首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
High in the Mojave desert, 130 miles northeast of Los Angeles, lies a vast field of mirrors. Crisscrossing rows of glass and met
High in the Mojave desert, 130 miles northeast of Los Angeles, lies a vast field of mirrors. Crisscrossing rows of glass and met
admin
2019-09-26
26
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.
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:https://kaotiyun.com/show/W58K777K
本试题收录于:
B类竞赛(英语专业本科专科)题库大学生英语竞赛(NECCS)分类
0
B类竞赛(英语专业本科专科)
大学生英语竞赛(NECCS)
相关试题推荐
Peter,DavidandPaulsaidfollowingsentences:Peter:Davidisaliar,Paulalwaystellsthetruth.David:Peteristruthful.
Todaymenarefacingnewexpectationsandnewchoicesabouttheircommitmentstosociety,familyandwork.Nolongercertainwha
Whatdoes’alittlebird’meaninthefollowingconversation?GivetheanswerinChinese.—Alittlebirdtoldmethatyourmo
Manyprocesseswithinourbodiesaretimedtoacycleofabouttwenty-fourhours.Ifthebodytemperatureistakeneveryhouror
Howmanyessaytitlescanstudentschoosefromfortheirfirstassignment?
Whichofthefollowing,whenthelettersareproperlyarranged,isnotatypeoffruit?ENAORGPHAECACLANYCHRER
CharlesDickens’sworks,______ATaleofTwoCitiesarecharacterizedbyaminglingofhumorandpathos.
AWorldWithoutTimeorNumberThePirahciareanisolatedAmazoniantribeofhunter—gathererswholivedeepintheBrazilian
【T1】近日,一份关于未来生活的报告称,超级摩天大楼、水下城市和3D打印房屋将在100年内全部成为现实。(beareality)该报告由一群学者和未来学家们撰写而成。他们表示,不出一个世纪,人们便有望住进向地下延伸至25层的“摩地大楼”。包括未
HighintheMojavedesert,130milesnortheastofLosAngeles,liesavastfieldofmirrors.Crisscrossingrowsofglassandmeta
随机试题
中国某大学张教授。2011年7~12月份除了从所在大学取得工资薪金收入外.还取得以下几项收入:(1)7月份受邀到某企业作演讲,主办方支付报酬5000元。(2)9月份有两篇论文在相关专业期刊上发表,分别取得稿酬3200元和4500元。(3)10月份,将
绛舌可见于
如果地面气象观测站与项目的距离超过()km,并且地面站与评价范围的地理特征不一致,还需要进行补充地面气象观测。
总分类账一般采用( )。
一般资料:求助者,女性,28岁,无业。案例介绍:求助者由于孩子的问题前来咨询。下面是心理咨询师与求助者之间的一段对话:求助者:“我儿子今年4岁,他胆子太小,到现在还不敢一个人去卫生间。我试着改他这个毛病,曾和孩子约定,他每次自
劳动合同管理制度的内容包括()。(2008年5月三级真题)
作为一名新时代教师,应该怎样才能上好一堂课?
对于一个堆栈、若其入栈序列为1,2,3,……,n,不同的出入栈操作将产生不同的出栈序列。其出栈序列的个数正好等于结点个数为n的二叉树的个数,且与不同形态的二叉树一一对应。请简要叙述一种从堆栈输入(固定为1,2,3,……,n)/输出序列对应一种二叉树形态的方
Aresomepeoplebornclever,andothersbornstupid?Orisintelligencedevelopedbyourenvironmentandourexperience?Strange
Ihadto______myselffromtellingherwhatIthoughtofher.
最新回复
(
0
)