一、光伏太陽能電池板原理

太陽能電池是一種(zhong)對光有響應并能將光能轉(zhuan)換(huan)成電力的器件。能產生光伏效(xiao)應的材料有許多(duo)(duo)種(zhong)，如(ru)：單(dan)晶(jing)硅，多(duo)(duo)晶(jing)硅，非晶(jing)硅，砷化鎵，硒(xi)銦銅(tong)等。它們的發電原理基(ji)本相同(tong)，現以(yi)晶(jing)體硅為例(li)描述光發電過程(cheng)。P型晶(jing)體硅經過摻雜磷(lin)可(ke)得N型硅，形成P-N結。

當(dang)光(guang)線照射(she)太陽電(dian)(dian)(dian)池表面(mian)時(shi)(shi)，一部分光(guang)子(zi)被硅材料(liao)吸(xi)收;光(guang)子(zi)的能(neng)量(liang)傳遞(di)給了硅原子(zi)，使電(dian)(dian)(dian)子(zi)發(fa)生(sheng)了躍遷(qian)，成(cheng)(cheng)為(wei)自由電(dian)(dian)(dian)子(zi)在P-N結兩側集聚形成(cheng)(cheng)了電(dian)(dian)(dian)位差，當(dang)外部接(jie)通電(dian)(dian)(dian)路時(shi)(shi)，在該電(dian)(dian)(dian)壓的作用下(xia)，將會有電(dian)(dian)(dian)流(liu)流(liu)過外部電(dian)(dian)(dian)路產(chan)生(sheng)一定的輸出功率(lv)。這(zhe)個(ge)過程的的實質(zhi)是：光(guang)子(zi)能(neng)量(liang)轉(zhuan)換成(cheng)(cheng)電(dian)(dian)(dian)能(neng)的過程。

該圖片由注冊用戶"知識君"提供，版權聲明反饋

太陽能(neng)發電(dian)有兩種(zhong)方(fang)式(shi)，一種(zhong)是光—熱(re)—電(dian)轉(zhuan)換方(fang)式(shi)，另一種(zhong)是光—電(dian)直接轉(zhuan)換方(fang)式(shi)。

（1）光—熱—電轉換方式通過利用太陽輻射產生的熱能發電，一般是由太陽能集熱器將所吸收的熱能轉換成工質的(de)(de)(de)(de)蒸氣，再(zai)驅動汽輪機(ji)發電(dian)。前(qian)一個過程是(shi)光—熱(re)轉換過程；后一個過程是(shi)熱(re)—電(dian)轉換過程，與普通(tong)的(de)(de)(de)(de)火(huo)力(li)發電(dian)一樣。太(tai)陽能(neng)熱(re)發電(dian)的(de)(de)(de)(de)缺(que)點是(shi)效(xiao)率(lv)很低而成本(ben)很高，估計它的(de)(de)(de)(de)投資至少要(yao)比普通(tong)火(huo)電(dian)站(zhan)(zhan)(zhan)貴5～10倍(bei)。一座(zuo)1000MW的(de)(de)(de)(de)太(tai)陽能(neng)熱(re)電(dian)站(zhan)(zhan)(zhan)需要(yao)投資20～25億美元，平均(jun)1kW的(de)(de)(de)(de)投資為2000～2500美元。因此，適用小規模特殊的(de)(de)(de)(de)場合，而大規模利用在經濟上很不合算，還不能(neng)與普通(tong)的(de)(de)(de)(de)火(huo)電(dian)站(zhan)(zhan)(zhan)或核電(dian)站(zhan)(zhan)(zhan)相競(jing)爭。

（2）光—電直接轉換方式該方式是利用光電效應，將太陽輻射能直接轉換成電能，光—電轉換的基本裝置就是太陽能電池。太陽能電池是一種由于光生伏特效應而將太陽光能直接轉化為電能的器件，是一個半導體光電二極管，當太陽光照到光電二極管上時，光電二極管就會把太陽的光能變成電能，產生電流。當許多個電池串聯或并聯起來就可以成為有比較大的輸出功率的太陽能電池方陣了。太陽能電池是一種大有前途的新型電源，具有永久性、清潔性和靈活性三大優點.太陽能電池壽命長，只要太陽存在，太陽能電池就(jiu)可(ke)以一(yi)次投資而長期(qi)使用(yong)；與火力發電(dian)(dian)(dian)、核能(neng)(neng)發電(dian)(dian)(dian)相(xiang)比(bi)，太(tai)陽(yang)能(neng)(neng)電(dian)(dian)(dian)池不會引起環境污染；太(tai)陽(yang)能(neng)(neng)電(dian)(dian)(dian)池可(ke)以大中小(xiao)(xiao)并舉，大到百萬(wan)千瓦的(de)(de)中型電(dian)(dian)(dian)站，小(xiao)(xiao)到只供一(yi)戶(hu)用(yong)的(de)(de)太(tai)陽(yang)能(neng)(neng)電(dian)(dian)(dian)池組(zu)，這是其它電(dian)(dian)(dian)源無法比(bi)擬的(de)(de)。

