What is the main source of energy for the water cycle?

The main source of energy for the water cycle is the sun. Solar radiation provides the heat energy needed to drive the processes of evaporation, transpiration, condensation, and precipitation that make up the water cycle. When the sun's rays heat up the Earth's surface, water evaporates from bodies of water, moisture evaporates from plants through transpiration, and water vapor rises into the atmosphere. As the water vapor cools, it condenses into clouds and eventually falls back to the Earth as precipitation. This continuous cycle of evaporation, condensation, and precipitation is fueled by the sun's energy.