首页
登录
职称英语
The need for solar electricity is clear. It is safe, ecologically sound, eff
The need for solar electricity is clear. It is safe, ecologically sound, eff
游客
2024-03-12
39
管理
问题
The need for solar electricity is clear. It is safe, ecologically sound, efficient, continuously available, and it has no moving parts. The basic problem with the use of solar photovoltaic devices is economics, but until recently very little progress had been made toward the development of low-cost photovoltaic devices. The larger part of research funds has been devoted to the study of single crystal silicon solar cells, despite the evidence that this technique holds little promise. The reason for this pattern is understandable and historical. Crystalline silicon, however, is particularly unsuitable to terrestrial solar cells.
Crystalline silicon solar cells work well and are successfully used in the space program, where cost is not an issue. While single crystal silicon has been proven in extraterrestrial use with efficiencies as high as 18 percent, and other more expensive and rare materials can have even higher efficiencies, costs must be reduced by a factor of more than 100 to make them practical for commercial uses. Besides the fact that the starting crystalline silicon is expensive, 95 percent of it is wasted and does not appear in the final device. Recently, there have been some imaginative attempts to make polycrystalline and ribbon silicon which are lower in cost than high-quality single crystals; but to date the efficiencies of these apparently lower-cost materials have unacceptably small.
This difficulty can be avoided by preparing completely disordered or amorphous materials. Amorphous materials have disordered atomic structure as compared to crystalline materials: that is, they have only short-range order rather than the long-range periodicity of crystal. The advantages of amorphous solar cells are impressive. Crystalline silicon must be made 200 microns thick to absorb a sufficient amount of sunlight for efficient energy conversion, whereas only 1 micron of the proper amorphous materials is necessary. Crystalline silicon solar cells cost in excess of 100 per square foot, but amorphous films can be created at a cost of about 50 cents per square foot.
Although many scientists were aware of the very low cost of amorphous solar cells, they felt that they could never be manufactured with the efficiencies necessary to contribute significantly to the demand for electric power. This was based on a misconception about the feature which determines efficiency. For example, it is not the conductivity of the material in the dark which is relevant, but only the photoconductivity, that is, the conductivity in the presence of sunlight. Already, solar cells with efficiencies well about 6 percent have been developed using amorphous materials, and further research will doubtlessly find even less costly amorphous materials with higher efficiencies. [br] By saying that "this technique holds little promise"(Line 5, Para. 1), the author means that______.
选项
A、crystal silicon is impractical for commercial use
B、little progress will be made on the research of crystal silicon
C、research funds will be cut down on the study of crystal silicon
D、researches will not continue to study crystal silicon
答案
A
解析
从首段和第2段可以概括出晶体硅电池最大的缺点是其费用昂贵,在不用考虑成本的航天计划中它发挥了很好的作用,由此可以推断,作者说晶体硅技术没有前途,实际上是指它难以普及于日常生活,A为最合理的推断。
转载请注明原文地址:https://tihaiku.com/zcyy/3528746.html
相关试题推荐
Theneedforsolarelectricityisclear.Itissafe,ecologicallysound,eff
Theneedforsolarelectricityisclear.Itissafe,ecologicallysound,eff
Theneedforsolarelectricityisclear.Itissafe,ecologicallysound,eff
Theneedforsolarelectricityisclear.Itissafe,ecologicallysound,eff
Theneedforsolarelectricityisclear.Itissafe,ecologicallysound,eff
Theneedforsolarelectricityisclear.Itissafe,ecologicallysound,eff
Theneedforsolarelectricityisclear.Itissafe,ecologicallysound,eff
Theneedforsolarelectricityisclear.Itissafe,ecologicallysound,eff
Theneedforsolarelectricityisclear.Itissafe,ecologicallysound,eff
Theneedforsolarelectricityisclear.Itissafe,ecologicallysound,eff
随机试题
ThemaindifferencebetweenChineseandWestern【T1】______isthatunlikethe
男,56岁,因牙周病全部拔除上下颌余留牙,已5个月余。缺牙后,咀嚼功能遭到破坏并
孕妇不宜用的H1受体阻断药是A、苯海拉明 B、布可立嗪 C、美克咯嗪 D、
2007年中部六省城镇单位就业人员平均工资的中位数为()。A.20
居民消费价格指数能够反映()。A.城乡商品零售价格的变动趋势 B.城乡居民购买
(2016年真题)下列税收中,按年计算、分期缴纳的是()。A.契税 B.
苏俄实行的战时共产主义政策() ①是在残酷战争条件下的非常措施②目的是集中财力
如果运价变动1个百分点,引起运输需求量的变动不足1个百分点,说明该运输需求()。
甲公司基本生产车间生产X和Y两种产品,供电和锅炉两个辅助生产车间分别为
下列选项中,必须有城建档案管理部门参加的预验收和验收的工程项目有()。A.国家重
最新回复
(
0
)