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  • A vast field of wind turbines generating renewable energy under a cloudy blue sky.

    Acre upon acre of wind turbines stretch over the landscape in this photo. The blades of the turbines spin in the wind like giant pinwheels. The of the moving blades is used to generate useful electrical energy . Wind is one of several renewable energy resources.
    ::这张照片中风力涡轮机的叶片在风中旋转,就像巨型针轮一样。移动的叶片被用来产生有用的电力。风是几种可再生能源资源之一。

    Q: What are some other renewable energy resources? 
    ::问题:有哪些其他可再生能源资源?

    A: You can read about the major renewable energy resources in this article. But here’s a hint in advance. Renewable energy resources include mechanical, electromagnetic, chemical, and thermal .
    ::A:您可以在文章中读到主要的可再生能源资源。但这里有一个预示。可再生能源资源包括机械、电磁、化学和热能。

    What Are Renewable Resources?
    ::什么是可再生能源?

    Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply. In addition to wind, renewable energy resources include sunlight, moving water, biomass, and geothermal energy. All of these resources are freely available and won’t run out. Most of them also have the advantage of producing little if any pollution or carbon dioxide, which contributes to global climate change. Nonetheless, these energy resources are used far less than , especially fossil fuels . 
    ::可再生资源是可以在相对较短的时间内被取代的自然资源,或者几乎无穷无尽的供应。 除了风,可再生能源资源还包括阳光、移动水、生物量和地热能源。 所有这些资源都可以免费获得并且不会耗尽。 大部分资源还具有造成全球气候变化的污染或二氧化碳极少的优势。 尽管如此,这些能源的使用远远少于化石燃料。

    Wind
    ::风风

    Wind is moving air, so it has mechanical energy that can do work. People have been using wind for energy for thousands of years. The old-fashioned windmill in the Figure is one way that wind energy can be used. The wind turbines in the opening photo above are a much newer way of using wind energy. They change the of the wind to electrical energy. However, only certain areas of the world get enough steady wind to produce much electricity. Many people also think that wind turbines are noisy, dangerous to birds, and unattractive in the landscape. 
    ::风能正在移动空气, 因此它有机械能源可以工作。 人们已经用风来提供能源数千年了。 图中的老式风车是使用风能的一种方式。 上面的开张照片中的风力涡轮机是使用风能的较新的方法。 它们将风力改变为电能。 然而, 世界上只有某些地区才有足够的稳定风能来生产大量电力。 许多人还认为风力涡轮机是吵闹的,对鸟类是危险的,在风景中是没有吸引力的。

    A traditional windmill used for pumping water, illustrating renewable wind energy use.

    This old windmill uses wind energy to operate a mechanical pump that lifts water out of a well. Windmills like this one have been used for centuries.
    ::这个老风车利用风能操作一个机械泵,把水从井里抬出来。像这样的风车已经使用了几个世纪了。

    Q: Where does the energy of the wind come from? Why does air move in the atmosphere?
    ::问题:风的能量从何而来?为什么空气在大气中流动?

    A: Wind is caused by unequal heating of the atmosphere by the sun. In other words, differences in cause air to move in the atmosphere.
    ::A:风是由太阳对大气层的不均匀加热造成的,换句话说,气的变化导致空气在大气层中流动。

    Launch the simulation below to further explore how a wind turbine generates electric power from the wind:
    ::进行以下模拟,进一步探索风力涡轮机如何从风中产生电力:

    Sunlight
    ::太阳光

    The sunlight that reaches Earth is the planet’s most important source of energy. The energy in sunlight, called solar energy, is electromagnetic energy . This is a form of energy that travels through space in electric and magnetic waves. Solar energy can be used to homes and produce electricity in solar cells like those on the roof seen in the Figure . Sunny areas receive plenty of sunlight to generate electricity, but solar energy may not be practical in areas that are often cloudy.
    ::到达地球的阳光是地球最重要的能源来源。 阳光中的能量被称为太阳能,是电磁能源。 这是一种在电磁波和磁波中穿梭于空间中的能源形式。 太阳能可以用于家庭和太阳能电池发电,就像图中看到的那些在天顶上的太阳能电池。 阳光地区获得大量阳光来发电,但太阳能在往往多云的地区可能并不实用。

    A roof equipped with solar panels generating electricity for a family home.

    Solar panels on the roof of this family home generate enough electricity to supply the family’s needs.
    ::家屋顶上的太阳能电池板发电量足以满足家庭需要。

    Q: In addition to the roofs of homes and other buildings, where else can you find solar cells?
    ::问题:除了住宅和其他建筑物的屋顶外,你还能在哪里找到太阳能电池?

