第十三篇 Better Solar Energy Systems: More Heat, More Light
Solar photovoltaic thermal energy systems, or PVTs, generate both heat and electricity, but __1__ now they haven't been very good at the heat-generating part compared to a stand-alone solar thermal collector. That's because they operate at low temperatures to cool crystalline silicon solar cells, which lets the silicon generate more __2__ but isn't a very efficient way to gather heat.
That's a problem of __3_ . Good solar hot-water systems can harvest much more energy than a solar-electric system at a substantially lower __4__. And it,s also a space problem:photovoltaic cells can take up all the space on the roof, leaving little room for thermal applications.
In a pair of studies, Joshua Pearce, an associate professor of materials science and engineering, has devised a __5__ in the form of a better PVT made with a different kind of silicon. His research collaborators are Kunal Girotra from ThinSilicon in California and Michael Pathak and Stephen Harrison from Queen's University, Canada."
Most solar panels are made with crystalline silicon,but you can also make solar cells out of amorphous silicon, __6__ known as thin-film silicon. They don't create as much electricity, but they are lighter, flexible, and cheaper. And, because they __7__ much less silicon, they have a greener footprint. Unfortunately,thin-film silicon solar cells are __8__ to some bad-news physics in the form of the Staebler-Wronski effect.
"That means that their efficiency __9__ when you expose them to light - pretty much the worst possible effect for a solar cell," Pearce explains,which is one of the __10__ thin- film solar panels make up only a small fraction of the market.
However, Pearce and his team found a way to engineer around the Staebler-Wronski effect by incorporating thin-film silicon in a new __11__ of PVT. You don't have to cool down thin-film silicon to make it work. In fact,Pearce's group discovered that by heating it to solar-thermal operating temperatures,near the boiling __12__ of water, they could make thicker cells that largely __13__ the Staebler-Wronski effect. When they applied the thin-film silicon directly to a solar thermal energy __14__ , they also found that by baking the cell once a day,they __15__ the solar cell's electrical efficiency by over 10 percent.
詞匯:
photovoltaic n.光電的
silicon n.硅
thermal adj.熱的,熱量的
amorphous adj.非晶形的
crystalline adj.晶體的
footprint n.足跡
注釋:
1.solar photovoltaic thermal energy systems:太陽能光伏熱能系統(tǒng)
2.they: 指代 solar photovoltaic thermal energy systems。
3.stand-alone:單機的
4.crystalline silicon solar cells:晶體硅太陽能電池
5.which:指前半句中的 to cool crystalline silicon solar cells 這件事
6.room:空間
7.solar panels:太陽能電池板
8.amorphous silicon:非晶硅
9.thin-film silicon:薄膜硅
10.Staebler-Wronski Effect: SWE效應。在光的照射下,非晶桂氫的導電性短時間內顯著衰退,這種特性被稱為SWE效應o
11.pretty much:幾乎
12.the worst possible effect:最可能壞的效應
13.engineer around:精心地設計以克服或繞過