二、太陽能電池板功率計算方法

太陽能(neng)交流發(fa)電(dian)(dian)系(xi)統(tong)是由太陽電(dian)(dian)池板、充電(dian)(dian)控(kong)制(zhi)器、逆(ni)變(bian)器和蓄電(dian)(dian)池共同(tong)組成；太陽能(neng)直流發(fa)電(dian)(dian)系(xi)統(tong)則不包括逆(ni)變(bian)器。為了(le)使太陽能(neng)發(fa)電(dian)(dian)系(xi)統(tong)能(neng)為負載提供足夠的電(dian)(dian)源，就要根據用(yong)電(dian)(dian)器的功率，合理(li)選(xuan)擇(ze)各(ge)部件。下面以(yi)100W輸(shu)出功率，每天(tian)使用(yong)6個小(xiao)時(shi)為例，介紹一下計算方法(fa)：

1、首先應計算(suan)出每天消耗(hao)的瓦(wa)時(shi)數（包(bao)括逆變器的損耗(hao)）：若逆變器的轉換效率為90%，則(ze)當(dang)輸(shu)出功率為100W時(shi)，則(ze)實際需要輸(shu)出功率應為100W/90%=111W；若按(an)每天使用(yong)5小(xiao)時(shi)，則(ze)輸(shu)出功率為111W*5小(xiao)時(shi)=555Wh。

2、計算太(tai)陽能電(dian)池板(ban)：按(an)每(mei)日有效日照時間為6小時計算，再考慮(lv)到充電(dian)效率(lv)(lv)(lv)和充電(dian)過程(cheng)中(zhong)的損耗，太(tai)陽能電(dian)池板(ban)的輸(shu)出功(gong)率(lv)(lv)(lv)應為555Wh/6h/70%=130W。其(qi)中(zhong)70%是充電(dian)過程(cheng)中(zhong)，太(tai)陽能電(dian)池板(ban)的實際使(shi)用功(gong)率(lv)(lv)(lv)。

三、發電效率

單(dan)(dan)晶(jing)硅(gui)(gui)太(tai)(tai)(tai)陽(yang)能(neng)(neng)的光電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)轉(zhuan)換(huan)效(xiao)率最高的達(da)到24%，這(zhe)是(shi)(shi)目前所有種類(lei)的太(tai)(tai)(tai)陽(yang)能(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)中光電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)轉(zhuan)換(huan)效(xiao)率最高的。但是(shi)(shi)單(dan)(dan)晶(jing)硅(gui)(gui)太(tai)(tai)(tai)陽(yang)能(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的制作成(cheng)本很大，以致于它還(huan)不能(neng)(neng)被(bei)大量(liang)廣泛和(he)普(pu)遍地(di)使用(yong)。多(duo)晶(jing)硅(gui)(gui)太(tai)(tai)(tai)陽(yang)能(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)從(cong)制作成(cheng)本上來(lai)(lai)講(jiang)，比單(dan)(dan)晶(jing)硅(gui)(gui)太(tai)(tai)(tai)陽(yang)能(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)要(yao)便宜一些，但是(shi)(shi)多(duo)晶(jing)硅(gui)(gui)太(tai)(tai)(tai)陽(yang)能(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的光電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)轉(zhuan)換(huan)效(xiao)率則要(yao)降低不少，此外，多(duo)晶(jing)硅(gui)(gui)太(tai)(tai)(tai)陽(yang)能(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)的使用(yong)壽命也要(yao)比單(dan)(dan)晶(jing)硅(gui)(gui)太(tai)(tai)(tai)陽(yang)能(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)短。因此，從(cong)性能(neng)(neng)價格比來(lai)(lai)講(jiang)，單(dan)(dan)晶(jing)硅(gui)(gui)太(tai)(tai)(tai)陽(yang)能(neng)(neng)電(dian)(dian)(dian)(dian)(dian)(dian)(dian)(dian)池(chi)還(huan)略好。

研究者發現有一些化合物半導體材料適于作太陽能光電轉化薄膜。例如CdS,CdTe；Ⅲ-V化合物半導體：GaAs，AIPInP等；用這些半導體制作的薄膜太陽能電池表現出很好光電轉化效率。具有梯度能帶間隙多元的半導體材料，可以擴大太陽能吸收光譜范圍，進而提高光電轉化效率。使薄膜太陽能電池大量實際的應用呈現廣闊的前景。在這些多元的半導體材料中Cu（In，Ga）Se2是一種性能優良太陽光吸收材料。以它為基礎可以設計出光電轉換效率比硅明顯地高的薄膜太陽能電池，可(ke)以達到的光電轉化(hua)率為18%。