20.12水力发电
Section outline
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Lesson
::经验教训What do dams do?
::水坝是做什么的?If you take a trip out of Las Vegas toward Phoenix you can visit the Hoover Dam. Completed in 1935, the dam provides power to over a million homes. It also stores water for use by the residents of the desert southwest. Hoover Dam is one of the engineering marvels of the 20th century.
::如果你从拉斯维加斯到凤凰城旅行,你可以参观胡佛大坝。1935年完工,该大坝为100多万户人家提供电力。它还储存水,供西南部沙漠居民使用。胡佛大坝是20世纪工程奇迹之一。Water Power
::水力发电Water flowing through a dam.
::水流穿过大坝Moving water has energy ( Figure ). That energy is used to make electricity. Hydroelectric power , or hydropower, harnesses the energy of water moving down a stream . Hydropower is the most widely used form of renewable energy in the world. This abundant energy source provides almost one fifth of the world’s electricity. The energy of waves and can also be used to produce water power. At this time, wave and tidal power are rare.
::移动水有能源(图 ) 。 能源被用来发电。 水电或水力发电利用水流下流的能源。 水力发电是世界上最广泛使用的可再生能源形式。 这种丰富的能源几乎提供了世界电力的五分之一。 海浪的能量也可用于发电。 此时,波浪和潮汐发电是稀有的。Hydropower Plants
::水力发电厂To harness water power, a stream must be dammed. Narrow valleys are the best for dams. While sitting in the reservoir behind the dam, the water has potential energy . Water is allowed to flow downhill into a large turbine . While flowing downhill, the water has kinetic energy . Kinetic energy makes the turbine spin. The turbine is connected to a generator, which makes electricity.
::要利用水力,水流必须被淹没。 狭小的河谷对水坝来说是最好的。 坐在水坝后面的水库里时,水有潜在的能量。 水允许下坡进入大型涡轮机。 在下坡流时,水有动能。 动能使涡轮机旋转。 涡轮机与发电机相连,产生电力。Hydropower as a Resource
::将水电作为一种资源Many of the suitable streams in the United States have been developed for hydroelectric power. Many streams worldwide also have hydroelectric plants. Hydropower is a major source of California’s electricity. It accounts for about 14.5 percent of the total. Most of California’s nearly 400 hydroelectric power plants are located in the Sierra Nevada mountains .
::美国许多合适的水力发电管道已经开发出来。 全世界许多水力发电管道也有水力发电厂。 水电是加利福尼亚州电力的主要来源之一,约占电力总量的14.5%。 加利福尼亚州近400座水力发电厂大多位于内华达山脉。Benefits and Problems of Hydropower
::水电的效益和水电问题Water power does not burn a fuel . So it causes less pollution than many other kinds of energy. Water power is also a renewable resource . Water keeps flowing downhill. Although we use some of the energy from this movement, we are not using up the water.
::水能不会燃烧燃料,因此它造成的污染比其他能源少。 水力也是可再生资源。 水能不断下坡。 尽管我们使用这种运动中的某些能源,但我们并没有耗尽水。The Colorado River backs up behind Hoover Dam. See the river coming in at the top of the photo.
::科罗拉多河倒在胡佛大坝后面,看到在照片顶端的河水。Water power does have problems. A large dam stops a stream's flow, which floods the land upstream ( Figure ). A beautiful may be lost. People may be displaced. The dams and turbines also change the downstream environment. Fish and other living things may not be able to survive. Dams slow the release of silt. Downstream deltas retreat and beaches may be starved of sand. Seaside cities may become exposed to storms and rising sea levels.
::水力确实存在问题。大坝阻止了河流的流,河流淹没了上游的陆地(图 ) 。 美丽的水可能消失。 人们可能会流离失所。 水坝和涡轮机也会改变下游环境。 鱼类和其他生物可能无法生存。 水坝会减缓淤泥的释放。 下游三角洲撤退和海滩可能因沙而绝食。 海滨城市可能会受到风暴和海平面上升的影响。Tidal power stations may need to close off a narrow bay or estuary . Wave power plants must withstand coastal storms and the corrosion of seawater.
::潮汐发电站可能需要关闭狭窄的海湾或河口,波浪发电站必须抵御海岸风暴和海水腐蚀。Summary
::摘要- Hydroelectric power is clean and is important in many regions of the world.
::水力发电是清洁的,在世界许多地区很重要。
- Hydroelectric dams change the river's ecosystem.
::水力发电堤坝改变了河流的生态系统。
- Hydropower utilizes the energy of falling water.
::水力发电利用下水的能量。
Review
::回顾- How does energy change forms as it goes from behind a dam to downstream of a dam?
::能源从大坝后面到大坝下游是如何变化的呢?
- How is hydroelectric energy collected?
::如何收集水电能源?
- What are some of the downsides of using hydropower?
::使用水力发电有什么不利之处?
- Hydroelectric power is clean and is important in many regions of the world.
