Water flows in river because of Hydrological cycle and it occurs only because of solar energy which leads to evaporation,that's why water flowing in river is considered to be an indirect form of energy.

Energy of Water Flowing in a River as an Indirect Form of Solar Energy
Water flowing in a river is considered an indirect form of solar energy because it is ultimately driven by the sun's heat. Below are some key points to explain this concept:

1. Solar Energy Cycle:
- The sun's energy heats the Earth's surface, causing water bodies like oceans and lakes to evaporate.
- This evaporation process forms clouds, which eventually lead to precipitation in the form of rain or snow.

2. Hydrological Cycle:
- The precipitation from the clouds falls onto the Earth's surface and collects in rivers, streams, and other bodies of water.
- This water flows downstream due to gravity, creating kinetic energy in the form of flowing water.

3. Hydropower Generation:
- The kinetic energy of the flowing water is harnessed by hydropower plants to generate electricity.
- Hydropower is a renewable energy source because the water cycle is continually replenished by the sun's heat.

4. Environmental Benefits:
- Utilizing the energy of flowing water reduces the reliance on fossil fuels, leading to lower carbon emissions and a smaller environmental footprint.
- Hydropower is a clean and sustainable energy source that helps in combating climate change.
In conclusion, the energy of water flowing in a river is an indirect form of solar energy as it is driven by the sun's heat through the water cycle. Harnessing this energy through hydropower plants provides a renewable and environmentally friendly source of electricity.