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  3. Widespread adoption of plug-in electric vehicles could dramatically cut greenhouse gas pollution and reduce U.S. dependence on f

Widespread adoption of plug-in electric vehicles could dramatically cut greenhouse gas pollution and reduce U.S. dependence on f

admin2023-02-20  56
问题     Widespread adoption of plug-in electric vehicles could dramatically cut greenhouse gas pollution and reduce U.S. dependence on foreign oil. But results of an electric-car pilot project presented recently at the annual meeting of the American Association for the Advancement of Science provide added incentive to go electric: Car owners could return unused electricity back to the grid (输电网) and make real money while doing it.
    Electric cars need big, powerful batteries to accelerate to highway speeds and travel scores or even several hundred kilometers on a single charge. But because most drivers drive just a few dozen kilometers a day, most of that battery capacity sits unused. To take advantage of that storage capacity, Willett Kempton, director of the University of Delaware’s Center for Carbon-Free Power Integration in Lewes, teamed up with an electric car maker, several utilities, a software company, and PJM Interconnection, one of 10 regional organizations that coordinate and control the U.S. electrical grid.
    To ensure that electricity flows steadily and without interruption, the U.S. government requires PJM Interconnection and its counterparts to have reserves of power in case a generator goes down and other electrical reserves to maintain the 60-Hz frequency of alternating current that our appliances and devices are accustomed to dealing with. Today, PJM Interconnection and its counterparts pay conventional power plants to maintain this reserve power. But as renewable energy sources such as wind and solar, which provide energy cleanly but intermittently, come online, these grid operators need to increase their storage capacity to ensure a steady electricity supply. So Kempton and his colleagues set out to provide some of the backup power from a fleet of parked electric cars.
    Kempton’s team used an electric car from AC Propulsions, a California car company, which was custom-built to provide electricity back to the grid. They used commercially available software and hardware that companies such as PJM Interconnection use to monitor and control energy flow. In November, the company hooked the grid up to the car, and Kempton’s team’s electric car became the first car in the world to earn its keep as a backup electric power source. At the rates that PJM Interconnection pays today to maintain power reserves, a hooked-in electric car could generate $1,800 a year for its owner.
    "I think it’s tremendously exciting," says Kathryn Clay, director of research for the Alliance of Automobile Manufacturers. "The extra dollars an electric car provides will not be enough by themselves to get consumers to adopt grictenabled vehicles—for that we also need better and less expensive batteries and tax incentives to give the market an encouragement" Nevertheless, "it’s an incentive to push in the right direction."  
In order to maintain the 60-Hz frequency of alternating current, PJM Interconnection must ________.
选项 A、have reserves of power
B、ensure the steady flow of electricity
C、have other electric reserves
D、ensure the operation of generators
答案B
解析 从原文该句可以知道为了维持60赫兹的交流电频率，PJM Interconnection必须have other electrical reserves。因此，本题应选B。在原句中，other electrical reserves是reserves of power的并列成分，如果误将其当作了and前的a generator goes down的并列成分，就有可能误选A或D。
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