Renewable energy sources like solar, wind, and hydropower generate electricity without depleting finite resources.
Solar panels convert sunlight directly into electricity using photovoltaic cells, with costs dropping dramatically over two decades.
Wind turbines capture kinetic energy from moving air and convert it into electricity.
Hydropower, generated by moving water through dams and turbines, is one of the oldest renewable energy sources.
Challenges remain around energy storage and grid infrastructure, since solar and wind depend on weather and time of day.