|
|
| Large-Scale Hydropower | |||
|
|
Click on a choice: |
||
|
Small-Scale Hydropower Unlike large-scale hydropower facilities, carefully designed, small hydropower alternatives can provide electricity without significant damage to the environment, and several energy marketers are exploring creative ways to combine energy sales with environmental benefits.
|
|||
|
© 2006 SJVAPCD. All Rights Reserved. |
lectricity from hydropower is produced when water is captured behind
a dam and then guided down a chute and over a turbine at high speeds.
Hydropower doesn't produce air pollution, but, dams and the reservoirs
behind them that store the water-especially large ones-flood many square
miles of valuable land, destroying entire ecosystems. Also, because the
natural flow of water is blocked, the water quality suffers and the oxygen
content in the river below the dam is decreased, damaging vegetation and
wildlife. Dams interfere with fish migration and with the upstream and
downstream water flow, so that even when fish ladders are installed, many
species are still being pushed toward extinction. Right now, hydropower
provides about 10% of the electricity generated in the U.S. Few sites
are still available to build large dams, and many people are concerned
about the environmental costs of building more. 