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 meta
High in the Mojave desert, 130 miles northeast of Los Angeles, lies a vast field of mirrors.Crisscrossing rows of glass and meta
admin
2021-03-30
79
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.
What is the present cost for the Mojave plant?
选项
答案
15 cents a kilowatt-hour.
解析
文章第四段提到,如果其中一些项目得以完成,未来8~10年,莫哈维电厂的成本可能会从目前的15美分每千瓦时降至每千瓦时8美分。因此,莫哈维电厂目前的成本是15美分每千瓦时。由此可知本题答案。
转载请注明原文地址:https://www.kaotiyun.com/show/Aq8K777K
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
Malnutritionduringweaningage—whenbreastmilkisbeingreplacedbysemi-solidfoods—ishighlyprevalentinchildrenofpoorh
RachelcametoseeDr.JonesbecauseDr.Jonesneedsherfurtherexplanationofanextensionforheressay.
Livinginthewesternpartofthecountryhasitsproblems,______obtainingfreshwaterisnottheleast.
Peopleoftenlaughwhentheyseepenguinswalking.Penguinslookveryfunnywaddlefromsidetosideontheirshortlittlelegs.
Englandisinnorth-westEuropeandisthelargestcountryintheUK.(TheUKalsoincludesScotland,WalesandNorthernIreland
Whatarethemissingnumbersinthelastdiamondinthesequencebelow?
HallwardLibrarysupportsthelearning,teachingandresearchneedsoftheFacultyofArtsandtheFacultyofSocialSciences.T
Thereisnothingworsethansomeonewhoisalwayslate.Latenesscanbeacharmingeccentricity—foralittlewhile.Thetroubleis
Thereisnothingserious______Ihadjumpedoutofthewindowwhenthebombexploded.
Halfofthemedicalsupplieshavealreadybeen______tothevictimsoftheearthquake.
随机试题
妇女病普查、普治的常用统计指标包括
下列不属于SQL查询的是()
下肢深静脉血栓形成的诊断方法有
下列何种情况不适宜制作金属烤瓷冠A.牙体缺损大,无法充填治疗B.四环素牙C.青少年恒牙D.前牙错位E.釉质发育不全
下述哪项属于卵巢肿瘤()
作为建设工程项目进度控制的依据,建设工程项目进度计划系统应()。
科学就是不断接近真理的过程,我们深信不疑的事情中很大部分是会过期的,所有理解这一点的人都明白在发展过程中不断更新知识才是科学进步的正道。然而这个过程有时会令人困惑和不安。如果以下各项为真,最能质疑上述论断的是()。
患者,女性,20岁,因左侧牙冷热痛就诊。查:36度重度磨损不均匀,未探及穿髓孔,热测引起疼痛并持续2min,叩(-),该患牙处理原则为()。
对随机变量X,已知EekX.存在(k>0常数),证明:P{X≥ε}≤.E(ekX).(其中ε>0).
MarathonRacesinAmericaManyAmericansenjoyrunning./Andonekindofrace,themarathon,hascapturedtheimaginationo
最新回复
(
0
)