Post by soumyasarkar59 on Feb 17, 2024 5:51:56 GMT -6
Hydroelectricity is a major source of energy in many regions of the world, providing 24% of global electricity needs. Brazil and Norway depend almost exclusively on hydroelectric power. In the United States, 7 to 12% of all electricity is produced by hydroelectric power. Hydroelectricity Hydroelectric power is when water is used to power moving parts, which in turn can operate a windmill, an irrigation system, or an electric turbine (in which case we can use the term hydroelectricity). Most often, hydroelectricity is produced when water is held back by a dam, runs down a pipe through a turbine, and then is released into the river below. The water is pushed by the pressure of the upper tank and pulled by gravity, and that energy spins a turbine coupled to a generator that produces electricity. The rarer hydroelectric plants on the river also have a dam, but there is no reservoir behind it; The turbines are powered by river water that flows past them at the natural flow. Ultimately, electricity generation relies on the natural water cycle to replenish the reservoir, making it a renewable process without the necessary fossil fuel input.
Our use of fossil fuels is associated with a multitude of environmental problems: for example, the extraction of oil from tar sands produces air pollution; fracking for natural gas is associated with water pollution; Burning fossil fuels produces greenhouse gas emissions that Cell Phone Number List induce climate change. Therefore, we consider renewable energy sources as clean alternatives to fossil fuels. However, like all energy sources, renewable or not, there are environmental costs associated with hydroelectricity. Here's a review of some of those costs, along with some benefits. Environmental Costs of Hydroelectricity Barrier to fish . Many migratory fish species swim up and down rivers to complete their life cycle. Anadromous fish, such as salmon, shad, or Atlantic sturgeon, go upstream to spawn, and young fish swim downstream to reach the sea. Catadromous fish, such as the American eel, live in rivers until they swim to the ocean to reproduce, and young eels (eels) return to fresh water after hatching. Dams obviously block the passage of these fish. Some dams are equipped with fish ladders or other devices to allow them to pass unharmed.
The effectiveness of these structures is quite variable but improving. Changes in the flood regime . Dams can buffer large, sudden volumes of water after the spring melt of heavy rains. That can be a good thing for downstream communities (see Benefits below), but it also deprives the river of a periodic influx of sediment and prevents high natural flows from backing up into the riverbed, renewing habitat for the aquatic life. To recreate these ecological processes, authorities periodically release large volumes of water downstream, with positive effects on native vegetation along the river. Temperature and oxygen modulation . Depending on the design of the dam, the water released downstream often comes from the deeper parts of the reservoir. Therefore, that water has the same cold temperature throughout the year. This has negative impacts on aquatic life adapted to large seasonal variations in water temperature. Likewise, low levels of oxygen in the released water can kill aquatic life downstream, but the problem can be mitigated by mixing air into the water at the outlet. Evaporation.