光伏(fu)(fu)發電(dian)是利用半(ban)導(dao)體(ti)界面的光生伏(fu)(fu)特效應而(er)將(jiang)光能直接轉(zhuan)變為(wei)電(dian)能的一種技術。主要由(you)太陽電(dian)池板(組(zu)件)、控制器(qi)和逆變器(qi)三大(da)部分組(zu)成,主要部件由(you)電(dian)子元器(qi)件構成。太陽能電(dian)池經(jing)過串聯后進行封裝(zhuang)保護可形(xing)成大(da)面積的太陽電(dian)池組(zu)件,再配(pei)合上功率控制器(qi)等部件就形(xing)成了(le)光伏(fu)(fu)發電(dian)裝(zhuang)置。
光伏發電(dian)(dian)(dian)(dian)(dian)的(de)(de)主要原(yuan)(yuan)理(li)是半導體的(de)(de)光電(dian)(dian)(dian)(dian)(dian)效(xiao)應。光子(zi)(zi)(zi)(zi)(zi)(zi)照射到金屬上時(shi)(shi),它的(de)(de)能(neng)量(liang)可以被金屬中(zhong)(zhong)某(mou)個(ge)電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)(zi)(zi)全部吸收,電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)(zi)(zi)吸收的(de)(de)能(neng)量(liang)足(zu)夠大,能(neng)克服金屬內部引力做功(gong),離開金屬表面(mian)逃逸(yi)出(chu)來,成(cheng)(cheng)為光電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)(zi)(zi)。硅(gui)(gui)原(yuan)(yuan)子(zi)(zi)(zi)(zi)(zi)(zi)有(you)(you)4個(ge)外(wai)層(ceng)(ceng)電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)(zi)(zi),如(ru)果在純硅(gui)(gui)中(zhong)(zhong)摻入有(you)(you)5個(ge)外(wai)層(ceng)(ceng)電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)(zi)(zi)的(de)(de)原(yuan)(yuan)子(zi)(zi)(zi)(zi)(zi)(zi)如(ru)磷(lin)原(yuan)(yuan)子(zi)(zi)(zi)(zi)(zi)(zi),就成(cheng)(cheng)為N型(xing)(xing)(xing)半導體;若在純硅(gui)(gui)中(zhong)(zhong)摻入有(you)(you)3個(ge)外(wai)層(ceng)(ceng)電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)(zi)(zi)的(de)(de)原(yuan)(yuan)子(zi)(zi)(zi)(zi)(zi)(zi)如(ru)硼原(yuan)(yuan)子(zi)(zi)(zi)(zi)(zi)(zi),形成(cheng)(cheng)P型(xing)(xing)(xing)半導體。當P型(xing)(xing)(xing)和N型(xing)(xing)(xing)結合在一(yi)起時(shi)(shi),接觸面(mian)就會形成(cheng)(cheng)電(dian)(dian)(dian)(dian)(dian)勢差(cha),成(cheng)(cheng)為太(tai)陽能(neng)電(dian)(dian)(dian)(dian)(dian)池。當太(tai)陽光照射到P-N結后,空穴由P極(ji)區往N極(ji)區移動,電(dian)(dian)(dian)(dian)(dian)子(zi)(zi)(zi)(zi)(zi)(zi)由N極(ji)區向P極(ji)區移動,形成(cheng)(cheng)電(dian)(dian)(dian)(dian)(dian)流。
光(guang)(guang)電效應(ying)就是(shi)光(guang)(guang)照使(shi)不(bu)均勻(yun)半(ban)導體或半(ban)導體與金屬結合(he)的(de)不(bu)同部位之間產生電位差(cha)的(de)現(xian)象(xiang)。它首先是(shi)由光(guang)(guang)子(zi)(光(guang)(guang)波)轉化為電子(zi)、光(guang)(guang)能量轉化為電能量的(de)過(guo)程;其次,是(shi)形成(cheng)電壓過(guo)程。