14.solar-thermal operating temperatures:太陽熱能操作溫度
練習:
1. A. unlessB. whenC. ifD. until
2. A. electricityB. magnetismC. ultravioletD. radioactivity
3. A. dynamicsB. geologyC. economicsD. biology
4. A. rewardB. costC. billD. pay
5. A. decisionB. solutionC. suggestionD. qualification
6. A. roughlyB. probablyC. commonlyD. specially
7. A. retrieveB. mergeC. exchangeD. require
8. A. vulnerableB. necessaryC. importantD. renewable
9. A. worksB. countsC. risesD. drops
10. A. restrictionsB. advancesC. reasonsD. strengths
11. A. sizeB. shapeC. typeD. brand
12. A. areaB. pointC. placeD. extent
13. A. overcameB. promotedC. improvedD. postponed
14. A. transformerB. adaptorC. transmitterD. collector
15. A. boostedB. definedC. wastedD. lower
答案與題解:
1.D文章介紹最近科學家已經完善了太陽能光伏熱能系統(tǒng),現(xiàn)在新型的太陽能系統(tǒng)能將太陽能轉換為更多的電能和熱能。第一段說明以往晶體硅太陽能電池在收集熱能方面效率很低。四個選項中,只有選用until才符合上下文的意思。"...until now they (太陽能光伏熱能系統(tǒng)) haven't been very good at the heat-generating part compared to a stand-alone solar thermal collector. "該句意為:與太陽熱能單機集熱器相比,直到現(xiàn)在,傳統(tǒng)太陽能光伏熱能系統(tǒng)在轉換熱能方面效率一直不是很高。
2.A本句說明了以往的太陽能光伏熱能系統(tǒng)在轉換熱能方面效率低的原因,"to cool crystalline silicon solar cells(冷卻晶體桂太陽能電池)"能產生更多的電能,但不利于收集熱能。electricity是答案。
3.C從上一段和本段的意思判斷,收集熱能效率低下不會是一個動力學(dynamics)問題,地質(geology) 問題或生物學(biology)問題。它是一個經濟上的問題。答案是economics。
4.B 本句說,good solar hot-water systems 在收獲能量方面比 solar-electric system 要好得多。從經濟學的角度上分析,成本就降低了。所以,選cost是對的。其他選項reward,bill和pay均不符合句意。
5.B上一段說光伏電池系統(tǒng)有兩個問題,即經濟問題和空間問題。Joshua Pearce采用另外一種硅制造PVT來解決上述問題。通過上述分析可以看出,他尋求的是一種解決問題的辦法(solution),而不是一個決定(decision)、一個建議(suggestion )或一種資格 ( qualification)。
6.C amorphous silicon (非晶硅)即為 thin-film silicon (薄膜硅)。選擇 roughly/probably/ wrongly( known as thin-film silicon)表達的意思都不合邏輯。選commonly才合理。"amorphous silicon, commonly known as thin-film silicon" 意為"非晶硅,通常被稱為薄膜硅"
7.D新型的太陽能電池采用薄膜硅制造,電能的轉換量雖然不如晶體硅太陽能電池,但薄膜硅太陽能電池用硅量小,比較環(huán)保。本題應選用require,理由是:require much less silicon與上下文的意思很連貫,而retrieve much less silicon (提取少得多的硅),merge much less silicon(混合少得多的硅)或exchange much less silicon(交換少得多的硅)都講不通,意思離題太遠。
8.A bad-news physics是解題的關鍵詞。既然是bad-news physics, 所連用的形容詞應該是負面意義的詞。四個選項中只有vulnerable(易受攻擊的)符合這個條件,所以是答案。
9.D本段第一句說明vulnerable的具體情況。既然是vulnerable,efficiency-定是drops,不會是rises。efficiency works(效率起作用)或efficiency counts(效率有重要意義)都離題太遠。
10.C薄膜硅太陽能電池效能低下,這是因。導致該產品市場占有份額很小,這是果。選 reasons為答案很合理。
11.C為了克服SWE效應,Pearce和他的團隊悉心改進光伏太陽熱能系統(tǒng)的結構。作者要寫的應該是 a new type of PVT(-種新型 PVT),不會是 a new shape/size/brand PVT(-種新形狀的/新尺寸的/新品牌的PVT)。
12.B 從上下文判斷,答案應該是 point。將 thin-film silicon 加熱到 solar-thermal operating temperatures 就是加熱到 near the boiling point of water(臨近水的沸點)。其他選項 area, place和extent均不切題。
13.A從上下文判斷,采用加熱t(yī)hin-film silicon的方法,就能消除SWE效應。四個選項中只有overcame表達了這層意思。
14.D答案是collector,因為solar thermal energy collector(太陽能集熱器)與上下文的意思接得上,意為"當把薄膜硅直接應用于太陽能集熱器時"。其他選項均與上下文不符。
15.A文章最后一段介紹研究人員克服SWE效應,提高了將太陽能轉換為電能的效率。所以,將最后一句的"by 10 percent"理解為"提高"而不是"降低"10%才合乎邏輯。答案是 boosted。
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