Any source of energy whether renewable or non-renewable source of energy contributes to environmental pollution directly or indirectly.

Let us take the example of hydro energy. Hydro energy does not emit any air pollutant but it harms environment in the following ways:

The negative impacts of hydro power plant on ecosystem are as follows:

1. Since dams always have a reservoir where abundant quantity of water is stored, the blocking of flowing water causes harm to aquatic animals and their migration.

2. Dams also cause submerging of the nearby lands and all the natural areas, agricultural lands and hence requires relocating of the people who lived previously near the dam area.

In case of wind energy the windmill blades are injurious to the birds.