Why did each of the alternative energy sources you named are considered renewable?

Alternative energy sources like solar, wind, and hydro are considered renewable because they harness natural processes that are continually replenished. Solar energy captures sunlight, which is abundant and inexhaustible on human timescales. Wind energy utilizes air currents generated by the sun's heating of the Earth's surface, while hydro energy relies on the water cycle, which is driven by solar energy. These sources are sustainable and have minimal environmental impact compared to fossil fuels.