多(duo)晶硅經過鑄錠、破錠、切片(pian)等程(cheng)序后,制(zhi)作成(cheng)(cheng)(cheng)(cheng)待加(jia)工(gong)的(de)硅片(pian)。在(zai)硅片(pian)上(shang)摻(chan)雜和擴散微量(liang)的(de)硼、磷等,就(jiu)(jiu)形(xing)成(cheng)(cheng)(cheng)(cheng)P-N結(jie)。然后采(cai)用(yong)絲網印刷,將精(jing)配(pei)好的(de)銀漿印在(zai)硅片(pian)上(shang)做(zuo)成(cheng)(cheng)(cheng)(cheng)柵線,經過燒結(jie),同時制(zhi)成(cheng)(cheng)(cheng)(cheng)背電(dian)(dian)(dian)(dian)極,并在(zai)有柵線的(de)面涂一(yi)層(ceng)防反射涂層(ceng),電(dian)(dian)(dian)(dian)池(chi)片(pian)就(jiu)(jiu)至此制(zhi)成(cheng)(cheng)(cheng)(cheng)。電(dian)(dian)(dian)(dian)池(chi)片(pian)排(pai)列(lie)組(zu)合(he)成(cheng)(cheng)(cheng)(cheng)電(dian)(dian)(dian)(dian)池(chi)組(zu)件(jian)(jian),就(jiu)(jiu)組(zu)成(cheng)(cheng)(cheng)(cheng)了大的(de)電(dian)(dian)(dian)(dian)路(lu)板。一(yi)般在(zai)組(zu)件(jian)(jian)四(si)周包鋁框,正面覆蓋玻璃,反面安(an)(an)裝(zhuang)電(dian)(dian)(dian)(dian)極。有了電(dian)(dian)(dian)(dian)池(chi)組(zu)件(jian)(jian)和其他輔助設(she)備,就(jiu)(jiu)可(ke)以組(zu)成(cheng)(cheng)(cheng)(cheng)發電(dian)(dian)(dian)(dian)系(xi)統(tong)(tong)。為(wei)了將直流(liu)電(dian)(dian)(dian)(dian)轉化交流(liu)電(dian)(dian)(dian)(dian),需要安(an)(an)裝(zhuang)電(dian)(dian)(dian)(dian)流(liu)轉換(huan)器。發電(dian)(dian)(dian)(dian)后可(ke)用(yong)蓄電(dian)(dian)(dian)(dian)池(chi)存儲,也可(ke)輸(shu)入公共(gong)電(dian)(dian)(dian)(dian)網。發電(dian)(dian)(dian)(dian)系(xi)統(tong)(tong)成(cheng)(cheng)(cheng)(cheng)本中(zhong),電(dian)(dian)(dian)(dian)池(chi)組(zu)件(jian)(jian)約占50%,電(dian)(dian)(dian)(dian)流(liu)轉換(huan)器、安(an)(an)裝(zhuang)費、其他輔助部件(jian)(jian)以及(ji)其他費用(yong)占另外(wai)50%。
無論從世界還是從中(zhong)國(guo)(guo)來看,常(chang)規能(neng)源都(dou)是很有限(xian)的(de)。中(zhong)國(guo)(guo)的(de)一次能(neng)源儲量遠(yuan)(yuan)遠(yuan)(yuan)低于(yu)世界的(de)平均水平,大約只有世界總儲量的(de)10%。太陽能(neng)是人(ren)類取之(zhi)不盡用之(zhi)不竭的(de)可再生能(neng)源,具有充分的(de)清(qing)潔性(xing)(xing)、絕對的(de)安全(quan)性(xing)(xing)、相對的(de)廣泛性(xing)(xing)、確實的(de)長(chang)壽命和免維(wei)護性(xing)(xing)、資(zi)源的(de)充足(zu)性(xing)(xing)及(ji)潛在(zai)(zai)的(de)經濟(ji)性(xing)(xing)等優點,在(zai)(zai)能(neng)源戰略中(zhong)具有重要地位。