovoltaic and solar thermal, wind power, hydropower, geothermal energy, and biomass. While these sources can provide long-term supply without depleting a stock, sustainable management and technology are needed to address variability and environmental impacts.

Non-renewable resources, such as fossil fuels and many minerals, form over geological timescales and can be depleted faster than they are replenished. Renewability also applies to biological and ecological stocks, such as forests and fisheries, where harvest rates should not exceed natural regeneration to maintain supply.

Policy, research, and market developments aim to enhance renewability by improving efficiency, reducing emissions, and expanding storage and transmission. Challenges include intermittency, land and water use, and lifecycle environmental effects. A variety of approaches—economic incentives, regulatory standards, and recycling—support sustainable use of renewable resources.