    A: Calculators often have solar cells. Solar-powered outdoor lights are very common as well.
    ::A:计算器往往有太阳能电池,太阳能室外灯也很常见。

    Moving Water
    ::移动水

    The mechanical energy of rapidly flowing water can turn a turbine and generate electricity. Electricity produced in this way is called hydroelectric power. The water may flow over a waterfall or through a dam. You can see a picture of a dam in the Figure . A drawback of dams is that they flood land upstream from the dam and reduce water flow downstream from the dam, and this can destroy ecosystems. 
    ::快速流水的机械能量可以转换涡轮机和发电。这样发电的电力被称为水电。水可以流过瀑布或大坝。你可以从图中看到大坝的图象。大坝的缺点是,大坝从大坝上游向上游淹没土地,减少大坝下游的水流量,这会破坏生态系统。

    Hoover Dam on the Colorado River, a hydroelectric power generation facility.

    This is Hoover dam on the Colorado River between Arizona and Nevada. Water flowing through the dam generates electricity for both of these states and southern California.
    ::这是亚利桑那州和内华达州之间的科罗拉多河上的胡佛大坝,通过大坝流水为这两个州和南加利福尼亚州发电。

    Q: Does a hydroelectric power plant release air pollution or carbon dioxide? Why or why not.
    ::问题:一个水电站是释放空气污染还是二氧化碳?为什么或为什么没有?

    A: No, it is doesn’t. A hydroelectric plant doesn’t burn fuel, which is what produces air pollution in power plants that generate electricity from fossil fuels or biomass.
    ::A:不,这是没有的。 水电厂不燃烧燃料,而燃料就是通过化石燃料或生物量发电的发电厂产生空气污染的原因。

    Biomass
    ::生物量

    The stored chemical energy in organic matter or wastes is called biomass energy. The organic matter may be trees or other plants, or it may be wastes from homes and industries. When biomass is burned, it produces thermal energy that can be used for heating homes, cooking, or generating electricity. Biomass—especially wood—is an important energy source in the poorer nations where most people can’t afford fossil fuels. However, burning biomass releases air pollution and contributes to global climate change. Biomass can be used to make ethanol, a fuel that is added to gasoline. Although ethanol releases less pollution than gasoline, large areas of land are needed to grow the plants needed to make it (see Figure ). This reduces the amount of land available for food production.
    ::有机物或废物中储存的化学能源称为生物量能源,有机物可以是树木或其他植物,也可以是家庭和工业的废物;当生物量被燃烧时,它产生热能,可用于取暖、烹饪或发电;生物量,特别是木材,是大多数人买不起化石燃料的较贫穷国家的一个重要能源来源;然而,燃烧生物量释放空气污染,造成全球气候变化;生物量可以用来制造乙醇,一种添加到汽油中的燃料;尽管乙醇释放的污染比汽油少,但需要大片土地来种植生产所需的植物(见图)。这减少了粮食生产可用的土地数量。

    A large machine harvesting crops, illustrating biomass energy production for ethanol.

    This large machine is harvesting and grinding plants to make ethanol.
    ::这台大型机器正在采摘和研磨植物 制造乙醇。

    Geothermal Energy
    ::地热热能

    Geothermal energy is thermal (“heat”) energy from below Earth’s surface. It can be used to heat homes or generate electricity. A geothermal system pumps water underground where it is heated and then pumps the warm water back to the home or power plant (see Figure ). The thermal energy of the water can be used directly to heat the home. Or it can be used to produce steam and generate electricity. Installing a geothermal system can be expensive because of the need to drill through underground rocks, but the energy it uses is free.
    ::地热能是地球表面以下的热能(热能),可用于对住宅加热或发电,地热系统在地下抽水,加热后将热水抽回住宅或发电厂(见图 ) 。 水的热能可以直接用于对住宅加热,也可以用于蒸汽和发电。安装地热系统可能很昂贵,因为需要通过地下岩层钻探,但它使用的能源是免费的。

    A geothermal power plant in a mountainous landscape with steam rising from the ground.

    This power plant uses geothermal energy.
    ::这个发电厂使用地热能源

    Summary
    ::摘要

    • Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply.
      ::可再生资源是自然资源,可以在相对较短的时间内被取代,或几乎无穷无尽的供应。
    • Renewable energy resources include wind, sunlight, moving water, biomass, and geothermal energy. Except for biomass, which is burned, these renewable energy resources produce little if any pollution, although each has other drawbacks.
      ::可再生能源资源包括风、阳光、移动水、生物量和地热能源。 除了被燃烧的生物物质之外,这些可再生能源资源几乎没有产生任何污染,尽管它们都有其他缺点。

    Review
    ::回顾

    1. What is a renewable resource?
      ::什么是可再生资源?
    2. List five renewable energy sources. What form of energy does each resource supply?
      ::列出五种可再生能源:每种资源供应的能源形式是什么?

    Explore More
    ::探索更多

    Use the resource to answer the questions that follow. 
    ::使用该资源回答下面的问题。

    1. Why are renewable energy resources needed?
      ::为什么需要可再生能源资源?
    2. Give two examples of renewable energy resources.
      ::举两个可再生能源资源的例子。
    3. What is one main advantage of the examples given in this video?
      ::这段影片所举例子的主要好处是什么?