This document discusses various renewable and non-renewable energy sources. It provides details on solar energy sources like solar cookers and solar water heaters that convert sunlight directly into heat. It also describes solar cells that convert sunlight into electricity. Other renewable sources discussed include wind energy from wind turbines, hydel energy from flowing water, and geothermal from underground heat. Non-renewable sources like fossil fuels are finite, while renewable sources like solar, wind and hydel are either unlimited or can be replenished.