Fast-flowing water released from dams in mountainous areas can turn water turbines to produce electricity. While it doesn’t cause pollution, there are many other environmental impacts to consider. Ecosystems may be destroyed, cultural sites may be flooded and sometimes people need to be resettled. There are also impacts on fish breeding, loss of wildlife habitat and changes in water flow of rivers.
Biomass is material of plants and animals that can be used for energy.
Geothermal energy uses heat energy from beneath the surface of the earth.
Solar cells convert sunlight into electrical energy.
Electricity can be obtained by the flow of water through turbines in a dam as the tide rises and falls.
Moving air turns the blades of windmills or generators to make electricity or to pump water out of the ground.