首页
登录
职称英语
High in the Mojave desert, 130 miles northeast of Los Angeles, lies a vast fi
High in the Mojave desert, 130 miles northeast of Los Angeles, lies a vast fi
游客
2023-10-14
52
管理
问题
High in the Mojave desert, 130 miles northeast of Los Angeles, lies a vast field of mirrors. Crisscrossing rows of glass and metal, glinting in the sunlight, cover a full square mile of dirt. It is a fully operational array of power plants churning out an average of 180 megawatts of electricity.
Most people think of solar power as a flat panel on every rooftop. But photovoltaic panels have limitations. They work fine when the sun is strong, but when the clouds roll in you’ d better have batteries to run the TV and dishwasher. And even on the sunniest days the panels are not very well suited for cities, where roof space is limited.
For decades, engineers have been working on ways to catch the sun over a broad area concentrating it and using it to produce electricity on the same scale as centralized coal, hydro or nuclear power plants—hundreds of megawatts at a time. Several pilot plants have been operating in California, some for decades, but so far they have not had enough volume to force costs down to competitive levels.
Some countries are expected to go with much larger plants capable of generating more than 100 megawatts each. If some of the projects are completed, costs could come down from the current 15 cents a kilowatt-hour for the Mojave plant to 8 cents per kwh in the next 8 to 10 years. That would go a long way toward closing the gap with gas and oil, which now cost as little as 4 cents per kwh.
The Mojave plant is one of the world’ s first commercial solar power plants, with five solar Electric Generating Systems (SEGS) supplying electricity to southern California. The basic component of a SEGS plant is a row of mirrors that reflect sunlight onto a pipe filled with oil. The oil heats up and is used to produce steam, which turns an electrical turbine. Assemble a few dozen rows of these trough-mirrors, and you have got capacity to generate 30 megawatts of power, enough for half a small town. The problem with trough technology is that the oil loses its heat too quickly. When the sun goes down, so does the power.
A Solar Tres design uses molten salt instead of oil. Since salt holds more heat longer than oil, it can drive turbine through the night. Concentric rings of mirrors direct sunlight to a tank of molten salt. When the stuff is hot enough, some goes straight to a generator to produce steam, while the rest is stored for use at night. The 15-megawatt Solar Tres plant would be the first long-term commercial power production project. Since the electricity is expected to be costly close to 20 cents per kwh, the Spanish government plans to subsidize the plant.
The next big thing—Dish systems—is already in the works. The building block of such a plant is a parabolic mirror, shaped like a satellite dish, that reflects sunlight onto a small generator suspended in front. The heat drives a turbine. Theoretically a dish configuration would produce more energy per acre than other solar concentrating plants, that is, if engineers could figure out a good way of linking many dishes together.
Questions 66 ~ 70
Answer the following questions with the information given in the passage. [br] What is the disadvantage of the Mojave plant compared with Solar Tres design?
选项
答案
The oil loses its heat too quickly.
解析
文章第五段提到,莫哈维电厂槽式技术的问题是油散热太快。由此可知本题答案。
转载请注明原文地址:http://tihaiku.com/zcyy/3098210.html
相关试题推荐
IfyouflyovertheNazcaDesertalongthesoutherncoastofPeru,youwill
IfyouflyovertheNazcaDesertalongthesoutherncoastofPeru,youwill
IfyouflyovertheNazcaDesertalongthesoutherncoastofPeru,youwill
IntheU.S.,thelargestcityalongthePacificCoastis______.A、LosAngeles
HighintheMojavedesert,130milesnortheastofLosAngeles,liesavastfi
HighintheMojavedesert,130milesnortheastofLosAngeles,liesavas
HighintheMojavedesert,130milesnortheastofLosAngeles,liesavas
HighintheMojavedesert,130milesnortheastofLosAngeles,liesavastf
HighintheMojavedesert,130milesnortheastofLosAngeles,liesavastf
HighintheMojavedesert,130milesnortheastofLosAngeles,liesavastf
随机试题
BOAtoAdd110NewBranchesBankofAmerica,oneofthenation’sbiggestbanks,
WhathappenedtothefourremaininglawyersafterPatrick’sdisappearance?[br]
A.听诊有高调笛音 B.呼气时间超过2秒 C.肋骨上抬、胸廓前后径增宽、膈肌
下列不属于金属矿山采空区的是()。A.空场法采空区 B.回采法采空区 C
某房地产开发有限公司因拒绝提供统计资料,被某市统计局依法予以统计行政处罚。该公司
女孩9个月,母乳喂养,面色蜡黄,肝肋下2cm,脾肋下1cm,红细胞2.8×10/
家长们担心孩子过度依赖手机会损害视力、看到不良信息。但值得注意的是,除了这些浅表
劳动法基本原则包括()。A.物质帮助权原则 B.平等就业原则 C.劳动关系民
专家型教师和新教师教学行为的差异主要表现在()、课堂教学过程和(
(2021年真题)根据《建设工程质量管理条例》,下列文件中,未经审查批准,不得使
最新回复
(
0
)